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QRS axis and the benefit of cardiac resynchronization therapy in patients with mildly symptomatic heart failure enrolled in MADIT-CRT.
- Source :
-
Journal of cardiovascular electrophysiology [J Cardiovasc Electrophysiol] 2013 Apr; Vol. 24 (4), pp. 442-8. Date of Electronic Publication: 2012 Dec 17. - Publication Year :
- 2013
-
Abstract
- Background: Mildly symptomatic heart failure (HF) patients derive substantial clinical benefit from cardiac resynchronization therapy with defibrillator (CRT-D) as shown in MADIT-CRT. The presence of QRS axis deviation may influence response to CRT-D. The objective of this study was to determine whether QRS axis deviation will be associated with differential benefit from CRT-D.<br />Methods: Baseline electrocardiograms of 1,820 patients from MADIT-CRT were evaluated for left axis deviation (LAD: quantitative QRS axis -30 to -90) or right axis deviation (RAD: QRS axis 90-180) in left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific interventricular conduction delay QRS morphologies. The primary endpoints were the first occurrence of a HF event or death and the separate occurrence of all-cause mortality as in MADIT-CRT.<br />Results: Among LBBB patients, those with LAD had a higher risk of primary events at 2 years than non-LAD patients (20% vs 16%; P = 0.024). The same was observed among RBBB patients (20% vs 10%; P = 0.05) but not in IVCD patients (22% vs 23%; P = NS). RAD did not convey any increased risk of the primary combined endpoint in any QRS morphology subgroup. When analyzing the benefit of CRT-D in the non-LBBB subgroups, there was no significant difference in hazard ratios for CRT-D versus ICD for either LAD or RAD. However, LBBB patients without LAD showed a trend toward greater benefit from CRT therapy than LBBB patients with LAD (HR for no LAD: 0.37, 95% CI: 0.26-0.53 and with LAD: 0.54, 95% CI: 0.36-0.79; P value for interaction = 0.18).<br />Conclusions: LAD in non-LBBB patients (RBBB or IVCD) is not associated with an increased benefit from CRT. In LBBB patients, those without LAD seem to benefit more from CRT-D than those with LAD.<br /> (© 2012 Wiley Periodicals, Inc.)
- Subjects :
- Action Potentials
Aged
Bundle-Branch Block diagnosis
Bundle-Branch Block etiology
Bundle-Branch Block mortality
Bundle-Branch Block physiopathology
Canada
Chi-Square Distribution
Electrocardiography
Europe
Female
Heart Failure complications
Heart Failure diagnosis
Heart Failure mortality
Heart Failure physiopathology
Humans
Kaplan-Meier Estimate
Male
Middle Aged
Multivariate Analysis
Patient Selection
Proportional Hazards Models
Risk Assessment
Risk Factors
Severity of Illness Index
Stroke Volume
Time Factors
Treatment Outcome
United States
Ventricular Function, Left
Ventricular Remodeling
Bundle-Branch Block therapy
Cardiac Resynchronization Therapy adverse effects
Cardiac Resynchronization Therapy mortality
Cardiac Resynchronization Therapy Devices
Heart Conduction System physiopathology
Heart Failure therapy
Subjects
Details
- Language :
- English
- ISSN :
- 1540-8167
- Volume :
- 24
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Journal of cardiovascular electrophysiology
- Publication Type :
- Academic Journal
- Accession number :
- 23252875
- Full Text :
- https://doi.org/10.1111/jce.12057