A small group of patients with heart failure (HF) who underwent a novel transcatheter nerve-ablation procedure seemed to benefit with improved hemodynamics, symptoms, and quality of life in an admittedly limited observational series.
All had HF with preserved ejection fraction (HFpEF) and remained on guideline-directed medical therapy during the study.
The open-label experience has launched a randomized trial, featuring a sham control group, that could ultimately challenge dogma about volume overload in patients with chronic and acute HF and the perceived essential role of diuretics.
Researchers see transvenous ablation of the right greater splanchnic nerve (GSN) as potentially appropriate for patients with HF, regardless of ventricular function or acuity. But the ongoing REBALANCE-HF trial aims to enroll up to 80 patients with chronic HFpEF.
Meanwhile, the current 18 patients with elevated resting or exertional pulmonary capillary wedge pressure (PCWP), given the procedure as part of the main trial’s “roll-in” phase, showed declines in exercise PCWP after 1 month (P = .007) and improved quality-of-life scores at both 1 and 3 months (P < .01). Also at 1 month, a third of the patients improved by at least one step in NYHA functional class.
The procedure, called splanchnic ablation for volume management (SAVM), could potentially be used “across the spectrum of acute and chronic heart failure, maybe even with reduced ejection fraction (HFrEF) and preserved ejection fraction,” Marat Fudim, MD, MHS, Duke University Medical Center, Durham, N.C., told this news organization.
However, “for outcomes, we’ve really only looked in the ambulatory setting,” and only at symptomatic and functional responses. To that extent, based on the current experience and a few small previous studies, Dr. Fudim said, SAVM seems to benefit patients with HF in general who have dyspnea at exercise. Beyond that, the kind of patient who may be most suitable for it “is something I hope we will be able answer once the randomized dataset is in.”
Dr. Fudim reported the REBALANCE-HF roll-in results at the Heart Failure Association of the European Society of Cardiology (HFA-ESC) 2022 sessions, held virtually and live in Madrid. He is also lead author on the same-day publication in the European Journal of Heart Failure.
A different treatment paradigm
Splanchnic-nerve blockade as a possible HF treatment is based on growing evidence that volume overload in patients with HF is not always the cause, at least not a main cause, of congestion and dyspnea. Rather, those classic HF signs and symptoms may often be triggered by adverse redistribution of stable fluid volume from primarily the splanchnic vascular compartment to the intrathoracic space.
In other words, what might seem like classic volume overload calling for diuresis often might actually be euvolemic redistribution of fluid from the abdomen to the chest, raising intracardiac pressures and causing dyspnea.
In that scenario, loop diuretics might only dehydrate the patient and potentially put the kidneys at risk, Dr. Fudim proposed. His recent experience with HF patients implanted with a pulmonary-artery pressure monitor, he said, suggests many who received standard volume-overload therapy had actually been normo- or hypovolemic.
More then half the patients “did not have high volume, they just had high pressures,” he said. “So there is a significant portion of the population that has pathological processes leading to high pressures, but it’s not volume overload. Diuresing those patients would probably not be the right decision.”
The unilateral SAVM procedure appears to attenuate sympathetically mediated splanchnic volume redistribution to the heart and lungs, but as it doesn’t affect the left GSN, preserves some normal sympathetic response.
Sometimes in studies of surgical or catheter-based SAVM, Dr. Fudim said, “we have observationally seen that people discontinued diuretics or decreased doses in the treatment arm.”