Frequency and Outcome of Postoperative Atrial Fibrillation Following Mitral Valve Replacement for Mitral Stenosis.

Objective: To determine the frequency and outcome of postoperative atrial fibrillation (POAF) in terms of in-hospital and 30-day mortality and morbidity after mitral valve replacement (MVR).

Study design: Observational study. Place and Duration of the Study: Department of Cardiac Surgery, Northwest General Hospital and Research Centre, Peshawar, Pakistan, from September 2017 to March 2023.

Methodology: A total of 186 patients between the ages of 20 and 70 years, who had severe mitral stenosis and normal sinus rhythm and underwent MVR surgery, were included in the study. The frequency of POAF within 7 days following surgery and outcomes in terms of in-hospital and 30-day mortality / morbidity were recorded.

Results: POAF occurred in 19.4% patients. Patients with POAF were predominantly male (p = 0.01), aged over 50 years (p = 0.002), diabetic (p = 0.02), hypertensive (p = 0.02), had impaired LV function (p <0.001), enlarged LA (p = 0.003), pulmonary hypertension (p = 0.009), previous PMBV (p <0.001), and previous infective endocarditis (p <0.001). In-hospital and 30-day mortality rates were 7% and 8.6%, respectively. POAF patients had prolonged ICU stays (p <0.001), hospital stays (p = 0.04), and higher mortality rates (p <0.001). Persistent AF (22%) contributed to 30-day morbidity in the form of embolic stroke, limb ischaemia, and congestive heart failure.

Conclusion: POAF commonly occurs following the MVR surgery and significantly impacts perioperative and 30-day morbidity and mortality.

Key words: Postoperative atrial fibrillation, Mitral stenosis, Mitral valve replacement.