Modeling defibrillation benefit for survival among cardiac resynchronization therapy defibrillator recipients.
Am Heart J. 2019 Dec 27;222:93-104
Authors: Bilchick KC, Wang Y, Curtis JP, Cheng A, Dharmarajan K, Shadman R, Dardas TF, Anand I, Lund LH, Dahlström U, Sartipy U, Maggioni A, O’Connor C, Levy WC
BACKGROUND: Patients with heart failure having a low expected probability of arrhythmic death may not benefit from implantable cardioverter defibrillators (ICDs).
OBJECTIVE: The objective was to validate models to identify cardiac resynchronization therapy (CRT) candidates who may not require CRT devices with ICD functionality.
METHODS: Heart failure (HF) patients with CRT-Ds and non-CRT ICDs from the National Cardiovascular Data Registry and others with no device from 3 separate registries and 3 heart failure trials were analyzed using multivariable Cox proportional hazards regression for survival with the Seattle Heart Failure Model (SHFM; estimates overall mortality) and the Seattle Proportional Risk Model (SPRM; estimates proportional risk of arrhythmic death).
RESULTS: Among 60,185 patients (age 68.6 ± 11.3 years, 31.9% female) meeting CRT-D criteria, 38,348 had CRT-Ds, 11,389 had non-CRT ICDs, and 10,448 had no device. CRT-D patients had a prominent adjusted survival benefit (HR 0.52, 95% CI 0.50-0.55, P < .0001 versus no device). CRT-D patients with SHFM-predicted 4-year survival ≥81% (median) and a low SPRM-predicted probability of an arrhythmic mode of death ≤42% (median) had an absolute adjusted risk reduction attributable to ICD functionality of just 0.95%/year with the majority of survival benefit (70%) attributable to CRT pacing. In contrast, CRT-D patients with SHFM-predicted survival <median or SPRM >median had substantially more ICD-attributable benefit (absolute risk reduction of 2.6%/year combined; P < .0001).
CONCLUSIONS: The SPRM and SHFM identified a quarter of real-world, primary prevention CRT-D patients with minimal benefit from ICD functionality. Further studies to evaluate CRT pacemakers in these low-risk CRT candidates are indicated.
PMID: 32032927 [PubMed – as supplied by publisher]