Myocardial perfusion and angiographic correlations in patients with ST-segment elevation during dobutamine stress perfusion imaging

BACKGROUND

There is scanty information on the angiographic and myocardial perfusion correlates of dobutamine-induced ST-segment elevation.

METHODS AND RESULTS

We studied 39 patients who exhibited ST-segment elevation during dobutamine perfusion tomography and had recent coronary angiography performed (ie, within 3 months of the dobutamine study). Baseline characteristics, extent of coronary artery disease, relationship of Q waves to ST-segment elevation, ischemic burden, and angiographic findings were assessed. Twenty-nine patients (74%) had prior myocardial infarction, and 77% had abnormal Q waves at baseline. Ninety-three percent of patients had abnormal perfusion imaging. Eighty percent of patients had multivessel coronary artery disease. The left ventricular ejection fraction by contrast ventriculography was 35% +/- 7% (mean +/- SD), the perfusion defect size was 32% +/- 15%, and 73% of patients had some degree of myocardial ischemia. A predominance of ischemia (>50% reversibility) occurred in 38% of patients with Q waves and in 70% of those without Q waves. There was also good agreement between the site of ST-segment elevation and the site of ischemia by perfusion imaging (79%) and between the site of ST-segment elevation and the location of the vessel with significant coronary stenosis (95%).

CONCLUSIONS

Patients with dobutamine-induced ST-segment elevation have a depressed left ventricular ejection fraction, a high frequency of multivessel disease, and markedly abnormal myocardial perfusion tomography. In patients with ST-segment elevation and abnormal Q waves, substantial scarring and superimposed ischemia coexist, whereas in patients without Q waves, ST-segment elevation usually denotes severe ischemia.

Long-term prognostic value of exercise echocardiography compared with exercise 201Tl, ECG, and clinical variables in patients evaluated for coronary artery disease

BACKGROUND

The accuracy of exercise echocardiography and 201Tl single photon emission computed tomography (SPECT) is similar in the diagnosis of coronary artery disease (CAD). However, comparative data on long-term prognosis are lacking.

METHODS AND RESULTS

Clinical variables and exercise, echocardiographic, and 201Tl tomographic parameters were studied in 248 patients (age, 56+/-12 years [mean+/-SD]; 189 men) who underwent simultaneous treadmill exercise 201Tl SPECT and echocardiography. Follow-up was obtained in 225 patients (91%) at a mean of 3.7+/-2.0 years. A total of 64 cardiac events occurred. With the use of stepwise logistic regression, 4 models simulating clinical stress testing scenarios were evaluated in the prediction of all cardiac events, ischemic events, and/or cardiac death. The best clinical models were exercise echocardiography with exercise ECG and exercise 201Tl SPECT with exercise ECG. Both models were comparable in the prediction of cardiac events. For the exercise echocardiography model, exercise wall motion score index and induction of ischemia were the strongest predictors of events with ORs of 2.63 per unit increment (95% CI, 1. 34 to 5.17; P=0.005) and 4.1 (95% CI, 1.32 to 12.79; P=0.015), respectively. For the model with exercise 201Tl SPECT, the strongest predictor was ischemic perfusion defect (OR, 4.93; 95% CI, 1.72 to 14.08; P=0.003). The absence of ST changes during exercise decreased the risk of events. For the prediction of ischemic events and/or cardiac death, echocardiographic and 201Tl parameters were the only predictive variables.

CONCLUSIONS

In patients evaluated for CAD, exercise echocardiography and 201Tl combined with ECG variables provide comparable prognostic information and can be used interchangeably for risk stratification.