Comparison of various calcium antagonist on vasospastic angina: a systematic review

BACKGROUND: Coronary artery vasospasm is an abnormal spasm of coronary arteries that cause transient or complete occlusion without exertion. It causes stable angina to ACS. However, this can be prevented by calcium channel blockers (CCBs) which suppress Ca(2+) influx into the vascular muscle cells. Nevertheless, several CCBs adverse effects are harmful for these patients. Selecting the right CCBs would give the best clinical practice. METHOD: The studies were obtained from four major medical databases by various keywords. Inclusion and exclusion criteria were implemented as adult >18 years, observational study, English language and drug of interest. Duplicates were eliminated, and the remaining studies were reviewed. Final full-texts assessment was conducted independently by Newcastle-Ottawa Scale and Revised Cochrane. RESULTS: The search found 1378 articles. However, six studies were selected after implementing the study criteria. Diltiazem was found to decrease angina and increase quality of life until 12th week of treatment; however, some adverse effects include atrioventricular block and recurrent angina up till 4th week were found. Meanwhile, nifedipine was found to decrease vasospastic angina (VSA) by the fourth and eighth weeks of treatment. Nevertheless, it caused excessive drop in BP and increase heart rate by eighth week. In addition, slow-release preparation of both CCBs were found to increase efficacy and compliance. Lastly amlodipine was also found to decrease VSA by 17%±140% and 33% after 6 weeks, but further studies needed. CONCLUSION: Diltiazem, nifedipine and amlodipine are potent in decreasing VSA, however, tailoring specific CCBs adverse reactions to patient condition and the drug preparation would be substantially beneficial for the outcome.