Could Zapping the Spine Help Prevent Afib in High-Risk CABG Patients?

Temporary spinal stimulation after coronary artery bypass graft (CABG) surgery for patients with a history of paroxysmal atrial fibrillation (Afib, AF) reduced postoperative arrhythmia incidence in a pilot randomized trial.

Spinal stimulation reduced the 30-day occurrence of any Afib or any atrial tachyarrhythmia lasting at least 30 seconds by a relative 89%, to just 3.8% versus 30.2% among usual care patients (P=0.04 for Cox regression, P=0.012 in the log-rank test).

In addition, Afib burden on ECG patch monitoring was lower (0.006% vs 0.2% of the time monitored, P=0.009), reported Alexander Romanov, MD, of the Meshalkin National Medical Research Center in Novosibirsk, Russia, at the hybrid Heart Rhythm Society meeting, held online and in Boston.

The primary safety endpoint was similar between groups (30-day composite rate of death, cerebrovascular accident, MI, or kidney or spinal cord injury), with the only incidents being one case of bleeding requiring transfusion or reoperation and one case of prolonged ventilation.

“This novel approach could represent a new paradigm for AF prevention and requires further investigations,” Romanov concluded.

These were “very impressive” findings for what has been an intractable problem despite decades of study, noted discussant Mina Chung, MD, of the Cleveland Clinic, at the late-breaking clinical trial session. “To my knowledge, this beats about any other therapies tried out there for postoperative AF.”

However, the Afib burden in both groups was “impressively small,” at a level that would typically be considered a success in the post-Afib ablation setting, said discussant Paul Friedman, MD, of the Mayo Clinic in Rochester, Minnesota.

“There are questions that remain to be answered as to whether the complexity of spinal cord stimulation warrants that treatment,” he said, pointing to the potential for other nervous system stimulation sites.

“We’ve seen work that’s used less invasive approaches, including tragus stimulation, and other strategies that may be safer,” Friedman noted.

Chung cautioned that the findings might not be generalizable to patients without Afib.

The trial included 52 patients who had three or more Afib episodes of up to 7 days each in the 6 months before enrollment. They were randomized to on-pump CABG alone or with spinal cord stimulation for 3 days before the procedure and 7 days afterward.

The procedure involved inserting leads in the posterior epidural space at the C7-T4 level of the spine, with the patient able to adjust the depth of stimulation to be comfortable while still achieving noticeable chest paresthesias.

Other than spinal stimulation time, the groups were similar in surgical, demographic, and hospital stay characteristics. Both groups took beta-blockers for at least 30 days after surgery.

Continuous external ECG recordings continued after the hospitalization with the Spyder ECG monitoring patch to 30 days post-op.

Limitations included the small sample size and lack of preoperative monitoring of Afib burden, so a baseline imbalance could not be ruled out.

The critical thing is to determine whether these benefits are transient or could hold long-term benefit for clinical outcomes, said Christine Albert, MD, MPH, of Cedars-Sinai Medical Center in Los Angeles and immediate past president of HRS, at a press conference.

The researchers plan to follow up on trial participants out to 3 and possibly 5 years, Romanov said.