Combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after acute reperfused myocardial infarction

OBJECTIVE: To evaluate the combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after myocardial infarction. DESIGN: Myocardial contrast echocardiography was performed in patients with acute myocardial infarction shortly after successful coronary reperfusion (TIMI 3 patency) by direct angioplasty. Collateral flow was assessed before coronary angioplasty, and contrast reflow was evaluated 15 minutes after reperfusion. The presence of contractile reserve was assessed by low dose dobutamine echocardiography (5 to 15 micrograms/kg/min) at (mean (SD)) 3 (2) days after myocardial infarction. Recovery of segmental function (myocardial viability) was evaluated by resting echocardiography at a two month follow up. The study was prospective. PATIENTS: 35 consecutive patients referred for acute transmural myocardial infarction. RESULTS: Contrast reflow was observed in 20 patients (57%) and collateral flow in 14 (40%). Contrast reflow and collateral contrast flow were both correlated with reversible dysfunction on initial dobutamine echocardiography and at follow up (p < 0.05). The presence of reflow or collateral flow on myocardial contrast echocardiography was a highly sensitive (100%) but weakly specific (60%) indicator of segmental dysfunction recovery. Simultaneous presence of contrast reflow and collateral flow was more specific of reversible dysfunction than reflow alone (90% v 60%). CONCLUSIONS: Combined assessment of reflow and collateral blood flow enhanced the sensitivity of myocardial contrast echocardiography in predicting myocardial viability after acute, reperfused myocardial infarction. The simultaneous presence of reflow and collateral blood flow was highly specific of recovery of segmental dysfunction.