CONGESTIVE-HEART-FAILURE SYMPTOMS IN PATIENTS WITH PRESERVED LEFT-VENTRICULAR SYSTOLIC FUNCTION - ANALYSIS OF THE CASS REGISTRY

The clinical characteristics and long-term survival of 284 patients from the Coronary Artery Surgery Study (CASS) registry data base who had moderate to severe congestive heart failure symptoms and a left ventricular ejection fraction greater-than-or-equal-to 0.45 were studied. A control group consisting of registry patients with an ejection fraction greater-than-or-equal-to 0.45 who did not have heart failure was used for comparison. Patients who had heart failure were older and more likely to be female and to have a higher incidence of hypertension, diabetes and chronic lung disease than registry patients who did not have heart failure. As a group, patients with heart failure had more severe angina and were more likely to have had a prior myocardial infarction than were registry patients without heart failure. At 6 year follow-up, 82% of patients in the heart failure group survived compared with 91 % of patients in the control group (p < 0.0001). Multivariate analysis using the Cox proportional hazards model identified the following independent predictors of mortality: regional ventricular systolic dysfunction, number of diseased coronary arteries, advanced age, hypertension, lung disease, diabetes, increased left ventricular end-diastolic pressure and heart failure symptoms. Among patients with heart failure, the 6-year survival rate of those who had three-vessel coronary artery disease was 68% compared with 92% for the group without coronary artery disease. However, the 6-year survival rate for patients with heart failure who underwent surgical revascularization of diseased coronary arteries was not significantly improved compared with that of patients treated medically. It appears from these data that the presence of moderate to severe heart failure symptoms in patients with an ejection fraction greater-than-or-equal-to 0.45 is a clinical marker for a distinct patient group characterized by increased age, more severe clinical coronary artery disease, hypertension and an increased incidence of additional medical illnesses that have independent value in predicting longterm survival. As a result of the high incidence of concurrent illnesses, this patient group has a significantly reduced 6-year survival rate compared with a CASS registry patient group that did not have heart failure, and the additional presence of coronary artery disease dramatically reduces their survival. However, surgical treatment of coronary artery disease is not associated with improved survival over a 6-year follow-up period in this CASS registry subgroup.