Dipyridamole stress echocardiography in patients with severe left main coronary artery narrowing

Abstract

From a population of 2,698 patients (579 evaluated early after an uncomplicated acute myocardial infarction) who underwent dipyridamole echocardiography testing (DET) and subsequent coronary angiography, left main (LM) stenosis ⩾50% was present in 73 (61 men and 12 women, mean age 62 ± 8 years). These 73 patients were compared with a control group comprising 100 consecutive coronary patients without LM disease/ Both groups were similar regarding mean age, sex, incidence of previous myocardial infarction, left ventricular function at rest, and severity of coronary artery disease by the number of diseased vessels excluding the LM. The proportion of patients receiving antianginal therapy during DET was higher in the LM than in the non-LM group (32 vs 14%; p <0.01). No major complication (severe hypotension, sustained arrhythmia, myocardial infarction or death) occurred during DET. Of 73 patients with LM disease, 68 had positive DET (sensitivity 93%), dipyridamole time was 7.1 ± 3.8 minutes, and the rest-peak stress variation in dipyridamole wall motion score index (1 = normal to 4 = dyskinesia, in an 11-segment model) was 0.37 ± 0.23; 14 patients (19%) were resistant to aminophylline and needed nitrates to resolve ischemia. In the non-LM group, DET was positive in 72% (p <0.001 vs LM), with a longer dipyridamole time (9.6 ± 5.2 minutes; p <0.001 vs LM), lower rest-peak stress wall motion score index variation (0.29 ± 0.25; p <0.05 vs LM), and less frequent antidote resistance (1%; p <0.001 vs LM). In the LM group, severity of LM stenosis, and the extent of associated disease did not influence the results of the test, whereas in the non-LM group, dipyridamole time, rest-peak stress variation of wall motion score index, and DET positivity increased with the number of narrowed arteries. DIET is feasible, safe and accurate in patients with LM disease/ Although no pathognomonic response for LM disease could be recognized, the DET positivity pat]tern in the time and space domain was characterized by a shorter dipyridamole time, larger extent and severity of the induced dyssynergy, and more frequent antidote resistance than in patients without LM disease.