PO-04-224 PRACTICE VARIATION AFTER AMBULATORY ECG DETECTION OF NON-SUSTAINED VENTRICULAR TACHYCARDIA IN THE NON-CARDIAC PATIENT

Abstract

Non-sustained ventricular tachycardia (NSVT) is frequently identified in patients without known cardiac disease. However, current practice guidelines for NSVT largely draw from expert opinion or studies of heart failure or coronary artery disease. These guidelines may have limited applicability to the non-cardiac patient. With limited guideline support, there is likely to be wide variation in care. We sought to examine practice variation after detection of NSVT on ambulatory ECG monitoring. We performed a retrospective cohort study using data from the Veterans Health Administration, the largest integrated health system in the U.S. We included patients who received a Zio® Patch between 11/18/2011 and 6/23/2020 and excluded those with history of arrhythmias, atherosclerotic disease, or heart failure. We defined NSVT as at least 1 VT episode ≥3 beats but <30s in duration. We determined healthcare utilization and medication prescription within 90 days of the Ziopatch, and examined site-level variation in care. We performed mixed-effects logistic regressions to evaluate the association of patient characteristics and site NSVT volume >/= 75th percentile with diagnostic testing or cardiology care. We analyzed 58279 patients (59±15 years, 16% female, 74% white) without known cardiac disease, of whom 18792 (32.2%) had NSVT. We matched 18263 NSVT patients (97.2%) to 89 unique sites for the site-level analysis. There was substantial site-level variation in the proportion of patients with echocardiograms, coronary angiograms, stress testing, cardiology care, and prescriptions filled within 90 days of Ziopatch (Figure). After adjusting for baseline characteristics and medications, we only found significant associations between Charlson Comorbidity Index and echocardiogram use (odds ratio [OR]: 0.95, 95% confidence interval [CI]:0.91-0.99, p=0.008), age and stress testing (OR 0.92, 95% CI: 0.88-0.95, p<0.0001), and high-volume sites and cardiology care (OR 1.83, 95% CI: 1.16-2.89, p=0.01). In patients without known cardiac disease referred for ambulatory ECG monitoring, NSVT is common. However, there is wide variation in care after detection of NSVT, which was not effectively accounted for by patient factors or site volume. This may reflect a fundamental lack of actionable evidence on management of NSVT in patients without other cardiac disease. Clinical trials and high-quality retrospective studies are needed to fill this crucial evidence gap.