We sought to update norms for peak systolic blood pressure (SBP) on the graded exercise test and ... more We sought to update norms for peak systolic blood pressure (SBP) on the graded exercise test and examine its prognostic value in patients without baseline cardiovascular disease. Mayo graded exercise test data (1993–2010) were reviewed for nonimaging tests using Bruce protocol, selecting Minnesota residents 30 to 79 years without baseline cardiovascular disease. We formed a pure cohort of patients without factors significantly affecting peak SBP to determine peak SBP percentile norms by age and sex. Then we divided the full cohort of patients into 5 groups based on peak SBP percentiles: low (<10th), borderline low (10th–25th), referent (25th–75th), borderline high (75th–90th), and high (>90th). The relationship between peak SBP and mortality was tested using Cox regression adjusting for age, sex, and comorbidities affecting peak SBP or mortality. We identified 20 760 eligible patients with 7313 females (35%) and mean age 51.5±10.7 years. Our pure cohort included 7810 patients. Over 12.5±5.0 years follow-up, there were 1582 deaths, including 541 cardiovascular deaths. In the fully adjusted model, low-peak SBP was associated with increased total mortality (heart rate, 1.41 [1.19–1.66],P<0.0001) and cardiovascular mortality (heart rate, 1.54 [1.16–2.03],P=0.001), while borderline low-peak SBP was associated with increased cardiovascular mortality only (heart rate, 1.36 [1.02–1.81],P=0.027). High peak SBP was associated with increased total mortality only in the age-sex adjusted model (heart rate, 1.18 [1.02–1.36],P=0.026), not after full adjustment. We conclude that low exercise peak SBP is an independent predictor of higher total and cardiovascular mortality.
Brief communication It is important for both good patient care and health care economics to gain ... more Brief communication It is important for both good patient care and health care economics to gain the most information possible from each test performed. This is true for the exercise test which provides both diagnostic and prognostic information. 1 This means not only looking at the ST segment response but also accurately reporting and identifying the significance of other exercise parameters including blood pressure (BP). A gradual decrease in diastolic blood pressure (DBP) with exercise has long been considered a normal response. 2,3 While various studies have shown that hypertensive BP response to exercise may be an independent predictor of left ventricular hypertrophy, 4 development of hypertension, 5,6 and total and cardiovascular (CV) mortality in a low-risk population, 7,8 these studies were focused on systolic blood pressure (SBP) responses to exercise. 9,10 The significance of an increase in DBP with exercise in a low-risk population has not been validated yet, either in terms of association with comorbidities such as diabetes, hypertension, obesity, and smoking that increase CV risk or in terms of the hard endpoints of death and CV death. Our aim was to determine the significance of an increase in DBP on an exercise test in terms of comorbidities and long-term total and CV mortality. METHODS This was a retrospective study approved by Mayo Clinic Rochester IRB. Patients not consenting to have their data used in this research under Minnesota Statute (§144.335) were excluded. 11 The Mayo Integrated Stress Center database was reviewed between 21 September 1993 and 20 December 2010. Study population In this study, we included Minnesota residents who had nonimaging, symptom-limited treadmill exercise tests on the Bruce protocol between ages 30 and 79 years. Where multiple qualifying tests were available for a given patient, the
To determine the peak blood pressure responses during symptom-limited exercise in a large sample ... more To determine the peak blood pressure responses during symptom-limited exercise in a large sample of apparently healthy subjects, including both men and women over a wide range of ages. We retrospectively studied the blood pressure response during maximal treadmill exercise testing with use of the Bruce protocol in apparently healthy subjects. Peak exercise blood pressures in 7,863 male and 2,406 female apparently healthy subjects who underwent a screening treadmill exercise test with the Bruce protocol between 1988 and 1992 were analyzed by age and gender. In this large referral population of apparently healthy subjects, peak exercise systolic and diastolic blood pressures and delta systolic blood pressure (rest to peak exercise) were higher in men than in women and were positively associated with age. In men, the 90th percentile of systolic blood pressure increased from 210 mm Hg for the age decade 20 to 29 years to 234 mm Hg for ages 70 to 79 years; the corresponding increase among women was from 180 mm Hg to 220 mm Hg. Delta diastolic blood pressure also increased with advancing age. The difference in peak and delta systolic blood pressures between men and women seemed to decrease after age 40 to 49 years. Exercise hypotension, defined as peak exercise systolic pressure less than rest systolic pressure, occurred in 0.23% of men and 1.45% of women and was not significantly related to age. Overall, peak exercise systolic and diastolic, as well as delta systolic, blood pressures were higher in men than in women and increased with advancing age. The reported data will enable clinicians to interpret more accurately the significance of peak exercise blood pressure response in a subject of a specific age and gender and will allow investigators to define exercise hypertension in statistical terms stratified by age and gender.
Journal of the American College of Cardiology, Mar 1, 2020
Background: Cardiopulmonary exercise testing (CPX) is recommended to determine the need of aortic... more Background: Cardiopulmonary exercise testing (CPX) is recommended to determine the need of aortic valve replacement (AVR) in patients with severe asymptomatic aortic stenosis (ASAS). Important exercise variables include abnormal systolic blood pressure (SBP) response. Our aim was to determine the significance of exercise SBP response on risk stratification in ASAS. Methods: We reviewed CPXs from 11-2007 to 4-2014 for patients with ASAS and ejection fraction >50%. We used Cox regression to assess the impact of exercise SBP on 3-year mortality adjusting for age, sex, exercise performance, and time-dependent AVR. We looked at the SBP response in 4 ways (all SBP values in mmHg): 1) delta SBP (peak-rest) < 20; 2) peak SBP < rest SBP (exercise hypotension); 3) difference of 10 in peak SBP and 4) difference of 10 in delta SBP as continuous variables. Results: Reviewing 22,305 CPX tests, we identified 195 adult patients with ASAS. Age was 70±14 years, 60 (30%) female. 125 patients (64%) underwent AVR, and 25 (28%) died during the first 3 years post-CPX. Peak SBP was 150±27; change in SBP 22±25. 78 patients (40%) had delta SBP < 20, and 31(16%) had exercise hypotension. Hazard ratios [95% confidence intervals] for 3-year mortality age-sex adjusted and fully adjusted are shown in Figure. None of the SBP measures were significant predictors of 3-year mortality. Conclusion: Our results suggest that SBP response during exercise, including exercise hypotension, does not contribute significantly to risk stratification in ASAS.
AimsAssess trends and factors associated with interhospital transfers (IHT) and 30-day acute coro... more AimsAssess trends and factors associated with interhospital transfers (IHT) and 30-day acute coronary syndrome (ACS) rehospitalizations in a national administrative database of patients admitted with an ACS between 2000–2015.Methods and resultsCohort study of patients hospitalized with ACS from 2000 to 2015, using a validated linkage algorithm to identify and link patient-level sequential hospitalizations occurring within 30 days from first admission (considering all hospitalizations within the 30-day timeframe as belonging to the same ACS episode of care-ACS-EC). From 212,481 ACS-EC, 42,670 (20.1%) had more than one hospitalization. ACS-EC hospitalization rates decreased throughout the study period (2000: 207.7/100.000 person-years to 2015: 185,8/100,000 person-years, p for trend <0.05). Proportion of IHT increased from 10.5% in 2000 to 20.1% in 2015 compared to a reduction in both planned and unplanned 30-day ACS rehospitalization from 9.0% in 2000 to 2.7% in 2015. After adjust...
BACKGROUND: Characterization of aerosol generation during exercise can inform the development of ... more BACKGROUND: Characterization of aerosol generation during exercise can inform the development of safety recommendations in the face of COVID-19. RESEARCH QUESTION: Does exercise at various intensities produce aerosols in significant quantities? STUDY DESIGN AND METHODS: In this experimental study, subjects were eight healthy volunteers (six men, two women) who were 20 to 63 years old. The 20-minute test protocol of 5 minutes rest, four 3-minute stages of exercise at 25%, 50%, 75%, and 100% of age-predicted heart rate reserve, and 3 minutes active recovery was performed in a clean, controlled environment. Aerosols were measured by four particle counters that were place to surround the subject. RESULTS: Age averaged 41 AE 14 years. Peak heart rate was 173 AE 17 beat/min (97% predicted); peak maximal oxygen uptake was 33.9 AE 7.5 mL/kg/min; and peak respiratory exchange ratio was 1.22 AE 0.10. Maximal ventilation averaged 120 AE 23 L/min, while cumulative ventilation reached 990 AE 192 L. Concentrations increased exponentially from start to 20 minutes (geometric mean AE geometric SD particles/liter): Fluke >0.3 mm ¼ 66 AE 1.8 / 1605 AE 3.8; 0.3-1.0 mm ¼ 35 AE 2.2 / 1095 AE 4.6; Fluke 1.0-5.0 mm ¼ 21 AE 2.0 / 358 AE 2.3; P-Trak anterior ¼ 637 AE 2.3 / 5148 AE 3.0; P-Trak side ¼ 708 AE 2.7 / 6844 AE 2.7; P-Track back ¼ 519 AE 3.1 / 5853 AE 2.8. All increases were significant at a probability value of <.05. Exercise at or above 50% of predicted heart rate reserve showed statistically significant increases in aerosol concentration. INTERPRETATION: Our data suggest exercise testing is an aerosol-generating procedure and, by extension, other activities that involve exercise intensities at or above 50% of predicted heart rate reserve. Results can guide recommendations for safety of exercise testing and other indoor exercise activities.
Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctatio... more Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctation of aorta (COA). However, it is unclear whether mild COA diagnosis is an independent risk factor of exercise-induced hypertension. We hypothesized that for every unit increase in exercise, patients with COA (without hemodynamically significant coarctation) will have a higher rise in systolic blood pressure (SBP) compared with matched controls. One hundred forty-nine patients with COA (aortic coarctation peak velocity <2 m/s) who underwent exercise testing were matched 1:1 to controls using propensity score method based on age, sex, body mass index, hypertension diagnosis, and SBP at rest. We compared exercise-induced change in SBP between patients with COA and controls and also assessed the correlation between Doppler-derived aortic vascular function indices (effective arterial elastance index and total arterial compliance index) and exercise-induced changes in SBP. Compared with con...
To investigate the effect of diabetes mellitus on exercise heart rate and the role of impaired he... more To investigate the effect of diabetes mellitus on exercise heart rate and the role of impaired heart rate in excess mortality in diabetes. Patients without cardiovascular disease who underwent exercise testing from September 1, 1993, through December 31, 2010, were included. Mortality was determined from Mayo Clinic records and the Minnesota Death Index. Multivariate linear regression was used to compare heart rate responses in patients with vs without diabetes. Cox regression was used to determine the effect of abnormal heart rate recovery and abnormal chronotropic index on survival. A total of 21,396 patients (65.4% men) with a mean ± SD age of 51±11 years, including 1200 patients with diabetes (5.4%), were included. Patients with diabetes had a higher resting heart rate (81±14 vs 77±13 beats/min), lower peak heart rate (154±20 vs 165±19 beats/min), heart rate reserve (73±19 vs 88±19 beats/min), chronotropic index (0.86±0.22 vs 0.99±0.20), and heart rate recovery (15±8 vs 19±9 bea...
OBJECTIVE: We investigated the documentation of obesity as a medical problem, and subsequent mana... more OBJECTIVE: We investigated the documentation of obesity as a medical problem, and subsequent management recommendations, in patients after myocardial infarction (MI). DESIGN: We performed a cross-sectional analysis of a randomly selected sample of 627 patients discharged after an MI, from five US teaching hospitals between 1/1/01 and 12/31/02. Information was extracted from clinical notes using standardized definitions. RESULTS: Mean body mass index (BMI) was 31713 kg/m 2 , which was documented in only 14% of patients and had to be calculated post hoc in the rest. Waist circumference and waist/hip ratio were not documented at all; 83% of patients were overweight, 55% obese, and 8% morbidly obese. In only 20% of patients with BMIZ30 kg/m 2 was the diagnosis of obesity documented either as a current medical problem, as part of past medical history or as a final diagnosis. A dietary counseling was carried out in 61% of patients with BMIZ25 kg/m 2 and in 61% of patients with BMIo25 kg/m 2 , P ¼ 0.96. Weight loss was described as part of the goals/plan at discharge in 7% of overweight and 9% of obese patients. There was no change in either the level of recognition of obesity (22 vs 19%, P ¼ 0.3) or in the proportion of obese patients for whom weight loss was described as part of the goals/plan at discharge (8 vs 10%, P ¼ 0.7) before (n ¼ 301) compared to after (n ¼ 326) the Call to Action in Obesity by the Surgeon General in December 2001. CONCLUSION: Obesity is underecognized, underdiagnosed and undertreated in persons with acute MI.
BACKGROUND Previous data has validated the benefit of digital health interventions (DHI) on weigh... more BACKGROUND Previous data has validated the benefit of digital health interventions (DHI) on weight loss in patients following acute coronary syndromes (ACS) entering cardiac rehabilitation (CR). OBJECTIVE The purpose of this study was to test the hypothesis that increased DHI usage associates with improved weight loss. METHODS We obtained DHI usage data including active days, total log-ins, tasks completed, educational modules reviewed, medication adherence, and non-monetary online incentive points in patients undergoing standard CR following ACS. Linear regression followed by multivariable models were used to evaluate associations between DHI log-ins and weight loss or dietary adherence. RESULTS The participants (n=61) were 79% male with mean age 61.0±9.7. We found a significant association of total log-ins during CR with weight loss (r2=0.10, P=.03) and dietary adherence (r2=0.42, P=.002). Educational modules viewed (r2=0.11, P=.009) and tasks completed (r2=0.10, P=.01) were signi...
ObjectivesTo assess validity of record linkage using multiple indirect personal identifiers to id... more ObjectivesTo assess validity of record linkage using multiple indirect personal identifiers to identify same-patient hospitalisations and definition of episode of care (EC) due to acute coronary syndrome (ACS).MethodsUsing national hospital discharge data to identify all admissions due to ACS, we used six different linkage rules using indirect identifiers with increasing level of detail and compared validity against a pseudonymised unique identifier used as gold standard (GS). Contiguous hospitalisations within each matched group of hospitalizations occurring within 28 days of each other were considered one EC. We classified hospitalisations according to time between the first pair of hospitalisations as hospital transfer (HT: ≤1 day), early readmission (ER: 2–28 days) or recurrent cases (>28 days).ResultsThere were 146 671 hospitalisations (unlinked), 121 987 ACS 28-day EC (linked GS), with 18 398 HTs (≤1 day), and 6286 ERs (≤28 days). Linkage rules using demographic and residen...
Journal of the American College of Cardiology, 2004
Background: Management of patients with organic mitral regurgitation (MR) relies on limitations o... more Background: Management of patients with organic mitral regurgitation (MR) relies on limitations of functional capacity (FC) assessed by symptoms but these are subjective. Cardiopulmonary exercise testing (CPET) can objectively assess FC but is inconsistently used as the information obtained has not been fully analyzed. Hence, the determinants of the variable FC of patients with organic MR are poorly understood. Methods: In 101 patients with organic non rheumatic MR we prospectively and quantitatively assessed MR severity (effective regurgitant orifice, ERO), left ventricular (LV) volumes, mass and diastolic function by Doppler-echo and FC (peak oxygen consumption, VO2) by CPET. Results: Determinants of FC: Mean ERO was 36±14 mm 2 (60% severe MR). Peak VO2 was 26±6 mL/kg/min (97±17% of age and gender predicted value). However FC varied widely (53 to 145 % of predicted). Independent determinants of low peak VO2 were degree of MR (ERO, p=0.006), hemodynamic (low forward stroke, p=0.0003), LV diastolic (high LV mass/volume ratio, p=0.003; high E/E' ratio by Doppler Tissue Imaging, p=0.006) and ventilatory alterations (high VE/VCO2 slope, p=0.04). Relationship between symptoms and FC: Overall FC was reduced in 17% (peak VO2 <84% predicted). Compared to patients in NYHA class I (n=72) or II (n=22), patients in class III (n=7) had more severe hemodynamic alterations and most of them (71%) had a reduced FC. In contrast, patients in class I and II had undistinguishable hemodynamics and had similar FC (99±15% vs. 95±15 % of predicted, p=0.25). Importantly, FC was frequently and similarly reduced in both classes (13 and 14%) particularly in patients with severe MR (18 and 21%). Conclusion: In patients with organic MR, FC quantitatively measured varies widely between patients. Although higher degrees of MR are associated with lower peak VO2, LV diastolic and ventilatory dysfunction are major predictors of reduced FC. Patients in NYHA class I and II are undistinguishable and in those patients CPET frequently reveals functional limitations not detected clinically. Therefore, CPET is an important tool for the detection and comprehension of reduced FC and hence for the management of patients with organic MR.
Journal of the American College of Cardiology, 2017
Background: Exercise testing is commonly performed in children, but protocols and guidelines are ... more Background: Exercise testing is commonly performed in children, but protocols and guidelines are optimized for the adult population. Our aim was to identify factors that may influence the objective versus subjective effort on exercise tests in children, as indicated by the peak respiratory exchange ratio (RER) and highest rating of perceived exertion (RPE). Methods: We retrospectively analyzed all cardiopulmonary tests performed on patients ≤ 18 years from January 2011 through July 2016 at the Mayo Integrated Stress Center, Rochester, MN. Patients were classified according to structural or arrhythmogenic heart disease and compared to patients without identified heart disease or only minor abnormalities. A second comparison was performed against adults with similar referral diagnoses tested in the same time frame. If more than one test was performed during the study period, we chose the most recent for analysis. Differences between groups were assessed by analysis of variance according to the General Linear model with adjustment for covariates. Results: 840 pediatric and 5827 adult patients were analyzed. Average peak RER was 0.99 ± 0.09, 1.06 ± 0.09, 1.14 ± 0.10, in children 5-9, 10-14, and 15-18 years of age respectively, which was lower compared to adults (1.16 ± 0.11) (P<.001). The percentage of patients achieving maximal effort (achieving a peak RER > 1.15) was significantly related to age: 5%, 13%, 44% in the three groups, respectively and 54% in adults (P<.001).
Journal of the American College of Cardiology, 2017
Background: CHA2DS2-VASc score has been shown to predict occurrences of perioperative atrial fibr... more Background: CHA2DS2-VASc score has been shown to predict occurrences of perioperative atrial fibrillation (A-Fib) in patients undergoing cardiac surgery. However, data on whether if CHA2DS2-VASc score would predict incidence of A-Fib/ Flutter in non-operative setting is lacking. Methods: From 1993 through 2010, all patients undergoing a clinically indicated treadmill exercise test (TMET) at the Mayo Clinic, Rochester, MN were identified (N= 76,857). From this, Olmsted and neighboring counties residents were selected (N=14,095). From this, patients with age <18 years; prior history of valvular heart disease or A-Fib/ Flutter were excluded. Patient undergoing only Bruce or accelerated Naughton protocols on TMET were considered. Patients were stratified into 4 groups at baseline based on CHA2DS2-VASc score as determined at the time of TMET; group-0 score=0; group-I=1; group-2=2; group-3>3. Patients were prospectively followed from the date of TMET until end of January 2016 for occurrence of A-Fib/ Flutter. A-Fib/ Flutter diagnosis was ascertained through retrospective chart review. Post-operative A-Fib/ Flutter (within 30 days of surgery) was not considered. Proportional hazard regression modeling was done to assess relationship of CHA2DS2-VASc score with the outcome while adjusting for METs achieved, sex, obesity, smoking status, and other relevant risk factors. Results: Final study population comprised of 12,624 patients with female comprising 37% of the cohort. Mean age in our study group was 52.2 ± 12.8 years. During an overall median follow-up of 14 (8 to 17) years, 1,501 (11.9%) patients developed incident A-Fib/ Flutter. While using CHA2DS2-VASc group-0 as referent, patients in CHA2DS2-VASc group-1[1.46(1.22-1.74, p<.0001)], group-2[2.20(1.83-2.65, p<.0001)], and group-3[4.1(3.5-5.0, p<.0001)] were at significantly increased risk for developing A-Fib/ Flutter. Each increase of one point on the CHA2DS2-VASc scale was associated with a 45% [1.45(1.40-1.51, p<.001
Journal of the American College of Cardiology, 1995
ABSTRACT Implantation of a dual-chamber permanent pacemaker (PPM) has recently been proposed as a... more ABSTRACT Implantation of a dual-chamber permanent pacemaker (PPM) has recently been proposed as a therapeutic alternative for patients with hypertrophic obstructive cardiomyopathy (HOCM). To objectively determine the short-term benefit of PPM, we entered 11 patients with severely symptomatic HOCM (mean age, 53 ± 13 years; 7 males, 4 females) into a prospective randomized, double-blind crossover trial with 2 months of continuous atrial synchronous pacing (DDD) and 2 months of backup pacing (WI). All medications were continued throughout the study. Clinical symptoms. oxygen consumption treadmills. and Doppler echocardiography were performed at baseline and after each ofthe two arms. During the DDD arm. 62% experienced subjective symptomatic improvement and 37% admitted to symptomatic improvement in the WI arm. The data at baseline and after each of the two arms for maximum treadmill time (TMET-max). maximum oxygen consumption (VO2-maxl, and Doppler outflow tract gradient (GRAD) are shown: TMET-max (min)VO2-max (mUkg/min)GRADlmmHg)BASE5.7 ± 1.919.0 ± 5.876 ± 20WI6.0 ± 2.320.0 ± 5.856 ± 25DOD6.0 ± 1.720.0 ± 6.047 ± 27**p &amp;lt; 0.05 vs. baselineFull-size tableTable optionsView in workspaceDownload as CSV Conclusion PPM for patients with HOCM provides subjective improvement and decrease in gradient for a select group of patients. However, not all patients will respond to PPM, and there is no overall statistically significant improvement in objective exercise parameters on short-term follow-up. DDD PPM should not be routinely implanted in all patients with HOCM until further results of larger prospectively randomized trials are available.
We sought to update norms for peak systolic blood pressure (SBP) on the graded exercise test and ... more We sought to update norms for peak systolic blood pressure (SBP) on the graded exercise test and examine its prognostic value in patients without baseline cardiovascular disease. Mayo graded exercise test data (1993–2010) were reviewed for nonimaging tests using Bruce protocol, selecting Minnesota residents 30 to 79 years without baseline cardiovascular disease. We formed a pure cohort of patients without factors significantly affecting peak SBP to determine peak SBP percentile norms by age and sex. Then we divided the full cohort of patients into 5 groups based on peak SBP percentiles: low (&lt;10th), borderline low (10th–25th), referent (25th–75th), borderline high (75th–90th), and high (&gt;90th). The relationship between peak SBP and mortality was tested using Cox regression adjusting for age, sex, and comorbidities affecting peak SBP or mortality. We identified 20 760 eligible patients with 7313 females (35%) and mean age 51.5±10.7 years. Our pure cohort included 7810 patients. Over 12.5±5.0 years follow-up, there were 1582 deaths, including 541 cardiovascular deaths. In the fully adjusted model, low-peak SBP was associated with increased total mortality (heart rate, 1.41 [1.19–1.66],P&lt;0.0001) and cardiovascular mortality (heart rate, 1.54 [1.16–2.03],P=0.001), while borderline low-peak SBP was associated with increased cardiovascular mortality only (heart rate, 1.36 [1.02–1.81],P=0.027). High peak SBP was associated with increased total mortality only in the age-sex adjusted model (heart rate, 1.18 [1.02–1.36],P=0.026), not after full adjustment. We conclude that low exercise peak SBP is an independent predictor of higher total and cardiovascular mortality.
Brief communication It is important for both good patient care and health care economics to gain ... more Brief communication It is important for both good patient care and health care economics to gain the most information possible from each test performed. This is true for the exercise test which provides both diagnostic and prognostic information. 1 This means not only looking at the ST segment response but also accurately reporting and identifying the significance of other exercise parameters including blood pressure (BP). A gradual decrease in diastolic blood pressure (DBP) with exercise has long been considered a normal response. 2,3 While various studies have shown that hypertensive BP response to exercise may be an independent predictor of left ventricular hypertrophy, 4 development of hypertension, 5,6 and total and cardiovascular (CV) mortality in a low-risk population, 7,8 these studies were focused on systolic blood pressure (SBP) responses to exercise. 9,10 The significance of an increase in DBP with exercise in a low-risk population has not been validated yet, either in terms of association with comorbidities such as diabetes, hypertension, obesity, and smoking that increase CV risk or in terms of the hard endpoints of death and CV death. Our aim was to determine the significance of an increase in DBP on an exercise test in terms of comorbidities and long-term total and CV mortality. METHODS This was a retrospective study approved by Mayo Clinic Rochester IRB. Patients not consenting to have their data used in this research under Minnesota Statute (§144.335) were excluded. 11 The Mayo Integrated Stress Center database was reviewed between 21 September 1993 and 20 December 2010. Study population In this study, we included Minnesota residents who had nonimaging, symptom-limited treadmill exercise tests on the Bruce protocol between ages 30 and 79 years. Where multiple qualifying tests were available for a given patient, the
To determine the peak blood pressure responses during symptom-limited exercise in a large sample ... more To determine the peak blood pressure responses during symptom-limited exercise in a large sample of apparently healthy subjects, including both men and women over a wide range of ages. We retrospectively studied the blood pressure response during maximal treadmill exercise testing with use of the Bruce protocol in apparently healthy subjects. Peak exercise blood pressures in 7,863 male and 2,406 female apparently healthy subjects who underwent a screening treadmill exercise test with the Bruce protocol between 1988 and 1992 were analyzed by age and gender. In this large referral population of apparently healthy subjects, peak exercise systolic and diastolic blood pressures and delta systolic blood pressure (rest to peak exercise) were higher in men than in women and were positively associated with age. In men, the 90th percentile of systolic blood pressure increased from 210 mm Hg for the age decade 20 to 29 years to 234 mm Hg for ages 70 to 79 years; the corresponding increase among women was from 180 mm Hg to 220 mm Hg. Delta diastolic blood pressure also increased with advancing age. The difference in peak and delta systolic blood pressures between men and women seemed to decrease after age 40 to 49 years. Exercise hypotension, defined as peak exercise systolic pressure less than rest systolic pressure, occurred in 0.23% of men and 1.45% of women and was not significantly related to age. Overall, peak exercise systolic and diastolic, as well as delta systolic, blood pressures were higher in men than in women and increased with advancing age. The reported data will enable clinicians to interpret more accurately the significance of peak exercise blood pressure response in a subject of a specific age and gender and will allow investigators to define exercise hypertension in statistical terms stratified by age and gender.
Journal of the American College of Cardiology, Mar 1, 2020
Background: Cardiopulmonary exercise testing (CPX) is recommended to determine the need of aortic... more Background: Cardiopulmonary exercise testing (CPX) is recommended to determine the need of aortic valve replacement (AVR) in patients with severe asymptomatic aortic stenosis (ASAS). Important exercise variables include abnormal systolic blood pressure (SBP) response. Our aim was to determine the significance of exercise SBP response on risk stratification in ASAS. Methods: We reviewed CPXs from 11-2007 to 4-2014 for patients with ASAS and ejection fraction >50%. We used Cox regression to assess the impact of exercise SBP on 3-year mortality adjusting for age, sex, exercise performance, and time-dependent AVR. We looked at the SBP response in 4 ways (all SBP values in mmHg): 1) delta SBP (peak-rest) < 20; 2) peak SBP < rest SBP (exercise hypotension); 3) difference of 10 in peak SBP and 4) difference of 10 in delta SBP as continuous variables. Results: Reviewing 22,305 CPX tests, we identified 195 adult patients with ASAS. Age was 70±14 years, 60 (30%) female. 125 patients (64%) underwent AVR, and 25 (28%) died during the first 3 years post-CPX. Peak SBP was 150±27; change in SBP 22±25. 78 patients (40%) had delta SBP < 20, and 31(16%) had exercise hypotension. Hazard ratios [95% confidence intervals] for 3-year mortality age-sex adjusted and fully adjusted are shown in Figure. None of the SBP measures were significant predictors of 3-year mortality. Conclusion: Our results suggest that SBP response during exercise, including exercise hypotension, does not contribute significantly to risk stratification in ASAS.
AimsAssess trends and factors associated with interhospital transfers (IHT) and 30-day acute coro... more AimsAssess trends and factors associated with interhospital transfers (IHT) and 30-day acute coronary syndrome (ACS) rehospitalizations in a national administrative database of patients admitted with an ACS between 2000–2015.Methods and resultsCohort study of patients hospitalized with ACS from 2000 to 2015, using a validated linkage algorithm to identify and link patient-level sequential hospitalizations occurring within 30 days from first admission (considering all hospitalizations within the 30-day timeframe as belonging to the same ACS episode of care-ACS-EC). From 212,481 ACS-EC, 42,670 (20.1%) had more than one hospitalization. ACS-EC hospitalization rates decreased throughout the study period (2000: 207.7/100.000 person-years to 2015: 185,8/100,000 person-years, p for trend <0.05). Proportion of IHT increased from 10.5% in 2000 to 20.1% in 2015 compared to a reduction in both planned and unplanned 30-day ACS rehospitalization from 9.0% in 2000 to 2.7% in 2015. After adjust...
BACKGROUND: Characterization of aerosol generation during exercise can inform the development of ... more BACKGROUND: Characterization of aerosol generation during exercise can inform the development of safety recommendations in the face of COVID-19. RESEARCH QUESTION: Does exercise at various intensities produce aerosols in significant quantities? STUDY DESIGN AND METHODS: In this experimental study, subjects were eight healthy volunteers (six men, two women) who were 20 to 63 years old. The 20-minute test protocol of 5 minutes rest, four 3-minute stages of exercise at 25%, 50%, 75%, and 100% of age-predicted heart rate reserve, and 3 minutes active recovery was performed in a clean, controlled environment. Aerosols were measured by four particle counters that were place to surround the subject. RESULTS: Age averaged 41 AE 14 years. Peak heart rate was 173 AE 17 beat/min (97% predicted); peak maximal oxygen uptake was 33.9 AE 7.5 mL/kg/min; and peak respiratory exchange ratio was 1.22 AE 0.10. Maximal ventilation averaged 120 AE 23 L/min, while cumulative ventilation reached 990 AE 192 L. Concentrations increased exponentially from start to 20 minutes (geometric mean AE geometric SD particles/liter): Fluke >0.3 mm ¼ 66 AE 1.8 / 1605 AE 3.8; 0.3-1.0 mm ¼ 35 AE 2.2 / 1095 AE 4.6; Fluke 1.0-5.0 mm ¼ 21 AE 2.0 / 358 AE 2.3; P-Trak anterior ¼ 637 AE 2.3 / 5148 AE 3.0; P-Trak side ¼ 708 AE 2.7 / 6844 AE 2.7; P-Track back ¼ 519 AE 3.1 / 5853 AE 2.8. All increases were significant at a probability value of <.05. Exercise at or above 50% of predicted heart rate reserve showed statistically significant increases in aerosol concentration. INTERPRETATION: Our data suggest exercise testing is an aerosol-generating procedure and, by extension, other activities that involve exercise intensities at or above 50% of predicted heart rate reserve. Results can guide recommendations for safety of exercise testing and other indoor exercise activities.
Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctatio... more Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctation of aorta (COA). However, it is unclear whether mild COA diagnosis is an independent risk factor of exercise-induced hypertension. We hypothesized that for every unit increase in exercise, patients with COA (without hemodynamically significant coarctation) will have a higher rise in systolic blood pressure (SBP) compared with matched controls. One hundred forty-nine patients with COA (aortic coarctation peak velocity <2 m/s) who underwent exercise testing were matched 1:1 to controls using propensity score method based on age, sex, body mass index, hypertension diagnosis, and SBP at rest. We compared exercise-induced change in SBP between patients with COA and controls and also assessed the correlation between Doppler-derived aortic vascular function indices (effective arterial elastance index and total arterial compliance index) and exercise-induced changes in SBP. Compared with con...
To investigate the effect of diabetes mellitus on exercise heart rate and the role of impaired he... more To investigate the effect of diabetes mellitus on exercise heart rate and the role of impaired heart rate in excess mortality in diabetes. Patients without cardiovascular disease who underwent exercise testing from September 1, 1993, through December 31, 2010, were included. Mortality was determined from Mayo Clinic records and the Minnesota Death Index. Multivariate linear regression was used to compare heart rate responses in patients with vs without diabetes. Cox regression was used to determine the effect of abnormal heart rate recovery and abnormal chronotropic index on survival. A total of 21,396 patients (65.4% men) with a mean ± SD age of 51±11 years, including 1200 patients with diabetes (5.4%), were included. Patients with diabetes had a higher resting heart rate (81±14 vs 77±13 beats/min), lower peak heart rate (154±20 vs 165±19 beats/min), heart rate reserve (73±19 vs 88±19 beats/min), chronotropic index (0.86±0.22 vs 0.99±0.20), and heart rate recovery (15±8 vs 19±9 bea...
OBJECTIVE: We investigated the documentation of obesity as a medical problem, and subsequent mana... more OBJECTIVE: We investigated the documentation of obesity as a medical problem, and subsequent management recommendations, in patients after myocardial infarction (MI). DESIGN: We performed a cross-sectional analysis of a randomly selected sample of 627 patients discharged after an MI, from five US teaching hospitals between 1/1/01 and 12/31/02. Information was extracted from clinical notes using standardized definitions. RESULTS: Mean body mass index (BMI) was 31713 kg/m 2 , which was documented in only 14% of patients and had to be calculated post hoc in the rest. Waist circumference and waist/hip ratio were not documented at all; 83% of patients were overweight, 55% obese, and 8% morbidly obese. In only 20% of patients with BMIZ30 kg/m 2 was the diagnosis of obesity documented either as a current medical problem, as part of past medical history or as a final diagnosis. A dietary counseling was carried out in 61% of patients with BMIZ25 kg/m 2 and in 61% of patients with BMIo25 kg/m 2 , P ¼ 0.96. Weight loss was described as part of the goals/plan at discharge in 7% of overweight and 9% of obese patients. There was no change in either the level of recognition of obesity (22 vs 19%, P ¼ 0.3) or in the proportion of obese patients for whom weight loss was described as part of the goals/plan at discharge (8 vs 10%, P ¼ 0.7) before (n ¼ 301) compared to after (n ¼ 326) the Call to Action in Obesity by the Surgeon General in December 2001. CONCLUSION: Obesity is underecognized, underdiagnosed and undertreated in persons with acute MI.
BACKGROUND Previous data has validated the benefit of digital health interventions (DHI) on weigh... more BACKGROUND Previous data has validated the benefit of digital health interventions (DHI) on weight loss in patients following acute coronary syndromes (ACS) entering cardiac rehabilitation (CR). OBJECTIVE The purpose of this study was to test the hypothesis that increased DHI usage associates with improved weight loss. METHODS We obtained DHI usage data including active days, total log-ins, tasks completed, educational modules reviewed, medication adherence, and non-monetary online incentive points in patients undergoing standard CR following ACS. Linear regression followed by multivariable models were used to evaluate associations between DHI log-ins and weight loss or dietary adherence. RESULTS The participants (n=61) were 79% male with mean age 61.0±9.7. We found a significant association of total log-ins during CR with weight loss (r2=0.10, P=.03) and dietary adherence (r2=0.42, P=.002). Educational modules viewed (r2=0.11, P=.009) and tasks completed (r2=0.10, P=.01) were signi...
ObjectivesTo assess validity of record linkage using multiple indirect personal identifiers to id... more ObjectivesTo assess validity of record linkage using multiple indirect personal identifiers to identify same-patient hospitalisations and definition of episode of care (EC) due to acute coronary syndrome (ACS).MethodsUsing national hospital discharge data to identify all admissions due to ACS, we used six different linkage rules using indirect identifiers with increasing level of detail and compared validity against a pseudonymised unique identifier used as gold standard (GS). Contiguous hospitalisations within each matched group of hospitalizations occurring within 28 days of each other were considered one EC. We classified hospitalisations according to time between the first pair of hospitalisations as hospital transfer (HT: ≤1 day), early readmission (ER: 2–28 days) or recurrent cases (>28 days).ResultsThere were 146 671 hospitalisations (unlinked), 121 987 ACS 28-day EC (linked GS), with 18 398 HTs (≤1 day), and 6286 ERs (≤28 days). Linkage rules using demographic and residen...
Journal of the American College of Cardiology, 2004
Background: Management of patients with organic mitral regurgitation (MR) relies on limitations o... more Background: Management of patients with organic mitral regurgitation (MR) relies on limitations of functional capacity (FC) assessed by symptoms but these are subjective. Cardiopulmonary exercise testing (CPET) can objectively assess FC but is inconsistently used as the information obtained has not been fully analyzed. Hence, the determinants of the variable FC of patients with organic MR are poorly understood. Methods: In 101 patients with organic non rheumatic MR we prospectively and quantitatively assessed MR severity (effective regurgitant orifice, ERO), left ventricular (LV) volumes, mass and diastolic function by Doppler-echo and FC (peak oxygen consumption, VO2) by CPET. Results: Determinants of FC: Mean ERO was 36±14 mm 2 (60% severe MR). Peak VO2 was 26±6 mL/kg/min (97±17% of age and gender predicted value). However FC varied widely (53 to 145 % of predicted). Independent determinants of low peak VO2 were degree of MR (ERO, p=0.006), hemodynamic (low forward stroke, p=0.0003), LV diastolic (high LV mass/volume ratio, p=0.003; high E/E' ratio by Doppler Tissue Imaging, p=0.006) and ventilatory alterations (high VE/VCO2 slope, p=0.04). Relationship between symptoms and FC: Overall FC was reduced in 17% (peak VO2 <84% predicted). Compared to patients in NYHA class I (n=72) or II (n=22), patients in class III (n=7) had more severe hemodynamic alterations and most of them (71%) had a reduced FC. In contrast, patients in class I and II had undistinguishable hemodynamics and had similar FC (99±15% vs. 95±15 % of predicted, p=0.25). Importantly, FC was frequently and similarly reduced in both classes (13 and 14%) particularly in patients with severe MR (18 and 21%). Conclusion: In patients with organic MR, FC quantitatively measured varies widely between patients. Although higher degrees of MR are associated with lower peak VO2, LV diastolic and ventilatory dysfunction are major predictors of reduced FC. Patients in NYHA class I and II are undistinguishable and in those patients CPET frequently reveals functional limitations not detected clinically. Therefore, CPET is an important tool for the detection and comprehension of reduced FC and hence for the management of patients with organic MR.
Journal of the American College of Cardiology, 2017
Background: Exercise testing is commonly performed in children, but protocols and guidelines are ... more Background: Exercise testing is commonly performed in children, but protocols and guidelines are optimized for the adult population. Our aim was to identify factors that may influence the objective versus subjective effort on exercise tests in children, as indicated by the peak respiratory exchange ratio (RER) and highest rating of perceived exertion (RPE). Methods: We retrospectively analyzed all cardiopulmonary tests performed on patients ≤ 18 years from January 2011 through July 2016 at the Mayo Integrated Stress Center, Rochester, MN. Patients were classified according to structural or arrhythmogenic heart disease and compared to patients without identified heart disease or only minor abnormalities. A second comparison was performed against adults with similar referral diagnoses tested in the same time frame. If more than one test was performed during the study period, we chose the most recent for analysis. Differences between groups were assessed by analysis of variance according to the General Linear model with adjustment for covariates. Results: 840 pediatric and 5827 adult patients were analyzed. Average peak RER was 0.99 ± 0.09, 1.06 ± 0.09, 1.14 ± 0.10, in children 5-9, 10-14, and 15-18 years of age respectively, which was lower compared to adults (1.16 ± 0.11) (P<.001). The percentage of patients achieving maximal effort (achieving a peak RER > 1.15) was significantly related to age: 5%, 13%, 44% in the three groups, respectively and 54% in adults (P<.001).
Journal of the American College of Cardiology, 2017
Background: CHA2DS2-VASc score has been shown to predict occurrences of perioperative atrial fibr... more Background: CHA2DS2-VASc score has been shown to predict occurrences of perioperative atrial fibrillation (A-Fib) in patients undergoing cardiac surgery. However, data on whether if CHA2DS2-VASc score would predict incidence of A-Fib/ Flutter in non-operative setting is lacking. Methods: From 1993 through 2010, all patients undergoing a clinically indicated treadmill exercise test (TMET) at the Mayo Clinic, Rochester, MN were identified (N= 76,857). From this, Olmsted and neighboring counties residents were selected (N=14,095). From this, patients with age <18 years; prior history of valvular heart disease or A-Fib/ Flutter were excluded. Patient undergoing only Bruce or accelerated Naughton protocols on TMET were considered. Patients were stratified into 4 groups at baseline based on CHA2DS2-VASc score as determined at the time of TMET; group-0 score=0; group-I=1; group-2=2; group-3>3. Patients were prospectively followed from the date of TMET until end of January 2016 for occurrence of A-Fib/ Flutter. A-Fib/ Flutter diagnosis was ascertained through retrospective chart review. Post-operative A-Fib/ Flutter (within 30 days of surgery) was not considered. Proportional hazard regression modeling was done to assess relationship of CHA2DS2-VASc score with the outcome while adjusting for METs achieved, sex, obesity, smoking status, and other relevant risk factors. Results: Final study population comprised of 12,624 patients with female comprising 37% of the cohort. Mean age in our study group was 52.2 ± 12.8 years. During an overall median follow-up of 14 (8 to 17) years, 1,501 (11.9%) patients developed incident A-Fib/ Flutter. While using CHA2DS2-VASc group-0 as referent, patients in CHA2DS2-VASc group-1[1.46(1.22-1.74, p<.0001)], group-2[2.20(1.83-2.65, p<.0001)], and group-3[4.1(3.5-5.0, p<.0001)] were at significantly increased risk for developing A-Fib/ Flutter. Each increase of one point on the CHA2DS2-VASc scale was associated with a 45% [1.45(1.40-1.51, p<.001
Journal of the American College of Cardiology, 1995
ABSTRACT Implantation of a dual-chamber permanent pacemaker (PPM) has recently been proposed as a... more ABSTRACT Implantation of a dual-chamber permanent pacemaker (PPM) has recently been proposed as a therapeutic alternative for patients with hypertrophic obstructive cardiomyopathy (HOCM). To objectively determine the short-term benefit of PPM, we entered 11 patients with severely symptomatic HOCM (mean age, 53 ± 13 years; 7 males, 4 females) into a prospective randomized, double-blind crossover trial with 2 months of continuous atrial synchronous pacing (DDD) and 2 months of backup pacing (WI). All medications were continued throughout the study. Clinical symptoms. oxygen consumption treadmills. and Doppler echocardiography were performed at baseline and after each ofthe two arms. During the DDD arm. 62% experienced subjective symptomatic improvement and 37% admitted to symptomatic improvement in the WI arm. The data at baseline and after each of the two arms for maximum treadmill time (TMET-max). maximum oxygen consumption (VO2-maxl, and Doppler outflow tract gradient (GRAD) are shown: TMET-max (min)VO2-max (mUkg/min)GRADlmmHg)BASE5.7 ± 1.919.0 ± 5.876 ± 20WI6.0 ± 2.320.0 ± 5.856 ± 25DOD6.0 ± 1.720.0 ± 6.047 ± 27**p &amp;lt; 0.05 vs. baselineFull-size tableTable optionsView in workspaceDownload as CSV Conclusion PPM for patients with HOCM provides subjective improvement and decrease in gradient for a select group of patients. However, not all patients will respond to PPM, and there is no overall statistically significant improvement in objective exercise parameters on short-term follow-up. DDD PPM should not be routinely implanted in all patients with HOCM until further results of larger prospectively randomized trials are available.
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Papers by Thomas Allison