Nonischemic Super-Responders in Fusion CRT Pacing with Normal Atrioventricular Conduction

Abstract

Background
 : Fusion CRT pacing (FCRT) is noninferior to biventricular pacing, according to the current data. The aim of this study is to assess the response to FCRT and to identify predictors of super-responders (SRs) in a nonischemic population with normal AV conduction. Methods: LV-only CRT patients (pts) with a right atrium/left ventricle pacing system implanted in two CRT centers in Romania were included. Device interrogation, exercise tests, echocardiography, and individualized drug optimization were performed every 6 months during close follow-up. SRs pts were defined as those with left ventricular end-systolic volume (LVESV) improvement ≥30% and stable ejection fraction (LVEF) ≥45%. Results: A total of 25 out of 83 pts (31%) were SRs, with nonischemic LBBB low EF cardiomyopathy (50 male, 62 ± 9 y.o.) initially included. Mean follow-up was 5 years ± 27 months. Patients were divided in two groups: SRs and non-SRs (52 responders/6 hypo-responders). Two predictors were found in the SRs group: a higher baseline LVEF (SRs 29 ± 5% vs. non-SRs 26 ± 5%, p = 0.02) and a lower pulmonary arterial systolic pressure (SRs 38 ± 11 mm Hg vs. non-SRs 50 ± 15 mmHg, p = 0.003). Baseline severe mitral regurgitation was found in 11% of SRs vs. 64% in the non-SRs group. Conclusions: SRs in the selected NICM-FCRT group are significative high. Higher baseline LVEF and mild pulmonary arterial hypertension were independently associated with super-response.

A Comparative Analysis of Apical Rocking and Septal Flash: Two Views of the Same Systole?

“…This increased comprehension could lead to a more accurate and focused evaluation of patients for CRT, possibly outlining the wide range of responses noticed, from significant LV reverse remodeling in “CRT super-responders” [ 72 ] to more modest effects or even deterioration of LV function [ 73 , 74 , 75 ]. Alternative CRT pacing, such as fusion pacing CRT or LV only pacing, was associated with a high rate of super-responders [ 76 , 77 ]. Fusion pacing CRT is defined as optimised LV only pacing (with or without a back-up RV lead) creating electrical and mechanical fusion with the intrinsec QRS.…”

Considering Diastolic Dyssynchrony as a Predictor of Favorable Response in LV-Only Fusion Pacing Cardiac Resynchronization Therapy

“…As is well known, poor reprogramming of AV delays contributes to the reduction of the effectiveness of CRT [ 24 , 25 , 26 ]. The key target of programming has been to deliver 100% of ventricular capture in order to achieve the maximal outcomes [ 7 , 27 , 28 ].…”

“…The study of LV contraction in diastole could be an important tool for the assessment of the CRT response and the improvement of hemodynamics, which until now has not been intensively studied [ 3 , 4 , 5 ]. An elegant alternative to classical triple CRT that can maintain the RV activation synchronism, may be achieved using bicameral pacemakers with right atrium/left ventricule leads (RA/LV) in a carefully selected nonischemic CRT-P population with normal atrioventricular conduction [ 6 , 7 ]. However, less data is available concerning diastolic dyssynchrony and fusion pacing CRT.…”

Future Perspectives to Improve CHA2DS2VASc Score: The Role of Left Atrium Remodelling, Inflammation and Genetics in Anticoagulation of Atrial Fibrillation

“…In HF patients with cardiac resynchronization therapy, in particular fusion pacing CRT, left atrium reverse remodelling was associated with a lower incidence of atrial fibrillation. [30][31][32] The relevance of sinus rhythm preservation in patients undergoing CRT pacing is linked to events free of hospitalisation and superior survival. LA function is an important determinant of outcome in these patients.…”