Serial Myocardial Fibrosis Assessments Predict Outcomes in Patients with Hypertrophic Cardiomyopathy：A Cardiac Magnetic Resonance Study (RF_FR_337)

Background: This study aims to investigate the progression of myocardial fibrosis assessed with serial cardiac magnetic resonance (CMR) imaging in patients with hypertrophic cardiomyopathy (HCM), as well as its associated clinical factors and prognostic value.


Methods: A total of 381 consecutive patients with HCM who underwent two CMRs (median interval 4.1 years) for assessment of myocardial fibrosis, quantified by late gadolinium enhancement (LGE), were retrospectively included. Primary endpoint included all-cause mortality, heart transplantation, aborted sudden cardiac death, appropriate implantable cardioverter defibrillator discharge, hospitalization for heart failure, stroke and new-onset atrial fibrillation. Secondary endpoint included all-cause mortality and heart transplantation.


Results: Among the study cohort, 75 of 109 patients without myocardial fibrosis on initial CMR developed new fibrosis on the latest CMR. No fibrosis regression was seen in any of the patients. LGE mass increased from a median of 2.88g (IQR: 0.00-8.04g) to 8.54g (IQR: 3.38-16.59g). On multivariable analysis, LGE mass progression was highly correlated with time interval, the LGE mass and left ventricular (LV) mass index on the initial CMR (all P< 0.02). During an average follow-up of 6.3 years from initial CMR, the primary endpoint occurred in 120 patients, of whom 4.5% reached the secondary endpoint (n=17). Fibrosis progression was significantly associated with increased hazards for primary (HR: 2.5, P< 0.001, 95%CI: 1.1-4.0) and secondary endpoint (HR: 2.3, P< 0.001, 95%CI: 1.1-3.9) after adjustment for clinical and CMR covariates including age, LV ejection fraction and end-diastolic volume index.


Conclusion: Given the prognostic value of myocardial fibrosis progression, a CMR enhancement scan is recommended as routine monitoring in HCM patients.