Longitudinal dyssynchrony correction and strain improvement by comparable cardiac resynchronization therapy techniques is unreported.
Aims
Our purpose was to compare echocardiographic dyssynchrony correction and strain improvement by conduction system pacing (CSP) vs. biventricular pacing (BiVP) as a marker of contractility improvement during one-year follow-up.
Methods and Results
A treatment-received analysis was performed in patients included in the LEVEL-AT trial (NCT04054895), randomized to CSP or BiVP, and evaluated at baseline (ON and OFF programming) and at 6 and 12 months (n = 69, 32% women). Analysis included intraventricular (septal flash), interventricular (difference between left and right ventricular outflow times), and atrioventricular (diastolic filling time) dyssynchrony and strain parameters (septal bounce, global longitudinal strain [GLS], left bundle branch block pattern and mechanical dispersion).
Baseline left ventricular ejection fraction (LVEF) was 27.5 ± 7% and left ventricular end-systolic volume (LVESV) was 138 ± 77 ml, without differences between groups. Longitudinal analysis showed LVEF and LVESV improvement (p < 0.001), without between-group differences. At 12-month follow-up, adjusted mean LVEF was 46% with CSP (95%CI 42.2%, 49.3%) vs. 43% with BiVP (95%CI 39.6%, 45.8%) (p = 0.31) and LVESV was 80 ml (95%CI 55.3 ml, 104.5 ml) vs. 100 ml (95%CI 78.7 ml, 121.6 ml), respectively (p = 0.66).
Longitudinal analysis showed a significative improvement of all dyssynchrony parameters and GLS over time (p < 0.001), without differences between groups. Baseline GLS significantly correlated with LVEF and LVESV at 12-month follow-up.
Conclusion
CSP and BiVP provided similar dyssynchrony and strain correction over time. Baseline global longitudinal strain correction predicted ventricular remodeling at 12-month follow-up.