Open AccessResponse to cardiac resynchronization therapy in non‐ischemic cardiomyopathy is unrelated to medical therapy
Author(s) -
Sinner Gregory,
Omar Hesham R.,
Lin You W.,
Elayi Samy C.,
Guglin Maya E.
Publication year - 2019
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.23123
Subject(s) - medicine , cardiac resynchronization therapy , ejection fraction , left bundle branch block , cardiology , qrs complex , cardiomyopathy , ischemic cardiomyopathy , statistical significance , cardiac function curve , heart failure
Current guidelines recommend at least 3 months of guideline‐directed medical therapy (GDMT) for patients with a new onset of non‐ischemic cardiomyopathy (NICM) and left bundle branch block (LBBB) prior to cardiac resynchronization therapy (CRT). For patients who do not receive optimal GDMT, response to CRT is unknown. Methods Patients with NICM and LBBB with QRS ≥ 120 ms were identified among all patients who underwent CRT. Patients who received GDMT for ≥ 3 months before CRT were compared to those who did not. Among 38 patients who met inclusion criteria, 24 received optimal GDMT prior to implantation (Group 1) and 14 did not (Group 2). Results QRS narrowing occurred in Group 1 (160 ± 9 ms to 138 ± 20 ms, P = 0.001) and Group 2 (160 ± 17 ms to 139 ± 30 ms, P = 0.021). Left ventricular ejection fraction (LVEF) improvement occurred in Group 1 (21.3 ± 5.9% to 34.4 ± 13.9%, P < 0.001) and Group 2 (18.8 ± 4.7% to 31.1 ± 13%, P = 0.010). QRS interval and LVEF changes were similar between groups ( P = NS). There was a trend towards greater CRT response in women than in men, although differences did not reach statistical significance. Conclusion In patients with NICM and LBBB, CRT is associated with improvements in LV size and function independent of prior GDMT. The ability of resynchronization to improve LVEF without GDMT suggests that CRT without waiting 3 months for GDMT optimization may benefit some patients with NICM and LBBB.