PROVOCATIVE TESTING WITH ERGONOVINE TO EVALUATE THE EFFICACY OF TREATMENT WITH CALCIUM ANTAGONISTS IN VARIANT ANGINA

Ten consecutive hospitalized patients with uncontrolled variant angina were studied to evaluate the efficacy of nifedipine and perhexiline maleate treatment and to determine if the results of incremental ergonovine testing during treatment predicted the short-term clinical response. During a mean control period of 5.2 days without treatment other than nitroglycerin, 3.9 ± 4.7 (mean ± SD) episodes of variant angina occurred per day. During the subsequent treatment period with nifedipine 20 mg every 6 hours, only 0.09 ± 0.15 episodes/day occurred (p < 0.02 vs control) and seven patients had no angina. During perhexiline treatment (400 mg twice daily), 2.3 ± 3.2 attacks/day were recorded; this was not significantly different than during the control period. Without treatment all 10 patients had positive ergonovine tests at doses ranging from 0.025-0.3 mg. During nifedipine treatment nine of the 10 tests became negative at doses as large as 0.4 mg (p < 0.0001). The results of ergonovine testing during perhexiline treatment did not differ significantly from the control period. Overall, 11 of the 12 ergonovine tests positive at 0.1 mg or less occurred during observation periods with more than one episode/day of variant angina, and all 16 negative tests, or tests positive only at 0.2 mg or more, occurred during periods with less than one episode/day of variant angina. The authors conclude that the results of ergonovine testing during treatment correlate with the short-term clinical response to therapy. Although the effect of chronic treatment with calcium antagonists on the natural evolution of this syndrome is unknown, nifedipine rapidly and effectively controls the acute clinical manifestation of variant angina.