Anticoagulation in patients following prosthetic heart valve replacement
General Surgery; Cardiothoracic Surgery
Purpose: To identify optimum international normalized ratio (INR) levels and required warfarin doses and anticoagulation-related complications in patients following mechanical prosthetic valve replacement.
Materials and Methods: Five hundred and seven patients were prospectively followed up for 10 years (2008.5 patient-years). Anticoagulation-related complications were classified into hemorrhage and thromboembolism.
Results: Two hundred and ninety-two (57.6%) were males and 215 (42.4%) were females with a mean age of 29.5 +/- 11.32 years. A total of 268 (52.9%) patients had mitral, 96 (18.9%) had aortic and mitral, and 76 (15%) had aortic valve replacement (AVR). Valves implanted totaled 345 (68%) ball and cage, 126 (24.9%) bileaflet, and 36 (7.1%) single disc. There were 10,669 total visits, with mean INR 2.6 +/- 0.59 and mean warfarin 5.17 +/- 1.6 mg. Sixty-four (3.2% per patient-years) events occurred during follow-up, of which 23 (1.13% per patient-years) events were due to thromboembolism and 41 (2.04% per patient-years) to bleeding. Atrial fibrillation occurred in 12 (52.4%) patients having thromboembolic events and in 24 (58.5%) suffering from bleeding complications. Among thromboembolic events, valve thrombosis occurred in 9 patients (0.44% per patient-years) and cerebrovascular accidents (CVAs) in 14 (0.69% per patient-years). Atrial fibrillation was present in 7 (77.8%) patients in the valve thrombosis group and in 5 (35.7%) in the CVA group. Of 41 bleeding events, 8 (0.39% per patient-years) were minor episodes, 20 (0.99% per patient-years) were major episodes, and severe hemorrhage occurred in 5 (0.34% per patient-years). Intracranial hemorrhage leading to CVA was seen in 8 patients (0.34% per patient-years). There were 22 (1.1% per patient-years) fatal hemorrhages and 15 (0.74% per patient-years) fatal thromboembolic events. In-hospital mortality was 25 (4.9%), and 62 (12.2%) were late deaths; of these, 37 (7.3%) were anticoagulation related.
Conclusions: Anticoagulation for mechanical heart valve replacement can be managed with INR levels of 2-2.5 with acceptable hemorrhagic and thromboembolic events.
Annals of Thoracic and Cardiovascular Surgery
Akhtar, R. P.,
Abid, A. R.,
Khan, J. S.
(2009). Anticoagulation in patients following prosthetic heart valve replacement. Annals of Thoracic and Cardiovascular Surgery, 15(1), 10-17.
Available at: https://ecommons.aku.edu/pakistan_fhs_mc_surg_gen/46