BACKGROUND: The question whether use of minimal extracorporeal circulation (MECC) influences patients' outcome remains unanswered. We performed a systemic review of the literature and a meta-analysis of randomized controlled trials to evaluate the impact of MECC compared to conventional extracorporeal circulation (CECC) on mortality and major adverse cardiovascular events in patients undergoing heart surgery.METHODS: We independently conducted a systemic review of English and non-English articles using Medline, Embase and Cochrane database. Random allocation to treatment with a minimum of 40 patients in both groups was considered mandatory for inclusion in the meta-analysis. Primary outcomes were operative mortality and major adverse cardiac and cerebrovascular events comprising death before discharge, myocardial infarction and neurologic damage.RESULTS: We included 24 studies comparing MECC vs. CECC with a total of 2770 patients. Use of MECC was associated with a significant decrease in mortality (0.5% vs. 1.7%, P=0.02), in the risk of postoperative myocardial infarction (1.0% vs. 3.8%, P=0.03) and reduced rate of neurologic events (2.3% vs. 4.0%, P=0.08). Additionally, MECC was associated with reduced systemic inflammatory response as measured by polymorphonuclear elastase, hemodilution as calculated by hematocrit drop after procedure, need for red blood cell transfusion, reduced levels of peak troponin release, incidence of low cardiac output syndrome, need for inotropic support, peak creatinine level, occurrence of postoperative atrial fibrillation, duration of mechanical ventilation and intensive care unit stay.CONCLUSIONS: Use of MECC in heart surgery resulted in improved short-term outcome as reflected by reduced mortality and morbidity compared with conventional extracorporeal circulation.