Short-Term Effects of Verapamil and Diltiazem in the Treatment of No Reflow Phenomenon: A Meta-Analysis of Randomized Controlled Trials

Currently, there is still a lack of an optimal treatment for no reflow phenomenon (NRP). We analyzed the efficacy and safety of using nondihydropyridine calcium channel antagonists (NDHP, verapamil/diltiazem) in patients suffering from NRP. Eight RCTs with 494 participants were eligible for analysis. The pooling analysis showed that intracoronary verapamil/diltiazem injection significantly decreased the occurrence of the coronary NRP (RR: 0.3, 95% CI: 0.16-0.57; P = 0.0002) and reduced corrected thrombolysis in myocardial infarction (TIMI) frame Count (WMD = -9.24, 95% CI -13.91-4.57; P = 0.0001) in patients with NRP. Moreover, verapamil/diltiazem treatment showed superiority in reducing wall motion index (WMI) compared to the control at day 1 (WMD = 0.11, 95% CI: 0.02-0.20; P = 0.02) (P < 0.05). There was also a significantly greater decline at occurrence of the major adverse cardiac events between verapamil/diltiazem and control groups (WMD: 0.4, 95% CI: 0.19-0.84; P = 0.02). However, using verapamil/diltiazem did not provide additional improvement of left ventricular ejection fraction post procedure (at 7 days, WMD, 0.1; 95% CI, -2.43-2.63; P = 0.94; at 30 days, WMD, 0.42; 95% CI, -2.09-2.92; P = 0.75). NDHP use is beneficial in attenuating NRP and reducing 6-month MACEs in patients with NRP.