CONGRESS ABSTRACT

Background: Hypertrophic cardiomyopathy (HCM) is a major health concern, with cardiac magnetic resonance (CMR) playing a crucial role in risk assessment. The utility of sequential CMR, particularly strain analysis, for tracking HCM progression remains to be established. Methods: We evaluated HCM patients undergoing two CMR scans over 10 years. We measured changes in left ventricular (LV) strain measures and examined their yearly changes as predictors of a composite of sudden cardiac death, life-threatening ventricular arrhythmias, stroke, new-onset atrial fibrillation, and heart failure hospitalizations. Results: Patients (n=114, 72% men, median age 51 years [interquartile range 36-60], obstructive HCM in 14%, median HCM risk score 2% [1-3%]) underwent 2 CMR scans over a median of 5.1 years (3.5-6.5). LGE extent increased from 0.5% of LV mass (0.1-3.6) to 1.6% (0.5-6.1; p<0.001). Longitudinal, circumferential and radial long-axis strain values changed significantly from the first to the second CMR scan. Several significant correlations between changes in strain values and the other CMR findings emerged, including a relationship between absolute changes in LV strain and increases in LGE mass. During a 4.3-year median follow-up after the second CMR scan (interquartile range 2.2-6.9), 40 patients experienced an endpoint event. Yearly absolute changes in longitudinal strain (p=0.044), radial long-axis strain (p=0.018) and radial short-axis strain (p=0.029) predicted the composite endpoint. Conclusions: Serial CMR-based strain analysis in HCM patients may reveal subtle variations in LV systolic function that are associated with progression of LV fibrosis and worse outcome.