FACTORS DETERMINING ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR UNDERUTILIZATION IN HEART-FAILURE IN A COMMUNITY SETTING

Background: Angiotensin-converting enzyme (ACE) inhibitors were underp rescribed for patients with congestive heart failure (CHF) treated in the community setting in the early 1990s despite convincing evidence o f benefit. Hypothesis: We postulated that (1) the prevalence of ACE in hibitor use has increased, and (2) prescribing biases have narrowed, a s community physicians have gained additional clinical experience with these drugs for treatment of CHF. Methods: We examined rates of ACE i nhibitor use among 1,150 patients with CHF hospitalized at 10 communit y hospitals in 1995, evaluated determinants of ACE inhibitor pre presc ription, and compared the results with survey data gathered among simi lar patients during 1992. Results: Compared with 1992, ACE inhibitor u se prior to hospital admission was increased among all patients (42 vs . 33%, p < 0.001) and the subset with a history of CHF (53 vs. 39%, p < 0.0005). Angiotensin-converting enzyme inhibitor prescription at hos pital discharge also increased among all survivors (64 vs. 51%, p < 0. 00005) and the subset eligible for ACE inhibitor treatment based on cl inical trial criteria (77 vs. 66%, p = 0.04). Multivariate analysis su ggested no change in the prescribing biases previously observed; ACE i nhibitor use was related to lower ejection fraction, lower serum creat inine, documentation of left ventricular systolic function, younger pa tient age, prescription of any diuretic drug, and nonprescription of a lternate vasodilators and calcium blockers. In multivariate analyses, physician specialty did not predict ACE inhibitor use. Conclusions: An giotensin-converting enzyme inhibitor use among patients with CHF is i ncreasing but remains below the 80-90% rates of drug tolerance documen ted in randomized clinical trials. This discrepancy is partially expla ined by the prevalence of renal impairment and ''diastolic'' heart fai lure in the community setting. However, age bias, use of alternative v asodilators, and substandard quality of care may also play a role.