Cardiac resynchronization therapy is associated with a reduction in ICD therapies as it improves ventricular function
Enrique Galve1,2, Gerard Oristrell1,2, Gabriel Acosta1
1Department of Cardiology, Vall d'Hebron University Hospital, Barcelona, Spain.
Insights
Cardiac resynchronization therapy-defibrillator (CRT-D) reduces device therapies in heart failure patients. Improvement in left ventricular ejection fraction (LVEF) with CRT-D is linked to fewer therapies, independent of patient profile.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Repeated implantable cardioverter-defibrillator (ICD) therapies can cause myocardial damage, increasing arrhythmia and mortality risks.
- Left ventricular dysfunction, defined by ejection fraction (LVEF) <50%, is a common indication for device therapy.
Purpose of the Study:
- To evaluate if cardiac resynchronization therapy-defibrillator (CRT-D) reduces appropriate therapies compared to ICD alone in patients with reduced LVEF.
- To identify predictors of first appropriate therapy in patients receiving ICD or CRT-D.
Main Methods:
- Retrospective study of 175 patients with reduced LVEF (<50%) treated with ICD or CRT-D between 2009-2014.
- Patients received devices for primary or secondary prevention of sudden cardiac death.
- Cox regression analysis was used to assess predictors of first appropriate therapy.
Main Results:
- 25.1% of patients received at least one appropriate therapy.
- CRT-D patients had lower baseline LVEF and worse NYHA class but experienced a significantly lower risk of first appropriate therapy (aHR: 0.24) if LVEF improved >35%.
- No significant difference in mortality was observed between ICD and CRT-D groups.
Conclusions:
- Despite a worse baseline clinical profile, CRT-D patients received fewer device therapies compared to ICD patients.
- The reduction in therapies for CRT-D recipients is significantly associated with improved LVEF.
Background:
Repeated implantable cardioverter-defibrillator (ICD) therapies cause myocardial damage and, thus, an increased risk of arrhythmias and mortality.
Hypothesis:
Cardiac resynchronization therapy-defibrillator (CRT-D) reduces the number of appropriate therapies in patients with left ventricular dysfunction (left ventricular ejection fraction [LVEF] <50%).
Methods:
The retrospective study involved 175 consecutive patients (mean age, 64.6 ±10.4 years; 86.9% males) with reduced LVEF of 27.9% ±7.6% treated with an ICD (56.6%) or CRT-D (43.4%), according to standard indications, between January 2009 and July 2014. Devices were placed for either primary (54.3%) or secondary prevention (45.7%). Mean follow-up was 2.5 ±1.5 years. Predictors of first appropriate therapy were assessed using Cox regression analysis.
Results:
Forty-four (25.1%) patients received ≥1 appropriate therapy. Although patients treated with CRT-D had lower LVEF and poorer New York Heart Association class, CRT-D patients with LVEF improvement >35% at the end of follow-up had a significantly lower risk of receiving a first appropriate therapy relative to those with an ICD (adjusted hazard ratio: 0.24, 95% confidence interval: 0.07-0.83, P = 0.025), independently of ischemic cardiomyopathy, baseline LVEF, and secondary prevention. There were no differences in mortality between the ICD and the CRT-D groups.
Conclusions:
Although patients receiving CRT-D had a worse clinical profile, they received fewer device therapies in comparison with those receiving an ICD. This reduction is associated with a significant improvement in LVEF.
Related Concept Videos
00:59Gene Therapy
01:26Group Therapy
01:22Behavior Therapy
Exposure therapy is a cornerstone of behavioral treatment for anxiety disorders. It involves systematic exposure to feared stimuli, either in real...
01:28Drug Therapy
Antianxiety Medications
01:25Cognitive Therapy
01:30Electroconvulsive Therapy