[Prognosis of silent myocardial ischemia: follow-up of 100 patients with positive treadmill test and exertion myocardial scintigraphy]

Prognosis of asymptomatic myocardial ischemia is largely unknown and the opportunity is still controversial of seeking for patients with silent ischemia. Aim of the present study is to evaluate the prognosis of painless myocardial ischemia documented by exercise test and myocardial scintigraphy. From June 1981 through November 1986, 206 patients without angina, history or ECG signs of old myocardial infarction, presenting a positive (decreases ST greater than or equal to 1.5 mm) exercise treadmill test, underwent exercise Thallium 201 myocardial imaging. Myocardial scintigraphy showed a normal scan in 85 cases and a reversible or fixed perfusion defect in 121. Patients with abnormal scan presenting ischemia at a low to moderate ergometric work-load were treated with betablockers or calcium-antagonist drugs. Out of patients with positive myocardial scintigraphy a sample of the first 100 consecutive subjects was considered. They were 87 men and 13 women aged 28-72 years (mean 54.8) observed during a mean follow up period of 33.1 +/- 1.6 months. Seven patients underwent coronary angiography which showed 3-vessel critical stenosis in 3 cases, 3-vessel lesions plus critical stenosis of the left main coronary-artery in 1 and 2-vessel lesions in 3. Two patients underwent coronary artery bypass surgery. A non fatal myocardial infarction occurred in 1 and 1 became symptomatic for angina, 11 and 20 months respectively after the diagnosis of ischemia. Three patients with ischemia at a low work-load and extensive scintigraphic perfusion defects died of sudden death and one of cancer.(ABSTRACT TRUNCATED AT 250 WORDS)