Incidence of Rapid Rate Non‐Sustained and Sustained Ventricular Tachycardia in Implantable Cardioverter‐Defibrillator Recipients and Its Correlation With Heart Failure Guideline‐Directed Medical Therapy Compliance

Background Ventricular arrhythmias are prevalent among heart failure with reduced ejection fraction (HFrEF) patients. Rapid rate non‐sustained ventricular tachycardia (RR‐NSVT) and sustained ventricular tachycardia (VT) can be detected on implantable cardioverter‐defibrillator (ICD) interrogation due to discrimination algorithms that differentiate supra‐ventricular from ventricular tachycardia. This study aims to assess the incidence of RR‐NSVT and sustained VT on ICD interrogation and their correlation with HFrEF guideline‐directed medical therapy (GDMT) compliance. Methods Design Cross‐sectional, analytical study. Setting Heart rhythm device clinic, Electrophysiology department, National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan. Participants Patients implanted with dual chamber ICD or cardiac resynchronization therapy defibrillator (CRT‐D), aged 18 years or above with HFrEF. Outcome Measure Covariates included demographics, comorbidities, medications, GDMT compliance, and cardiac rhythm device parameters. Incidence of RR‐NSVT, sustained VT, and their correlation with HFrEF GDMT compliance was assessed using multivariate logistic regression. Results Study evaluated 139 patients. Men 77.7%. The mean age was 56.4 ± 13.9 years. The mean LV ejection fraction was 26.4% ± 5.5%. 109 (78.4%) were GDMT compliant (94.3% on beta‐blockers, 93.5% on renin‐angiotensin inhibitors, 71.9% on aldosterone antagonists, and 15.8% on SGLT‐2 inhibitors). RR‐NSVT episodes were observed in 54 (38.8%) patients, out of whom 37 had RR‐NSVT despite GDMT compliance, although this correlation was not statistically significant. Twelve (8.6%) patients had sustained VT, which was significantly less common with GDMT compliance. Conclusion More than one‐third of participants had RR‐NSVT episodes despite HFrEF GDMT compliance. These patients also had associated sustained VT episodes, the occurrence of which was significantly less with GDMT compliance.