Postconditioning during primary percutaneous coronary intervention: a review and meta-analysis

Myocardial postconditioning (POC), defined as intermittent interruptions of blood flow at the onset of reperfusion after sustained ischemia, may attenuate reperfusion injury. In order to weigh the current evidence linking POC to reduction of myocardial infarct size in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI), we performed a systematic review and meta-analysis of the available data from small randomised trials.

A Web-based search was performed for relevant studies, and retrieved data were subjected to systematic review and meta-analysis.

Six studies were identified and the meta-analysis included a total of 244 patients with STEMI undergoing pPCI with or without POC. Pooled analysis of all studies demonstrated a significant reduction of peak creatine kinase with POC relative to standard care (weighted mean peak creatine kinase difference -609.59 IU/L, 95% confidence interval [CI] -1030 to -189; p=0.005). A secondary analysis of 4 of the studies also showed an improvement of left ventricular ejection fraction with POC (weighted mean ejection fraction difference 4.2%, 95% CI 2.1% to 6.2%; p=0.0001).

This first systematic review and meta-analysis of randomized trials of POC in patients with STEMI undergoing primary PCI, demonstrated a significant benefit of POC over standard care for reduction of myocardial infarct size as determined by peak creatine kinase release and left ventricular ejection fraction. The effects of POC on clinical outcomes remain to be determined.