Primary angioplasty has become the preferred therapeutic modality in patients with acute myocardial infarction (AMI). Despite restoration of antegrade epicardial flow by mechanical reperfusion therapy, angiographically assessed microvascular function and myocardial reperfusion (blush) allows for the stratification of patients with epicardial TIMI 3 flow into different strata of survival. Despite this fact, the best approach to achieving good myocardial blush has not yet been established. We sought to determine the efficacy of 3 different vasodilators.
Methods: A cohort of 40 patients were referred for primary angioplasty in the setting of STEMI; their TIMI 3 flow was achieved and myocardial blush (MB) was 0-1 (no myocardial opacification) according to the vant'Hof classification. The patients were assigned to 1 of 3 investigational groups: intracoronary (IC) injection of nitroprusside, adenosine and verapamil, and were compared with the control group: IC injection of nitroglycerin, their effect on MB, the sum ST-segment resolution and the left ventricular ejection fraction (LVEF) at 30 days.
Results: Nitroprusside proved to have the best effect on MB (p = 0.023). This correlated with an improvement in LVEF from the baseline (p = 0.048). Also, the sum ST-segment resolution showed a trend in favor of nitroprusside, but without statistical significance.
Conclusion: IC injection of nitroprusside was more beneficial in reaching MB grade 3 in the setting of primary angioplasty for AMI, correlating with a significant improvement in LVEF at 30 days. Also, a trend toward the best ST-segment resolution was observed in the nitroprusside-treated group.