Thallium 201 perfusion imaging after the treatment of unstable angina pectoris--relationship to clinical outcome.

Unstable angina usually responds to medical management. Unfortunately, a third of patients with this condition may be expected to have severe angina in the ensuing year. We tested the ability of thallium 201 imaging with submaximal exercise to identify patients who have a poor clinical prognosis after an episode of unstable angina. In all, 37 patients were evaluated with (201)TI before hospital discharge and were assessed for severity of angina over the next 12 weeks. Of these, 20 had New York Heart Association class I or II angina during follow-up, 4 of whom had defects on (201)TI imaging that showed redistribution. In 17 patients class III or IV angina developed or they suffered an acute myocardial infarction after hospital discharge, and 15/17 had reversible defects on (201)TI imaging after submaximal stress (P<.001). (201)TI scintigraphy frequently identifies areas of ischemia with only submaximal exercise in patients whose unstable angina has responded to medical therapy.

Alterations in left ventricular function during therapy of unstable angina pectoris: relationship to clinical outcome.

We studied 30 consecutive patients with unstable angina during pain-free intervals with gated blood pool scintigraphy. The initial study was performed within 18 hours of admission to the coronary care unit. A second study was performed near the time of hospital discharge, after stabilization with medical therapy. Three months thereafter patients were categorized according to their worst anginal status following hospital discharge. Fifteen patients were New York Heart Association functional class I or II (group A); 15 patients were in functional class III or IV (group B). Left ventricular ejection fraction was similar at the time of initial study (55.9 +/- 2.18% and 56.0 +/- 3.55% for groups A and B respectively). At the time of hospital discharge the ejection fraction had risen to 60.3 +/- 1.85% (p less than 0.01) in group A and in group B it had fallen to 48.1 +/- 3.4% (p less than 0.005). End-systolic volume index in group B rose from 37 ml/m2 +/- 6.1 to 43 +/- 6.2 ml/m2 (p less than 0.005) at the time of the follow-up study. There were no significant intergroup patients during the two scintigraphic examinations. Eleven group B patients subsequently underwent coronary artery bypass surgery. A significant increase in ejection fraction and a significant decrease in end-systolic volume index were noted when these patients were restudied an average of 3.2 months after surgery. This study suggests that changes in left ventricular function during the course of unstable angina pectoris are common and may be detected by serial gated blood pool scintigraphy.(ABSTRACT TRUNCATED AT 250 WORDS)