Which protocol for which segment: a comparative study of different pharmacological stress echocardiography protocols for predicting viability in segments with varying degrees of dyssynergy.

OBJECTIVE

Pharmacological stress echocardiography is widely accepted for identifying potential contractile recovery after revascularization. We sought to compare the prognostic power of three pharmacological stress protocols for predicting contractile recovery of myocardial segments at varying degrees of dyssynergy.

METHODS

We enrolled 100 consecutive patients with significant coronary stenosis amenable for revascularization and regional wall motion abnormality in the distribution of the affected artery. All patients underwent an assessment of regional wall motion according to the standard 16-segment model. The patients underwent three stress echocardiography protocols in separate sessions: low-dose dobutamine, infra-low-dose dipyridamole, and combined protocol. The patients underwent thereafter coronary revascularization either by percutaneous coronary angioplasty or by surgical bypass grafting. A follow-up echocardiography was performed 8 weeks after revascularization to assess regional wall motion abnormality. The predicted recovery by any of the three protocols for each category of segments was compared with actual contractility improvement.

RESULTS

The combined protocol had a significantly higher sensitivity for predicting contractility recovery in all segment categories compared with the other two protocols. In addition, it had a similar specificity in hypokinetic and dyskinetic segments, though with a lower specificity in akinetic segments when compared with the low-dose dobutamine protocol, and a similar specificity in dyskinetic segments, though with a lower specificity in hypokinetic and akinetic segments when compared with the infra-low-dose dipyridamole protocol.

CONCLUSION

In patients with predominantly akinetic/dyskinetic segments, the combined pharmacological stress protocol would better predict functional recovery after revascularization, as compared with the low-dose dobutamine and the infra-low-dose dipyridamole protocols.