ObjectiveTo investigate predictive value of intraoperative graft flow measurements during off-pump coronary artery bypass grafting (OPCAB) for early clinical prognosis. MethodsWe retrospectively analyzed the clinical data of 133 patients with three-vessel disease who underwent OPCAB in the Department of Cardiac Surgery of People's Hospital of Peking University in 2013 year. There were 103 males and 30 females with mean age of 62.84±7.13 years. Pulsatility index (PI) and mean flow were measured using a flow metre before the end of surgery. Then the total graft flow and the average graft flow were calculated. Univariate, bivariate correlation and logistic regression analysis were performed for statistical analysis. ResultsThe blood flow and PI of LIMA-to-LAD graft was respectively 28.69±16.90 ml/min and 2.70±1.39, and the total graft flow and the average graft flow was respectively 79.94±37.20 ml/min and 35.55±16.75 ml/min. The PI of LIMA-to-LAD graft was significantly correlated with serum cardiac troponin I(cTnI)level in 12 hours, with the highest serum cTnI level within 48 hours, with ICU stay and with ventilator time (P<0.01), but the correlation was not strong(coefficient correlation <0.4). Compared with the patients without perioperative myocardial infarction (PMI), the blood flow of LIMA-to-LAD graft, the total graft flow and the average graft flow were lower in the patients with PMI (P<0.01). Logistic regression analysis revealed that the total graft flow was an independent predictor of PMI (P=0.004, RR=0.950, 95%CI 0.918-0.984). ConclusionIntraoperative graft flow measurements during OPCAB can predict shortterm prognosis. The lower total graft flow is a risk factor for PMI.