C58 A NEW MAGNETIC RESONANCE IMAGING TECHNIQUE TO ASSESS PROGNOSIS IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY AND LOW–INTERMEDIATE 5–YEAR RISK OF SUDDEN DEATH

Abstract

Abstract Background Late gadolinium enhancement (LGE) is an important prognostic marker in hypertrophic cardiomyopathy and an extent >15% it is associated with high risk of sudden cardiac death. We proposed a novel method, the LGE–dispersion mapping, to assess heterogeneity of scar, and evaluated its prognostic role in patients with hypertrophic cardiomyopathy. Methods One hundred eighty–three patients with hypertrophic cardiomyopathy and a low– or intermediate 5–year risk of sudden cardiac death underwent cardiac magnetic resonance imaging. A parametric map was generated from each LGE image. A score from 0 to 8 was assigned at every pixel of these maps, indicating the number of the surrounding pixels having different quality (nonenhancement, mild–enhancement, or hyperenhancement) from the central pixel. The Global Dispersion Score (GDS) was calculated as the average score of all the pixels of the images. Results During a median follow–up time of 6 (25th–75th, 4–10) years, 22 patients had hard cardiac events (sudden cardiac death, appropriate implantable cardioverter–defibrillator therapy, resuscitated cardiac arrest, and sustained ventricular tachycardia). Kaplan–Meier analysis showed that patients with GDS>0.86 had worse prognosis than those with lower GDS (P<0.0001). GDS>0.86 was the only independent predictor of cardiac events (hazard ratio, 9.9 [95% CI, 2.9–34.6], P=0.0003). When compared with LGE extent >15%, GDS improved the classification of risk in these patients (net reclassification improvement, 0.39 [95% CI, 0.11–0.72], P<0.019). Conclusions LGE–dispersion mapping is a marker of scar heterogeneity and provides a better risk stratification than LGE presence and its extent in patients with hypertrophic cardiomyopathy and a low intermediate 5–year risk of sudden cardiac death.