According to the 1992 Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure, ß-blockers and diuretics are the preferred drugs for treating hypertension [1]. Hoes and colleagues [2] challenge that view and report that the use of non-potassium-sparing diuretics and ß-blockers is associated with increased risk for sudden death [2]. Although the authors also came to the former conclusion in a review of published studies on non-potassium-sparing diuretics [3], the latter finding is unexpected.

In a recent overview, Kendall and colleagues [4] concluded that none of the available therapies is more effective than ß-blockers in preventing sudden cardiac death [4]. Although the design of this case–control study (which investigated all sudden deaths in residents of Rotterdam, the Netherlands, who received drug therapy for hypertension compared with surviving age- and sex-matched controls who received such therapy) is straightforward, the presentation of the data needs further clarification.

With regard to the recent media attention on calcium antagonists, especially those of the dihydropyridine class [5], we suggest that this excellent data set be analyzed further. Currently, calcium antagonists seem to be hidden in reference category 4 (antihypertensive medication with neither non-potassium-sparing diuretics nor ß-blockers). This category encompasses a wide range of medications, including potassium-sparing diuretics (65%), calcium antagonists, and angiotensin-converting enzyme inhibitors. Could Hoes and colleagues provide further details on the number of patients treated with calcium antagonists, especially dihydropyridines? What percentage of patients who died were receiving such drugs, either without or in combination with ß-blockers?

Furthermore, case-patients had a much higher risk for death, with significant differences in the prevalences of myocardial infarction, heart failure, and angina pectoris. Obviously, patients with heart failure are often treated with non-potassium-sparing diuretics, just as patients with angina are treated with ß-blockers. Thus, ß-blockers and non-potassium-sparing diuretics should be seen instead as a marker for patients at high risk for sudden death in this case–control study. Because prescription bias and confounding cannot be ruled out in the case–control design (controls were only matched by age and sex), it is impossible to conclude that the association of the use of non-potassium-sparing diuretics and ß-blockers with an increased risk for sudden death may offset the mortality benefit of these drugs in the treatment of hypertension.