What Are the Expectations for Cardiac Resynchronization Therapy? A Validation of Two Response Definitions

Abstract

Background: The definition of response to cardiac resynchronization therapy (CRT) varies across clinical trials. There are two main definitions, i.e., echocardiographic response and functional response. We assessed which definition was more reasonable. Methods: In this study of 260 patients who had undergone CRT, an echocardiographic response was defined as a reduction in a left ventricular end-systolic volume of greater than or equal to 15% or an improvement in left ventricular ejection fraction of greater than or equal to 5%. A functional response was defined as an improvement of at least one class category in the New York Heart Association functional classification. We assessed the response to CRT at 6 months after device implantation, based on each definition, and investigated the relationship between response and clinical outcomes. Results: The echocardiographic response rate was 74.2%. The functional response rate was 86.9%. Non-responder status, based on both definitions, was associated with higher all-cause mortality. Cardiac death was only associated with functional non-responder status (hazard ratio (HR) 2.65, 95% confidence interval (CI) 1.19–5.46, p = 0.0186) and heart failure hospitalization (HR 2.78, 95% CI, 1.29–5.26, p = 0.0111). Conclusion: After CRT implantation, the functional response definition of CRT response is associated with a higher response rate and better clinical outcomes than that of the echocardiographic response definition, and therefore it is reasonable to use the functional definition to assess CRT response.

Cardiac resynchronization therapy: Current status and near-future prospects

“…Thus, they concluded that it is not appropriate to consider only patients with improvement as responders [23] . In our study, there was a difference between echocardiographic response and functional response based on improvement in symptoms; prognosis was better in patients who obtained a functional response [22] . If patients in the stabilized and improved groups in the graph of Gold et al ( Fig.…”

“…We questioned judging response based on the echocardiographic index. We investigated improvement in symptoms, that is, functional response and response based on the echo index, that is, reverse remodeling [22] . In our study, echocardiographic assessment of reverse remodeling was associated with a response rate of approximately 70%, but the functional response rate based on improvement in symptoms was 86% ( Fig.…”

Prognostic importance of the Controlling Nutritional Status (CONUT) score in patients undergoing cardiac resynchronisation therapy

“…Functional CRT response was defined as the combination of improved functional status in at least one New York Heart Association (NYHA) functional class and the absence of death or hospitalisation of HF at 6 months after CRT device implantation. 17 18 Echocardiographic CRT response was defined as an improvement in LVEF of at least 5% or a reduction in LV end-systolic volume (LVESV) of at least 15% at 6 months after CRT implantation.…”

Prognostic value of the MELD‐XI score in patients undergoing cardiac resynchronization therapy

“…As previously described, atrioventricular delay was optimized automatically by each device, but if the QRS duration did not narrow sufficiently, the atrioventricular and interventricular delays were optimized manually based on the QRS duration observed on the electrocardiogram. 17 Thereafter, patients were followed up in dedicated device therapy clinics at regular 3-6 month intervals. We evaluated two definitions of CRT response: functional and echocardiographic.…”

“…We evaluated two definitions of CRT response: functional and echocardiographic. 17 The functional CRT response was defined as the combination of improvement by at least one New York Heart Association (NYHA) functional class and the absence of death or hospitalization due to HF at 6 months after CRT implantation. 17,18 The echocardiographic CRT response was defined as an improvement in the LVEF of at least 5% or a reduction in the LV end-systolic volume (LVESV) of at least 15% at 6 months after CRT implantation.…”