(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.Keywords Cardiac resynchronisation therapy · Ventricular arrhythmias · Appropriate ICD
IntroductionThe majority of patients eligible for cardiac resynchronisation therapy (CRT) also have an indication for primary prophylactic implantable cardioverter defibrillator (ICD) therapy based on their depressed left ventricular ejection fraction (LVEF ≤ 35 %) [1]. Although LVEF is the strongest predictor of ventricular arrhythmias in patients without a history of ventricular arrhythmias, its value in patients eligible for CRT is questionable. CRT aims to improve LVEF and induces reverse remodelling of the left ventricle. Both reverse remodelling and overcrossing a certain threshold in LVEF post-CRT have previously been linked to a decreased risk of ventricular arrhythmias, but inconclusively [2-11]. As a CRT-defibrillator (CRT-D) device is much more expensive than a CRT-pacemaker (CRT-P) and the additional ICD induces the risk of inappropriate ICD therapy, it is clinically relevant to identify those patients at low risk of ventricular arrhythmias prior to CRT-D implant
AbstractBackground 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