Abstract 351: Optimizing the Frequency of Surveillance Echocardiography in Clinically Stable Patients With Hypertrophic Cardiomyopathy
Authors: Carr Christina W , Conner Lauren M , McCarthy Caitlyn A , Greenberg Jeffrey O , Laskowski Karl R , Parambi Ron J , Graham Dionne A , Szent-Gyorgyi Lara E , Cirino Allison L , Ho Carolyn Y , MacRae Calum A , Seidman Christine E , Ghazinouri Roya , Lakdawala Neal K 
Published: March 2022

Background:
Hypertrophic cardiomyopathy (HCM) affects 0.2% of the population and is an important cause of sudden cardiac death, heart failure and stroke. However, most patients with HCM experience normal longevity. Optimal longitudinal management of stable HCM patients is poorly defined, although consensus guidelines advise annual echocardiography (echo). We report the clinical impact of surveillance echo and a protocol to improve the efficiency of repeat testing in a cohort of HCM patients followed at one center.

Methods and Results:
A Standardized Clinical Assessment and Management Plan (SCAMP) was developed by clinicians, supported by a quality improvement (QI) team, to maximize the utility of cardiac imaging in patients with HCM. SCAMPs are an established approach to QI that aim to optimize outcomes and resource utilization through standardization of care. The HCM SCAMP was designed to achieve these goals through implementation of a practice algorithm, data capture at the time of outpatient encounters, and iterative analysis. This SCAMP recommended decreased frequency of surveillance echo in stable patients, from every 12 to every 24 months. Stability was defined as >3 years since diagnosis, stable symptoms for ≥2 years, >2 unchanged echos, and no family history of end stage HCM. All patients with HCM followed longitudinally in one HCM clinic from 7/17/13 to 12/15/13 (n=127) were enrolled. After excluding patients with a new diagnosis (n=16), no recent echo (n=15), or incomplete SCAMP documentation (n=1), 92 were included in this analysis. At enrollment, baseline echo (mean interval from prior echo: 15.8±5.8 months) identified clinically significant changes in 13 (14%) patients; including new pulmonary hypertension (n=6), and significant change (≥Δ50mmHg) or interval appearance of severe left ventricular outflow tract obstruction (LVOTO) (n=6). Clinical management was impacted by echo findings in 8/92 (9%); including medication adjustment (n=6), referral for exercise testing (n=2) and refined sudden cardiac death risk stratification (n=1). In the 79 patients with stable echo findings (86%), 25 (32%) were qualified by the SCAMP as clinically stable and were advised to undergo repeat echo in 24 (instead of 12) months. Providers adhered to this recommendation in 19 patients (76%). Reasons for deviating from recommendations and continuing annual echo in SCAMP defined stable patients included patient preference, atrial fibrillation, severe LVOTO, and pulmonary hypertension.

Conclusions:
In select clinically stable patients with HCM, repeat echo may be unlikely to identify significant changes or impact practice. In these patients, a decreased frequency of echocardiography could decrease resource utilization without compromising care. Ongoing data collection and better risk stratification tools may allow more targeted surveillance strategies in the future.