Ischaemic postconditioning significantly reduced elevated cardiac enzyme levels (SMD -0.84; 95% CI -1.26 to -0.43; P<0.00001) and improved LVEF (WMD 3.98%; P=0.004) in STEMI patients during primary PCI.
Meta-Analysis (n=560)
Does ischaemic postconditioning improve myocardial enzyme levels and LVEF in STEMI patients undergoing primary PCI?
Ischaemic postconditioning during primary PCI for STEMI improves surrogate markers of cardioprotection (cardiac enzymes and LVEF), with greater benefits seen in younger patients, males, and when direct-stenting is used.
Standardized Mean Difference: -0.84 (95% CI -1.26–-0.43)
p-value: p=<0.00001
AIMS: We sought to perform a systematic review and meta-analysis to evaluate the potential factors affecting ischaemic postconditioning (IPoC) for patients with ST-segment elevation acute myocardial infarction (STEMI) in primary percutaneous coronary intervention (PCI). METHODS AND RESULTS: Ten randomized controlled trials (RCTs) on IPoC reporting myocardial enzyme levels or left ventricular ejection fraction (LVEF) in a total of 560 STEMI patients were identified in PubMed, EMBase, and Cochrane Library (up to February 2012). Compared with controls, IPoC significantly reduced elevated cardiac enzyme levels standardized mean difference = -0.84; 95% confidential interval (CI): -1.26 to -0.43; P < 0.00001; heterogeneity test, I(2) = 81.0% and improved LVEF weighted mean difference (WMD) = 3.98%; 95% CI: 1.27-6.70%; P = 0.004; heterogeneity test, I(2) = 87.1%. The effect on LVEF remained significant after 1 year (WMD = 5.04%; 95% CI: 4.20-5.88%; P < 0.00001; heterogeneity test, I(2) = 0.0%). Univariate meta-regression analysis suggested that the major sources of significant heterogeneity (P < 0.1) were the use of direct-stenting technique (%) (coefficient = -0.886; P = 0.069; adjusted R(2) = 0.34) and male proportion (%) (coefficient = -0.022; P = 0.098; adjusted R(2) = 0.28) for myocardial enzyme levels, and age (coefficient = -1.34; P = 0.025; adjusted R(2)= 0.55) for LVEF (%). Subsequent multivariate regression and subgroup analysis confirmed these results. CONCLUSION: Available evidence from this systematic review and meta-analysis of 10 RCTs suggests that IPoC may confer cardioprotection in terms of myocardial enzyme levels and LVEF for STEMI during primary PCI. These effects are more pronounced among young and male patients, and those in whom direct-stenting techniques were used. Future studies should focus on the mortality in high-quality, large-scale clinical trials with long-term follow-up.
Zhou et al. (Sun,) conducted a meta-analysis in ST-segment elevation acute myocardial infarction (STEMI) (n=560). Ischaemic postconditioning (IPoC) vs. Controls was evaluated on Myocardial enzyme levels (SMD -0.84, 95% CI -1.26 to -0.43, p=<0.00001). Ischaemic postconditioning significantly reduced elevated cardiac enzyme levels (SMD -0.84; 95% CI -1.26 to -0.43; P<0.00001) and improved LVEF (WMD 3.98%; P=0.004) in STEMI patients during primary PCI.