TDNet Discover

Objective: To assess whether implantable cardiac defibrillators (ICDs) with intrathoracic impedance monitoring reduce hospitalizations in patients with heart failure with reduced ejection fraction (HFrEF), compared to patients receiving no intrathoracic impedance monitoring. Background: HFrEF is a progressive condition marked by high rates of morbidity, mortality, and hospitalizations. ICDs are standard for preventing sudden cardiac death in this population. Newer ICDs include intrathoracic impedance monitoring, which may detect fluid overload early and allow for timely interventions. The clinical benefit of this technology in reducing hospitalizations remains unclear. Methods: A systematic review was conducted using PubMed, Medline, and Cochrane Review databases for studies published between 2014 and 2024. Included studies examined adult patients with New York Heart Association (NYHA) class II, III, or IV HFrEF and compared hospitalization rates in those with ICDs with and without impedance monitoring. Studies were evaluated using the National Heart, Lung, and Blood Institute (NHLBI) quality assessment tool. Relevant data was extracted and analyzed using Microsoft Excel. Results: Of 46 screened articles, three met inclusion criteria: one randomized controlled trial, one prospective, and one retrospective observational study. A total of 421 patients were analyzed (224 with impedance monitoring, 197 without). The Pulmonary Fluid Overload Monitoring in Heart Failure Patients with Single and Dual Chamber Defibrillators (PFOM-HF) and Improving Clinical Outcomes for Patients with Class III Heart Failure (ICO) studies showed significantly fewer hospitalizations in the impedance group (P = 0.02 and P < 0.001). The Lung Impedance Monitoring in Treatment of Chronic Heart Failure (LIMIT-CHF) study showed a non-significant increase in hospitalizations in the impedance group (P = 0.16). Overall, two of the three studies demonstrated a reduction in hospitalizations with impedance monitoring. Conclusion: ICDs with intrathoracic impedance monitoring may reduce hospitalizations in patients with HFrEF. While one study showed conflicting results, the overall trend supports the potential clinical benefit of this feature. Further research is warranted to guide clinical decision making.