Editor—In his analysis of the major results of the recently published antihypertensive and lipid lowering treatment to prevent heart attack trial (ALLHAT), Williams concludes that the key message from this trial is that what matters most is getting blood pressure controlled and that this is overwhelmingly more important than the means.1,2
ALLHAT showed that all blood pressure drugs were not “created” equally.2 Williams correctly points out important differences in the secondary cause specific end points between chlorthalidone and its active comparators: doxazosin (increased congestive heart failure), lisinopril (increased stroke and coronary end points), and amlodipine (increased stroke). For this very reason, the data safety monitoring board of the ALLHAT trial recommended discontinuance of the doxazosin arm.
There are other characteristics of blood pressure drugs, other than their effect on so called hard end points, that are as important as getting blood pressure controlled. These include cost, profile of adverse effects, ease of use (once daily versus several daily doses), and interactions with other drug agents. In all aspects, thiazide type diuretics come up tops as first line agents. This was amply shown in the systolic hypertension in the elderly programme (SHEP) and Medical Research Council studies, in which thiazide diuretics were associated with a greater than 40% reduction in the risk of stroke in patients with isolated systolic hypertension; these studies were conducted and completed more than a decade ago.3,4 ALLHAT also showed the differences in tolerability between agents, and the particular difficulty in controlling blood pressure to target values especially with angiotensin converting enzyme inhibitors in black patients.
In choosing a therapeutic agent to lower blood pressure and reduce cardiovascular risk, one must look at not only the blood pressure lowering effect but also important clinical end points that we are aiming to prevent, as well as issues such as cost and tolerability.