Does leukocyte-depleted blood cardioplegia reduce myocardial reperfusion injury in cardiac surgery? A systematic review and meta-analysis.

Blood cardioplegia in cardiac surgery contains leukocytes, which causes the inflammatory reaction and promotes myocardial reperfusion injury. The removal of leukocytes from the cardioplegia line, using specialized filters, has been proposed as one of the effective methods in attenuating the inflammatory response. We performed a two-level search to identify randomized, controlled trials concerning the effects of leukocyte-depleted blood cardioplegia on myocardial reperfusion injury. Sixteen studies, comprising 738 patients, met the selection criteria. There are significant reductions in creatinine kinase isoenzyme MB (CK-MB) during 4-8h postoperatively (SMD - 0.577; 95% CI -0.795 to -0.358; p=0.000), CK-MB peak (SMD - 0.713; 95% CI -1.027 to -0.400; p=0.000), troponin in the period of 4-8h postoperatively (SMD - 0.502; 95% CI -0.935 to -0.069; p=0.023), troponin peak (SMD - 0.826; 95% CI -1.373 to -0.279; p=0.003) and inotropic support (RR, 0.500; 95% CI 0.269 to 0.931; p=0.029). Leukocyte-depleted blood cardioplegia may reduce myocardial reperfusion injury in the early postoperative period, but there has been no evidence to support the clinically significant difference. Larger and more precise randomized control trials are needed to further elucidate the cardioprotective effects of cardioplegia leukofiltration.