Clinical predictors of morbidity and mortality in patients with myocardialinfarction or revascularization who underwent cardiac rehabilitation, and importance of diabetes mellitus and exercise capacity

This investigation was a prospective, follow-up study to assess whether bas eline clinical and investigational parameters were predictors of cardiovasc ular morbidity and mortality in patients enrolled into the cardiac rehabili tation program. A cohort of 418 patients (70% were men) with coronary heart disease was followed up 3.2 +/- 1.1 years. Two hundred twenty-seven of the m (54%) had a recent myocardial infarction (MI), with a thrombolytic rare o f 54%. Percutaneous transluminal coronary angioplasty (PTCA) was performed in 45% of patients. The covariates assessed include age, gender, smoking ha bit, body mass index, the presence of hypertension or diabetes mellitus, ex ercise habit, site and severity of MI, status of thrombolytic therapy, peak creatine phosphokinase, plasma lipid profiles, ejection fraction, PTCA per formed, number of diseased coronary arteries, and exercise capacity. Low-de nsity lipoprotein cholesterol decreased significantly (3.2 +/- 1.0 vs 2.7 /- 0.7 mmol/L, p <0.001). The cumulative mortality was 13%. In a univariate model, the parameters that significantly predict mortality included older age, diabetes, low exercise capacity (less than or equal to 4 metabolic equ ivalents) 3-vessel disease, those without PTCA performed, and a low ejectio n fraction. In the Cox proportional-hazards model analysis, the independent factors were coexisting diabetes (chi-square 6.1, p = 0.01) and a low meta bolic equivalent (chi-square 6.5, p = 0.01). One hundred six patients were rehospitalized for nonfatal cardiovascular events that included unstable an gina (48%), heart failure (21%), acute MI (6%), symptomatic arrhythmia (6%) , and severe hypertension (1%). Factors that independently predicted rehosp italization were low exercise capacity (p = 0.02) and the presence of diabe tes (chi-square 4.8, p = 0.03). Diabetes was also associated with more epis odes of hospital admission (2.3 +/- 2.1 vs 1.6 +/- 1.4, p = 0.04) and a lon ger cumulative hospital stay (25.5 +/- 34.6 vs 11.4 +/- 19.6 days, p = 0.02 ). Thus, in patients with MI or after PTCA receiving conventional medical t herapy, the cardiac rehabilitation program should focus on aggressive diabe tic control and enhancement of exercise capacity. (C)2000 by Excerpta Medic a, Inc.