Higher cardiac arrest risk seen with subcutaneous implantable cardioverter defibrillators
Despite similar short-term complication risks, patients treated with subcutaneous implantable cardioverter defibrillators had a higher risk of cardiac arrest compared with those who had transvenous implantable devices.
“Some have advocated for the preferential use of subcutaneous [implantable cardioverter defibrillators] ICDs over transvenous ICDs among eligible patients on dialysis to reduce high risk of device-related complications; however, to date, no large-scale studies have been performed to examine prevalent use of subcutaneous [implantable cardioverter defibrillators] among patients on dialysis and associated outcomes,” Patrick H. Pun, MD, and colleagues wrote in an article published in the Clinical Journal of the American Society of Nephrology.
Pun and colleagues used data from the National Cardiovascular Data Registry ICD Registry collected between September 2012 and March 2018 for a retrospective analysis of trends in subcutaneous ICD use and compared outcomes among patients treated with subcutaneous ICDs with patients treated with transvenous ICDs. For the analysis of subcutaneous ICD proportion, researchers included patients with no history of bradycardia or previous ICD who were treated with maintenance hemodialysis or peritoneal dialysis and elected hospital treatment for ICD implantation. They included only patients who were eligible for a subcutaneous ICD in their comparison of outcomes between ICD types. Outcome measures were ICD type, in-hospital adverse events and individual adverse events, such as in-hospital death or length of hospital stay.
Subcutaneous ICD use increased from 5% of all implants from 2012 to 2013 to 20% of all implants in 2018. Of 23,136 total implantations during the study period, 3,195 were subcutaneous ICDs. Among patients who were eligible for a subcutaneous ICD, 1,539 received a subcutaneous ICD and 1,788 received a transvenous ICD. Overall, cardiac event rate was not significantly different between patients who received subcutaneous ICDs (2.39 events per 100 implants) and transvenous ICDs (1.48 events per 100 implants; OR = 1.63; 95% CI, 0.95-2.82), but cardiac arrest occurred more frequently in subcutaneous ICD recipients (1.53 vs. 0.36 events per 100 implants; OR = 4.72; 95% CI, 1.71-11.17). However, researchers wrote, “there were no other significant differences in other adverse events, including the risk of in-hospital death.” Patients’ length of hospital stay was also similar, with a mean difference of 0.34 days (95% CI, –0.04 to –0.70).
“The utilization of subcutaneous ICDs among U.S. patients on dialysis has been steadily increasing,” researchers wrote. “The overall risk of short-term complications is low and comparable with transvenous ICDs, but higher risk of in-hospital cardiac arrest merits closer monitoring and further investigation.”