Comparison of aspirin plus heparin with heparin alone on asymptomatic perioperative deep vein thrombosis in candidates for elective off-pump coronary artery bypass graft: a randomized clinical trial.

BACKGROUND Symptomatic or asymptomatic deep vein thrombosis (DVT) is a common complication following coronary artery bypass graft (CABG), in which less than 1% of these patients suffer from clinically evident pulmonary embolism (PE). DVT and PE can increase other morbidities of coronary revascularization from short to long period, but no clear consensus still exists regarding proper thromboprophylaxis strategy in the literatures. This study was designed to compare the anti-platelet prophylaxis of aspirin plus heparin with heparin alone on asymptomatic perioperative DVT in patients that are candidates for elective off-pump CABG. METHODS One hundred and twenty patients, who are candidates for elective off-pump CABG, were randomly assigned to two groups: the aspirin plus heparin group (Group 1, n = 60) that received 80 mg daily aspirin orally and 5000 U unfractionated heparin per 8 h subcutaneously from admission to discharge time, and the heparin group (group 2, n = 60) that received same dose of heparin alone. All patients underwent right and left leg venous ultrasound examination during hospitalization, after which post-operative off-pump CABG complications such as deep vein thrombosis, bleeding and pulmonary embolism were evaluated in this study cases. RESULTS The mean age of the patients was 62.10 ± 10.71 years with a male to female ratio of 2.24. Asymptomatic DVT occurred in 12 (10%) patients who underwent elective off-pump CABG. DVT was found more in Group 2 (16.6%) as compared to Group 1 (3.3%) with statistical significant difference (p = 0.015). Bleeding was detected in 5 (4.1%) cases in the patients sampled in this study (p = 0.34), 4 cases of which are from Group 1 and 1 case from Group 2. However, PE was shown in none of this study cases. CONCLUSIONS The incidence of DVT decreased more with aspirin plus heparin as compared to heparin alone in patients who underwent elective off-pump CABG. As regards the results obtained in this study, more studies need to be conducted to establish this strategy for prophylaxis of DVT in CABG.