Introduction: Mitral Valve Disease (MVD) is associated with atrial fibrillation (AF) and can worsen its prognosis. Left Atrial (LA) fibrosis is a known substrate for AF and its extent affects the management.
Hypothesis: We hypothesize MVD increases LA fibrosis in AF patients and the chance of AF ablation failure. Secondly, even in patients with low levels of LA fibrosis that are optimal candidates for ablation, presence of MVD still worsens the outcome.
Methods: Patients were categorized in two groups: 140 patients had coexisting MVD and AF, and 100 patients AF without MVD. MVD was defined as any dysfunctionality of mitral valve including mitral stenosis, mitral regurgitation, and history of previous mitral valve surgery . LA fibrosis was quantified by Late Gadolinium Enhancement MRI (LGE-MRI). Baseline characteristics were gathered through chart reviewing. Following ablation, patients were followed for median of 71 months for AF recurrence.
Results: Patients were 76.4 ± 10.7 years of age in MVD+AF group and 64.2 ± 14.7 in AF group (p < 0.0001). Extent of LA fibrosis was 18.1% ± 9.3 and 10.3% ± 5.3 in MVD+AF and AF group, respectively (p < 0.0001). The result of our statistical model adjusted for possible cofounders showed that coexistence of MVD in AF patients result in presence of 6.4% more LA fibrosis (p < 0.00001) and lowered the chance of remaining AF free after the ablation (recurrence-free ratio of 0.554 vs 0.757 in MVD+AF and AF group respectively, P < 0.05) (Figure 1). In patients with LA fibrosis less than 20% who would be ideal AF ablation candidate, the presence of MVD decreased the chance to remain AF free (0.574 vs 0.775 in MVD+AF and AF respectively, p < 0.05) (Figure 2).
Conclusions: MVD increases LA fibrosis in AF patients and the chance of AF recurrence post-ablation.