NICE thromboprophylaxis guidelines are not associated with increased pericardial effusion after surgery of the proximal thoracic aorta

Abstract

(40mg), early mobilisation and hydration. The 40mg enoxaparin dose over the previous 20mg regimen was worrisome, and its effect on pericardial effusion rates and mortality in proximal aortic surgery was investigated. METHODS Proximal aortic reconstructions performed between December 2008 and April 2011 were identified from prospectively collected data in a tertiary centre database. Retrospective analysis of patient notes was performed. Proximal aortic surgery patients were categorised as low dose (20mg) enoxaparin and high dose (40mg) enoxaparin, and compared for confounding variables. In-hospital, early and one-year readmission rates for pericardial effusion were ascertained from echocardiography reports. The primary outcome was total pericardial effusion rate. Secondary outcomes consisted of 30-day and 1-year mortality. RESULTS A total of 198 patients underwent proximal thoracic aortic surgery. Nine patients were excluded due to early postoperative death (n=5) and missing patient records (n=4). This left 189 cases for analysis. There were 93 patients in the low dose group and 96 in the high dose group. Groups were comparable for age, cardiopulmonary bypass time, aortic cross-clamp time, postoperative warfarin and antiplatelet agents. Pericardial effusion rates up to one year were comparable (low dose 19% vs high dose 21%). Thirty-day mortality was lower in the low dose group (0 vs 3 deaths). There were four deaths up to one year but these were not attributable to increased enoxaparin. CONCLUSIONS Increased perioperative thromboprophylaxis dosage does not increase pericardial effusion rates or mortality in proximal aortic surgery.

Incidence of Venous Thromboembolism and Benefits and Risks of Thromboprophylaxis After Cardiac Surgery: A Systematic Review and Meta‐Analysis

“…Similar to bleeding after cardiac surgery, therapeutic systemic anticoagulation (INR >2.5) was the only reported risk factor for cardiac tamponade after valvular surgery in another observational study not included in this review 85. No multivariate analysis on risk factors for cardiac tamponade or pericardial effusion was, however, presented in these studies 27, 75, 76, 85…”

“…Although pericardial effusion was common after cardiac surgery (up to 84%),76 using different doses of enoxaparin (20 vs. 40 mg/day) for VTE prophylaxis after proximal aortic surgery did not affect the incidence of pericardial effusion (19% vs. 21%, respectively) nor the risk of cardiac tamponade requiring surgical interventions 75. Similarly, initiation of systemic anticoagulation for confirmed VTE also did not increase the risk of pericardial effusion in patients who took aspirin after CABG surgery 27.…”

“…The majority of the studies were observational studies (n=49), 16 studies were RCTs, and 3 were meta‐analyses (Tables 1 and 2). 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84 Of the 16 RCTs identified,1...…”

“…In one large, retrospective cohort study, use of UFH or LMWH at 48 hours post‐CABG was not associated with an increased risk of bleeding compared to no VTE prophylaxis 19. Using different doses of enoxaparin (20 vs. 40 mg/day) for VTE prophylaxis after proximal aortic surgery also did not appear to affect incidence of pericardial effusion nor risk of cardiac tamponade requiring surgical interventions 75. In fact, most studies reported that bleeding after cardiac surgery only occurred in the presence of systemic anticoagulation,35, 52, 53, 54, 78 especially when patients were overanticoagulated 53, 54.…”

“…85 No multivariate analysis on risk factors for cardiac tamponade or pericardial effusion was, however, presented in these studies. 27,75,76,85…”