Even mild mitral regurgitation is associated with incident atrial fibrillation in the general population.

Aims: 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 atrial fibrillation (AF) in the general population.
Methods and Results: The study included 4466 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. MR was quantified in 4042 participants (mean age: 57 years, 43% men). Of these, 198 (4.9%) developed AF during a median follow-up period of 5.3 years (interquartile range: 4.4-6.1 years). MR was present in 1938 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: MR, including even trace regurgitations quantified by MR/LA ratio, is independently associated with incident AF in individuals ≤ 73 years of age.
Competing Interests: Conflict of interest: M.Y.: none. F.J.O.: none. A.S.: none. K.G.S.: advisory board: Sanofi Pasteur. M.C.H.L.: none. N.D.J.: none. M.T.J.: none. G.B.J.: none. P.S.: none. R.M.: none. T.B.-S.: Steering Committee member of the Amgen financed GALACTIC-HF trial. Chief investigator of the Sanofi Pasteur financed ‘NUDGE-FLU’ trial. Chief investigator of the Sanofi Pasteur financed ‘DANFLU-1’ trial. Chief investigator of the Sanofi Pasteur financed ‘DANFLU-2’ trial. Steering Committee member of ‘LUX-Dx TRENDS Evaluates Diagnostics Sensors in Heart Failure Patients Receiving Boston Scientific’s Investigational ICM System’ trial. Advisory board: Sanofi Pasteur, Amgen, and GSK. Speaker honorarium: Bayer, Novartis, Sanofi Pasteur, and GSK. Research grants: GE Healthcare, Sanofi Pasteur, Novo Nordisk, and AstraZeneca.
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