Long-term prognostic value of dipyridamole stress myocardial contrast echocardiography.

Aims: The aim of this prospective study was to determine long-term prognostic value of myocardial contrast echocardiography (MCE) combined with high-dose dipyridamole stress echocardiography (DSE) in patients undergoing diagnostic work-up for stable coronary artery disease (CAD).

Methods: A total of 202 consecutive patients (67% males, age 57±8 years) with suspected or known stable CAD scheduled for coronary angiography underwent high-dose dipyridamole/atropine stress echocardiography (dipyridamole 0.84 mg/kg, iv; atropine up to 1 mg, iv) with MCE at baseline and peak stress. In 102 patients MCE was performed using electrocardiographic-triggered end-systolic harmonic imaging and in 100 patients using real-time MCE. Contrast enhancement was obtained by repeated iv boluses of contrast and was visually scored in 18 segments by consensus of 2 experienced observers. All patients completed prospective follow-up regarding major adverse cardiovascular events (cardiac mortality, revascularization, infarction and unstable angina) for a mean period of 32±11 months (range: 1-89 months). The prognostic value of inducible wall motion abnormalities (WMA) and perfusion defects (PD) was then analysed.

Results: CAD defined as ≥70% stenosis was found in 152 patients (75%). During follow-up major adverse cardiovascular events (MACE) occurred in 109 (54%) patients (10 deaths, 16 infarctions, 83 revascularizations). The presence of inducible WMA in DSE was associated with high risk of MACE [hazard ratio (HR): 5.4; 95% CI: 3.64-8.05, P<0.0001]. Cardiovascular complications were best predicted by the presence of any inducible abnormality-PD or WMA (HR: 6.1; 95% CI: 4.1-9.1, P<0.0001).

Conclusion: Stress MCE is highly predictive of cardiovascular events in patients with suspected or known CAD in long-term follow-up.