Septal contraction patterns LBBB-1 and LBBB-2 prior to CRT were associated with a lower risk of death, LVAD, or heart transplant compared to LBBB-4 (HR 0.14; 95% CI 0.06-0.34; P<0.001).
Cohort (n=208)
Yes
Do specific baseline septal deformation patterns and lateral wall strain amplitudes predict long-term clinical outcomes in patients with heart failure and LBBB receiving CRT-D?
Specific echocardiographic septal contraction patterns (LBBB-1 and LBBB-2) strongly predict favorable long-term clinical outcomes in patients with heart failure and LBBB receiving CRT-D.
Effect estimate: HR 0.14 (95% CI 0.06-0.34)
p-value: p=<0.001
Abstract Aims A typical left bundle branch block (LBBB) contraction pattern prior to cardiac resynchronization therapy (CRT) has been demonstrated to be highly associated with response beyond QRS morphology and duration. This study investigates whether septal deformation type and lateral wall strain amplitude may be of particular importance for long-term outcome after CRT implantation. Methods From two centres, 208 CRT candidates with LBBB, New York Heart Association functional class II–IV, left ventricular ejection fraction ≤35%, and QRS duration ≥ 120 ms underwent echocardiography before CRT-defibrillator (CRT-D) implantation. Results Four septal contraction patterns were identified: 36 patients (17%) had double-peaked systolic pattern (LBBB-1), 51 (25%) had early pre-ejection peak shortening followed by systolic stretch (LBBB-2), 43 (21%) had shortening with one systolic peak inside 70% of the ejection phase (LBBB-3), and 78 (38%) had normal septal peak timing outside early 70% of ejection phase (LBBB-4). The primary outcome (freedom from death, implantation of a left ventricular assist device, and heart transplantation) occurred in 48 patients during a median follow-up of 4 years (interquartile range 3.25–4). The most favourable outcome was associated with LBBB-1 and LBBB-2, which had one-seventh the risk of the primary outcome compared to LBBB-4 (HR: 0.14 95% confidence interval: 0.06–0.34; P 0.001). Patients in the lowest tertile of lateral wall strain (−7.4%) were at high risk of an event compared to the other patients (HR: 2.57 1.46–4.55; P = 0.001). Conclusion The long-term clinical benefit of CRT-D in patients with LBBB pre-implantation varies. Subtypes of septal contraction patterns and, to a lesser degree, lateral function are important determinants of outcome in patients with CRT-D.
Risum et al. (Thu,) conducted a cohort in Heart failure with left bundle branch block (n=208). Septal contraction patterns LBBB-1 and LBBB-2 vs. Septal contraction pattern LBBB-4 was evaluated on Freedom from death, implantation of a left ventricular assist device, and heart transplantation (HR 0.14, 95% CI 0.06-0.34, p=<0.001). Septal contraction patterns LBBB-1 and LBBB-2 prior to CRT were associated with a lower risk of death, LVAD, or heart transplant compared to LBBB-4 (HR 0.14; 95% CI 0.06-0.34; P<0.001).