The Interaction Between Tricuspid Regurgitation and Cardiac Resynchronization Therapy Response in Patients with Congestive Heart Failure

Background: Aggravation of tricuspid regurgitation (TR) is a predictable issue following cardiac device implantation, while its clinical importance is subject to debate. Objectives: We aimed to recognize the alteration of TR following cardiac resynchronization therapy (CRT) and its effect on the response to CRT. Methods: In this prospective study, 70 candidates were recruited for CRT from those who visited two university hospitals in Tehran and Ahvaz (Iran) from January 2012 to March 2013. Baseline specifications were recorded for all the participants. All the patients underwent echocardiography before and 6 months after CRT administration. They were then divided into two categories for further comparison: (1) Patients with no or mild TR and (2) patients with moderate-to-severe TR. The echocardiographic response to CRT was defined as a left ventricular end-systolic volume (LVESV) decrease of 15% or left ventricular ejection fraction (LVEF) advancement of 5%. The clinical response to CRT was one class improvement based on the New York Heart Association (NYHA) class. Results: Of the patients, 24 had moderate-to-severe TR. Although the increase in cases with moderate-to-severe TR after CRT was not significant, the aggravation of TR degree after the procedure was significant (P = 0.002). Moreover, the NYHA class significantly improved after the CRT (P = 0.02). The number of cases with a clinical response to CRT based on improvement of the NYHA class was significantly greater in patients with no TR or mild TR at baseline (P = 0.003). There was no significant variation in response to CRT among patients who experienced TR exacerbation after CRT compared with those who had no change or a reduction in TR. Conclusions: This study demonstrated that TR severity was exacerbated following CRT, but this alternation in TR severity had no significant effect on the response to CRT. Therefore, the presence and development of TR before and after CRT must not affect the criteria for choosing cardiac resynchronization therapy for appropriate patients.