Prediction of clinical outcome after mechanical revascularization in acute myocardial infarction by markers of myocardial reperfusion

Abstract

Objectives: We sought to evaluate and compare recently suggested parameters of reperfusion after angioplasty in acute myocardial infarction (AMI) for risk stratification during long-term follow-up.

Background: Abnormal myocardial perfusion has a detrimental impact on survival. Several parameters of reperfusion have been evaluated in controlled study populations for risk stratification.

Methods: In 253 consecutive patients undergoing intervention in AMI on a native coronary vessel, angiographic myocardial blush grade (MBG), corrected TIMI (thrombolysis in myocardial infarction) frame count (CTFC) and persistent ST-segment elevation (STE) were determined to evaluate reperfusion. This was a high-risk population, including referral for treatment failure at a primary center in 29.2%, failed thrombolysis in 22.1% and cardiogenic shock in 13.4% of cases.

Results: In addition to age, patient referral, LBBB and heart rate on admission, MBG 0 to 1 (odds ratio [OR] = 3.23, p < 0.001), CTFC (OR = 1.01, p = 0.015) and persistent STE >2 leads (OR = 3.46, p = 0.010) were univariate predictors of mortality during a 22.1 +/- 15.6 months follow-up. Myocardial blush grade 0 to 1 (OR = 2.17, p = 0.033) and persistent STE (OR = 3.61, p = 0.017) persisted as independent predictors of mortality, whereas CTFC failed. Differences in mortality between reperfusion groups at 30 days remained throughout the complete follow-up. In sequential Cox models, the predictive power of clinical data alone for mortality (model chi-squared 55.8) was strengthened by adding MBG (model chi-squared 64.2) and ECG postintervention (model chi-squared 69.2).

Conclusions: Myocardial blush grade 0 to 1 and persistent STE are independent predictors for long-term mortality after angioplasty in AMI. Corrected TIMI frame count is a less powerful predictor. Combining both parameters to consider quality of reperfusion in the myocardium at risk and extent of the infarct zone increases the predictive power.