Perioperative Management of Anticoagulation in Patients With Mechanical Heart Valves

Importance Perioperative interruption of vitamin K antagonist (VKA) therapy in patients with mechanical heart valves (MHVs) is complex, and contemporary data to inform management are limited. Objectives To describe perioperative anticoagulation management and to estimate 30-day risks of arterial thromboembolism (ATE) and bleeding after VKA interruption in adults with left-sided MHVs. Design, Setting, and Participants This retrospective cohort study included consecutive adult patients (aged ≥18 years) with left-sided aortic, mitral, or dual MHVs undergoing planned invasive procedures requiring VKA interruption from January 1, 2016, to December 31, 2023, with 30-day follow-up. The study was conducted at the thrombosis clinic at The Ottawa Hospital in Ontario, Canada. Exposure Planned invasive procedure requiring temporary interruption of VKA therapy. Main Outcomes and Measures Primary outcomes were 30-day postoperative ATE and major bleeding. Secondary outcomes included clinically relevant nonmajor bleeding (CRNMB) and all-cause mortality. Major bleeding and CRNMB were defined according to the International Society on Thrombosis and Hemostasis. Results The cohort included 373 patients (median [IQR] age, 67 [60-73] years; 217 [58.2%] male) contributing 613 interruptions. Therapeutic-dose bridging was used preoperatively in 516 interruptions (84.2%) and postoperatively in 193 (31.5%) (99 of 215 [46.0%] in mitral or dual MHV vs 94 of 398 [23.6%] in aortic MHV interruptions). Patients with mitral or dual (vs aortic) valve position and prior thromboembolism had higher estimated odds of receiving postoperative therapeutic-dose bridging (mitral or dual vs aortic: adjusted odds ratio [aOR], 2.90; 95% CI, 1.91-4.41; prior thromboembolism: aOR, 1.91; 95% CI, 1.05-3.46). Estimated 30-day risks of ATE and major bleeding were 1.5% (95% CI, 0.8%-2.8%) and 2.1% (95% CI, 1.2%-3.6%), respectively. Clinically relevant bleeding (composite of major bleeding and CRNMB) occurred in 3.9% (95% CI, 2.6%-5.8%) of interruptions. Three deaths occurred (0.5%; 95% CI, 0.2%-1.5%), 1 attributed to fatal ischemic stroke. Omission of postoperative bridging was associated with higher estimated ATE risk (4.9% vs 0.9%; subdistribution hazard ratio [sHR], 5.30; 95% CI, 1.45-19.40; P = .01); this finding was no longer statistically significant in landmark analysis (sHR, 3.26; 95% CI, 0.62-17.21). Conclusions and Relevance In this retrospective cohort study, patients with MHVs experienced clinically meaningful risks of perioperative ATE and bleeding. These data do not establish a causal protective effect of postoperative bridging. However, omitting bridging in patients with MHVs was associated with a higher estimated risk of ATE in exploratory analyses and should be approached cautiously, pending stronger evidence from representative cohorts.