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)

Echocardiography in unstable angina.

This study was undertaken to determine whether abnormalities on the echocardiograms of patients with unstable angina have any prognostic significance. 27 male patients, mean age 53 years, who fulfilled criteria for unstable angina and who responded to medical therapy, had echocardiograms within 48 h of admission and at discharge. Follow-up data were obtained from 7 patients during a postdischarge period of 6-26 weeks. 13 patients had mild exertional angina or were pain-free (group I) and 14 patients had either severe, stable angina pectoris or recurrence of their unstable angina (group II) during the follow-up period. When admission and discharge values were compared, the echocardiographic ratio of left ventricular end-diastolic dimension to mitral valve closure time (EDD/PR-AC) showed significant differences for both group I and group II (p less than 0.05). An abnormal EED/PR-AC ratio was present at discharge in 8 of 14 group II patients compared to only 1 of 13 group I patients (p less than 0.05). The mean values for end-diastolic dimension, mitral valve closure time, and amplitudes of interventricular septal and posterior left ventricular wall motion were not significantly different in comparisons between admission and discharge studies and between group I and group II patients. In 19 patients who had cardiac catheterization druing the follow-up period, the discharge EED/PR-AC ratio correlated inversely with the angiographic ejection fraction (r = 0.79; p less than 0.001).

Submaximal exercise testing after unstable angina.

Sixty-one consecutive men, mean age 56 years, who fulfilled criteria for unstable angina and who responded to medical therapy, underwent submaximal exercise testing prior to hospital discharge and at least 3 days after their last episode of angina. Forty-two patients were receiving propranolol at the time of exercise. Submaximal exercise was targeted to 120 beats/minute and strict criteria for the premature termination of each study were followed. Follow-up data were available on 55 patients post-discharge over a period of 6 to 36 weeks. No patient suffered recurrence of unstable angina or myocardial infarction due to the exercise test. Exercise was prematurely terminated by an ischemic response (chest pain and/or ST segment changes) in 34 patients (56%) and by leg fatigue in 13 patients (21%). Only five patients had exercise-induced ventricular ectopic activity, four of whom were not receiving propranolol. Nine patients achieved the target heart rate. Exercise-induced abnormal electrocardiographic changes predicted the postdischarge recurrence of episodes of unstable angina (p less than 0.05). Comparison of predischarge submaximal exercise data with postdischarge maximal exercise shows that recovery in cardiovascular function after unstable angina occurs soon after stabilization and prior to the submaximal test.