Calcium Channel Blockers Raise Heart Attack Risk?

A presentation at the American Heart Association's annual meeting has caused a stir by suggesting that use of calcium channel blockers to treat hypertension may increase a patient's risk of heart attack by 60%. The study, by researchers at the University of Washington in Seattle, is the first to indicate that calcium blockers are dangerous in otherwise healthy people. It was funded by the National Institutes of Health.

US guidelines recommend the use of beta blockers and diuretics for hypertensive patients but many cardiologists use calcium channel blocking drugs such as nifedipine, diltiazem and verapamil. Half of the 50 million Americans with hypertension are receiving pharmacological treatment for the condition, and 25% of these take calcium blockers. Paul Ridker of Brigham and Women's Hospital in Boston said that doctors continue to use the drugs partly because drug companies have marketed them beyond what the data shows.

As expected, the study had a very mixed reception. Some cardiologists cautioned that the case control study did not prove an effect, and others commented that even if the findings were correct the risk to patients would be miniscule. Nanette Wenger of Emory University noted that case control studies are clearly unreliable, and that it would be extremely difficult to rule out hidden biases that might sway the conclusions.