Deep vein thrombosis among patients entering cardiac rehabilitation after coronary artery bypass surgery

Background: Little information is available about the prevalence of deep vein thrombosis (DVT) after discharge from cardiac surgery units and its impact on rehabilitation programs. Objectives: To estimate the rate of DVT, in relation to different thromboprophylaxis strategies, in patients with a recent coronary artery bypass graft (CABG) entering cardiac rehabilitation. Methods: Two hundred seventy consecutive patients admitted to three rehabilitation facilities after CABG surgery from 19 cardiac surgery units (male patients, 81%; mean +/- SD age, 64 +/- 9 years; interval after operation, 4 to 19 days) underwent serial leg venous ultrasound examination on admission to three rehabilitative units. Results: At admission, antiplatelet treatment was present in all patients except 10 with absolute contraindications. In 171 patients (63%), heparin prophylaxis (low-molecular-weight hepairin once daily, 87%; unfractionated heparin twice daily, 13%) was reported, limited to, the early postoperative period (less than or equal to 3 days) in 102 patients (38%). DVT was detected in 47 patients (17.4%). The rate of proximal and isolated distal DVT was 2.6% (7 cases) and 14.8% (40 cases), respectively. DVT was complicated in two cases (0.7%) by symptomatic pulmonary embolism, fatal in one case (0.4%). Clots were found in the leg contralateral to the saphenous vein harvest site in half of all DVT cases. Forty-three DVT cases (91%) were diagnosed at admission, while serial ultrasound testing allo wed diagnosis of an additional 4 distal DVT cases. At multivariate analysis, female sex (p < 0.001) and length of stay in the surgery unit > 8 days (p < 0.05) were independently associated with risk of DVT in the rehabilitation setting. The adoption of heparin prophylaxis until discharge predicted the absence of DVT after adjustment for immobility (p < 0.05). Conclusions: This study showed a high rate of DVT in patients entering cardiac rehabilitation after CABG surgery. Wearing unilateral graded compression stockings after CABG surgery had limited efficacy, as clots were often localized in legs contralateral to the saphenous vein harvest site.