Autonomic modulation in functional tricuspid regurgitation: effects of transcatheter valve repair

To assess the impact of functional tricuspid regurgitation (FTR) and transcatheter tricuspid valve repair (TTVR) on sympathetic nerve activity (SNA). Increased SNA is associated with adverse outcomes and reduced survival in patients with valvular heart disease and chronic heart failure (CHF). However, the effect of interventional treatment of FTR on SNA remains unclear. Twenty-eight patients with symptomatic FTR ≥ grade III underwent TTVR (either edge-to-edge repair or direct annuloplasty). Muscle sympathetic nerve activity (MSNA) was assessed via microneurography. While all patients completed the 12-month follow-up, repeated MSNA assessment was feasible in 10. In patients with symptomatic severe FTR, baseline MSNA was markedly elevated (incidence: 192.8 bursts/100 beats; frequency: 167.8 bursts/min). At 12-month follow-up, tricuspid regurgitation severity was significantly reduced (median grade 3 [IQR 3-4] vs. 2 [IQR 1-2]; p < 0.01), accompanied by improved functional status (NYHA class 3 [IQR 3-4] vs. 2 [IQR 1-3], p < 0.01; 53% ≤ NYHA II). NT-proBNP showed a non-significant decline (p = 0.09), while LV function, MR severity, and renal function remained unchanged. MSNA incidence decreased to 72.6 bursts/100 beats (p = 0.01), and frequency to 93.4 bursts/min (p = 0.001). Patients with FTR exhibit markedly increased SNA. TTVR was associated with a significant reduction in MSNA, suggesting a neurophysiological mechanism contributing to clinical improvement beyond hemodynamic relief.