Aims: The severity of tricuspid regurgitation (TR) is a predictor of outcome among heart failure patients. The interaction between cardiac resynchronization therapy (CRT) and TR has not been described. In this study, we examined the effect of pre-implant TR, and worsened TR post-implant, on response to CRT and overall survival.
Methods and results: We included all patients with successfully implanted CRT systems between 2007 and 2010. Patients were divided into two groups pre-implant: (Gp 1) no-or-mild TR; and (Gp 2) moderate-or-severe TR. Post-implant, patients were divided into two groups: (Gp A) improved or stable TR; and (Gp B) worsened TR. The clinical and echocardiographic outcome of all patients was assessed. The study included 193 patients. Thirty-five subjects (18%) had moderate or severe TR pre-implant (Gp 2). Baseline echo parameters and 6 min walk distance were worse in Gp 2 compared with Gp 1 (mild or no TR). There was no significant difference in clinical response to CRT between the two groups. However, Gp 2 had a significantly lower echocardiographic response (35 vs. 60%, P = 0.01) and higher mortality over 3 years (OR = 6.70, 95% CI = 1.8-24.5, P = 0.004). Post-implant, 25 patients (13%) developed worsened TR (Gp B), not associated with deterioration in right ventricle function or elevation in pulmonary artery pressure. Worsened TR predicted a reduced clinical response to CRT (42 vs. 70%, P = 0.006), when compared with Gp A.
Conclusions: The presence of baseline moderate or severe TR is associated with increased mortality but does not predict clinical or echocardiographic response to CRT. Patients with worsened TR following CRT are less likely to clinically respond to CRT. Pacing leads passing through the tricuspid valve may worsen TR. It is conceivable that avoidance of lead-induced TR by alternative implantation techniques could improve the response rate to CRT.