Temporary spinal cord stimulation to prevent postoperative atrial fibrillation after coronary surgery. First results of the feasibility study

Background

Atrial fibrillation (AF) is the most common arrhythmia after cardiac surgery with typical appearance at early days after operation and leads to increase morbidity and mortality in the short and long term follow up. Spinal cord stimulation (SCS) was proven to be effective in chronic pain and intractable angina pectoris treatment. Recently, animal studies demonstrated that spinal cord stimulation could suppress AF and reduce AF burden.

Aim

To test safety and efficacy of the temporary SCS in early postoperative period in patients undergoing coronary artery bypass grafting

Methods

Fifteen patients (10 men, mean age 61±7.5 years) with indications for coronary artery bypass grafting (CABG) and history of paroxysmal AF underwent percutaneous lead placement for temporary SCS. Under local anesthesia and fluoroscopic guidance, the leads were placed at C7-Th4 level according to patient's sense of paresthesia and connected with spinal cord stimulator externally fixed on patient's chest. Temporary SCS was performed 3 days before CABG and turned off during surgery. At the end of CABG, the SCS was turned on in the intensive care unit and continued for 7 days. After that the temporary leads were removed. The primary safety objective was to test safety of the temporary SCS in early postoperative period, including 30 days occurrence of MACE (Death, stroke or TIA, myocardial infarction), acute spinal cord and kidney injury. The efficacy endpoint included occurrence of AF or any atrial tachyarrhythmias lasting ≥30 seconds during 30 days after surgery. All patients had continuous external ECG monitoring for 30 days after surgery.

Results

In all (100%) patients temporary leads for SCS were implanted successfully and standard on-pump elective CABG was performed thereafter. There were no any adverse events related to temporary SCS in either patient till the end of follow up. There were no significant differences in CK-MB and creatinine levels as compared with baseline data (p=0.2 and 0.3, respectively). No patients developed AF or atrial tachyarrhythmias during follow up according 30-days ECG monitoring.

Conclusions

The first results of the temporary spinal cord stimulation to prevent AF after coronary surgery demonstrated safety and efficacy of this therapy. The parallel group randomizes study is under way (NCT 03539354)

Funding Acknowledgement

Type of funding source: None

4282Pulmonary artery denervation in patients with residual pulmonary hypertension after pulmonary endarterectomy: one-year results of the first -in-man, sham-controlled, pilot randomized clinical trial

Background

Pulmonary endarterectomy (PE) is the method of choice in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Despite the positive effect after surgery combined with medical treatment, 10–40% of patients develop residual CTEPH. Pulmonary artery denervation (PAD) is a novel treatment in PAH with optimistic results but was not tested in patients with residual CTEPH.

Objective

To assess the safety and efficacy of PAD using remote magnetic navigation system in patients with residual CTEPH after PE.

Methods

278 patients with CTEPH after PE were screened. 50 patients (mean age 47.6±14.3, 50% female) with a history of residual CTEPH (a resting pulmonary artery pressure ≥25 mm Hg or pulmonary vascular resistance >400 dyn sec cm–5 despite medical therapy 6 months after PE) were randomized into two groups: PAD (n=25; PAD group) or medical therapy with riociguat (n=25; MED group). In both groups right heart catheterization (RHC)was performed after randomization. In the PAD group, remote magnetic navigation systemwas used to target sympathetic nerve fibers, located near bifurcation and ostia of the main brunches of right and left pulmonary arteries. This study was conducted as double-blind and sham-controlled and the primary endpoint was change in pulmonary vascular resistance (PVR) by RHC at 12 months. Secondary endpoints included 6-minute walk test (6MWT), pulmonary artery pressure, and clinical outcomes. All patients were followed for 12 months after randomization. Unpaired t-test and Fisher's exact test were used for between-group comparisons of continuous and categorical variables, respectively. A p value of less than 0.05 was considered statistically significant.

Results

Two patients (one in each group) developed groin hematoma which resolved without any consequences. At the end of 12 month, the PVR was significantly low in PAD group as compared with MED group (343±149 dyn sec cm–5 vs 444±145 dyn sec cm–5, respectively; mean difference −101, 95% confidence interval: −193 to −10; p=0.032). The mean, systolic and diastolic PA pressure was also reduced significantly in PAD group compared to MED group (25.8±7.3mm Hg vs 33.8±6.4 mm Hg, 46.2±14.1mm Hg vs 54.2±8.1 mm Hg,13.2±5.3mm Hg vs 20.2±4.8mm Hg; p<0.001, p=0.002, p<0.001, respectively). The PAD group demonstrated significant improvement of the 6MWT over MED group (470±84 m vs 399±116 m, respectively, p=0.031). In the PADN group 1 (4%) patient was hospitalized due to heart failure progression compared to 7 (29%) patients in MED group (p=0.049). One patient in PAD group and two patients in MED group died.

Conclusions

Pulmonary artery denervation in patients with residual pulmonary hypertension was safe and effective, and resulted in substantial reduction of pulmonaryvascular resistance and pulmonary artery pressure during 12 months follow up, accompanied by improved 6-minute walk test and reduced need for hospitalization. Clinical Trials Registration: NCT02745106

Acknowledgement/Funding

Grant from Biosense Webster