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Page 2 of 21 Dokko et al. Vessel Plus 2022;6:37 https://dx.doi.org/10.20517/2574-1209.2021.121

Keywords: Atrial fibrillation, mitral valve repair, mitral valve replacement, mitral valve surgery, short-term
outcomes, long-term outcomes

INTRODUCTION
Mitral valve (MV) procedures are increasing in frequency. Pre- and post-operative atrial fibrillation are
common in patients undergoing MV procedures, with approximately one-third of these patients meeting
the criteria for pre-operative atrial fibrillation , and new-onset post-operative atrial fibrillation estimates
[1-4]
[5-8]
range as high as 40% . Mitral valve procedures have been associated with post-operative atrial fibrillation
(OR = 1.91) and more frequently result in post-operative atrial fibrillation compared to other cardiac
[8,9]
procedures . In spite of their high rates of occurrence, significant challenges in patient management, and
impact on morbidity and mortality of pre- and post-operative atrial fibrillation in patients with mitral valve
disease are not well understood. There is a gap in the literature regarding the effects of AF on MV patients’
outcomes and resource utilization. In this manuscript, the etiology, incidence, and outcomes of atrial
fibrillation are summarized for MV patients with pre-operative and new-onset post-operative atrial
fibrillation.

PRE-OPERATIVE ATRIAL FIBRILLATION IN MITRAL VALVE DISEASE
Etiology
[10]
Valvular heart disease has been associated with the development of atrial fibrillation . Both mitral stenosis
and mitral regurgitation can result in increased left atrial (LA) pressure and LA enlargement (LAE) [11-14] .
Several studies report that age, LA diameter changes due to mitral regurgitation, severity of mitral stenosis,
and reduced left ventricular function are associated with atrial fibrillation [15-21] . Vulnerability to atrial
fibrillation at increased atrial pressure has been demonstrated in animal models and in patients with
[22]
mitral stenosis .
[23]

In addition to LA pressure, LAE has been associated with atrial fibrillation development [10,24-26] . Despite its
[27]
enlargement, the LA undergoes loss of myocardium . Loss and scarring of the atrial myocardium create
conduction abnormalities and susceptibility to atrial fibrillation. This has been attributed to myocardial
fibrosis, which prevents adequate transmission of electrical impulses . Thus, interrupted electrical signals
[28]
may instead follow reentry pathways. In mitral stenosis, the increased degree of fibrosis is associated with
the increased incidence of atrial fibrillation . Decreased LA strain and increased lateral wall
[29]
electromechanical conduction time can predict the development of atrial fibrillation in mitral stenosis
patients at 5-year follow-up . These parameters can be monitored via speckle tracking echocardiography
[30]
and may allow earlier detection of atrial fibrillation .
[31]

LA stretch is also thought to contribute to conduction anomalies arising from the pulmonary veins . This
[31]
location is commonly a point of origin of atrial fibrillation but has been poorly studied in atrial fibrillation
induced by MV disease. An early report of a patient with mitral stenosis recorded atrial activation
originating adjacent to and on the side of the left pulmonary veins, in addition to activation in the LA
appendage . Additional research on MV disease is needed to identify specific conduction abnormalities
[32]
and their precise origins.

Prevalence
MV operations are among the fastest growing cardiac procedures, with about a third of patients having pre-
[1]
operative atrial fibrillation [33,34] . Noubiap et al. ’ recent meta-analysis has shown atrial fibrillation to be
prevalent in 33.9% of patients with rheumatic mitral stenosis and 21.6% of patients with rheumatic mitral