Papers by Andrea Giuliano
Respiratory Physiology & Neurobiology, Jun 1, 2014
Journal of the American College of Cardiology, Dec 1, 2015
Acute exposure to high altitude induces a blood pressure (BP) rise in healthy humans (1). Arteria... more Acute exposure to high altitude induces a blood pressure (BP) rise in healthy humans (1). Arterial hypertension is associated both with enhanced BP response to exercise and with increased sympathetic discharge in hypoxic conditions (2,3), which may increase the risk of adverse consequences in physically active patients who are exposed to high altitude; however, there is scant evidence available about BP in these conditions. We aimed to evaluate
International Journal of Cardiology, Feb 1, 2020
Background: Travel to mountain areas is popular. However, the effects of acute exposure to modera... more Background: Travel to mountain areas is popular. However, the effects of acute exposure to moderate altitude on the cardiovascular system and metabolism are largely unknown. Objectives: To investigate the effects of acute exposure to moderate altitude on vascular function, metabolism and systemic inflammation. Methods: In 51 healthy male subjects with a mean (SD) age of 26.9 (9.3) years, oxygen saturation, blood pressure, heart rate, arterial stiffness, lipid profiles, low density lipoprotein (LDL) particle size, insulin resistance (HOMA-index), highly-sensitive Creactive protein and pro-inflammatory cytokines were measured at 490 m (Zurich) and during two days at 2590 m, (Davos Jakobshorn, Switzerland) in randomized order. The largest differences in outcomes between the two altitudes are reported. Results: Mean (SD) oxygen saturation was significantly lower at 2590 m, 91.0 (2.0)%, compared to 490 m, 96.0 (1.0)%, p,0.001. Mean blood pressure (mean difference +4.8 mmHg, p,0.001) and heart rate (mean difference +3.3 bpm, p,0.001) were significantly higher at 2590 m, compared to 490 m, but this was not associated with increased arterial stiffness. At 2590 m, lipid profiles improved (median difference triglycerides 20.14 mmol/l, p = 0.012, HDL +0.08 mmol/l, p,0.001, total cholesterol/HDL-ratio 20.25, p = 0.001), LDL particle size increased (median difference +0.45 nm, p = 0.048) and hsCRP decreased (median difference 20.18 mg/l, p = 0.024) compared to 490 m. No significant change in proinflammatory cytokines or insulin resistance was observed upon ascent to 2590 m. Conclusions: Short-term stay at moderate altitude is associated with increased blood pressure and heart rate likely due to augmented sympathetic activity. Exposure to moderate altitude improves the lipid profile and systemic inflammation, but seems to have no significant effect on glucose metabolism.
Journal of Hypertension, Jun 1, 2011
Background: Patients with rheumatoid arthritis (RA) are at an increased risk of cardiovascular (C... more Background: Patients with rheumatoid arthritis (RA) are at an increased risk of cardiovascular (CV) disease and are commonly prescribed non-selective non-steroidal anti-inflammatory drugs (ns-NSAIDS). New in vitro evidence suggests that this increased CV risk may be mediated through aldosterone glucuronidation inhibition (AGI), which differs between NSAIDS (in the order of diclofenac > naproxen > indomethacin > ibuprofen). Our aim was to explore the association between ns-NSAID-related-AGI and arterial dysfunction in patients with RA. Methods: The extent (augmentation index, AIX%) and timing (reflected wave transit time, RWT, msec) of aortic wave reflection (measured using radial applanation pulse wave analysis, PWA, SphygmoCor device) were assessed in 114 consecutive RA patients without overt CV disease aged 40-65 years. A 'higher AIX%' and 'lower RWT' indicate arterial dysfunction. All patients were assessed by a single research nurse after having rested supine for 10-15 minutes. Assessment also included a fasting blood sample, and self-completed patient questionnaire. A detailed medical record review was undertaken by a rheumatologist. Participants were similar to patients receiving outpatient care elsewhere in the UK. Multivariate analysis was used to adjust for age, sex, mean blood pressure, smoking, cumulative erythrocyte sedimentation rate (ESR-years) and Stanford HAQ disability score. Results: We identified 60 patients taking ns-NSAIDS (for 3 months or more) and 25 non-users. Using a ns-NSAID with the highest AGI was associated with a higher AIX% (and lower RWT) versus treatment with a ns-NSAID with the lowest AGI (diclofenac AIX% 32.3, RWT 132.7 msec; versus ibuprofen AIX% 23.8, RWT 150.9 msec): adjusted mean differences AIX% 6.5 (95% CI 1.0 to 11.9; p = 0.02); RWT-14.2 milliseconds (95% CI-22.2 to-6.3; p = 0.001). Multivariate analysis explained a high proportion of the variability in arterial dysfunction among chronic ns-NSAID users. Naproxen and indomethacin demonstrated intermediate levels of arterial dysfunction. Conclusion: ns-NSAID-related AGI appears to be independently associated with arterial dysfunction in patients with RA. These findings provide a novel insight into the CV toxicity of commonly used ns-NSAIDS.
Journal of Hypertension, Jun 1, 2010
Objective: Natriuretic peptides (NP) control cardiovascular functions through diuretic, natriuret... more Objective: Natriuretic peptides (NP) control cardiovascular functions through diuretic, natriuretic, vasodilatory properties. Several anthropometric, cardiac and renal parameters were found to be independently correlated to their levels. Few studies, however, systematically investigated the independent determinants of NP levels in large populations. Design and Method: The present analysis was carried out in a large unselected sample of adult male population in Southern Italy (The Olivetti Heart Study, n ¼ 806 men, mean age ¼ 59.5, range 35-82 years). We examined: a) the relationship of plasma NT-proANP levels with relevant anthropometric, clinical and biochemical variables; b) the impact of age; c) the association of NT-proANP levels with cardiovascular risk. Results: NT-proANP was directly associated to age, pulse pressure (PP), renal sodium fractional excretion (FENa) (p < 0.005), and inversely to diastolic blood pressure (DBP), heart rate (HR), creatinine clearance (CC), body mass index (BMI), arm and leg circumferences (p < 0.005). After adjustment for age, DBP, CC, FENa and HR remained independent determinants of NT-proANP levels (all p < 0.01, cumulative R2 ¼ 0.186). Upon stratification of our population by tertile of age, NT-proANP was significantly (p 0.01) associated to arm circumference in the lowest age tertile (mean age: 53.8 yrs), and to FENa, DBP, HR, CC and HOMA index in the highest tertile (mean age: 66.7 yrs). There was a direct association between NT-proANP levels and cardiovascular risk score in the whole cohort as estimated by the Progetto Cuore algorithm.
Hypertension, Jul 1, 2017
T he exposure to hypobaric hypoxia at high altitude (HA) is responsible for complex modifications... more T he exposure to hypobaric hypoxia at high altitude (HA) is responsible for complex modifications in both systemic and pulmonary circulation. Activation of the peripheral chemoreflex leads to a sympathetic nervous system activation, which increases blood pressure (BP), heart rate, and cardiac output counteracting the direct systemic vasodilator effect of hypoxia. 1-4 Previous studies have shown that systemic vascular dysfunction both in lowlanders during acute HA exposure 5 and in native highlanders 6,7 is related to increased sympathetic nervous system activity, increased oxidative stress, and decreased nitric oxide bioavailability. However, until now, there is no data supporting a role of the renin-angiotensin-aldosterone system (RAAS) in this setting. Hypoxia may also have a direct effect on RAAS, and retention of fluid and sodium has been proposed as one of the mechanisms involved in the pathogenesis of acute mountain sickness and possibly also of HA pulmonary edema. 8 Although most available HA studies focused on pathophysiology of HA pulmonary hypertension, 9 only few data are available on changes in cardiac function and in systemic circulation, and in particular, in arterial wall properties, primarily when explored in relation to changes in sympathetic and RAAS activity. HIGHCARE Himalaya project (HA cardiovascular research) was designed to fill-in this gap, based on a randomized, double-blind, parallel group, placebo-controlled study design, and focusing on changes in several cardiovascular variables related to systemic circulation in response to acute Abstract-This randomized, double-blind, placebo-controlled study was designed to explore the effects of exposure to very high altitude hypoxia on vascular wall properties and to clarify the role of renin-angiotensin-aldosterone system inhibition on these vascular changes. Forty-seven healthy subjects were included in this study: 22 randomized to telmisartan (age, 40.3±10.8 years; 7 women) and 25 to placebo (age, 39.3±9.8 years; 7 women). Tests were performed at sea level, pre-and post-treatment, during acute exposure to 3400 and 5400-m altitude (Mt. Everest Base Camp), and after 2 weeks, at 5400 m. The effects of hypobaric hypoxia on mechanical properties of large arteries were assessed by applanation tonometry, measuring carotid-femoral pulse wave velocity, analyzing arterial pulse waveforms, and evaluating subendocardial oxygen supply/demand index. No differences in hemodynamic changes during acute and prolonged exposure to 5400m altitude were found between telmisartan and placebo groups. Aortic pulse wave velocity significantly increased with altitude (P<0.001) from 7.41±1.25 m/s at sea level to 7.70±1.13 m/s at 3400 m and to 8.52±1.59 m/s at arrival at 5400 m (P<0.0001), remaining elevated during prolonged exposure to this altitude (8.41±1.12 m/s; P<0.0001). Subendocardial oxygen supply/demand index significantly decreased with acute exposure to 3400 m: from 1.72±0.30 m/s at sea level to 1.41±0.27 m/s at 3400 m (P<0.001), remaining significantly although slightly less reduced after reaching 5400 m (1.52±0.33) and after prolonged exposure to this altitude (1.53±0.25; P<0.001). In conclusion, the acute exposure to hypobaric hypoxia induces aortic stiffening and reduction in subendocardial oxygen supply/demand index. Reninangiotensin-aldosterone system does not seem to play any significant role in these hemodynamic changes.
Journal of Applied Physiology, Jun 1, 2011
increases lung diffusing capacity in humans High-altitude exposure of three weeks duration You mi... more increases lung diffusing capacity in humans High-altitude exposure of three weeks duration You might find this additional info useful...
BMJ, Mar 25, 2010
Objective To investigate the possibility that statins reduce blood pressure as well as cholestero... more Objective To investigate the possibility that statins reduce blood pressure as well as cholesterol concentrations through clinic and 24 hour ambulatory blood pressure monitoring. Design Randomised placebo controlled double blind trial. Setting 13 hospitals in Italy Participants 508 patients with mild hypertension and hypercholesterolaemia, aged 45 to 70 years. Intervention Participants were randomised to antihypertensive treatment (hydrochlorothiazide 25 mg once daily or fosinopril 20 mg once daily) with or without the addition of a statin (pravastatin 40 mg once daily). Main outcome measures Clinic and ambulatory blood pressure measured every year throughout an average 2. 6 year treatment period. Results Both the group receiving antihypertensive treatment without pravastatin (n=254) (with little change in total cholesterol) and the group receiving antihypertensive treatment with pravastatin (n=253) (with marked and sustained reduction in total cholesterol and low density lipoprotein cholesterol) had a clear cut sustained reduction in clinic measured systolic and diastolic blood pressure as well as in 24 hour, and day and night, systolic and diastolic blood pressure. Pravastatin performed slightly worse than placebo, and between group differences did not exceed 1.9 (95% confidence interval −0.6 to 4.3, P=0.13) mm Hg throughout the treatment period. This was also the case when participants who remained on monotherapy with hydrochlorothiazide or fosinopril throughout the study were considered separately. Conclusions Administration of a statin in hypertensive patients in whom blood pressure is effectively reduced by concomitant antihypertensive treatment does not have an additional blood pressure lowering effect. Trial registration BRISQUI_*IV_2004_001 (registered at Osservatorio Nazionale sulla Sperimentazione Clinica dei Medicinali-National Monitoring Centre on Clinical Research with Medicines).
Journal of Hypertension, Jun 1, 2015
ABSTRACT A blood pressure (BP) rise and sleep disturbances are known effects of high altitude exp... more ABSTRACT A blood pressure (BP) rise and sleep disturbances are known effects of high altitude exposure. Most available data have been collected at altitudes &gt;3300m, while the possible effects of moderate altitude (MA) exposure (around 2000 m) are still poorly understood in spite of the fact that such altitude is easily reachable even by subjects suffering from cardiovascular diseases. Aim of HIGHCARE (HIGH altitude CArdiovascular REsearch)-Sestriere study was thus to evaluate the effect of exposure to an altitude of 2035m (Sestriere, Italy) on BP and sleep disturbances.(Figure is included in full-text article.) DESIGN AND METHOD:: 58 healthy lowlanders were evaluated both at sea level (SL,Milan, Italy) and during acute exposure to MA (2035m, barometric pressure 80% of that at SL). 46 individuals (18 male, 28 females, age 41.52 ± 12.65y) completed the study, having conventional BP measures and 24 h ambulatory BP monitoring (ABPM, validated oscillometric TM-2430 A&amp;D device; measurements every 15 minutes during daytime and 20 minutes during nighttime) performed both at SL and at MA. During both study conditions subjects&#39; daily life behaviour was carefully standardized, only light physical exercise being allowed. During MA exposure mean 24 h systolic (S) and diastolic (D) BP significantly increased compared to SL (p &lt; 0.005), with no difference between day and night (Figure1). This was the case also for mean daytime and nighttime SBP and DBP (respectively, p &lt; 0.05) and for heart rate (p &lt; 0.005) (Figure1). No statistically significant between-condition differences were found for conventional BP nor for nocturnal BP dipping, and there were no effects of age, gender or BMI. Low sleep quality was reported by 22% of individuals (sleep quality questionnaire), with no correlation between reported sleep quality and BP nocturnal dipping. Our data offer the first demonstration, in healthy subjects, that exposure to an easy-to-reach MA is associated with an increase in 24 h ambulatory BP. No changes were observed in conventional BP, further emphasizing the superior sensitivity of ABPM in assessing BP response to environmental challenges. Our results may have clinical implications for the protection of cardiovascular patients travelling to such altitude for either leisure or work.
European Journal of Echocardiography, Jul 4, 2015
Previous studies investigating the effect of hypoxia on left ventricle focused on its global func... more Previous studies investigating the effect of hypoxia on left ventricle focused on its global function, an approach that may not detect a selective dysfunction of subendocardial layers that are most sensitive to an inadequate oxygen supply. In the HIGHCARE study, aimed at exploring the effects of high altitude hypoxia on multiple biological variables and their modulation by an angiotensin receptor blocker, we addressed the effects of hypobaric hypoxia on both systolic and diastolic left ventricular geometry and function, focusing on echocardiographic assessment of left ventricle twist to indirectly examine subendocardial left ventricular systolic function. Methods and results In 39 healthy subjects, physiological and echocardiographic variables, including left ventricular twist and a simplified torsion-to-shortening ratio (sTSR), were recorded at sea level, at 3400 m, and at 5400 m altitude (Mount Everest base camp). Both left ventricular twist and sTSR were greater at 5400 m than at sea level (12.68 vs. 9.68 and 0.285 vs. 0.202, P , 0.05 for both), were linearly related to the reduction in arterial oxygen partial pressure (P , 0.01 for both), and were associated with significant changes in LV dimensions and contractility. No effects of angiotensin receptor blockade were observed on these variables throughout the study. Conclusion Our study, for the first time, demonstrates an increase in left ventricular twist at high altitude in healthy subjects exposed to high altitude hypoxia, suggesting the occurrence of subendocardial systolic dysfunction in such condition.
Hypertension, Apr 1, 2013
High-altitude tourism is increasingly frequent, involving also subjects with manifest or subclini... more High-altitude tourism is increasingly frequent, involving also subjects with manifest or subclinical coronary artery disease. Little is known, however, on the effects of altitude exposure on factors affecting coronary perfusion. The aim of our study was to assess myocardial oxygen supply/demand ratio in healthy subjects during acute exposure at high altitude and to evaluate the effect of acetazolamide on this parameter. Forty-four subjects (21 men, age range: 24-59 years) were randomized to double-blind acetazolamide 250 mg bid or placebo. Subendocardial viability ratio and oxygen supply/demand ratio were estimated on carotid artery by means of a validated PulsePen tonometer, at sea level, before and after treatment, and after acute and more prolonged exposure to high altitude (4559 m). On arrival at high altitude, subendocardial viability ratio was reduced in both placebo (from 1.63±0.15 to 1.18±0.17; P<0.001) and acetazolamide (from 1.68±0.25 to 1.35±0.18; P<0.001) groups. Subendocardial viability ratio returned to sea level values (1.65±0.24) after 3 days at high altitude under acetazolamide but remained lower than at sea level under placebo (1.42±0.22; P<0.005 versus baseline). At high altitude, oxygen supply/demand ratio fell both under placebo (from 29.6±4.0 to 17.3±3.0; P<0.001) and acetazolamide (from 32.1±7.0 to 22.3±4.6; P<0.001), its values remaining always higher (P<0.001) on acetazolamide. Administration of acetazolamide may, thus, antagonize the reduction in subendocardial oxygen supply triggered by exposure to hypobaric hypoxia. Further studies involving also subjects with known or subclinical coronary artery disease are needed to confirm a protective action of acetazolamide on myocardial viability under high-altitude exposure. (Hypertension. 2013;61:793-799.) • Online Data Supplement Key Words: acetazolamide ■ altitude ■ arterial stiffness ■ hypobaric hypoxia ■ myocardial oxygen demand ■ pulse wave analysis
Journal of Hypertension, Sep 1, 2012
Results The average level of blood pressure in the day and night were signifi cant higher in the ... more Results The average level of blood pressure in the day and night were signifi cant higher in the severe OSAS group (144.7/100.3 Ϯ 12.5/10.0mmHg, 136.5/91.1 Ϯ 13.3/9.5mmHg)than the pure hypertensive group (131.2/92.4 Ϯ 15.6/8.6mmHg, 124.9/84.7 Ϯ 18.3/11.7 mmHg, P Ͻ 0.05), while there were no signifi cant differences in light and moderate OSAS group. The variability of daytime blood pressure was signifi cant higher in the severe OSAS group (13.0/10.5 Ϯ 3.0/2.0 mmHg) than the pure hypertensive group (11.3/9.3 Ϯ 3.2/1.8 mmHg). The variability of nighttime blood pressure were signifi cant higher in the severe OSAS group (12.6/12.4 Ϯ 4.2/4.2 mmHg) than the pure hypertensive group (12.1/9.9 Ϯ 2.8/2.3 mmHg), the light OSAS group (11.3/10.0 Ϯ 2.8/3.0 mmHg), the moderate OSAS group (11.9/9.4 Ϯ 3.6/2.5 mmHg)(P Ͻ 0.05). Multiple regression analysis show that minSaO2 was an important factor affecting the nighttime and daytime blood pressure variability ( ϭ-0.103 P Ͻ 0.001; B ϭ-0.086, P Ͻ 0.003). Conclus s Severe OSAS is correlated with hypertension and increase the variability of blood pressure. Hypoxia is an important factor for increasing the blood pressure variability in OSAS patients. Conclusions There is a high prevalence of undiagnosed hypertension in patients with suspected sleep apnea syndrome. The BP and prevalence of hypertension is higher in SAS than in snorers without SAS. Only 1 of 3 patients with suspected SAS has a normal circadian BP rhythm.
Journal of Hypertension, Jun 1, 2010
Psoriasis is a chronic inflammatory skin condition and angiotensin-converting enzyme (ACE) is a k... more Psoriasis is a chronic inflammatory skin condition and angiotensin-converting enzyme (ACE) is a key circulating enzyme converting angiotensin (Ang) I to the vasoactive peptide Ang II. The exact role of ACE insertion (I)/deletion (D) polymorphism (rs106180) in psoriasis is not clear. We aimed to examine whether the ACE I/D and Ang II type 1 receptor (AT1R) A 1166 C-polymorphisms (rs106165), lipid profile, and stress oxidative are associated with susceptibility to psoriasis. One hundred patients with psoriasis and 100 sex-and age-matched unrelated healthy controls were recruited for this case-control study. ACE I/D and AT1R A 1166 C polymorphisms were identified by the polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism, respectively, malondialdehyde (MDA) was detected by the high-performance liquid chromatography, serum arylesterase (ARE) activity of paraoxonase and catalase activities were detected by the spectrophotometry, superoxide dismutase (SOD) activity and vascular adhesion protein (VAP)-1 were measured by ELISA. The presence of C allele of AT1R A 1166 C and I allele of ACE considerably increased the risk of psoriasis by 6.42-fold (P < 0.001). The distribution of II-genotype of ACE was significantly higher in psoriasis patients than in control group and increased the risk of disease by 3.11-times (P = 0.023). The higher levels of MDA in patients and the higher activity of SOD, ARE, and CAT was observed in healthy controls with I/D+I/I-genotype of ACE I/D. This study for the first time demonstrated that the ACE I/D and AT1R A 1166 C genes polymorphisms robustly increases the risk of developing psoriasis in population from west of Iran. In addition, these individuals had significantly higher VAP-1 and MDA concentration and lower enzymatic and nonenzymatic antioxidant-status, suggesting that psoriatic patients carrying C allele of AT1R 1166 polymorphism may be more susceptible to cardiovascular disease and myocardial infarction compared with A allele.
European Heart Journal, Aug 2, 2013
Treatment of hypertension 269 agement studies of its kind resulted in significantly enhanced leve... more Treatment of hypertension 269 agement studies of its kind resulted in significantly enhanced levels of BP control. Applying refined strategies to optimise the potential of this type of intervention (including overcoming prescription resistance) are of clinical importance to optimise BP control.
Autonomic Neuroscience: Basic and Clinical, Aug 1, 2009
not consistent with the above changes in mRNA. For example, ERαpositive nuclei in the NTS, coloca... more not consistent with the above changes in mRNA. For example, ERαpositive nuclei in the NTS, colocalised predominantly with tyrosine hydroxylase (TH) and occasionally with nitric oxide synthase (NOS) immunoreactive neurones, showed no significant changes between OVX and sham-OVX rats. This may reflect temporal differences in changes in mRNA and receptor protein expression. These results demonstrate that the complete removal of oestrogen results in significant changes in ER mRNA expression, but not receptor protein levels, in several autonomic nuclei of the brain. This suggests an oestrogen sensitive expression of these receptors in these nuclei and further points to a role for this subtype in the control of autonomic outflow.
Journal of Hypertension, Jun 1, 2010
This study prospectively evaluated the relation between OSA severity, plasma aldosterone concentr... more This study prospectively evaluated the relation between OSA severity, plasma aldosterone concentration (PAC), and blood pressure in subjects with resistant hypertension. Methods: Twenty five consecutive subjects (age 56.2 AE 8.7 years; 76% female) with resistant hypertension referred to an ambulatory for resistant hypertension were prospectively evaluated with plasma renin activity (PRA), PAC, blood pressure (BP). All subjects were evaluated by full-night attended diagnostic polysomnography. Patients were divided in two groups: with OSA clinically significant [apnea-hypopnea index (AHI) > ¼ 15 events/hr] and mild or absent OSA (AHI <¼ 15 event/hr). Results: Clinically significant OSA was diagnosed in 68% of subjects. Overall, ambulatory BP was 155 AE 29.9 / 95.4 AE 18.6 mmHg, body mass index (BMI) 34.1 AE 7.8 kg/m 2 andthe number of anti-hypertensivedrugs in usewas4.8 AE 0.9. There was no difference between groups in neck circumference, BMI, PAC, PRA, number of medicine, and BP. In subjects with clinically significant OSA, AHI correlated to PAC (r ¼ 0.654; p ¼ 0.015), however it was not present in patients with mild or absent of OSA (r ¼ 0.609; p ¼ 0.198), and in the total group (r ¼ 0.404; p ¼ 0.096). There was no significant correlation between both PAC and AHI with blood pressure. Values are reported as mean AE SD, and compared by t-test, Kruskal-Wallis (KW) test, qui 2 test or Fisher's exact test, where appropriate. Correlations were evaluated by Pearson or Spearman where applicable. Two-tailed p-values < 0.05 were considered significant. Conclusion: OSA is extraordinarily common in patients with resistant hypertension. A significant positive correlation between PAC and severity of OSA is observed in resistant hypertension patients with clinically significant OSA but not in the control group. The correlation observed in the current analysis suggests that aldosterone may contribute to the development or worsen of OSA.
Journal of Hypertension, Jun 1, 2010
Objective: To investigate whether the putative (pro)renin receptor blocker, the handle region pep... more Objective: To investigate whether the putative (pro)renin receptor blocker, the handle region peptide (HRP), affects the blood pressure lowering and end-organ protective effects of the renin-inhibitor aliskiren in spontaneously hypertensive rats (SHR).
Molecular BioSystems, 2012
International Journal of Cardiology, Feb 1, 2014
European Heart Journal, Nov 10, 2009
Patients with heart failure or OSA (obstructive sleep apnoea) have reduced HF-HRV (highfrequency ... more Patients with heart failure or OSA (obstructive sleep apnoea) have reduced HF-HRV (highfrequency heart rate variability), indicating reduced cardiac vagal modulation, a marker of poor prognosis. CPAP (continuous positive airway pressure) abolishes OSA in patients with heart failure, but effects on daytime HF-HRV have not been determined. We hypothesized that, in patients with heart failure, treatment of coexisting OSA by CPAP would increase morning HF-HRV. In 19 patients with heart failure (left ventricular ejection fraction < 45 %) and OSA (20 apnoeas and hypopnoeas/h of sleep), HF-HRV was quantified before and 1 month after randomization to a control or CPAP-treated group. In the control group (n = 7), there were no changes in HF-HRV over the 1 month study during wakefulness in the morning. In the CPAP-treated group (n = 12) HF-HRV increased significantly during wakefulness in the morning [from 2.43 + − 0.55 to 2.82 + − 0.50 log(ms 2 /Hz); P = 0.002] due to an increase in transfer function between changes in lung volume and changes in HF-HRV (92.37 + − 96.03 to 219.07 + − 177.14 ms/l; P = 0.01). In conclusion, treatment of coexisting OSA by nocturnal CPAP in patients with heart failure increases HF-HRV during morning wakefulness, indicating improved vagal modulation of heart rate. This may contribute to improved prognosis.
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Papers by Andrea Giuliano