Abstract Body (Do not enter title and authors here): Background: Implantable cardioverter-defibrillators (ICDs) are a proven therapy for reducing mortality in patients at risk for ventricular arrhythmias that can lead to sudden cardiac death. Despite their documented benefit, previous data have shown that ICD-indicated women are implanted at a significantly lower rate than indicated men. A major contributing factor is a perception that females benefit less from device therapy than males, owing to underrepresentation of females in major ICD trials and an overall lack of gender-specific ICD efficacy data.
Research Question: Using a large database of over 200,000 contemporary ICD recipients, we assessed the rate of appropriate therapy stratified by gender.
Methods: Data were obtained from a query of the deidentified Medtronic CareLink database. Individuals implanted with their first Medtronic ICD from JAN 2013 to SEP 2023 were included. The main objective was rate of first appropriate ICD therapy [antitachycardia pacing (ATP) or shock], ATP therapy only, or shock therapy only through 10 years. A random subset of 595 treated episodes were adjudicated for therapy appropriateness. Results from adjudication were used to model appropriateness of the nearly 1 million additional treated episodes detected from patients in the cohort. From these results, time to first appropriate therapy was determined at the patient level and cumulative incidence of ICD therapy was determined using time to event methods.
Results: Of 237,627 ICD patients included in the query, 67,080 (28.2%) were female and 170,547 were male (71.8%). Female patients on average were slightly younger (61.8 ± 14.8 vs. 63.9 ± 13.5) with a similar proportion having a secondary prevention indication in both groups (Female:19.9%; Male: 20.4%). Through 10 years, the rate of first appropriate therapy (ATP or shock) was 40% in females versus 51% in males (P<0.0001). Broken down by type of therapy, the 10-year rate of first appropriate shock was 28% and 35% and the rate of first appropriate ATP was 33% and 45% for females and males, respectively (Figure).
Conclusions: While female patients received less ICD therapy than males, 40% of females received appropriate ICD therapy through 10 years with a narrower gap than might have been expected previously, especially for shock therapy. Thus, female ICD recipients remain at high risk for receiving potentially life-saving device therapy, shining a light on the concerning underutilization of ICDs in women.