Utilization and dosing of angiotensin-converting enzyme inhibitors for heart failure

Abstract

To determine if physician specialty is associated with underutilization and underdosing of angiotensin-converting enzyme inhibitors among patients with heart failure, we reviewed the charts of 214 outpatients with decreased systolic function at an urban academic medical center. Regardless of whether patients were cared for by cardiologists, generalist physicians, or a combination of the two specialties, approximately 75% of the patients were taking an angiotensinconverting enzyme inhibitor. However, only approximately 60% of these patients were taking dosages proved to be efficacious in trials. Emphasis on adequate dosing is needed among all specialty groups.KEY WORDS: angiotensin-converting enzyme (ACE) inhibitor; congestive heart failure; physician behavior; specialty; quality of care. J GEN INTERN MED 1997;12:563-566. lthough randomized controlled trials have convincingly demonstrated that angiotensin-converting enzyme (ACE) inhibitors decrease mortality and hospitalization in patients with ejection fractions of 0.35 or less, 1-3 physicians often underutilize these medications. [4][5][6][7][8][9][10][11] Moreover, physicians may prescribe dosages that are less than those proved to be effective in large, multicenter trials. 7,9,11 Little is known, however, about the factors associated with underutilization and underdosing. 4,9 Some studies suggest that cardiologists are more likely than generalist physicians to prescribe ACE inhibitors in circumstances and dosages that accord with established guidelines. 7,9,12,13 However, these latter studies are limited because they either were surveys of physicians' knowledge, or else did not limit their population to patients with decreased systolic function. Therefore, to determine if physician specialty and patient characteristics are associated with underutilization and underdosing of ACE inhibitors, we performed a cross-sectional study of outpatients with heart failure. METHODS Study PopulationWe retrospectively identified all patients seen at the University of Chicago's cardiology, general internal medicine, and geriatrics clinics between January 1, 1994, and June 30, 1996, who received an outpatient billing diagnosis of International Classification of Diseases code 428 (congestive heart failure) or 425.4 (cardiomyopathy). 14 We reviewed the medical records of these patients, and then selected those patients with moderately or severely decreased systolic function (fractional shortening 18% to 24% and less than 18%, respectively), determined primarily through echocardiogram, and rarely through cardiac catheterization or nuclear scan. We divided the patients into three groups: (1) patients seen by a cardiologist, but not by a general internist or geriatrician, as determined through both the administrative computer system and review of the medical record; (2) patients seen by either a general internist or geriatrician, but not by a cardiologist; and (3) patients seen by a cardiologist and either a general internist or a geriatrician. Data CollectionWe obtained the histor...

Differences in generalist and specialist physicians’ knowledge and use of angiotensin-converting enzyme inhibitors for congestive heart failure

“…Also, few investigators have attempted to determine physician and patient factors associated with underutilization, 13,15 and whether underdosing occurs. 16 Therefore, we surveyed physicians about their knowledge of ACE inhibitors to explore whether underutilization of these medications persists. We aimed to determine whether patterns of self-reported use of ACE inhibitors vary by specialty type and other attitudinal, cognitive, and demographic attributes of the physicians, as well as by indication for the medication and the severity of the patient's illness.…”

What Is the Strength of Evidence for Heart Failure Disease-Management Programs?

“…Systematic review has identified that trials of programs currently do not detail sufficiently what "usual" or "routine" care comparison groups received (20,22,25,26). This lack of detail creates bias because pharmacological care for HF varies widely over place, time, and sector (27,28). Prescription rates of key pharmacotherapies have differed historically and are influenced by geographic location (28), the availability of specialists (29,30), and the aggressiveness of management (31,32).…”

“…This lack of detail creates bias because pharmacological care for HF varies widely over place, time, and sector (27,28). Prescription rates of key pharmacotherapies have differed historically and are influenced by geographic location (28), the availability of specialists (29,30), and the aggressiveness of management (31,32). These differences are crucial because any apparent effect (or lack thereof) in a trial could be attributed equally to variations in usual care as to the intervention (7).…”

Comparing Generalist and Specialty Care

“…However, on chart review of patients with congestive heart failure at one academic medical center, only three quarters of eligible patients were taking an angiotensin-converting enzyme inhibitor, and only 60% of these were at doses known to be efficacious. 24 Then, in a recent survey, Jancin 25 found that cardiologists reported greater adherence than generalists to the 1994 Agency for Health Care Policy and Research guidelines for the treatment of congestive heart failure.…”

“…Deficiencies have been documented for the care of hypertension (recognition and treatment), 87,88 atrial fibrillation (knowledge regarding anticoagulation guidelines), 38 congestive heart failure (use of angiotensinconverting enzyme inhibitors), 24 hyperlipidemia (recognition and treatment), [89][90][91] and myocardial infarction (use of aspirin, thrombolytics, and ␤-blockers).…”