Abstract 4158: Postconditioning by Brief Cycles of Reperfusion-ischemia Does Not Induce Cardioprotection in Patients With Acute Myocardial Infarction Treated With an Optimum Reperfusion Strategy
Purpose: Experimental and clinical studies have shown that brief cycles of reperfusion-ischemia (postconditioning) performed immediately at reperfusion following an acute myocardial infarction (AMI) induce a cardioprotection. However, the effectiveness of postconditioning in patients simultaneously treated with an optimum reperfusion strategy has not been evaluated.
Methods: We conducted a randomized controlled trial in 33 patients with AMI. Patients were randomly assigned to the control (C) or the postconditioning groups (PCD) before undergoing coronary angiography. The standard procedure for percutaneous coronary intervention (PCI) used in each group thrombectomy and GIIbGIIIa inhibitor. Within the first minute after reperfusion, patients randomized to the PCD group were treated by three cycles of 30 seconds reperfusion/30 seconds occlusion of the culprit vessel using a proximal occlusive device (Proxis®, St Jude Medical). Coronary flow reserve was measured at the end of the procedure. Cardiac function was assessed by echocardiography (Day 6) and MRI (Day 10).
Results: PCI was successfully performed in all patients. The frequency of treatment by GIIbGIIIa inhibitors was similar between PCD and C groups (87.5 vs 94.1% respectively, ns). After postconditioning, the coronary flow reserve was not modified as compared to controls (1.6±0.1 vs 1.7±0.1, ns). During the first 24 hours, the peak of creatine kinase was similar between PCD and C groups (2645±419 vs 2558±592 IU/L, ns). The infarct size was not reduced by the postconditioning protocol (23.1±6.7 vs 20.2±4.1 ml in PCD and C groups respectively, ns). Similarly, left ventricular ejection fraction was not different between PCD and C groups as assessed by MRI (42.9±2.6 vs 44.1±1.7 % respectively, ns) or echocardiography (51.6±2.6 vs 56.3±2.8 % respectively, ns).
Conclusions: This study shows that a limited number of cycles of reperfusion-ischemia in patients with acute myocardial infarction does not provide an additional cardioprotective effect on the top off a systematic thrombectomy and an optimal antithrombotic treatment. The effectiveness of this procedure on patients with severe left ventricular dysfunction and the effectiveness of a higher number of cycles remains to be determined.