Identification of whole body impedance cardiography-derived hemodynamic parameters associated with outcomes in heart failure patients with reduced ejection fraction
Heart failure (HF) affects over 600,000 Canadians and causes over 45,000 hospitalizations annually. Patients with new-onset HF are referred to an outpatient HF clinic where they are categorized into risk groups based heavily on subjective symptoms and occurrence of poor outcomes, which impacts management and follow-up. Regardless, mortality remains high in chronic HF, with approximately 32% and 64% of patients succumbing to their illness by 1 year and 5 years, respectively. Thus, earlier identification of high-risk HF patients is warranted to prevent poor outcomes, including death. Non-Invasive Cardiac System (NICaS) is a validated technology, which uses whole body impedance cardiography to measure hemodynamic parameters. In this study, we evaluated whether hemodynamic parameters measured at rest and post-exercise by NICaS could be used to predict outcomes in patients HF with reduced ejection fraction (HFrEF). A cohort of 65 HFrEF patients was recruited and NICaS-derived parameters were taken at rest and after up to 12 minutes of exercise on a mounted ergometer. At 6-month follow-up, subjects who experienced poor outcomes, including HF hospitalizations and death, demonstrated lower resting cardiac power index (CPI) when supine and lower resting stroke index (SI) when seated. In addition, patients with poor outcomes demonstrated increased augmentation of Granov-Goor Index (GGI), a surrogate marker of ejection systolic time. Thus, resting and/or exercise-augmented NICaS-derived hemodynamic measurements demonstrate potential to identify high-risk HF patients in the HF clinic. Early identification of high-risk patients may enable early intervention and optimal follow-up to prevent unplanned hospitalization and mortality.
Heart failure, whole body impedance cardiography