The combined pharmacological stress echocardiography protocol for predicting viability in territories supplied by coronary arteries at varying degrees of obstruction.

BACKGROUND

Pharmacological stress echocardiography has gained wide acceptance for identification of myocardial viability.

AIM

We sought to explore the diagnostic accuracy of the combined pharmacological stress echocardiography protocol to predict viability of myocardial segments supplied by arteries at varying degrees of stenosis/occlusion.

METHODS

We enrolled 100 consecutive patients with significant coronary stenosis/occlusion, prior myocardial infarction, and regional wall motion abnormality in the distribution of the affected artery. All patients underwent assessment of global and regional left ventricular systolic function. Patients underwent 3 pharmacological stress echocardiography protocols: low dose dobutamine, infra-low dose dipyridamole, and combined protocols. They underwent thereafter successful coronary revascularisation either by percutaneous coronary angioplasty, or by surgical bypass grafting. Follow-up echocardiography was performed 8 weeks later. Segments were subdivided according to the severity of stenosis/occlusion of the supplying artery into 3 subgroups, namely: those supplied by totally occluded, critically stenosed, or subcritically stenosed arteries. Predicted recovery by any of the 3 protocols for each category of segments was compared with real contractility improvement after revascularisation.

RESULTS

The combined protocol had a significantly higher sensitivity for predicting contractile recovery in all segment categories compared with the other 2 protocols. In addition, it had a similar specificity in segments supplied by subcritically stenosed arteries, though with a lower specificity in segments supplied by totally occluded and critically stenosed arteries when compared with the other two protocols.

CONCLUSION

The combined pharmacological stress protocol would better predict viability, as compared to the low dose dobutamine and the infra-low dose dipyridamole protocols, particularly in segments supplied by subcritically stenosed arteries.