Carotid body resection for sympathetic modulation in systolic heart failure: results from first‐in‐man study

Abstract

(2017). Carotid body resection for sympathetic modulation in systolic heart failure -results from first-in-man study. ABSTRACT AimsAugmented reflex responses from peripheral chemoreceptors, which are mainly localized in the carotid bodies (CB), characterize patients with systolic heart failure (HF) and contribute to adrenergic hyperactivation. We investigated whether surgical resection of CB in these patients can be performed safely to decrease sympathetic tone. Methods and resultsWe studied 10 male patients with systolic HF (age: 59±3 years, left ventricular ejection fraction: 27±7%) who underwent unilateral right-sided CB resection (4 patients) or bilateral CB resection (6 patients).Primary endpoints of the study were changes in muscle sympathetic nerve activity (MSNA) and peripheral chemosensitivity measured as ventilatory response to hypoxia from baseline to 1 month post-CB resection. Safety analysis included analysis of arterial blood gas and oxygenation at night through 2 months post-procedure and adverse events assessed up to 12-months.At 1-month visit, CB resection was associated with a significant decrease in both MSNA (86.6±3.1 vs.79.7±4.2 bursts/100 beats, p=0.03) and in peripheral chemosensitivity (1.35±0.19 vs. 0.41±0.17 L/min/SpO2, p=0.005). It also resulted in improved exercise tolerance. Amongst some patients with bilateral CB resection there was a trend towards worsening of oxygen saturation at night, which in one case required therapy with non-invasive ventilation. ConclusionWe present first-in-man evidence that CB resection in patients with systolic HF is associated with decrease in sympathetic activity. Bilateral procedure may carry a risk of worsening oxygenation at night.CB modulation constitutes an interesting research avenue, but careful consideration of the balance between safety and efficacy is necessary before further clinical trials.

Variable role of carotid bodies in cardiovascular responses to exercise, hypoxia and hypercapnia in spontaneously hypertensive rats

“…; Ward, ) and improved exercise tolerance after CBR in humans (Niewinski et al . ), we were surprised to find no difference in the cardiovascular response after CBR. Although the cardiovascular responses were not reported, Lugliani et al .…”

“…This is borne out by the recent observation of worsening blood oxygen saturations at night in heart failure patients after bilateral CBR (Niewinski et al . ). This supports our contention that carotid body therapy should modulate, not abolish, its function (Pijacka et al .…”

“…) and other cardiovascular diseases such as heart failure (Schultz & Marcus, ; Niewinski et al . , ; Andrade et al . ), where the peripheral chemoreceptors exhibit increases in both sensitivity and tonicity (Abdala et al .…”

Translating carotid body function into clinical medicine

“…; Niewinski et al . ). Accordingly, a clinical trial is on course to assess the feasibility of unilateral endovascular CB ablation in a large cohort of patients with refractory hypertension (http://clinicaltrials.gov:NCT02519868).…”

“…Niewinsky et al . () reported the effects CB resection on sympathetic hyperactivity in human systolic HF. This first‐in‐man study was performed in 10 male patients with systolic HF with a left ventricle ejection of 27 ± 7%.…”