Left atrial enlargement of degenerative mitral regurgitation: A valuable marker of outcome in routine practice?

Abstract

We aimed to assess whether LA-volume-index (LAVI) measured in routine clinical practice of multiple sonographers/cardiologist is associated independently with DMR survival. A cohort of all 5769 (63 ± 16 years, 47% women) consecutive patients with degenerative mitral valve disease, in whom LAVI was prospectively measured, was enrolled and their long-term survival analyzed. LAVI (43 ± 24 ml/m 2 ) was widely distributed (< 40 mL/m 2 in 3154 patients, 40–59 ml/m 2 in 1606 and ≥ 60 ml/m 2 in 1009). Overall survival throughout follow-up (10-year 66 ± 1%) was strongly associated with LAVI (79 ± 1% vs. 65 ± 2% and 54 ± 2% for LAVI < 40, 40–59 and ≥ 60 mL/m 2 , P < 0.0001) even adjusting comprehensively, including for DMR severity [adjusted-hazard-ratio 1.05(1.03–1.08) per-10 mL/m 2 , P < 0.0001]. Mortality under medical management was profoundly affected by LAVI (adjusted-hazard-ratio 1.07[1.04–1.10] per-10 ml/mm 2 ; 1.55[1.31–1.84] for LAVI ≥60 vs. <40 mL/m 2 , both P < 0.0001) incrementally to adjusting variables ( P < 0.0001) and in all subgroups, particularly Sinus-Rhythm [adjusted-hazard-ratio 1.25(1.21–1.28)] or Atrial-Fibrillation [adjusted-hazard-ratio 1.10(1.06–1.13) per-10 mL/m 2 , both P < 0.0001]. Thresholds of excess-mortality in spline curve analysis were approximated 40 mL/m 2 in all subgroups. Survival markedly improved after mitral surgery [time-dependent adjusted-hazard-ratio 0.43(0.36–0.53), P < 0.0001] but remained modestly linked to LAVI (10-year 85 ± 3% vs. 86 ± 2% and 75 ± 3% for LAVI < 40, 40–59 and ≥ 60 ml/m 2 , P < 0.0001) ( Fig. 1 ). The frequent LA enlargement of DMR, measured by LAVI in routine practice, displays, overall and in all subsets, powerful, incremental and independent link to excess-mortality, partially alleviated by mitral surgery. Hence, LAVI measurement should be part of routine DMR evaluation and clinical-decision-making process.