ABSTRACT
BACKGROUND: About half of all patients with type 2 diabetes will eventually die because of a cardiovascular disease–related event. This study compared whether captopril was better than other beta blockers or diuretics at decreasing cardiovascular morbidity and mortality in the patient with diabetic hypertension.
POPULATION STUDIED: Patients were 572 diabetics enrolled in the larger captopril prevention project (Lancet 1999; 353:611-6), a study of 10,985 hypertensive patients from 536 health centers in Sweden and Finland. Subjects were male and female, aged 25 to 66 years, with primary hypertension (untreated and treated) and untreated diastolic blood pressure of at least 100 mg Hg on 2 occasions. Factors for exclusion: secondary hypertension, elevated serum creatinine levels, or conditions requiring beta blocker therapy.
STUDY DESIGN AND VALIDITY: This research was a randomized controlled trial. Neither patients nor physicians were blinded, although endpoints were assessed by a committee blinded to treatment assignment. Initial allocation to treatment group was concealed from enrolling physicians. Patients were initially randomized to receive blood pressure treatment with either captopril (up to 100 mg per day) or conventional treatment with a diuretic agent or beta blocker. Patients not achieving blood pressure control were treated at the discretion of the physician with a diuretic in the captopril group or with a combination of beta blocker and diuretic in the conventional group. A calcium channel blocker could be added as a third step in either group. The goal of therapy was diastolic blood pressure less than 90 mm Hg. Patients were evaluated for an average of 6.1 years.
OUTCOMES MEASURED: The primary outcome measured was fatal and nonfatal myocardial infarction (MI) and stroke as well as other cardiovascular deaths in patients with diabetes. Other outcomes measured were the development of other cardiac disorders and noncardiovascular effects.
RESULTS: The primary outcome of fatal and nonfatal MI and stroke, as well as that of other cardiovascular deaths, was significantly lower in the captopril-treated group than in the conventional treatment group (RR = 0.59, 95% CI 0.38-0.91, number needed to treat [NNT] = 16). Overall mortality was lower as well (RR = 0.54, 95% CI 0.31-0.95). Individually, the rates of stroke, fatal cardiovascular events, and overall mortality did not differ between the 2 groups. MI (fatal and nonfatal) was markedly less frequent in the captopril group (RR = 0.34, 95% CI 0.17-0.67, NNT = 16).
Captopril may be the initial agent of choice for hypertension in diabetic hypertensive patients, especially those with poor glycemic or lipid control. Captopril was shown to reduce overall mortality, MI risk, and overall cardiac events significantly better than did treatment initiated with either a diuretic agent or a beta blocker.