Key result
A single inappropriate ICD shock linked to ~60% higher all-cause mortality risk.
Why the study?
Despite the benefits of ICD therapy, inappropriate defibrillator shocks remain a drawback, and their prognostic importance outside clinical trials remains unclear.
Does the occurrence of inappropriate ICD shocks increase the risk of all-cause mortality in patients with implantable cardioverter-defibrillators?
Cohort (n=1,544)
Does the occurrence of inappropriate ICD shocks increase the risk of all-cause mortality in patients with implantable cardioverter-defibrillators?
Effect estimate: HR 1.6
p-value: p=0.01
Inappropriate ICD shocks are common in real-world practice and are independently associated with a dose-dependent increase in all-cause mortality.
Encourages attention to preventing inappropriate shocks but should not yet change practice; leaves open causality and is hypothesis-generating pending RCTs.
OBJECTIVES: The purpose of this study was to assess the incidence, predictors, and outcome of inappropriate shocks in implantable cardioverter-defibrillator (ICD) patients. BACKGROUND: Despite the benefits of ICD therapy, inappropriate defibrillator shocks continue to be a significant drawback. The prognostic importance of inappropriate shocks outside the setting of a clinical trial remains unclear. METHODS: From 1996 to 2006, all recipients of defibrillator devices equipped with intracardiac electrogram storage were included in the current analysis and clinically assessed at implantation. During follow-up, the occurrence of inappropriate ICD shocks and all-cause mortality was noted. RESULTS: A total of 1,544 ICD patients (79% male, age 61 ± 13 years) were included in the analysis. During the follow-up period of 41 ± 18 months, 13% experienced ≥1 inappropriate shocks. The cumulative incidence steadily increased to 18% at 5-year follow-up. Independent predictors of the occurrence of inappropriate shocks included a history of atrial fibrillation (hazard ratio [HR]: 2.0, p < 0.01) and age younger than 70 years (HR: 1.8, p = 0.01). Experiencing a single inappropriate shock resulted in an increased risk of all-cause mortality (HR: 1.6, p = 0.01). Mortality risk increased with every subsequent shock, up to an HR of 3.7 after 5 inappropriate shocks. CONCLUSIONS: In a large cohort of ICD patients, inappropriate shocks were common. The most important finding is the association between inappropriate shocks and mortality, independent of interim appropriate shocks.
No takes yet. Share an insight, caveat, or question.
Rees et al. (2011) conducted a cohort in Implantable cardioverter-defibrillator (ICD) patients (n=1,544). Inappropriate ICD shocks vs. No inappropriate shocks was evaluated on All-cause mortality (HR 1.6, p=0.01). Experiencing a single inappropriate ICD shock was associated with an increased risk of all-cause mortality (HR 1.6, p=0.01), with the risk increasing up to HR 3.7 after 5 shocks.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: