Cardiac arrhythmias with or without apnea among patients with epilepsy are associated with increased mortality risk. This risk may play an important role in cases of sudden unexpected death in epilepsy (SUDEP), according to study results presents at the American Epilepsy Society 2019 Annual Meeting, held in Baltimore, Maryland from December 6 to 10.
Previous studies have reported that cardiac arrhythmias and apnea may play a significant part in cases of SUDEP, the second most common cause potential life-years lost in patients with epilepsy. The incidence rate of SUDEP is 1.16 cases per 1000 patients, but may be higher in those with intractable epilepsy.
The goal of the current study was to explore the prevalence of apnea and/or arrhythmias among patients with epilepsy, and to investigate their association with mortality.
The retrospective, cross-sectional study included data on pediatric and adult epilepsy hospitalizations collected from the Nationwide Inpatient Sample (NIS) between 2003 and 2014.
Of more than 2.6 million epilepsy hospitalizations, apnea was evident in 73,908 (2.75%) cases, arrhythmias were documented in 239,179 cases (8.91%), and both apnea and arrhythmias were reported in 13,222 cases (0.49%).
Intractable epilepsy was diagnosed in 207,264 patients, and in this subgroup, apnea was evident in 7501 (3.62%) cases, arrhythmias were documented in 6924 cases (3.34%), and both apnea and arrhythmias were reported in 755 cases (0.36%).
During the follow-up from 2003 to 2014 there was an incremental prevalence trend of apnea (1.38% to 3.87%), arrhythmias (7.40% to 10.43%) and both together (0.15% to 0.83%) in the entire group of patients with epilepsy. A similar trend was evident in those with intractable epilepsy (apnea: 1.92% to 4.72%; arrhythmias: 2.03% to 4.72%; apnea + arrhythmias: 0.14% to 0.54%). (P-trend <.001).
The prevalence of mortality was highest among patients with arrhythmias (3.10%) or both arrhythmias and apnea (2.91%), compared to patients with apnea (0.48%), or with no evidence for apnea or arrhythmias (0.46%). Statistical analysis indicated a significant association between mortality and intractable epilepsy, apnea, arrhythmias, and both arrhythmias and apnea. The mortality risk associated with apnea, arrhythmias, and both together was greater among patients with intractable epilepsy (apnea: odds ration [OR], 0.79 vs OR, 2.07, respectively; arrhythmias: OR, 3.21 vs OR, 8.39, respectively; apnea+ arrhythmias: OR, 3.01 vs OR, 11.64, respectively).
“The data shows the increase in mortality in [patients with epilepsy] with arrhythmias and those with a combination of arrhythmias and apnea. This study indicates that attention to these variables would be important in identifying patients at risk for SUDEP,” conclude the researchers.
Patel UK, Sankaraneni RR, Singh SP. Apnea and arrhythmia prevalence and associated mortality amongst epilepsy hospitalizations. Presented at: The American Epilepsy Society 2019 Annual Meeting. Abstract 2.14; December 6-10, 2019; Baltimore, MD.