Effects of angiotensin-converting enzyme inhibitors and digoxin on health outcomes of very old patients with heart failure

Background: Randomized trials have shown that angiotensin-converting enzyme (ACE) inhibitors reduce mortality and morbidity, and improve symptoms and exercise tolerance in selected patients with congestive heart failure (CHF) . There is, however, no evidence on the effectiveness of ACE inhibitors in the typical, very old and frail patients with CHF. Objective: To compare the effects of ACE inhibitors and digoxin on 1-year m ortality, morbidity, and physical function among patients aged 85 years. Methods: We conducted a retrospective cohort study using the SAGE database, a long-term care database linking patient information with drug utilizatio n data. Among 64 637 patients with CHF admitted to all nursing homes in 5 s tates between 1992 and 1995, we identified 19 492 patients taking either an ACE inhibitor (n = 4911) or digoxin (n = 14 890). Record of date of death was derived from Medicare enrollment files, and we used the part A Medicare files to identify hospital admissions and discharge diagnoses. As a measur e of physical function, we used a scale for activities of daily living perf ormance. The effect of ACE inhibitors was estimated using Cox proportional hazards models with digoxin users as the reference group. Results: The overall mortality rate among ACE inhibitor recipients was more than 10% less than that of digoxin users (relative rate, 0.89; 95% confide nce interval, 0.83-0.95). Mortality was equally reduced regardless of conco mitant cardiovascular conditions and baseline physical function. Treatment with ACE inhibitors was associated with a tendency toward reduced hospital admissions that was more evident among patients with greater functional imp airment. The adjusted relative rate for hospitalization for any reason was 0.96 (95% confidence interval, 0.91-1.01). The rate of functional decline w as greatly reduced among ACE inhibitor recipients (relative rate, 0.74; 95% confidence interval, 0.69-0.80), and this effect was consistent and indepe ndent of background comorbidity and baseline physical function. Conclusions: These data suggest that survival and functional benefits of AC E inhibitor therapy extend to patients with CHF 85 years and older, and mos tly women, both systematically underrepresented in randomized trials. Alter natively, digoxin has a detrimental effect in this population.