QI-452785-3 CARDIAC MONITORING PATHWAYS AND RATES OF THERAPEUTIC INTERVENTION IN AN UNEXPLAINED SYNCOPE POPULATION

Abstract

Guidelines recommend insertable cardiac monitoring (ICM) early in the evaluation of unexplained syncope. This increases the rate of establishing a formal diagnosis and instituting directed treatment compared to conventional care. Little is known about short-term cardiac monitoring usage prior to ICM in this population and how monitoring pathways may impact patient outcomes. To characterize the short-term external cardiac monitor (ECM) usage prior to ICM in a U.S. Medicare fee-for-service (FFS) unexplained syncope population and test the relationship between ECM use and time to ICM insertion and related therapeutic interventions. We used 2010-2020 U.S. de-identified Medicare 5% FFS claims to identify patients with a first syncope event with an emergency department (ED) or inpatient hospitalization who received ICM during or after the event. Patients with diagnoses for specific syncopal diagnoses were excluded (e.g., anemia, diabetes, drug intoxication, orthostatic hypotension), as were patients with a history of cardiovascular implantable electronic devices (CIEDs), dementia, severe brain injury, severe mental illness, metastatic cancer, or cerebral palsy. ECMs used prior to ICM were identified. ECM costs were estimated using U.S. national average Medicare payments. Time from syncope to ICM insertion and to arrhythmia treatment (CIED implant, ablation, or medication initiation) were characterized. Of 1,323 patients with a first acute syncope monitored by ICM, 56.7% were female and mean age was 75.1±9.1 years. Before ICM insertion, 20.6% of patients received 1 prior ECM, with an average 17 days of monitoring, while 23.3% received ≥2 prior ECMs with 43 days of monitoring. In patients with ECMs prior to ICM placement, the estimated ECM cost averaged $792 per patient. ICM insertion was delayed in patients with prior ECMs: from a median of 18 days post-syncope in patients with no prior ECM, to 310 days post-syncope in those with ≥2 prior ECMs (Figure), p<0.0001. Median time to arrhythmia treatment also increased, from 148 to 588 days post-syncope (p<0.0001). In unexplained syncope patients who ultimately received an ICM, prior ECM was associated with significant delays to ICM insertion, definitive diagnosis and arrhythmia treatment, indicating potential patient loss to follow-up. Future work could focus on optimizing syncope evaluation pathways to ensure timely access to monitoring.