Determinants of mortality in elderly patients with heart failure: the role of angiotensin-converting enzyme inhibitors.

Abstract

Despite randomized controlled trials demonstrating mortality reduction, many studies have documented persistent low rates of prescription of angiotensin-converting enzyme inhibitors (ACE-I) in patients with heart failures; the reasons for this pattern remain poorly defined. In addition, some authors have argued that the results of carefully controlled clinical trials do not translate well into the uncontrolled world of clinical practice, and the mortality benefits of ACE-I may not extend into special populations such as the elderly. To understand the reasons for failure to prescribe ACE-I to Medicare patients with heart failure and to assess the impact of this failure on mortality. We obtained data by reviewing charts of Medicare patients discharged from 7 Colorado hospitals with a diagnosis of heart failure during 1994. We identified a diagnosis of heart failure in 1016 patients without a contraindication to ACE-I. Three hundred seventy-eight of these patients were receiving ACE-I at the time of admission. Of the 638 remaining, 257 had their left ventricular systolic function assessed and 92 had diminished function. Of these 92, 50 (54.3%) were discharged on a regimen of ACE-I. The only significant difference in baseline comorbidity or demographic variables between those given and those not given ACE-I was that patients not prescribed ACE-I were older. Using multivariate analysis, younger age and cardiology consultation predicted ACE-I prescription (P = .02). By life-table analysis, mortality at 1 year following discharge from the index hospitalization was lower in those treated with ACE-I than in those not so treated (P = .03). The Deyo index of comorbidity, prescription of an ACE-I, site of treatment, and presence or absence of cardiology consultation were significantly associated with 1-year mortality by multivariate analysis (P<.001). Underinvestigation and undertreatment of chronic heart failure persists. Failure to treat elderly patients with ACE-I is associated with a mortality that appears to be greater than that seen in the placebo arms of large clinical trials of ACE-I therapy. Within the population studied, older patients are less likely to be treated. Failure of age to significantly add to prediction of mortality implies that the apparent bias against treating older patients with chronic heart failure with ACE-I is not justified. Because mortality is dependent on provider and site of treatment, further reductions in mortality from chronic heart failure may require intensive and selective local efforts, or development of regional heart failure centers.