Heart Failure Duration Combined with Left Atrial Dimension Predicts Super-Response and Long-Term Prognosis in Patients with Cardiac Resynchronization Therapy Implantation

Abstract

Background. Response to cardiac resynchronization therapy (CRT) varies significantly among patients. This study aimed to identify baseline characteristics that could predict super-response to CRT and to evaluate the long-term prognosis in super-responders. Methods. We retrospectively reviewed the data of 73 consecutive patients who received CRT. Patients were considered as super-responders after 6-month follow-up when NYHA class reduction to I or II combined with left ventricular ejection fraction (LVEF) ≥ 50% was observed. Patients were divided into super-responders group and non-super-responders group. All-cause mortality or hospitalization for heart failure (HF) was referred to the combined end point. Results. 17 (23.3%) patients were super-responders. HF duration, left atrial dimension (LAD), and left bundle branch block (LBBB) were independent predictors of super-response to CRT. The combination of HF duration and LAD could provide more robust prediction of super-response than standalone HF duration (0.899 versus 0.789, Z = 2.207, P = 0.027) or standalone LAD (0.899 versus 0.775, Z = 2.487, P = 0.013). super-responders had excellent LV reverse remodeling. The cumulative incidences of combined end point were significantly lower in the super-responders group, LAD ≤ 42mm group, and combination of HF duration ≤ 48 months and LAD ≤ 42mm group. LBBB remained associated with a lowered risk of the combined end point (HR: 0.19, 95% CI: 0.07-0.57, P = 0.003), whereas LAD was associated with a raised risk of the combined end point (HR: 1.09, 95% CI: 1.02-1.17, P = 0.014). Conclusions. HF duration, LAD, and LBBB independently predicted super-response. The combination of HF duration and LAD makes more robust prediction of CRT super-response. Super-responders had excellent LV reverse remodeling and decreased the incidences of the combined end point. LBBB and LAD were independently associated with the combined end point.

Mechanisms of myocardial reverse remodelling and its clinical significance: A scientific statement of the ESC Working Group on Myocardial Function

“…For instance, advanced myocardial AR characterized by LV and/or LA dilatation diminishes the likelihood of a 'super-response' to CRT, defined as a combination of NYHA class reduction with preserved systolic function. 250,251 Additionally, a longer history of HF may hinder post-CRT RR success. Conversely, provided that the myocardial substrate is responsive to electrical stimuli and the global contractile reserve is preserved, a response to CRT is expected, manifesting as improved LVEF and/or a decrease in LVESV.…”

“…Maximal RR typically occurs within the first 6 months, although it is influenced by the preoperative myocardial condition. For instance, advanced myocardial AR characterized by LV and/or LA dilatation diminishes the likelihood of a ‘super‐response’ to CRT, defined as a combination of NYHA class reduction with preserved systolic function 250,251 . Additionally, a longer history of HF may hinder post‐CRT RR success.…”