TY - JOUR
T1 - Impaired Recovery of Left Ventricular Function in Patients With Cardiomyopathy and Left Bundle Branch Block
AU - Sze, Edward
AU - Samad, Zainab
AU - Dunning, Allison
AU - Campbell, Kristen Bova
AU - Loring, Zak
AU - Atwater, Brett D.
AU - Chiswell, Karen
AU - Kisslo, Joseph A.
AU - Velazquez, Eric J.
AU - Daubert, James P.
N1 - Publisher Copyright:
© 2018 American College of Cardiology Foundation
PY - 2018/1/23
Y1 - 2018/1/23
N2 - Background: Patients with left bundle branch block (LBBB) often respond to cardiac resynchronization therapy (CRT) with left ventricular ejection fraction (LVEF) improvement. Guideline-directed medical therapy (GDMT), not CRT, is first-line therapy for patients with reduced LVEF with LBBB. However, there are little data on how patients with reduced LVEF and LBBB respond to GDMT. Objectives: This study examined patients with cardiomyopathy and sought to assess rates of LVEF improvement for patients with LBBB compared to other QRS morphologies. Methods: Using data from the Duke Echocardiography Laboratory Database, the study identified patients with baseline electrocardiography and LVEF ≤35% who had a follow-up LVEF 3 to 6 months later. The study excluded patients with severe valve disease, a cardiac device, left ventricular assist device, or heart transplant. QRS morphology was classified as LBBB, QRS duration <120 ms (narrow QRS duration), or a wide QRS duration ≥120 ms but not LBBB. Analysis of variance testing compared mean change in LVEF among the 3 groups with adjustment for significant comorbidities and GDMT. Results: There were 659 patients that met the criteria: 111 LBBB (17%), 59 wide QRS duration ≥120 ms but not LBBB (9%), and 489 narrow QRS duration (74%). Adjusted mean increase in LVEF over 3 to 6 months in the 3 groups was 2.03%, 5.28%, and 8.00%, respectively (p < 0.0001). Results were similar when adjusted for interim revascularization and myocardial infarction. Comparison of mean LVEF improvement between patients with LBBB on GDMT and those not on GDMT showed virtually no difference (3.50% vs. 3.44%). The combined endpoint of heart failure hospitalization or mortality was highest for patients with LBBB. Conclusions: LBBB is associated with a smaller degree of LVEF improvement compared with other QRS morphologies, even with GDMT. Some patients with LBBB may benefit from CRT earlier than guidelines currently recommend.
AB - Background: Patients with left bundle branch block (LBBB) often respond to cardiac resynchronization therapy (CRT) with left ventricular ejection fraction (LVEF) improvement. Guideline-directed medical therapy (GDMT), not CRT, is first-line therapy for patients with reduced LVEF with LBBB. However, there are little data on how patients with reduced LVEF and LBBB respond to GDMT. Objectives: This study examined patients with cardiomyopathy and sought to assess rates of LVEF improvement for patients with LBBB compared to other QRS morphologies. Methods: Using data from the Duke Echocardiography Laboratory Database, the study identified patients with baseline electrocardiography and LVEF ≤35% who had a follow-up LVEF 3 to 6 months later. The study excluded patients with severe valve disease, a cardiac device, left ventricular assist device, or heart transplant. QRS morphology was classified as LBBB, QRS duration <120 ms (narrow QRS duration), or a wide QRS duration ≥120 ms but not LBBB. Analysis of variance testing compared mean change in LVEF among the 3 groups with adjustment for significant comorbidities and GDMT. Results: There were 659 patients that met the criteria: 111 LBBB (17%), 59 wide QRS duration ≥120 ms but not LBBB (9%), and 489 narrow QRS duration (74%). Adjusted mean increase in LVEF over 3 to 6 months in the 3 groups was 2.03%, 5.28%, and 8.00%, respectively (p < 0.0001). Results were similar when adjusted for interim revascularization and myocardial infarction. Comparison of mean LVEF improvement between patients with LBBB on GDMT and those not on GDMT showed virtually no difference (3.50% vs. 3.44%). The combined endpoint of heart failure hospitalization or mortality was highest for patients with LBBB. Conclusions: LBBB is associated with a smaller degree of LVEF improvement compared with other QRS morphologies, even with GDMT. Some patients with LBBB may benefit from CRT earlier than guidelines currently recommend.
KW - guideline directed medical therapy
KW - heart failure
KW - left bundle branch block
KW - left ventricular functional recovery
UR - http://www.scopus.com/inward/record.url?scp=85044518376&partnerID=8YFLogxK
U2 - 10.1016/j.jacc.2017.11.020
DO - 10.1016/j.jacc.2017.11.020
M3 - Article
C2 - 29348023
AN - SCOPUS:85044518376
SN - 0735-1097
VL - 71
SP - 306
EP - 317
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
IS - 3
ER -