Preemptive left stellate ganglion block (SGB) was associated with a reduced incidence of postoperative atrial fibrillation (POAF) within five postoperative days in patients undergoing CABG with cardiopulmonary bypass, according to results from a prospective controlled trial published Sept. 29 in JACC: Clinical Electrophysiology.

In the single-center study conducted in China, Shunping Tian, MD, et al., randomized 124 patients to the preemptive SGB group or the control group from June 2023 to June 2024. Their mean age was 65 years and 35% were women. Patients had an American Society of Anesthesiologists physical status of II to IV and were scheduled to undergo CABG with cardiopulmonary bypass via a midline thoracic incision.

The primary endpoint was the incidence of POAF within five days postoperatively; secondary endpoints included POAF-associated characteristics and recovery indicators.

Results showed that, in the modified intention-to-treat analysis with 108 patients, POAF occurred in 19% of the SGB group and 44% of the control group (odds ratio [OR], 0.288; p=0.007). The results were consistent in the per-protocol analysis with 98 patients.

Other findings in the SGB group, compared with the control group, included a significantly lower POAF burden, a shorter duration of the first POAF episode, fewer POAF episodes and antiarrhythmic treatments, and decreased levels of C-reactive protein, interleukin-6, high-sensitivity cardiac troponin T and creatine kinase-MB at certain postoperative time points (all p<0.05). The postoperative hospital stay was also significantly shorter.

Additionally, exploratory subgroup analyses suggested that the association between SGB and a lower incidence of POAF was more pronounced in patients without diabetes (OR, 0.10; p=0.004) and those with a lower risk of POAF at baseline (OR, 0.10; p=0.040).

The authors write that preemptive left SGB is an "effective intervention" to reduce POAF incidence in these cases, but "whether preemptive left SGB can reduce POAF in patients undergoing the entire spectrum of cardiac operations requires testing in a large sample and multicenter study."

"Whether SGB itself ultimately becomes part of routine perioperative care remains uncertain and will require confirmation in adequately powered multicenter trials with longer follow-up," write Sunny S. Po, MD, and Praloy Chakraborty, MD, DM, FACC, in an accompanying editorial. "The future of POAF prevention may therefore depend less on suppressing atrial fibrillation after it occurs and more on precisely modulating the neural circuits that make it possible."