Impact of atrial fibrillation on clinical status, atrial size and hemodynamics in patients after mitral valve replacement

Background and aim of the study: The association between mitral valve disea se and atrial fibrillation (AF) is well known, but few data exist regarding the impact of AF after mitral valve replacement (MV-R) on NYHA functional class, atrial size and hemodynamic parameters. The present study was conduc ted to evaluate these issues. Methods: Eighty-six patients (26 men, 60 women) who underwent MVR were eval uated by transthoracic echo cardiography. Fifty-nine patients had chronic A F (AF group), and 27 were in sinus rhythm (sinus group). Variables analyzed included end-systolic left atrial and right atrial areas, tricuspid regurg itation, and presence and duration of AR Peak and mean transprosthetic mitr al valve gradients and pulmonary pressure were estimated by Doppler echocar diography, Results: Groups were matched for age, sex and time from MVR (mean 6.6 years ). Sixty-four patients (77%) had rheumatic heart disease, 18 (21%) had mitr al valve disease, and two (2%) had mitral valve prolapse. Mean duration of AF was 11 +/- 12 years (range: 8-50 years). Preoperatively, AF patients had a worse NYHA class than sinus patients (2.8 +/- 0.8 versus 1.1 +/- 0.7, p = 0.001), but both had similar fractional shortening of the left ventricle and preserved prosthetic mitral valve function. Multivariate analysis ident ified AF as a single predictor of NYHA class after MVR. Although left and r ight atrial areas were larger in AF patients (47 +/- 25 versus 27 +/- 7 cm( 2), p = 0.0001 and 30 +/- 12 versus 17 +/- 5 cm(2), p = 0.0001, respectivel y), the left:right atrial size ratio was not significantly different betwee n groups. Multivariate analysis identified mean transmitral gradient and du ration of AF as independent predictors of left atrial size after MVR (p = 0 .01 and p = 0.0001, respectively). Tricuspid regurgitation and duration of AF were independent predictors of right atrial size (p 0.003 and p = 0.0001 , respectively). Conclusion: The presence of AF after MVR is associated with a worse NYHA fu nctional class, increased transmitral gradients, and larger areas of both a tria, when compared with sinus rhythm. Hence, a special effort should be ma de to correct arrhythmia during surgery and in case of paroxysmal arrhythmi a, earlier surgery should be considered before the condition becomes chroni c.