FUNCTIONAL-ROLE OF MICROVASCULAR INTEGRITY IN PATIENTS WITH INFARCT-RELATED ARTERY PATENCY AFTER ACUTE MYOCARDIAL-INFARCTION

Aims The study was set up to evaluate the functional role of post-infa rct preserved microvascular integrity. Low dose dobutamine echocardiog raphy and myocardial contrast echocardiography were used to study pati ents before hospital discharge who had suffered a recent myocardial in farction and had a patent infarct-related artery (TIMI flow grade 3). Method In the dysfunctioning infarct area, the wall motion score index was calculated at baseline, during the dobutamine infusion and al the 3 month follow-up echocardiogram; contrast echocardiography was perfo rmed at the time of coronary angiography, before hospital discharge. R esults In patients with more than 50% of the dysfunctioning infarct ar ea opacified at contrast echocardiography (group A), regional wall mot ion score index decreased, compared to baseline, during the dobutamine infusion (1.97 +/- 0.78 vs 2.5 +/- 0.35 at baseline, P<0.001) and at follow-up echocardiography (1.83 +/- 0.63 vs 2.5 +/- 0.35 at baseline; P<0.001). In patients with less extensive microvascular integrity as revealed by contrast echocardiography (group B), regional wall motion score index did not decrease from baseline during either the dobutamin e infusion (2.73 +/- 0.21 vs 2.81 +/- 0.20 at baseline; P=ns) or at fo llow-up (2.81 +/- 0.20 vs 2 81 +/- 0.20 at baseline; P=ns). Conclusion In patients with post-infarct dysfunctioning myocardium but a patent infarct-related artery, microvascular integrity, as assessed by myocar dial contrast echocardiography, is an indicator of myocardial viabilit y in terms of preserved contractile reserve, as demonstrated by dobuta mine infusion and functional recovery at follow-up.