The risk of ventricular arrhythmias in a Dutch CRT population: CRT-defibrillator versus CRT-pacemaker
I A H Ter Horst1, J van 't Sant2, S C Wijers3,4
1Department of Cardiology, University Medical Center Utrecht, Heidelberglaan 100, 3508 GA, PO Box 85500, Utrecht, The Netherlands. i.a.h.terhorst@umcutrecht.nl.
Insights
Cardiac resynchronisation therapy (CRT) may reduce the need for implantable cardioverter defibrillators (ICDs). A left ventricular ejection fraction (LVEF) above 35% after CRT identifies patients at low risk for ventricular arrhythmias, potentially allowing downgrading to a CRT-pacemaker.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Patients undergoing cardiac resynchronisation therapy (CRT) often have an indication for prophylactic implantable cardioverter defibrillator (ICD) therapy.
- CRT response may alter arrhythmogenesis, potentially influencing the need for ICD therapy.
Purpose of the Study:
- To retrospectively analyze the association between baseline variables, echocardiographic outcomes, and the risk of appropriate ICD therapy in CRT patients.
- To determine if echocardiographic parameters post-CRT can predict the need for ICD therapy.
Main Methods:
- Analysis of 202 CRT-defibrillator patients, examining baseline characteristics and 6-month echocardiographic outcomes.
- Assessed volume response (left ventricular end-systolic volume decrease) and left ventricular ejection fraction (LVEF) in relation to appropriate ICD therapy events.
Main Results:
- 25% of patients received appropriate ICD therapy during follow-up.
- Ischemic cardiomyopathy and elevated B-type natriuretic peptide levels were associated with increased ICD therapy risk.
- A post-CRT LVEF >35% was strongly associated with a lower risk of ventricular arrhythmias compared to volume response alone.
Conclusions:
- Assessing the necessity of ICDs in CRT-eligible patients remains challenging.
- A post-CRT LVEF >35% at 6 months identifies patients at low risk for ventricular arrhythmias.
- LVEF measurements post-CRT could guide decisions on downgrading to a CRT-pacemaker at generator replacement.
Background:
Patients eligible for cardiac resynchronisation therapy (CRT) have an indication for primary prophylactic implantable cardioverter defibrillator (ICD) therapy. However, response to CRT might influence processes involved in arrhythmogenesis and therefore change the necessity of ICD therapy in certain patients.
Method:
In 202 CRT-defibrillator patients, the association between baseline variables, 6-month echocardiographic outcome (volume response: left ventricular end-systolic volume decrease < ≥15 % and left ventricular ejection fraction (LVEF) ≤ >35 %) and the risk of first appropriate ICD therapy was analysed retrospectively.
Results:
Fifty (25 %) patients received appropriate ICD therapy during a median follow-up of 37 (23-52) months. At baseline ischaemic cardiomyopathy (hazard ratio (HR) 2.0, p = 0.019) and a B-type natriuretic peptide level > 163 pmol/l (HR 3.8, p < 0.001) were significantly associated with the risk of appropriate ICD therapy. After 6 months, 105 (52 %) patients showed volume response and 51 (25 %) reached an LVEF > 35 %. Three (6 %) patients with an LVEF > 35 % received appropriate ICD therapy following echocardiography at ± 6 months compared with 43 patients (29 %) with an LVEF ≤ 35 % (p = 0.001). LVEF post-CRT was more strongly associated to the risk of ventricular arrhythmias than volume response (LVEF > 35 %, HR 0.23, p = 0.020).
Conclusion:
Assessing the necessity of an ICD in patients eligible for CRT remains a challenge. Six months post-CRT an LVEF > 35 % identified patients at low risk of ventricular arrhythmias. LVEF might be used at the time of generator replacement to identify patients suitable for downgrading to a CRT-pacemaker.
More Related Videos
Related Concept Videos
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
01:25Dysrhythmias VI: Management of Dysrhythmias
01:30Dysrhythmias V: Evaluating Dysrhythmias
01:23Cardiopulmonary Resuscitation III: AED Use
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:29Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...