Reperfusion syndrome: Relationship of coronary blood flow reserve to left ventricular function and infarct size

OBJECTIVES We rested the hypothesis that the reperfusion syndrome (RS), defined as an additional elevation of the ST segment upon reperfusion, may be a marker of microcirculatory reperfusion injury during acute myocardial infarction (AMI). BACKGROUND The pathophysiology of the RS is unknown, and its prognostic implications are controversial. METHODS Twenty-one patients with an anterior AMI treated less than or equal to 12 h after onset by primary coronary angioplasty (PTCA) were studied. Coronary velocity reserve (CVR), an index of microcirculatory function, was measured using a Doppler guidewire. Left ventricular (LV) ejection fraction, infarct size (percent defect) and LV end-systolic volume index (LVESVi) were evaluated by radionuclide ventriculography, (201)T1 single-photon emission computed tomography and contrast ventriculography, respectively. RESULTS Baseline ST elevation and pain-to-TIMI 3 time were similar in patients with and without RS. Patients with RS (10/21) had a lower post-PTCA CVR than patients without RS (median [95% confidence interval]: 1.2 [1-1.3] vs. 1.6 [1.5-1.7], p < 0.005). Even though predischarge CVR was similar in the two groups, infarct size at six weeks (26 [21 to 37] vs. 14 [10-17] % (201)T1 defect, p = 0.001) and predischarge LVESVi (45% [40 to 52] vs. 30% [29 to 38] mL/m(2), p = 0.001) were larger, and LV ejection fraction at six weeks (40% [37 to 46] vs. 55% [50 to 60], p = 0.004) was lower in patients with RS than in patients without RS. CONCLUSIONS Patients with RS during primary PTCA for an anterior AMI have a transiently lower CVR than patients without RS, but sustained LV dysfunction and larger infarct size, suggesting that RS is a marker of microcirculatory reperfusion injury. (J Am Coll Cardiol 2000;35: 1162-9) (C) 2000 by the American College of Cardiology.