Prognostic value of noninvasive programmed stimulation in patients with implantable cardioverter defibrillator

BACKGROUND: Implantable cardioverter defibrillator (ICD) offers an opportunity to examine vulnerability to ventricular tachycardia (VT) or ventricular fibrillation (VF) by performing noninvasive programmed ventricular stimulation (NIPS). Whether NIPS can predict VT/VF recurrences has not yet been established. PURPOSE: To examine the predictive value of NIPS for identification of patients with VT/VF recurrences. METHODS: The study group consisted of consecutive 105 ICD recipients included in the prospective NIPS-ICD study (ClinicalTrials ID: NCT02373306) (88 males, age 65 ± 11 years). The patients underwent NIPS using the protocol up to three premature extrastimuli at 600-500- and 400-ms drive cycle lengths. The endpoint of NIPS was induction of sustained VT or VF or completion of the protocol. RESULTS: VT/VF was induced in 29 (27.6%) patients. During a 12-month follow-up NIPS-inducible patients had significantly more frequently appropriate ICD therapy than noninducible patients (17% vs 4%, P = 0.023). NIPS-induced VT/VF had a sensitivity of 63%, specificity of 75%, positive predictive value of 17%, and negative predictive value of 96% for identification of patients with future VT/VF. Apart from NIPS, age ≥ 65 years, QRS duration, treatment with angiotensin-converting enzyme, history of coronary artery bypass grafting, history of VT/VF prior to NIPS, and prior appropriate ICD therapy were also associated with VT/VF recurrences. Multivariate analysis showed that, together with QRS duration, NIPS result was an independent predictor of future VT/VF. Predictive value of NIPS was significantly higher in ischemic than nonischemic patients. CONCLUSIONS: NIPS result is associated with future VT/VF. Noninducibility at NIPS identifies those patients with high accuracy who will have uneventful follow-up.