[Clinical study of the month. The CAPPP study: "The Captopril Prevention Project"]

The Captopril Prevention Project (CAPPP) was a prospective, randomized, open trial which aimed at comparing the prevention by captopril (n = 5492) or by a conventional treatment (n = 5493; diuretics or beta-blockers) of cardiovascular morbidity and mortality in patients with hypertension (diastolic blood pressure > 100 mmHg). After a mean follow-up of 6.1 years, the results regarding the primary endpoint and most secondary endpoints were not significantly different between the two therapeutic modalities. The only differences (perhaps due to a randomisation bias) were a slightly higher incidence of stroke, but a lower risk of diabetes mellitus, in the captopril group than in the group receiving conventional treatment. In conclusion, the CAPPP study demonstrates, for the first time, that captopril, an angiotensin-converting-enzyme inhibitor, is as effective as conventional treatment with diuretics or beta-blockers, two drugs whose efficacy has already been demonstrated when compared to placebo, in the prevention of cardiovascular morbidity and mortality in hypertensive patients.