Key result
Clinical classification overestimates SCD versus device interrogation, with ~50% of cases lacking a ventricular tachyarrhythmia.
Why the study?
Data are limited regarding factors identifying ICD patients who experience ventricular tachyarrhythmic versus non-arrhythmic mortality, and clinical classification of sudden versus non-sudden cardiac death may lack accuracy.
Does clinical adjudication of sudden vs. non-sudden cardiac death accurately reflect ventricular tachyarrhythmic events at the time of death in ICD patients?
Observational (n=746)
Yes
Does clinical adjudication of sudden vs. non-sudden cardiac death accurately reflect ventricular tachyarrhythmic events at the time of death in ICD patients?
Effect estimate: HR 8.0
p-value: p=<0.001
Standard clinical classification of sudden vs. non-sudden cardiac death is frequently inaccurate when compared to ICD interrogation data, highlighting the importance of device data for determining the true arrhythmic nature of mortality.
Clinical SCD adjudication may misclassify arrhythmic events in ICD patients; leaves open whether device data should refine endpoints in future studies.
AIMS: There are limited data regarding factors that identify implantable cardioverter-defibrillator (ICD) patients who will experience either ventricular tachyarrhythmic (VTA) or non-arrhythmic (NA) mortality, and the commonly used clinical classification of sudden cardiac death (SCD) vs. non-sudden cardiac death (NSCD) may not be accurate enough. We aimed to correlate clinical adjudication of mortality events to device interrogation data and to identify risk factors for VTA mortality in Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II). METHODS AND RESULTS: Of the 746 patients who received an ICD in MADIT-II, 44 died from cardiac causes and had available interrogation data at the time of death. Sudden cardiac death vs. NSCD was defined by an adjudication committee. Ventricular tachyarrhythmic and NA arrhythmic deaths were categorized by the presence or absence of ventricular tachycardia or fibrillation (VT/VF) during the terminal event. Mode of death was found to be inaccurate when validated by device interrogation for VTA events: 50% patients adjudicated as SCD did not have a VTA event at the time of death; and 25% of adjudicated NSCD were found to have VT/VF during the mortality event. Multivariate analysis showed that factors independently associated with VTA mortality included: VT/VF >72 h prior to the mortality event [hazard ratio (HR) 8.0; P < 0.001], hospitalization for heart failure (HR 6.7; P = 0.001), and a history of hypertension (HR 4; P = 0.04). CONCLUSION: Current classification of SCD vs. NSCD fails to identify VTA events at the time of death in a significant proportion of patients, and simple clinical parameters can be used to identify ICD recipients with increased risk for VTA mortality.
No takes yet. Share an insight, caveat, or question.
Chernomordik et al. (2019) conducted an observational in Implantable cardioverter-defibrillator (ICD) recipients (n=746). Device interrogation data vs. Clinical adjudication of mortality events (SCD vs NSCD) was evaluated on Ventricular tachyarrhythmic (VTA) mortality associated with VT/VF >72 h prior to the mortality event (HR 8.0, p=<0.001). Clinical classification of sudden cardiac death was inaccurate compared to device interrogation, with 50% of adjudicated sudden deaths lacking a ventricular tachyarrhythmic event.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: