Prognostic significance of myocardial fibrosis in hypertrophic cardiomyopathy using cardiovascular magnetic resonance

Introduction

The role of myocardial fibrosis in the prediction of sudden death and heart failure in hypertrophic cardiomyopathy (HCM) is unclear.

Purpose

We sought to investigate the prognostic significance of fibrosis detection by cardiovascular magnetic resonance (CMR) to predict major clinical events in HCM using the late gadolinium-enhanced (LGE) technique.

Methods

A prospective cohort study of 217 consecutive HCM patients followed for 3.1 + 1.7 years to determine the role of fibrosis detected using LGE-CMR on morbidity and mortality.

Results

LGE was present in 136/217 (LGE+, 63%). Thirty four of the 136 patients (25%) in the LGE+ group and 6/81 (7.4%) in the LGE- group reached the combined primary endpoint of cardiovascular death, unplanned cardiovascular admission, sustained VT/VF, or appropriate ICD discharge, (HR 3.4, p = 0.006). In the LGE+ group, overall risk increased with the percentage of LGE present (HR 1.03 per percent LGE increase, p = 0.008). The risk of unplanned heart failure admissions, deterioration to NYHA III or IV, or heart failure related death was greater in LGE+ group (HR 2.5, p = 0.021), and this risk increased as the percentage of LGE increased (HR 1.03 per percent LGE increase, p = 0.017). All relationships remained significant after multivariate analysis. The overall percentage of LGE was an important univariate predictor for arrhythmic endpoints (sustained VT/VF, appropriate ICD discharge, SCD), HR 1.05 per percent LGE increase, p = 0.014), but did not reach significance after multivariate analysis.

Conclusion

In patients with HCM, myocardial fibrosis is an independent predictor of adverse outcome particularly due to heart failure