PO-04-202 RESUSCITATED OUT OF HOSPITAL CARDIAC ARREST AS THE INITIAL PRESENTATION OF HYPERTROPHIC CARDIOMYOPATHY

Abstract

Hypertrophic cardiomyopathy (HCM) is the most common heritable cardiomyopathy, and it is associated with ventricular arrhythmias and sudden death. Out-of-hospital cardiac arrest (OHCA) may be the first presentation of HCM in some patients. To determine the frequency of resuscitated OHCA as the initial presentation of HCM, as well as the characteristics, initial management, and outcomes of these patients. Patients with HCM were identified with a comprehensive phenotyping approach, including natural language processing of electronic medical records, cardiac imaging reports, and diagnosis codes. HCM diagnoses were validated by trained reviewers. Among these, we focused on patients who had resuscitated OHCA as the initial presentation leading to the HCM diagnosis. Baseline characteristics, HCM treatments and outcomes were obtained from the electronic medical record. Of 6,276 patients diagnosed with HCM at our institution between 2001-2019, we identified 29 (0.5%) patients with resuscitated OHCA as their initial HCM presentation (17% female; mean age at the time of OHCA 34 ± 17 years). Ventricular tachyarrhythmia was the confirmed cause of OHCA in 24 patients. No patients had a primary acute coronary event as the etiology of OHCA. The median of the thickest wall segment was 30.5 mm and 8 (28%) patients had obstructive HCM. An apical pouch was present in 5 (17%) patients. All patients underwent ICD implantation following OHCA and survived hospital discharge. The mean follow-up post-OHCA was 9 ± 6.6 years. During follow-up, 13 (45%) patients underwent septal reduction therapy. 8 (28%) patients had at least one appropriate ICD shock or antitachycardia pacing event for VT/VF. Two (7%) patients died during follow-up, one from a cardiac non-arrhythmic cause and one from an unknown cause. Resuscitated OHCA is an infrequent initial presentation of HCM. These patients remain at risk for recurrent VT/VF, but overall long-term survival is favorable with secondary prevention ICDs and other HCM-directed therapies.