Efficacy and safety of intracoronary verapamil versus sodium nitroprusside for the prevention of microvascular obstruction during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction.

OBJECTIVE: The aim of this study was to compare the role of intracoronary (IC) verapamil versus sodium nitroprusside (SNP) in the prevention of microvascular obstruction (MVO) during a primary percutaneous coronary intervention (pPCI).

BACKGROUND: A head-to-head comparison between verapamil and SNP in the prevention of MVO lacks evidence.

PATIENTS AND METHODS: Sixty patients with ST-segment elevation myocardial infarction were randomized to receive IC verapamil (n=30) versus SNP (n=30) during pPCI. The primary outcome was the incidence of angiographic MVO as defined by Thrombolysis In Myocardial Infarction flow less than 3 or Thrombolysis In Myocardial Infarction flow 3 with myocardial blush grade less than 2. The secondary outcomes were the percentage of ST-segment resolution on 12-lead ECG, left ventricular ejection fraction and wall motion score index by two-dimensional echocardiography at 3-5 days after pPCI, as well as major adverse cardiovascular events at 30 days. Safety outcomes were the incidence of hypotension and/or bradycardia during pPCI.

RESULTS: Verapamil was associated with lower incidence of angiographic MVO compared with SNP (13.3 vs. 40%, respectively; P=0.02), as well as superior ST-segment resolution greater than or equal to 70% (33.3 vs. 6.7%, respectively; P=0.01). There was a trend towards improved left ventricular ejection fraction with verapamil (42.6±4.9 vs. 40.4±4.7%, respectively; P=0.09), but with similar wall motion score index (1.43±0.1 vs. 1.45±0.2, respectively; P=0.14). Both groups had similar 30-day major adverse cardiovascular events (3.3 vs. 6.7%, respectively; P=0.55). Verapamil was associated with lower incidence of hypotension compared with SNP (3.3 vs. 20%, respectively; P=0.04).

CONCLUSION: In pPCI, IC verapamil results in significant improvements in MVO with a better safety profile compared with SNP. Larger trials should be conducted to confirm these results.