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

Abstract

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 signifi cant 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.