Effectiveness of Ventricular Intrinsic Preference (VIP™) and Ventricular AutoCapture (VAC) algorithms in pacemaker patients: Results of the validate study.

BACKGROUND Several past clinical studies have demonstrated that frequent and unnecessary right ventricular pacing in patients with sick sinus syndrome and compromised atrio-ventricular conduction (AVC) produces long-term adverse effects. The safety and efficacy of two pacemaker algorithms, Ventricular Intrinsic Preference™ (VIP) and Ventricular AutoCapture (VAC), were evaluated in a multi-center study in pacemaker patients. METHODS We evaluated 80 patients across 10 centers in India. Patients were enrolled within 15 days of dual chamber pacemaker (DDDR) implantation, and within 45 days thereafter were classified to either a compromised AVC (cAVC) arm or an intact AVC (iAVC) arm based on intrinsic paced/sensed (AV/PV) delays. In each arm, patients were then randomized (1:1) into the following groups: VIP OFF and VAC OFF (Control group; CG), or VIP ON and VAC ON (Treatment Group; TG). Subsequently, the AV/PV delays in the CG groups were mandatorily programmed at 180/150 ms, and to up to 350 ms in the TG groups. The percentage of right ventricular pacing (%RVp) evaluated at 12-month post-implantation follow-ups were compared between the two groups in each arm. Additionally, in-clinic time required for collecting device data was compared between patients programmed with the automated AutoCapture algorithm activated (VAC ON) vs. the manually programmed method (VAC OFF). RESULTS Patients randomized to the TG with the VIP algorithm activated exhibited a significantly lower %RVp at 12 months than those in the CG in both the cAVC arm (39±41% vs. 97±3%; p=0.0004) and the iAVC arm (15±25% vs. 68±39%; p=0.0067). In-clinic time required to collect device data was less in patients with the VAC algorithm activated. No device-related adverse events were reported during the year-long study period. CONCLUSIONS In our study cohort, the use of the VIP algorithm significantly reduced the %RVp, while the VAC algorithm reduced in-clinic time needed to collect device data.