Serial Myocardial Fibrosis Assessments Predict Outcomes in Patients With Hypertrophic Cardiomyopathy

Area of Science:

• Cardiology
• Medical Imaging
• Fibrosis Research

Background:

• The prognostic significance of tracking myocardial fibrosis over time in hypertrophic cardiomyopathy (HCM) is not well-established.
• Serial assessments of myocardial fibrosis using late gadolinium enhancement (LGE) via cardiac magnetic resonance (CMR) are needed.

Purpose of the Study:

• To evaluate the progression of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients using serial cardiac magnetic resonance (CMR) imaging.
• To determine the prognostic value of LGE progression in predicting adverse clinical events in HCM.

Main Methods:

• Retrospective analysis of 313 HCM patients with two CMR studies between 2010-2019.
• Quantified LGE mass progression (ΔLGE mass/y) and assessed its association with primary (mortality, transplantation, aborted SCD, HF hospitalization, stroke) and secondary (mortality, transplantation, aborted SCD) endpoints.
• Utilized maximally selected rank statistics and multivariable Cox regression for analysis, with external validation.

Main Results:

• Median LGE mass increased from 2.9 g to 8.3 g over a median interval of 4.2 years.
• Optimal cutoffs for ΔLGE mass/y predicting primary and secondary endpoints were >1.50 g/y and >3.75 g/y, respectively.
• ΔLGE mass/y >1.50 g/year independently predicted the primary endpoint (HR: 2.22), improving model discrimination and risk reclassification (C-statistic 0.81 to 0.84).

Conclusions:

• Myocardial fibrosis demonstrably increases over time in patients with HCM.
• Serial LGE assessment by CMR offers valuable prognostic information.
• Integrating serial LGE data into CMR assessments can enhance risk stratification and guide clinical decisions in HCM management.