Impedance-based remote monitoring in patients with heart failure and concomitant chronic kidney disease

Remote monitoring (RM) of thoracic impedance represents an early marker of pulmonary congestion in heart failure (HF). Chronic kidney disease (CKD) may promote fluid overload in HF patients. We investigated whether concomitant CKD affected the efficacy of impedance-based RM in the OptiLink HF trial.

Among HF patients included in the OptiLink HF trial, time to the first cardiovascular hospitalization and all-cause death according to the presence of concomitant CKD was analysed. CKD was defined as GFR < 60 mL/min/1.73 m² at enrolment. Of the 1002 patients included in OptiLink HF, 326 patients (33%) had HF with concomitant CKD. The presence of CKD increased transmission of telemedical alerts (median of 2 (1-5) vs. 1 (0-3); P = 0.012). Appropriate contacting after alert transmission was equally low in patients with and without CKD (57% vs. 59%, P = 0.593). The risk of the primary endpoint was higher in patients with CKD compared with patients without CKD (hazard ratio (HR), 1.62 [95% confidence interval (CI), 1.16-2.28]; P = 0.005). Impedance-based RM independently reduced primary events in HF patients with preserved renal function, but not in those with CKD (HR 0.68 [95% CI, 0.52-0.89]; P = 0.006).

The presence of CKD in HF patients led to a higher number of telemedical alert transmissions and increased the risk of the primary endpoint. Inappropriate handling of alert transmission was commonly observed in patients with chronic HF and CKD. Guidance of HF management by impedance-based RM significantly decreased primary event rates in patients without CKD, but not in patients with CKD.