Complications of Warfarin in Patients with Mechanical Mitral Valve Replacement

Mahmud, Bassam Abdullah; Taha, Abdulsalam Y; Sewan, Nada Mahdi

doi:10.33762/basjsurg.2026.169522.1161

	Complications of Warfarin in Patients with Mechanical Mitral Valve Replacement
Basrah Journal of Surgery
Article 7, Volume 32, Issue 1, 2026, Pages 67-76 PDF (1.09 M)
Document Type: Research Paper
DOI: 10.33762/basjsurg.2026.169522.1161
Authors
Bassam Abdullah Mahmud¹; Abdulsalam Y Taha^* ²; Nada Mahdi Sewan¹
¹Department of Cardiothoracic and Vascular Surgery/Ibn Al-Nafees Teaching Hospital/Baghdad/Iraq
²Mamostayan Street 112, Road 33, House 5, POBox 1155/64
Abstract
Background: Warfarin remains the standard anticoagulant following mechanical mitral valve replacement (MVR); however, bleeding and thromboembolic events continue to pose significant clinical challenges. This study evaluated warfarin-related complications and anticoagulation monitoring in our local setting. Methods: This prospective observational study was conducted over nine months at Ibn Al-Nafees Teaching Hospital. Among 104 patients undergoing mechanical MVR with or without concomitant aortic valve replacement, 19 who developed warfarin-related complications were analyzed. Clinical characteristics, INR values, and adverse events were prospectively recorded. Results: The cohort comprised 13 females and 6 males (age range 18–65 years). Minor bleeding predominated (14 patients), while major complications (stroke) occurred in two patients, including one fatal case. All affected patients had elevated International Normalized Ratio (INR) values (4.0–10.0). The annualized major complication rate was 2.6% per patient-year, and minor bleeding occurred at 18% per patient-year. Rheumatic valve disease, preoperative atrial fibrillation, renal impairment, and low educational level were common among patients with complications. Events were more frequent after discharge, though this was not statistically significant. Conclusion: Warfarin-related complications after mechanical MVR were mainly minor bleeding events and were consistently associated with over-anticoagulation. Multiple comorbidities and limited patient education may contribute to INR instability. Structured anticoagulation monitoring and enhanced patient education may improve dose control and reduce complications.
Keywords
Warfarin; complications; mitral valve; heart valve prostheses implantation; international normalized ratios

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