Early evolution of symptoms and long-term prognosis in variant angina: importance of the functional component of coronary arterial disease.

PURPOSE

Most investigations describing the long-term outcome of large groups of patients with variant angina pectoris have focused on such endpoints as myocardial infarction, coronary artery surgery, and death, and have asked how the risk of these events is related to the severity of existing organic coronary disease. It is also possible to ask what is the relative importance of organic and functional components in causation of symptoms and outcomes, as was done in this study.

PATIENTS AND METHODS

The early and long-term clinical course was observed in a group of 80 patients with variant angina and a low prevalence of severe organic coronary disease (diameter stenosis greater than 70 percent of one vessel in 28.3 percent, of two or more vessels in 2.7 percent). Patients were seen at the UCLA Medical Center between July 1963 and June 1985.

RESULTS

The following observations were made: Compared with those experiencing a first episode of angina at rest, subjects whose first episode of vasospastic angina occurred during strenuous effort were more likely subsequently to have a positive exercise test result and a more stable but long-term anginal course. A good initial response to vasodilator therapy indicated a likelihood of being alive and symptom-free without an intervening myocardial infarction by five years after diagnosis, which was twice the rate as if initial response to such treatment was poor. The presence or absence of severe coronary artery obstruction as detected by angiography could not be predicted from the nature or severity of angina, the historical presence of effort angina, or the occurrence of a positive result on an exercise test. The existence of severe coronary stenosis in at least one vessel was not associated with an increased incidence of myocardial infarction, cardiac arrest, or death in the first nine years after diagnosis.

CONCLUSION

These findings are consistent with the hypothesis that manifestations of ischemic heart disease in these patients were more directly caused by coronary vasospasm than by the degree of organic coronary obstruction seen by coronary arteriography. In addition, the presence of severe organic stenosis in one coronary artery did not appear to be associated with measurably increased adverse effects on clinical course or survival over the first nine years after diagnosis.