Nifedipine Therapy for Coronary-Artery Spasm: Experience in 127 Patients

We report clinical experience with the coronary vasodilator nifedipine in 127 patients with symptoms of myocardial ischemia associated with electrocardiographic or angiographic evidence, or both, of coronary-artery spasm. In the majority of patients conventional antianginal therapy including nitrates and beta-adrenergic blockers failed, and in one third of the patients at least one episode of ventricular tachycardia developed during an attack of angina. Nifedipine (40 to 160 mg every 24 hours) significantly reduced the mean weekly rate of anginal attacks from 16 to two (P<0.001). Similar marked reductions in the nitroglycerin requirement were noted. In 63 per cent of the patients complete control of anginal attacks was achieved, and in 87 per cent the frequency of angina was reduced by at least 50 per cent. Nifedipine was generally well tolerated, with only 5 per cent of the patients requiring termination of the drug because of intolerable side effects. This experience with nifedipine suggests that it is a highly effective drug for the treatment of coronary-artery spasm and variant angina. (N Engl J Med. 1980; 302:1269–73.) INTEREST in coronary-artery spasm has recently been heightened by evidence suggesting that spasm has a fundamental role in some forms of ischemic heart disease and by the availability of potent coronary spasmolytic agents.^{1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17} The dihydropyridine derivative nifedipine belongs to the class of coronary vasodilators that appear to exert their effect by inhibiting the slow calcium current responsible for the contraction of vascular smooth muscle.¹⁸ Initial reports of its effectiveness in limited groups of patients with documented coronary spasm have been quite encouraging.^{19 20 21 22 23 24} Since 1974, nifedipine has been available in the United States for use on an investigational basis. We report.