Author + information
- Ahmed AlTurki,
- Alexios Hadjis,
- Riccardo Proietti and
- Vidal Essebag
Background: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in heart failure with reduced ejection fraction (HFrEF). CRT efficacy is greater in patients with left bundle branch block (LBBB). This study aimed to determine if strict LBBB criteria predicts an improved CRT response.
Methods: HFrEF patients who received a de novo CRT device at a single tertiary center were included. Patients were divided into 3 groups based on QRS morphology. Strict LBBB was defined as mid QRS notching or slurring in two of the following leads (I, aVL, V1, V2, V5, V6), QRS> 140ms in men and >130ms in women in addition to conventional criteria, defined as QS or rS in V1 and a monophasic R with no q waves in I, V6; for conventional LBBB, the QRS had to be >120ms. Group 1 consisted of patients with strict LBBB. Group 2 had conventional LBBB and group 3 had non-LBBB morphology. The primary endpoint was change in QRS duration after CRT. The secondary endpoints were change in EF and the correlation between change in QRS duration and change in EF.
Results: In 204 patients, mean age was 73.1 years, 74% were men and 51% had ischemic cardiomyopathy. In addition, 74% were hypertensive, 38% had diabetes mellitus and 13% had a previous stroke. 51% of patients were in group 1, 27% were in group 2 and 22% were in group 3. The mean change in QRS was −20.7±12.6, +5.2±17.0 and +18.5±28.4 in groups 1, 2 and 3 respectively. Strict LBBB predicted a significant improvement in QRS compared to conventional LBBB (p<0.0001) and non-LBBB morphology, (p<0.0001); there was no significant difference between groups 2 and 3 (p=0.46). Regarding EF, the mean change was +19.4±11.3, +6.9±15.3 and +0.5±11.7 in groups 1, 2 and 3 respectively. Strict LBBB also predicted a significant improvement in EF compared to conventional LBBB (p=<0.0001) and non-LBBB morphology (p<0.0001); there was no significant difference between groups 2 and 3 (p=0.18). There was a statistically significant, moderate negative correlation between change in QRS duration and change in EF (correlation coefficient =-0.48, p<0.0001).
Conclusions: Strict LBBB predicted an improved QRS and EF response compared to conventional LBBB and non-LBBB morphology in patients with HFrEF who received CRT.
Poster Hall, Hall C
Saturday, March 18, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Arrhythmias and Clinical EP: Devices 3
Abstract Category: 5. Arrhythmias and Clinical EP: Devices
Presentation Number: 1188-076
- 2017 American College of Cardiology Foundation