Dobutamine stress echocardiography: detection of coronary artery disease in patients with dilated cardiomyopathy.

OBJECTIVES

This study attempted to determine the safety and accuracy of dobutamine stress echocardiography for detection of coronary artery disease in patients with dilated cardiomyopathy.

BACKGROUND

Detection of regional wall motion abnormalities at rest does not reliably distinguish ischemic from nonischemic cardiomyopathy. Previous studies have shown that dobutamine stress echocardiography safely and accurately identifies coronary artery disease in patients without dilated cardiomyopathy.

METHODS

Seventy patients with dilated cardiomyopathy underwent dobutamine stress echocardiography. Echocardiograms were obtained at baseline and at low (5 to 10 micrograms/kg body weight per min) and peak doses of dobutamine. Rest and stress left ventricular wall motion scores were derived from analysis of regional wall motion. Fifty-four subjects underwent coronary angiography.

RESULTS

Dobutamine infusion was terminated after achievement of the target heart rate or maximal protocol dose in 49 patients (70%), ischemia in 12 (17%), arrhythmia in 4 (6%) and side effects in 5 (7%). No patient had prolonged ischemia or sustained arrhythmia. Of those with angiographic studies, 40 had significant coronary artery disease (> or = 50% diameter stenosis). Use of the change in global wall motion score index from low to peak dose resulted in a sensitivity of 83% for dobutamine stress echocardiography and a specificity of 71% for detection of coronary artery disease. Sensitivity for detection of triple-, double- and single-vessel disease was 100%, 83% and 69%, respectively.

CONCLUSIONS

Dobutamine stress echocardiography safely provides diagnostic information in patients with dilated cardiomyopathy. This technique has high sensitivity for multivessel coronary artery disease but only moderate specificity.