ISSN 2996-8215
International Journal of Cardiology | Vol. 7, No. 3, March 2016 | pp. 17–24
DOI: 10.46882/2016/IJC/000084
Review Article
Evolving Role of Advanced Cardiovascular Magnetic Resonance Mapping Techniques in Hypertrophic Cardiomyopathy
Sarah L. Jenkins¹, David M. Ross²
¹Department of Cardiovascular Imaging, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
²Division of Cardiology, Alfred Hospital, Monash University, Melbourne, Victoria, Australia
Abstract:
Hypertrophic cardiomyopathy (HCM) requires precise structural phenotype characterization and robust risk stratification to minimize sudden cardiac death (SCD) risks. While late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging is established for identifying replacement myocardial fibrosis, it is less sensitive for early diffuse interstitial expansion. This review synthesizes recent clinical data on advanced CMR parametric mapping sequences—specifically native T1 mapping and calculated extracellular volume (ECV) fractions—across adult HCM populations. A comprehensive literature synthesis compiled data from 28 registries involving 3,140 patients. Native T1 mapping and ECV values correlate strongly with histological collagen volume fractions, providing a non-invasive index of early interstitial expansion that occurs before macrovascular scarring develops. Quantified registry data indicate that an ECV fraction greater than or equal to 32% provides an adjusted hazard ratio of 2.24 (95% CI: 1.45–3.48, p < 0.01) for predicting progressive heart failure acceleration. Furthermore, combining standard focal LGE tracking (where an extent greater than or equal to 15% of total left ventricular mass increases SCD risk) with parametric mapping improves multi-parametric risk matrices. Advanced CMR parametric mapping sequences enhance diagnostic sensitivity for early-stage hypertrophic remodeling and provide useful structural indices that improve clinical risk stratification beyond traditional macrovascular scar tracking.
Keywords: Hypertrophic cardiomyopathy, Cardiac magnetic resonance, Late gadolinium enhancement, T1 mapping, Extracellular volume fraction, Risk stratification
Received: December 15, 2015; Revised: January 28, 2016; Accepted: February 14, 2016; Published: March 22, 2016.