Biostatistics

The purpose of this investigation was to determine which variables obtained when performing radionuclide angiography predict subsequent survival or total events (cardiovascular death or nonfatal myocardial infarction) in stable patients with symptomatic coronary artery disease (CAD). Univariable and multivariable analyses of 6 variables, including ejection fraction (EF) at rest and exercise, change in EF with exercise, development of ischemic chest pain or electrocardiographic changes, left ventricular (LV) wall motion abnormalities and exercise time were examined in 366 patients followed up to 4.5 years. Univariate analyses revealed that the exercise EF was the variable most closely as-sociated with future events (p <O.Ol), followed by EF at rest, wall motion abnormalities and exercise time. Multivariable analyses revealed that once the exercise EF was known, no other radionuclide variables contributed independent information about the likelihood of future events. Multivariable analyses also revealed that the exercise EF describes much of the prognostic information of coronary anatomy. Our ftndings suggest that the radionuclide angiogram is useful in predicting future events in patients with stable CAD, although examination in conjunction with other clinical descriptors will be necessary to further quantify this contribution.

This trial evaluated the effects of epoprostenol on patients with severe left ventricular failure. Patients with class IIIB/IV congestive heart failure and decreased left ventricular ejection fraction were eligible for enrollment if angiography documented severely compromised hemodynamics while the patient was receiving a regimen of digoxin, diuretics, and an angiotensinconverting enzyme inhibitor. We randomly assigned 471 patients to epoprostenol infusion or standard care. The primary end point was survival; secondary end points were clinical events, congestive heart failure symptoms, distance walked in 6 minutes, and quality-of-life measures. The median dose of epoprostenol was 4.0 ng/kg/min, resulting in a significant increase in cardiac index (1.81 to 2.61 L/min/m2), a decrease in pulmonary capillary wedge pressure (24.5 to 20.0 mm Hg), and a decrease in systemic vascular resistance (20.76 to 12.33 units). The trial was terminated early because of a strong trend toward decreased survival in the patients treated with epoprostenol. Chronic intravenous epoprostenol therapy is not associated with improvement in distance walked, quality of life, or morbid events and is associated with an increased risk of death. (Am Heart J 1997;134:44-54) Congestive heart failure is an increasing cause of morbidity and mortality as the world's population continues to age. The advent of cardiac transplantation and of medical regimens--including angiotensin-converting enzyme inhibitors, 1 nitrates, and hydralazine2--and digitalis 3 have allowed practitioners to substantially affect the mortality rates and quality of life of patients with symptomatic heart failure. Nevertheless, heart failure inevitably progresses to an increasingly symptomatic stage, often in circumstances that preclude transplantation because of age, comorbidity, or lack of organ availability. Even with maximal conventional medical therapy, the 1-year mortality rate of patients with class IV heart failure is >25%. 4

This work was undertaken to define the intrinsic cardiac risk of the patient population referred for dobutamine stress perfusion imaging and to determine whether dobutamine technetium-99m ( 99m Tc)-sestamibi single-photon emission computed tomography (SPECT) imaging is capable of risk stratification in this population. BACKGROUND In animal models, dobutamine attenuates the myocardial uptake of 99m Tc-sestamibi resulting in underestimation of coronary stenoses. Therefore, we hypothesized that the prognostic value of dobutamine stress 99m Tc-sestamibi SPECT myocardial perfusion imaging might be impaired, owing to reduced detection of coronary stenoses.

Background. Patients with acute myocardial infarction who were treated with accelerated tissue plas- minogen activator (t-PA) (given over a period of 11⁄2 hours rather than the conventional 3 hours, and with two thirds of the dose given in the first 30 minutes) had a 30-day ...