Gleva, Marye J.

AbstractBackgroundAccurate automated wide QRS complex tachycardia (WCT) differentiation into ventricular tachycardia (VT) and supraventricular wide complex tachycardia (SWCT) can be accomplished using calculations derived from computerized electrocardiogram (ECG) data of paired WCT and baseline ECGs.ObjectiveDevelop and trial novel WCT differentiation approaches for patients with and without a corresponding baseline ECG.MethodsWe developed and trialed WCT differentiation models comprised of novel and previously described parameters derived from WCT and baseline ECG data. In Part 1, a derivation cohort was used to evaluate five different classification models: logistic regression (LR), artificial neural network (ANN), Random Forests [RF], support vector machine (SVM), and ensemble learning (EL). In Part 2, a separate validation cohort was used to prospectively evaluate the performance of two LR models using parameters generated from the WCT ECG alone (Solo Model) and paired WCT and baseline ECGs (Paired Model).ResultsOf the 421 patients of the derivation cohort (Part 1), a favorable area under the receiver operating characteristic curve (AUC) by all modeling subtypes: LR (0.96), ANN (0.96), RF (0.96), SVM (0.96), and EL (0.97). Of the 235 patients of the validation cohort (Part 2), the Solo Model and Paired Model achieved a favorable AUC for 103 patients with (Solo Model 0.87; Paired Model 0.95) and 132 patients without (Solo Model 0.84; Paired Model 0.95) a corroborating electrophysiology procedure or intracardiac device recording.ConclusionAccurate WCT differentiation may be accomplished using computerized data of (i) the WCT ECG alone and (ii) paired WCT and baseline ECGs.

AbstractIntroductionA wearable cardioverter defibrillator (WCD) is indicated in appropriate patients to reduce the risk for sudden cardiac death. Challenges for patients wearing a WCD have been frequent false shock alarms primarily due to electrocardiogram noise and wear discomfort. The objective of this study was to test a contemporary WCD designed for reduced false shock alarms and improved comfort.MethodsOne hundred and thirty patients with left ventricular ejection fraction ≤40% and an active implantable cardioverter defibrillator (ICD) were fitted with the ASSURE WCD (Kestra Medical Technologies) and followed for 30 days. WCD detection was enabled and shock alarm markers recorded, but shocks and shock alarms were disabled. All WCD episodes and ICD ventricular tachycardia/ventricular fibrillation (VT/VF) episodes were adjudicated. The primary endpoint was the false‐positive shock alarm rate with a performance goal of 1 every 3.4 days (0.29 per patient‐day).ResultsOf 163 WCD episodes, 4 were VT/VF and 159 non‐VT/VF (121 rhythms with noise, 32 uncertain with noise, 6 atrial flutter without noise). Only three false‐positive shock alarm markers were recorded; one false‐positive shock alarm every 1333 patient‐days (0.00075 per patient‐day, 95% confidence interval: 0.00015–0.00361; p < .001). No ICD recorded VT/VF episodes meeting WCD detection criteria (≥170 bpm for ≥20 s) were missed by the WCD during 3501 patient‐days of use. Median wear was 31.0 days (interquartile range [IQR] 2.0) and median daily use 23.0 h (IQR 1.7). Adverse events were mostly mild: skin irritation (19.4%) and musculoskeletal discomfort (8.5%).ConclusionThe ASSURE WCD demonstrated a low false‐positive shock alarm rate, low patient‐reported discomfort, and no serious adverse events.