The Impact of Pulmonary Venous Flow Pattern (PVFP) on Atrial Fibrillation (AF), Mortality, and Mitral Intervention Rates in Patients with Degenerative Mitral Regurgitation (dMR)

Background: AF is associated with increased mortality and deteriorating LV function in patients with dMR (ie, due to leaflet prolapse/flail). As both conditions result in LA remodeling, abnormal PVFP (systolic flow blunting or reversal) may signify worse prognosis and thus aid in timing of mitral intervention.

Aim: To assess whether abnormal PVFP predicts AF, mortality and mitral intervention in patients with dMR.

Methods: Based on the Rabin Medical Center echo lab database (May 1995 through June 2017), we identified 296 adult patients with TEE-confirmed dMR of greater than moderate severity. We excluded patients with non-NSR, previous valvular procedures or significant non-MR valvulopathies. Analysis was then undertaken according to PVFP (normal vs abnormal), using baseline and outcome parameters derived from electronic medical records. Study endpoints were AF, all-cause mortality, and mitral intervention. Mean follow-up duration was 86 months.

Results: A total of 103 patients qualified for analysis, with missing data serving as the main reason for exclusion. The study cohort comprised mostly (68%) of women. PVFP was deemed abnormal on both sides in 54 patients, on the left side only in 2, and on the right side only in 7. As compared to those with normal PVFP, patients with abnormal PVFP were older (69.3 vs 63.4years, p=0.03) and had a higher prevalence of severe MR (81 vs 45%, p<0.001) with higher EROA (54 vs 40mm, p<0.03) and systolic pulmonary artery pressure (45.5 vs 32.6mmHg, p<0.001). No other significant differences were noted at baseline, specifically in regard to mean LVEF (59.2%), LVESD (31.4mm), and LA area (16.4mm/m²), and in prolapse site distribution (with posterior, anterior and both leaflets involvement in 68%, 10%, and 22%, respectively). While AF and death rates were comparable among the groups (28-29% and 27-30%, respectively), mitral intervention was performed more often in those with abnormal PVFP (11 vs 5%, p<0.05). The composite of AF and death at 5 years was higher in those with abnormal PVFP, reaching statistical significance on the left side (p=0.002) and almost so on the right (p=0.05). For as yet speculative reasons, this correlation faded afterwards.

Conclusion: Abnormal PVFP is associated with higher rates of mitral intervention and a worse 5-year composite outcome of AF and death in dMR.