Lack of indication of myocardial cell damage after myocardial ischaemia in patients with severe stable angina

To evaluate myocardial cell damage in relation to spontaneous and exercise-induced ischaemia, release of myoglobin, creatine kinase (CK) and its isoenzyme MB (CK-MB) into the serum was estimated in 10 patients with severe stable angina. All patients had a positive exercise test, significant stenosis of one or more of the main coronary arteries and more than five ischaemic attacks per week. ST-segment monitoring was performed for 36 h. During the last 24 h of that period (period A) serial blood samples were analysed for myoglobin, CK and CK-MB using sensitive assays. Three days later (period B) the patients performed an exercise test at 0815 h, with ST-segment monitoring and blood sampling carried out as described for period A. During period A, 47 ischaemic episodes (100% silent) with a total duration of 599 min were noted in four patients. Forty-seven ischaemic episodes (94% silent) with a total duration of 804 min, were observed in seven patients during period B. Release of myoglobin, CK, and CK-MB did not increase in relation either to spontaneous or exercise-induced ischaemia. Thus even frequent and prolonged episodes of transient myocardial ischaemia (symptomatic or asymptomatic) in patients with severe stable angina pectoris does not seem to cause irreversible myocardial damage.