Short-Term Heart Rate Variability as a Biomarker for SUDEP: Orrin Devinsky, MD

WATCH TIME: 4 minutes

"If only we could have a biomarker that says, ‘This looks like a well-controlled person who should be at low-risk but might actually be at high-risk based on their heart rate variability or other markers.’ The only biomarker that’s been proposed, has some support, and makes logical sense, is post ictal EEG suppression."

Sudden unexplained death in epilepsy (SUDEP) affects nearly 3000 individuals each year and remains among the most complicated events to tackle in epilepsy care. While there are no FDA-approved medications to treat SUDEP, clinicians have focused on controlling patient’s seizures to try to reduce the risk. In the largest SUDEP biomarker study conducted to date, senior author Orrin Devinsky, MD, and colleagues found an association between short-term heart rate variability and SUDEP.

The study featured 31 SUDEP cases and 56 controls. Investigators found normalized low-frequency power (LFP) to be lower in SUDEP cases (median, 42.5 [interquartile range (IQR), 32.6-52.6]) than epilepsy controls (median, 55.5 [IQR, 40.7-68.9]; P = .015; critical value = 0.025). Additionally, there was a negative correlation between LFP and the latency to SUDEP, where each 1% incremental reduction in normalized LFP conferred a 2.7% (95% CI, 0.95-0.995) decrease in the latency to SUDEP (P = .017; critical value = .025).

Devinsky, director, Comprehensive Epilepsy Center, NYU Langone, feels as though these results carry extreme weight, being that the community has struggled to find a biomarker for SUDEP. He sat down with NeurologyLive to discuss the reasons for conducting this study, the critical clinical implications the results bear, and how they can continue to build upon these findings.

REFERENCE

Sivathamboo S, Friedman D, Laze J, et al. Association of short-term heart rate variability and sudden unexpected death in epilepsy. Neurology. Published online October 14, 2021. Doi:10.1212/WNL.0000000000012946