Ergonovine testing to detect spontaneous remissions of variant angina during long-term treatment with calcium antagonist drugs

Abstract

A subgroup of 22 patients with variant angina who had responded well to calcium antagonist drugs were studied to determine if ergonovine testing could help assess the need for continued therapy. Before treatment all 22 patients exhibited angina with S-T elevation during ergonovine testing done in the coronary care unit according to a previously described protocol with sequential ergonovine doses of 0.0125, 0.025, 0.05, 0.1, 0.2, 0.3 and 0.4 mg administered at 5 minute intervals. After 9.4 ± 4.7 (range 1 to 24) months of treatment (nifedipine 7 patients, diltiazem 3, verapamil 8, perhexiline 3, nifedipine and diltiazem 1), all patients were free from anginal attacks. Medication was discontinued and ergonovine testing repeated 24 to 48 hours later (3 weeks for perhexiline). In 12 of the 22 patiénts, angina or S-T segment shifts did not occur during the second ergonovine test to a maximal dose of 0.4 mg. Treatment was not restarted in these patients and all 12 remain free of variant anginal attacks 4.2 ± 2.9 (range 1 to 13) months later. In seven patients angina and S-T elevation occurred during the second ergonovine test, in the same electrocardiographic leads as during the test before treatment. In three patients the ergonovine test induced angina with S-T depression in the leads where S-T elevation had occurred during the previous test. Treatment was reinstituted in these 10 patients with a positive test. No complications resulted from ergonovine testing in any patient. We conclude that in many patients with variant angina, symptoms will disappear spontaneously and the ergonovine test will revert to negative. Treatment with calcium antagonist drugs can probably be safely discontinued in some patients with variant angina; ergonovine testing appears to be helpful in identifying such patients. Longer periods of follow-up are required to confirm that symptoms do not recur.