Volume status assessment in left ventricular assist device (LVAD) patients remains challenging. Cardiac resynchronization therapy (CRT) devices are common in LVAD patients, and the impedance across the CRT leads may be associated with hemodynamics and serve as a tool for noninvasive estimation of volume status. Ninety-one sets of measurements including cardiac filling pressures and lead impedances were prospectively obtained during ramp tests from 11 LVAD patients (65.5 ± 9.7 years old; nine male) with CRT devices. Right atrial (RA), right ventricular (RV), and left ventricular (LV) lead impedances were all significantly associated with central venous pressure (CVP) (p < 0.05). We derived the following equation: estimated CVP = 47.90-(0.086 × RA lead impedance) + (0.013 × RV lead impedance)-(0.020 × LV lead impedance). The estimated CVP had a significant correlation (r = 0.795) and good agreement with the measured CVP (mean difference -0.14 ± 1.77 mmHg). Applying the above equation on the validation cohort of twenty-one patients also maintained a strong association with measured CVP (r = 0.705). In conclusion, we have derived a novel equation to estimate CVP using lead impedance measurements. This finding may allow noninvasive monitoring of volume status in LVAD patients.

Aims

In heart failure (HF) with preserved ejection fraction (HFpEF), excessive redistribution of blood volume into the central circulation leads to elevations of intracardiac pressures with exercise limitations. Splanchnic ablation for volume management (SAVM) has been proposed as a therapeutic intervention. Here we present preliminary safety and efficacy data from the initial roll-in cohort of the REBALANCE-HF trial.

Methods and results

The open-label (roll-in) arm of REBALANCE-HF will enrol up to 30 patients, followed by the randomized, sham-controlled portion of the trial (up to 80 additional patients). Patients with HF, left ventricular ejection fraction (LVEF) ≥50%, and invasive peak exercise pulmonary capillary wedge pressure (PCWP) ≥25 mmHg underwent SAVM. Baseline and follow-up assessments included resting and exercise PCWP, New York Heart Association (NYHA) class, Kansas City Cardiomyopathy Questionnaire (KCCQ), 6-min walk test, and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Efficacy and safety were assessed at 1 and 3 months. Here we report on the first 18 patients with HFpEF that have been enrolled into the roll-in, open-label arm of the study across nine centres; 14 (78%) female; 16 (89%) in NYHA class III; and median (interquartile range) age 75.2 (68.4-81) years, LVEF 61.0 (56.0-63.2)%, and average (standard deviation) 20 W exercise PCWP 36.4 (±8.6) mmHg. All 18 patients were successfully treated. Three non-serious moderate device/procedure-related adverse events were reported. At 1-month, the mean PCWP at 20 W exercise decreased from 36.4 (±8.6) to 28.9 (±7.8) mmHg (p < 0.01), NYHA class improved by at least one class in 33% of patients (p = 0.02) and KCCQ score improved by 22.1 points (95% confidence interval 9.4-34.2) (p < 0.01).

Conclusion

The preliminary open-label results from the multicentre REBALANCE-HF roll-in cohort support the safety and efficacy of SAVM in HFpEF. The findings require confirmation in the ongoing randomized, sham-controlled portion of the trial.