European guidelines on perioperative venous thromboembolism prophylaxis: Cardiovascular surgery

Venous thromboembolism (VTE), thus comprising deep venous thrombosis (DVT) and pulmonary artery embolism (PE), are associated with high morbidity and mortality [1–4]. However, particularly after major surgery, the risk of early institution of pharmacological thrombosis prophylaxis has to be balanced against the risk of postoperative bleeding events. In a large analysis of the National Inpatient Sample (NIS) of patients after coronary artery bypass grafting surgery, the incidence of VTE was 1.3–1.75% and associated with an increased mortality of 6.8% vs 1.7% (adjusted odds ratio 1.92 [95% confidence interval 1.40–2.65] p < 0.001) [5]. According to a meta-analysis in cardiac surgery, risk factors for VTE are a history of VTE, obesity, heart failure, prolonged bed rest, and mechanical ventilation [3]. In vascular surgery, the reported incidence of VTE is 0.7%, with an incidence of PE of 0.2% [6]. The highest VTE rate was observed in patients with thoraco-abdominal aortic aneurysm [4.2%], followed by thoracic endovascular repair (TEVAR) [2.2%], open abdominal aortic surgery [1.7%], abdominal endovascular aneurysm repair (AEVAR) [0.7], infra-inguinal bypass graft surgery [1.0%], and carotid endarterectomy [0.2%]. Patient-related risk factors after open AAA repair are obesity, postoperative pneumonia, and prolonged postoperative mechanical ventilation (>48) [1]. Of note, according to current guidelines, early administration of aspirin, which is recommended in a large percentage of these patient populations, including the special condition of transcatheter aortic valve replacement (TAVI), as an antithrombotic drug to preserve graft/prosthesis patency and decrease thromboembolic complications, might be regarded as an effective medication to decrease VTE [7–9]. In cardiac surgery, the early administration of medical venous thrombosis prophylaxis reduces the risk of PE (RR, 0.45, 95% CI, 0.28–0.71; p < 0.01) and symptomatic VTE (RR, 0.44, 95% CI 0.28–0.71, p < 0.01) and is not associated with clinically relevant increased bleeding risk, including cardiac tamponade or the need for re-exploration of bleeding [3]. In vascular surgery, pharmacological prophylaxis has been associated with a trend towards a reduction of VTE and PE [2; 4]. Current literature on patients following cardiac or vascular surgery does not show a substantial difference in the efficacy of unfractionated heparin (UFH) or low molecular weight heparin (LMWH) when used for thrombosis prophylaxis [1]. LMWH can be administered once daily by subcutaneous injection, usually without routine coagulation monitoring. However, renal impairment might impact plasma levels and the need for dose adjustment and drug effect monitoring [10]. The pharmacological profile of UFH renders it more amenable to reversal, thus making it preferable in conditions of a higher bleeding risk as immediately postoperatively after major surgery. However, when using UFH, the increased risk of heparin-induced thrombocytopaenia complications and more challenging mobilization with i.v. use, particularly after major trauma/surgery, has to be considered [11]. The research questions used for the systematic literature review and summary of findings are provided in Tables 1 and 2. PICOT Questions Utilized for Systematic Literature Review ASA: acetylsalicylic acid; DOAC: direct oral anticoagulant; DVT: deep vein thrombosis; EVAR: endovascular treatment of abdominal aortic aneurysms; LMWH: low molecular weight heparin; PE: pulmonary embolism; TAVI: transcatheter aortic valve implantation; TEVAR: thoracic endovascular aortic repair; UFH: unfractionated heparin; VTE: venous thromboembolism. PICOT Questions Utilized for Systematic Literature Review ASA: acetylsalicylic acid; DOAC: direct oral anticoagulant; DVT: deep vein thrombosis; EVAR: endovascular treatment of abdominal aortic aneurysms; LMWH: low molecular weight heparin; PE: pulmonary embolism; TAVI: transcatheter aortic valve implantation; TEVAR: thoracic endovascular aortic repair; UFH: unfractionated heparin; VTE: venous thromboembolism. The Summary of Findings and Risk of Bias Assessment 16 Randomized controlled trials 49 Observational studies 3 Meta-analysis Thromboprophylaxis and incidence and risk factors for deep vein thrombosis and pulmonary embolism 8 Randomized controlled trials 3.130 patients 2 prospective cohort studies 1 retrospective cohort study 2 randomized controlled studies 5.248 Patients included in meta-analysis Venous thrombosis and pulmonary embolism frequent after chest and abdominal vascular surgery and are associated with 4- fold mortality (deep vein thrombosis 1.5% vs 6.2%, p = 0.05 and pulmonary embolism 1.5% vs 5.7%, p = 0.05) 16 Randomized controlled trials 49 Observational studies 3 Meta-analysis Thromboprophylaxis and incidence and risk factors for deep vein thrombosis and pulmonary embolism 8 Randomized controlled trials 3.130 patients 2 prospective cohort studies 1 retrospective cohort study 2 randomized controlled studies 5.248 Patients included in meta-analysis Venous thrombosis and pulmonary embolism frequent after chest and abdominal vascular surgery and are associated with 4- fold mortality (deep vein thrombosis 1.5% vs 6.2%, p = 0.05 and pulmonary embolism 1.5% vs 5.7%, p = 0.05) The Summary of Findings and Risk of Bias Assessment 16 Randomized controlled trials 49 Observational studies 3 Meta-analysis Thromboprophylaxis and incidence and risk factors for deep vein thrombosis and pulmonary embolism 8 Randomized controlled trials 3.130 patients 2 prospective cohort studies 1 retrospective cohort study 2 randomized controlled studies 5.248 Patients included in meta-analysis Venous thrombosis and pulmonary embolism frequent after chest and abdominal vascular surgery and are associated with 4- fold mortality (deep vein thrombosis 1.5% vs 6.2%, p = 0.05 and pulmonary embolism 1.5% vs 5.7%, p = 0.05) 16 Randomized controlled trials 49 Observational studies 3 Meta-analysis Thromboprophylaxis and incidence and risk factors for deep vein thrombosis and pulmonary embolism 8 Randomized controlled trials 3.130 patients 2 prospective cohort studies 1 retrospective cohort study 2 randomized controlled studies 5.248 Patients included in meta-analysis Venous thrombosis and pulmonary embolism frequent after chest and abdominal vascular surgery and are associated with 4- fold mortality (deep vein thrombosis 1.5% vs 6.2%, p = 0.05 and pulmonary embolism 1.5% vs 5.7%, p = 0.05) In cardiac surgery: We recommend early initiation (between 6h-24h) post-surgery of pharmacological VTE prophylaxis in the absence of significant bleeding risk. (Grade 1C) In vascular surgery: We suggest early initiation (<24h) of pharmacological VTE prophylaxis should be considered in patients with an increased procedural risk, such as open Thoracoabdominal aortic aneurysm, Abdominal aortic aneurysm repair and Thoracic Endovascular Aortic Repair, and in patients with increased VTE risk factors. (Grade 2C) Therapeutic approach: We suggest Low Molecular Weight Heparin should be considered a first-line therapy over Unfractionated Heparin in view of the increased risk of Heparin-induced thrombocytopenia in cardiac and vascular surgery. (Grade 2B) None. ESAIC, EACTAIC, EACTS, ISTH, EURAPS and EKS funded the work. Aamer Ahmed—Receipt of Grants/Research Support: Research Grant LFB Pharma, Receipt of honoraria or consultation fees: Medtronic, Abbott, Participation in a company-sponsored speaker’s bureau: Medtronic, Abbott. The other authors have reported that they have no relationships relevant to the contents of this paper to disclose. This article is part of the Updated European guidelines on perioperative venous thromboembolism prophylaxis. For details concerning background, methods, classification of recommendations, and members of the ESA VTE Guidelines Task Force, please refer to: Samama CM, for the ESAIC, EACTAIC, EACTS, ISTH, EURAPS and EKS VTE Guidelines Task Force. European guidelines on perioperative venous thromboembolism prophylaxis. Eur J Anaesthesiol 2024; 41(8):547-626. This article was reviewed by ESAIC members and approved by ESAIC Board and EACTS Council.