Splanchnic Nerve Modulation Effects on Surrogate Measures of Venous Capacitance.

Background Splanchnic nerve modulation (SNM) is an emerging procedure to reduce cardiac filling pressures in heart failure. Although the main contributor to reduction in cardiac preload is thought to be increased venous capacitance in the splanchnic circulation, supporting evidence is limited. We examined changes in venous capacitance surrogates pre- and post-SNM. Methods and Results This is a prespecified analysis of a prospective, open-label, single-arm interventional study evaluating the effects of percutaneous SNM with ropivacaine in chronic heart failure with elevated filling pressures at rest and with exercise. Patients underwent cardiopulmonary exercise testing with invasive hemodynamic assessment pre- and post-SNM. Blood pressure changes with modified Valsalva maneuver and hemoconcentration, pre- and post-SNM were compared using a repeated measures model. Inferior vena cava diameter and collapsibility (>50% decrease in size with inspiration), and presence of bendopnea pre- and post-SNM were also compared. Fifteen patients undergoing SNM (age 58 years, 47% women, 93% with left ventricular ejection fraction ≤35%) were included. After SNM, changes in systolic blood pressure during Valsalva (peak-to-trough) were greater (41 versus 48 mm Hg, P=0.025). Exercise-induced hemoconcentration was unchanged (0.63 versus 0.43 g/dL, P=0.115). Inferior vena cava diameter was reduced (1.59 versus 1.30 cm, P=0.034) with higher collapsibility (33% versus 73%, P=0.014). Bendopnea was less (47% versus 13%, P=0.025). Conclusions SNM resulted in increased venous capacitance, associated decreased cardiac preload, and decreased bendopnea. Minimally invasive measures of venous capacitance could serve as markers of successful SNM. Long-term effects of SNM on venous capacitance warrant further investigation for heart failure management. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03453151.

Splanchnic Nerve Block for Chronic Heart Failure.

OBJECTIVES: We hypothesized that splanchnic nerve blockade (SNB) would attenuate increased exercise-induced cardiac filling pressures in patients with chronic HF. BACKGROUND: Chronic heart failure (HF) is characterized by limited exercise capacity driven in part by an excessive elevation of cardiac filling pressures. METHODS: This is a prospective, open-label, single-arm interventional study in chronic HF patients. Eligible patients had a wedge pressure ≥15 mm Hg at rest or ≥25 mm Hg with exercise on baseline right heart catheterization. Patients underwent cardiopulmonary exercise testing with invasive hemodynamic assessment, followed by percutaneous SNB with ropivacaine. RESULTS: Nineteen patients were enrolled, 15 of whom underwent SNB. The average age was 58 ± 13 years, 7 (47%) patients were women and 6 (40%) were black. Left ventricular ejection fraction was ≤35% in 14 (93%) patients. No procedural complications were encountered. SNB reduced mean pulmonary arterial pressure at peak exercise from 54.1 ± 14.4 (pre-SNB) to 45.8 ± 17.7 mm Hg (p < 0.001) (post-SNB). Similarly, SNB reduced exercise-induced wedge pressure from 34.8 ± 10.0 (pre-SNB) to 25.1 ± 10.7 mm Hg (p < 0.001) (post-SNB). The cardiac index changed with peak exercise from 3.4 ± 1.2 (pre-SNB) to 3.8 ± 1.1 l/min/m2 (p = 0.011) (post-SNB). After SNB, patients exercised for approximately the same duration at a greater workload (33 ± 24 W vs. 50 ± 30 W; p = 0.019) and peak oxygen consumption VO2 (9.1 ± 2.5 vs. 9.8 ± 2.7 ml/kg/min; p = 0.053). CONCLUSIONS: SNB reduced resting and exercise-induced pulmonary arterial and wedge pressure with favorable effects on cardiac output and exercise capacity. Continued efforts to investigate short- and long-term effects of SNB in chronic HF are warranted. Clinical Trials Registration (Abdominal Nerve Blockade in Chronic Heart Failure; NCT03453151).