Elevated gradient after mitral valve repair: The effect of surgical technique and relevance of postoperative atrial fibrillation.

Objectives: We sought to investigate the effect of surgical technique in mitral valve repair on postoperative transmitral gradient (PTMG) and the relationship between PTMG and postoperative atrial fibrillation (AF).

Methods: In this retrospective study, 390 patients who underwent mitral valve repair for degenerative mitral regurgitation without AF were included. PTMG was measured using transthoracic echocardiography before patient discharge. At follow-up, occurrences of AF within 6 months of surgery (early AF) and 6 months after surgery (late AF), as well as clinical and echocardiographic data were documented and investigated.

Results: The in-hospital mortality was 0, and the mean gradient was 3.1 ± 1.2 mm Hg before patient discharge. The risks for higher PTMG included cleft closure, edge-to-edge technique, full ring annuloplasty, and smaller indexed prosthetic size (P < .05 for all). After a median follow-up of 46 months, stable sinus rhythm was maintained in 73.1% of the overall cohort and early AF occurred in 22.7% of patients. A total of 32 patients (8.5%) had late AF, which was significantly associated with PTMG (odds ratio, 3.93; P = .004). The minimum P value approach identified a mean gradient of ≥4.5 mm Hg as the best threshold for predicting late AF (χ = 40.704; P < .001).

Conclusions: Patients who undergo mitral valve repair for degenerative mitral insufficiency might benefit from modification of the existing leaflet repair and annuloplasty techniques to achieve a lower PTMG level, which is associated with a decreased incidence of late AF during midterm follow-up.