Estimation of OptiVol Alert for Identifying Heart Failure in Conventional Bradyarrhythmia Pacing Patients with Preserved Left Ventricular Function: A Multicenter Prospective Cohort Study (OptiVol Study).

BACKGROUND: The usefulness of OptiVol, an algorithm to detect heart failure (HF) using continuous intrathoracic impedance monitoring, is established in high-power device patients with reduced left ventricular ejection fraction (LVEF). However, the utility of OptiVol in conventional bradyarrhythmia pacing patients with preserved LVEF is not established.
OBJECTIVES: This study aimed to describe the utility of the OptiVol alert feature in monitoring HF in conventional pacemaker or implantable-cardioverter defibrillator (ICD) patients with preserved LVEF.
METHODS: Forty-three patients implanted with a conventional pacemaker or ICD with the OptiVol function were enrolled. Of these, 39 completed the observation period. OptiVol fluid index and cumulative percentage of right ventricular pacing (%RVp) were obtained every three months for 12 months after device implantation. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) to predict HF hospitalization of the OptiVol alert defined by an OptiVol fluid index >100Ω-day or >60Ω-day were compared. The combination of OptiVol positivity and right ventricular pacing site and/or %RVp >40% for the prediction of HF hospitalization were also assessed.
RESULTS: Three patients (7.6%) had HF hospitalization within one year after device implantation. The sensitivity, specificity, PPV and NPV of OptiVol alert definition with OptiVol fluid index >100Ω-day were 100%, 64%, 19%, and 100%, while those of OptiVol alert definition with OptiVol fluid index >60Ω-day were 100%, 42%, 13% and 100%, respectively. These parameters were improved by the combination of OptiVol fluid index >100Ω-day and RV apex pacing and/or %RVp >40%, attaining values of 100%, 97%, 75%, and 100%, respectively; by the combination of OptiVol alert and RV apex pacing; or their combination.
CONCLUSION: The OptiVol alert using cut-off value of 100Ω-day would be useful for the prediction of HF hospitalization in conventional bradyarrhythmia pacing patients with preserved LVEF. The utility of OptiVol alert would be emphasized in patients with RV apex pacing and/or %RVp >40%.