β-Blockers for hypertension

Nadia Khan and Finlay McAlister¹ re-examined our meta-analysis² of β-blockers in primary hypertension but came to a different conclusion than we did. We would like to clarify why the conclusions differ.

First, we examined the effect of β-blocker treatment on the incidence of myocardial infarction (MI), stroke or death separately, whereas Khan and McAlister focused on the composite end point of all 3 conditions. However, antihypertensive drugs do not have the same relative effect on stroke incidence as on MI or death.

Second, we excluded the results of the Captopril Prevention Project (CAPPP) trial,³ because it is impossible to retrieve data on how many patients in that study were receiving β-blockers.² CAPPP had a PROBE design (prospective, randomized, open treatment with blinded end-point evaluation),³ as well as some other major quality concerns; for example, randomization was imbalanced, with more high-risk patients receiving captopril than conventional treatment (diuretics and/or β-blockers), and suboptimal use of captopril once daily was encouraged in an unknown number of patients. There is no way of extrapolating from other Scandinavian trials the percentage of patients in the CAPPP study who were treated with β-blockers, since both investigators and patients differed among these trials.

Finally, cardiovascular outcome after treatment of primary hypertension in subjects under 60 years of age is poorly documented. Therefore β-blockers cannot be recommended for any age group.