Study patientsįor the present study we included patients without a device (pacemaker, CRT or implantable cardioverter-defibrillator) and a baseline QRS duration between 60 and 240 ms ( Figure 1). All patients provided written informed consent. 10- 14 Both trials were approved by the ethics committee at each study centre.
#IVCD INTRAVENTRICULAR CONDUCTION DELAY TRIAL#
The design, baseline characteristics and primary results of the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure trial (PARADIGM-HF) and the Aliskiren Trial to Minimize OutcomeS in Patients with HEart FailuRE trial (ATMOSPHERE) are published. The trials had nearly identical enrolment criteria. In the present study we examined the prognostic importance of prevalent and incident QRS widening to a duration of ≥130 ms using data from two HFrEF trials which included a broad spectrum of ambulatory patients receiving contemporary therapy. 8, 9 This information is important as a new diagnosis of IVCD may be of prognostic importance and may identify an indication for CRT. More importantly, very little is known about the incidence and clinical consequences of new-onset QRS widening in patients with HFrEF. 2- 7 Less is known about the prevalence and prognostic significance of right bundle branch block (RBBB) and non-specific IVCD (nsIVCD) in HFrEF. 1 LBBB is known to be associated with worse outcomes in patients with heart failure (HF) and reduced ejection fraction (HFrEF), and cardiac resynchronization therapy (CRT) reduces the risk of worsening heart failure and improves survival in such patients with a QRS duration ≥130 ms. Intra-ventricular conduction delay (IVCD), particularly with a left bundle branch block (LBBB) morphology, results in a dyssynchronous electrical activation sequence of the heart. Trial Registration: Identifier NCT0083658 (ATMOSPHERE) and NCT01035255 (PARADIGM-HF). The annual incidence of new-onset LBBB was around 2.5%, and associated with a higher risk of adverse outcomes, highlighting the importance of repeat electrocardiogram review. In patients with HFrEF, a wide QRS was associated with worse clinical outcomes irrespective of morphology. Incident LBBB occurred in 495 (6.3%) patients (2.4 per 100 patient-years) and was associated with a higher risk of the primary composite outcome. A total of 1234 (15.6%) patients developed new-onset QRS widening ≥130 ms (6.1 per 100 patient-years). During a median follow-up of 2.5 years, the risk of the primary composite endpoint was higher among those with a wide QRS, irrespective of morphology: hazard ratios (95% confidence interval) LBBB 1.36 (1.23–1.50), RBBB 1.54 (1.31–1.79), non-specific IVCD 1.65 (1.40–1.94) and QRS 110–129 ms 1.35 (1.23–1.47), compared with QRS duration <110 ms. The risk of the primary composite outcome of cardiovascular death or heart failure hospitalization and all-cause mortality were estimated by use of Cox regression according to baseline QRS duration and morphology in 11 861 patients without an intracardiac device. We addressed these questions in the PARADIGM-HF and ATMOSPHERE trials. The importance of intra-ventricular conduction delay (IVCD), the incidence of new IVCD and its relationship to outcomes in heart failure and reduced ejection fraction (HFrEF) are not well studied.