Quantification of heart failure decompensation through mixed digital methodology

Abstract Background While natriuretic peptides (NPs) quantification and echocardiographic assessments are recommended for diagnosis of heart failure (HF), yet electrocardiographic determinants of cardiac rhythm alterations predisposing to sudden cardiac death (SCD) are lacking. Premature ventricular contractions (PVCs) are common in HF. In some patients, PVCs are triggered by the same mechanism that gives rise to ventricular tachycardia (VT). Appropriate clinical evaluation is important in these patients. Currently, smartwatches are becoming particularly popular to enhance health monitoring. Purpose The aims of this study were: to evaluate the feasibility and reliability of the clinical use of a smartwatch, to detect main features of QRS-complex (width, voltage), and to correlate PVCs with VT originating in different aetiologies of HF. Methods From November ‘22 to February ’23, 53 patients admitted to the Division of Cardiology of our academic hospital underwent standard ECG and smartwatch-based lead I acquisitions. Concordance between the two technologies was assessed by Cohen κ coefficient. Bland-Altman method for analysis of measurement agreement was used for comparison. Results Clinical characteristics of the subjects included in this study are described in the Table. All patients had diagnosis of acute or chronic HF and had PVCs (N= 47) and/or VT (N=3). Sustained and non-sustained VT were more common in patients with HF and reduced ejection fraction. In 7 cases we detected PVCs with the same standard ECG’s morphology and axis during recording ECG with the smartwatch. The Cohen κ coefficients for the measurement of the voltage and width of QRS complex were 0.833 (95% CI, 0.725-0.936) and 0.869 (95% CI, 0.747- 0.956), respectively; voltage and width of PVCs were 0.860 (95% CI, 0.579-1.00) and 0.822 (95% CI, 0.429-1.00), respectively. Concordance was found between the smartwatch ECG and standard ECG for QRS width (bias, −0.05; SD, 0.395; lower limit, −0.821; and upper limit, 0.727), for QRS voltage (bias, −0.004; SD, 0.034; lower limit, −0.073; and upper limit, 0.062), for PVC width (bias, −0.7; SD, 2.167; lower limit, −4.372; and upper limit, 4.12), PVC voltage (bias, −0.02; SD, 0.07; lower limit, -0.112; and upper limit, 0.162) using the Bland-Altman analysis. Conclusions Smartwatch can accurately measure QRS width and voltage and reproducibly detect PVCs compared with standard ECG. Valid correlation indices and good concordance between the two methods were observed using digitally-assessed lead I. These data could be of great interest due to the widespread diffusion of wearable devices; the smartwatch could be helpful especially when frequent monitoring of VT becomes necessary. Currently available smartwatches display, in this regard, an implementation for PVCs detection.