To the Editor.
—We thank Drs Adyanthaya and Gaasch for their comments in the Archives (135:747,1975) on our paper on Prinzmetal angina,1 and we welcome the opportunity to restate our position in the light of more recent contributions.The high incidence (usually short-term) of myocardial infarction and sudden death in Prinzmetal angina has been reported in the literature reviews by both McAlpin et al2 and us1 as 25% and 24%, respectively, for myocardial infarction, and 15% and 14%, respectively, for sudden death. Five additional deaths have been reported recently in medically treated patients.3-5 The prognosis of patients with Prinzmetal angina remains guarded; hence, the surgical approach is appealing in principle.The distinctive feature of Prinzmetal angina is the occurrence of spasm of the coronary arteries. Spasm may develop in an angiographically normal vessel or be superimposed on a subcritical or critical organic constriction. Our paper was