Relationship between myocardial perfusion with myocardial contrast echocardiography and function early after acute myocardial infarction for the prediction of late recovery of function.

BACKGROUND

Following ST elevation acute myocardial infarction (STEMI) and reperfusion therapy, there are often persistent wall thickening (WT) abnormalities and perfusion defects due to variable degree of myocardial stunning and necrosis. We hypothesised that following STEMI and reperfusion therapy, the extent of residual perfusion assessed by myocardial contrast echocardiography (MCE) and not the extent of WT abnormalities would predict subsequent global recovery of left ventricular (LV) function.

METHODS

Accordingly, 112 patients with STEMI underwent simultaneous assessment of WT abnormality and perfusion using MCE 7+/-2 days after AMI and reperfusion therapy. Both WT and perfusion were scored on a 16 segment LV model. Contrast perfusion index (CPI), and global LV function were calculated. Echocardiography was repeated 12 weeks after reperfusion to assess recovery of LV function.

RESULTS

Of the 112 patients recruited, follow up echocardiography 12 weeks after reperfusion was available in 98 patients. CPI was significantly higher (p<0.0001) in the 66 patients, who showed late recovery of LV function (1.67+/-0.27) compared to those who did not show recovery of function (1.25+/-0.04). No significant difference was noted in the indices of baseline LV function in patients with (1.67+/-0.32) and without (1.80+/-0.36) recovery of LV function. The multivariable predictors of late recovery of function were MCE (p=0.02), absence of diabetes (p=0.02) and lower peak creatine kinase (p=0.01).

CONCLUSION

The extent of residual contrast perfusion and not WT abnormalities predicts late recovery of global LV function after acute myocardial infarction and reperfusion therapy.