Association of noninvasive markers of coronary artery reperfusion to assess microvascular obstruction in patients with acute myocardial infarction treated with primary angioplasty

Early restoration of coronary artery patency through primary angioplasty li mits infarct size and improves survival. Increasing evidence, however, sugg ests that microvascular obstruction is often present despite coronary arter y recanalization. This may limit the benefits of reperfusion therapy. We st udied the use of noninvasive markers of coronary artery reperfusion as indi cators of microvascular obstruction and determinants of prognosis in 98 pat ients with acute myocardial infarction (AW) who were successfully treated w ith primary angioplasty (Thrombolysis In Myocardial Infarction grade 3 flow and residual stenosis < 30%). Plasma creatine kinase (CK) levels and 12-le ad electrocardiograms were performed on admission, at 90 minutes, and at 6, 12, and 24 hours after treatment. We defined: (1) reperfusion as resolutio n of ST-segment elevation > 50% at 90 minutes, with peak CK levels within 1 2 hours, and T-wave inversion within 24 hours; and (2) failed reperfusion, as the absence of these parameters. Of the 98 patients studied, 87 (88.8%) had reperfusion and 11 (11.2%) had failed reperfusion. Infarct location was anterior (versus inferior) in 9 patients in the failed reperfusion group ( 81.8%) compared with 41 patients in the reperfusion group (47.1%) (p < 0.01 ). Congestive heart failure > 24 hours after presentation or in-hospital de ath occurred in 11 patients (12.6%) in the reperfusion group versus 5 (45.5 %) in the failed reperfusion group (p < 0.01). One-year survival was 96.1% for the reperfusion group and 60.6% for the failed reperfusion group (p < 0 .0001). We conclude that the association of noninvasive markers of reperfus ion better identifies patients with microvascular obstruction among those w ho had a "successful" primary angioplasty. Evidence of impaired microvascul ar reperfusion is associated with a poor in-hospital and 1-year outcome. (C ) 2001 by Excerpta Medica, Inc.