Comparison of Venous Thromboembolism Prophylactic Measures Post Coronary Artery Bypass Graft Surgery.

Abstract

There is considerable debate surrounding venous thromboembolism (VTE) prophylaxis in patients post coronary artery bypass grafting (CABG) procedures. The American College of Chest Physicians guidelines report weak recommendations for starting VTE prophylaxis, but provide no specific guidance regarding timing or preferred prophylactic agent. This retrospective cohort study was designed to compare outcomes of post-cardiac surgery patients admitted to the cardiovascular intensive care unit (ICU) who received subcutaneous unfractionated heparin (UFH), with those who received subcutaneous enoxaparin for VTE prophylaxis. Between January 2013 and September 2017, 1085 patients were identified, and, after propensity score matching, 850 patients were selected for analysis. The primary outcomes were postoperative VTE and the occurrence of bleeding events up to 30 days postoperatively. Secondary outcomes included chest tube output, days mechanically ventilated, ICU length of stay, total hospital length of stay, and 30-day readmission rates. During the study period, rates of 2.03% for VTE events and 1.38% for bleeding events were reported in the entire cohort. After matching, the rates of VTE events (2.12% vs. 1.41%, p=0.43) and bleeding events (1.18% vs. 0.94%, p=1.00) were more frequent in the heparin group versus the enoxaparin group; these differences were not statistically significant. However, we did find a statistically significant increase in several secondary endpoints, including chest tube output, days mechanically ventilated, ICU length of stay, and total hospital length of stay, within the heparin cohort. Bleeding rates were similar to those previously published, despite the early initiation of VTE prophylaxis. We report no statistical difference in the rates of VTE or bleeding between chemical agents, but our results suggest enoxaparin may be a preferred agent over UFH.