JAMA Study Ups Debate Over Calcium Blockers

A study suggesting that a frequently-used class of antihypertensive drugs may actually increase the risk of a heart attack is bound to cause controversy, and the publication of just such a study in the August 23 issue of the Journal of the American Medical Association, to coincide with a major international cardiology conference, has reignited an issue which first erupted at the American College of Cardiology meeting earlier this year.

The study in question is Bruce Psaty's population-based case control trial which showed that compared to diuretics alone, the use of calcium channel blockers, with or without diuretics, was associated with a 58%-70% increase in the risk of myocardial infarction. Final results of the study, conducted by Dr Psaty and colleagues from the University of Washington in Seattle, have now been published in the August 22 issue of JAMA, and suggest a relative risk for patients taking calcium channel blockers versus diuretics or beta blockers of 1.6.

Media Reports Sparked Patient Panic After the oral presentation of the results at the ACC in March, which was followed by many reports in both the lay and specialist media, many patients on the drugs reportedly called their physicians expressing their concerns, and asking whether they should stop taking the medication. Now that the final results have been presented, manufacturers and some cardiologists have been outspoken in their defence of the class and have insisted that the Psaty trial is no basis for patients discontinuing or changing their treatment.