< Back CME Module 9: Peri-Operative Cardiac Risk Reduction Next >


Medical Therapy - Calcium Channel Blockers

There is some hesitation to use calcium channel blockers, stemming from the initial problems with the
dihydropyridines. For example, drugs like nifedipine were shown to increase the myocardial infarction rates in stable angina patients. Dihydropryidines are primarily vasodilators and have no negative chronotropic effect.

At present, the experience with calcium channel blockers in non-cardiac surgery is limited, with fewer than 1100 patients entered into RCT’s. However, a recent meta-analysis found that they reduced the incidence of ischemia, post operative SVT, myocardial infarction and major morbid events (20). These effects were almost entirely due to the experience with diltiazem. This analysis also confirmed that the dihydropyridine class of calcium channel blockers increased ischemia and the incidence of postoperative SVT.

All trials in this meta-analysis were testing the calcium channel blockers as single agents. Only 13% of patients in these trials were taking a beta-blocker during the trial, so we know little of the combination of calcium channel blockers in combination with other drugs, notably beta-blockers. We can only speculate that the calcium channel blockers in the long acting formulations, given in combination with a beta-blocker, will prove to be beneficial.

< Back Next >