Abstract 15668: The Incidence and Predictors of Delayed and Late Response to Cardiac Re-Synchronization Therapy

Abstract

Background: The incidence and predictors of delayed response to cardiac resynchronization therapy (CRT) have not been well established. Our study aimed to investigate the incidence and predictors of delayed and late response in CRT patients. Research Question: What patient-specific characteristics are associated with delayed or late response to CRT? Goal/Aim: To investigate the incidence and predictors of delayed and late response in CRT patients. Methods: We conducted a retrospective analysis of 201 patients who underwent CRT implantation with placement of a CS lead. Patients meeting the enrollment criteria were categorized into three groups: Group A comprised conventional responders with a response observed at the 6-month follow-up, Group B consisted of delayed responders with a response seen between 6 months and 1-year follow-up, and Group C included late responders with a response observed after 1 year of follow-up. CRT response was defined as an absolute increase of ≥ 5% in left ventricular ejection fraction. All echocardiograms were performed at the same institution. Only patients who were defined as responders to CRT were included in the analysis. Results: Among the patients analyzed, 59 patients (67.2 ± 12.3 years, 39 male) achieved a conventional response to CRT, while 40 patients (69.6 ± 9.5 years, 30 male) experienced a delayed response, and 29 patients exhibited a late response (66.1 ± 11.4 years, 18 male). The mean follow-up time was 267 days (± 341 days). The incidence of delayed and late responses was 19.9% and 14.43%, respectively. In univariable logistic regression analysis, a history of coronary artery disease (p = 0.047) was associated with delayed and late CRT responses. Conclusions: Our findings demonstrate a significant proportion of patients experiencing delayed and late responses to CRT. This study suggests the need for reconsidering the waiting time for CRT response, particularly in patients with a history of coronary artery disease. Keywords: cardiac resynchronization therapy, delayed response, heart failure