ISSN 2996-8215
International Journal of Cardiology | Vol. 5, No. 5, May 2014 | pp. 33–40
DOI: 10.46882/2014/IJC/000062
Original Research Article
Comparison of Low-Dose versus Standard-Dose Anticoagulation After Mechanical Mitral Valve Replacement
Ahmed Al-Hassan¹, Fatima Al-Sayed¹, Sami Al-Otaibi²
¹Department of Cardiology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
²Division of Cardiac Surgery, King Abdulaziz Medical City, Riyadh, Saudi Arabia
Abstract:
Mechanical mitral valve replacement demands lifelong oral anticoagulation with vitamin K antagonists to prevent thromboembolic complications. However, standard-intensity regimens are associated with significant bleeding risks. This randomized, open-label trial compared the safety and efficacy of a lower-intensity warfarin regimen versus the standard-intensity regimen in patients undergoing mechanical mitral valve replacement. We randomized 280 stable patients post-mitral valve replacement into two groups: the low-intensity group (target international normalized ratio [INR] 2.0–2.5, n = 140) or the standard-intensity group (target INR 2.5–3.5, n = 140). The primary safety endpoint was the 24-month incidence of major bleeding according to ISTH criteria, and the primary efficacy endpoint was a composite of thromboembolism, valve thrombosis, or ischemic stroke. At 24 months, the incidence of major bleeding was significantly lower in the low-intensity INR group than in the standard-intensity group (3.6% vs. 9.3%, hazard ratio: 0.38, 95% CI: 0.16–0.90, p = 0.02). The primary efficacy endpoint of thromboembolic events did not differ significantly between the cohorts (low-intensity: 2.1% vs. standard-intensity: 1.4%, hazard ratio: 1.48, 95% CI: 0.28–7.84, p = 0.64). Intracranial hemorrhage was completely absent in the lower-intensity cohort. A lower-intensity warfarin regimen targeting an INR of 2.0–2.5 safely reduces major bleeding complications compared to standard-intensity anticoagulation without a significant increase in thromboembolic risks in patients with mechanical mitral valves.
Keywords: Mechanical heart valve, Mitral valve replacement, Warfarin, Anticoagulation, International normalized ratio, Major bleeding
Received: February 02, 2014; Revised: March 15, 2014; Accepted: April 08, 2014; Published: May 20, 2014
Citation: International Journal of Cardiology, 2014, Vol. 5, No. 5, pp. 33–40, DOI: 10.46882/2014/IJC/000062