Even Mild Mitral Regurgitation is Associated with Incident Atrial Fibrillation in the General Population.

ABSTRACT

BACKGROUND: Mitral regurgitation (MR) can be difficult to quantify. We sought to investigate whether the MR jet area to left atrial (LA) area ratio (MR/LA-ratio) method for quantifying MRs can be used to predict incident AF in the general population. METHODS: The study included 4,466 participants from the 5th Copenhagen City Heart Study, a prospective general population study, who underwent transthoracic echocardiography. MR jet area was measured and indexed to LA area. The endpoint was incident AF. RESULTS: MR was quantified in 4,042 participants (mean age 57 years, 43% men). Of these, 198 (4.9%) developed AF during a median follow-up period of 5.3 years (IQR 4.4-6.1 years). MR was present in 1,938 participants (48%) including 1593 (39%) trace/mild MRs (MR/LA-ratio ≤ 20% and ≤4 cm2). In unadjusted analysis, MR/LA-ratio was associated with incident AF (HR 1.06 (1.00-1.13), p = 0.042 per 5% increase) but not after adjusting for CHARGE-AF score. However, the association was modified by age (p for interaction = 0.034), such that MR/LA-ratio was associated with AF only in participants ≤73 years. In these participants, MR/LA-ratio was independently associated with AF after adjusting for CHARGE-AF score (HR 1.14 (1.06-1.24), p = 0.001, per 5% increase). This finding persisted when restricting the analysis to participants without moderate or severe MR and normal LA size (HR 1.35 (1.09-1.68), p = 0.005, per 5% increase). CONCLUSION: Mitral regurgitation, including even trace regurgitations quantified by MR/LA-ratio is independently associated with incident AF in individuals ≤73 years of age.