Medical therapy of Prinzmetal's variant angina

Coronary vasospasm: A narrative review

Coronary artery vasospasm (CAVS) plays an important role in acute chest pain syndrome caused by transient and partial or complete occlusion of the coronary arteries. Pathophysiology of the disease remains incompletely understood, with autonomic and endothelial dysfunction thought to play an important role. Due to the dynamic nature of the disease, its exact prevalence is not entirely clear but is found to be more prevalent in East Asian and female population. Cigarette smoking remains a prominent risk factor, although CAVS does not follow traditional coronary artery disease risk factors. Many triggers continue to be identified, with recent findings identifying chemotherapeutics, allergens, and inflammatory mediators as playing some role in the exacerbation of CAVS. Provocative testing with direct visualization is currently the gold-standard for diagnosis, but non-invasive tests, including the use of biomarkers, are being increasingly studied to aid in the diagnosis. Treatment of the CAVS is an area of active research. Apart from risk factor modification, calcium channel blockers are currently the first line treatment, with nitrates playing an important adjunct role. High-risk patients with life-threatening complications should be considered for implantable cardioverter defibrillator (ICD), although timing criteria for escalated therapy require further investigation. The role of pharmaceuticals targeting oxidative stress remains incompletely understood.

A controlled trial of verapamil for Prinzmetal's variant angina

To assess the efficacy and safety of verapamil in variant angina pectoris, we entered 16 patients in a double-blind, randomized trial of nine months, duration. During treatment with verapamil, the frequency of angina fell substantially (12.6 +/- 25.9 chest pains per week with placebo, 1.7 +/- 2.8 pains per week with verapamil, mean +/- S.D.; P less than 0.01), as did the use of nitroglycerin tablets (14.4 +/- 34.4 tablets per week with placebo, 2.1 +/- 3.3 tablets per week with verapamil; P less than 0.05). The number of hospitalizations for clinical instability was significantly lower with verapamil (P less than 0.01). The number of episodes of transient ST-segment deviation during treatment with verapamil was reduced (33.1 +/- 39.3 ST-segment deviations per week with placebo, 7.7 +/- 11.7 deviations per week with verapamil; P less than 0.01). Verapamil caused no side effects forcing a reduction in dosage or a discontinuation. We conclude that verapamil is safe and effective in the therapy of variant angina pectoris.