ETIOLOGY AND RESPONSE TO DRUG-TREATMENT IN HEART-FAILURE

Clinical trials in heart failure (HF) tend to randomize patients accor ding to demographic characteristics and severity of left ventricular d ysfunction, without taking account of the precise diagnosis. This arti cle reviews results from recent trials suggesting that the etiology of HF, and particularly whether it is ischemic or nonischemic, may influ ence the long-term prognosis and the response to treatment. Some studi es, but not all, suggest that nonischemic HF has a better prognosis th an ischemic HF, The data on the benefits of angiotensin converting enz yme inhibitors in ischemic versus nonischemic HF are conflicting, Carv edilol, and recently, bisoprolol have been shown to reduce mortality i n ischemic and non-ischemic HF, whereas metoprolol has, to date, impro ved prognosis only in dilated cardiomyopathy. Better responses to digo xin, amlodipine and amiodarone have been reported in non-ischemic HF. There is at present no clear explanation for the apparent therapeutic differences between ischemic and nonischemic HF, Absence of a rigorous definition of ''nonischemic HF'' in many studies makes interpretation of the results difficult. Further studies to clarify the effects of e tiology of HF'' on the response to treatment could be particularly imp ortant for preventing progression to more advanced stages, in which an y type of drug therapy may have limited value in prolonging survival. An individualized therapeutic approach, based on etiology of HF and po ssibly other factors such as plasma drug levels or the levels of neuro hormones, could result in major progress in treating HF patients. (C) 1998 by the American College of Cardiology.