Leaders in Pharmaceutical Business Intelligence (LPBI) Group

1. Anne Marie Valente1,
2. Neal K. Lakdawala2,
3. Andrew J. Powell3,
4. Sarah P. Evans3,
5. Allison L. Cirino4,
6. E. J. Orav4,
7. Calum A. MacRae4,
8. Steven D. Colan3 and
9. Carolyn Y. Ho4*

+Author Affiliations

1. 
   
   ¹Brigham and Women’s Hospital & Boston Children’s Hospital, Boston, MA
2. 
   
   ²Brigham and Women’s Hospital & VA Boston Healthcare System, Boston, MA
3. 
   
   ³Boston Children’s Hospital, Boston, MA
4. 
   
   ⁴Brigham and Women’s Hospital, Boston, MA

1. ↵* Cardiovascular Division, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115 cho@partners.org

Abstract

Background—Left ventricular hypertrophy (LVH) typically manifests during or after adolescence in sarcomere mutation carriers at risk for developing hypertrophic cardiomyopathy (HCM). Guidelines recommend serial imaging of mutation carriers without LVH (G+/LVH-) to monitor for phenotypic evolution, but the optimal strategy is undefined. Compared with echocardiography (echo), cardiac magnetic resonance imaging (CMR) offers improved endocardial visualization and potential to assess scar. However the incremental advantage offered by CMR for early diagnosis of HCM is unclear. Therefore, we systematically compared echo and CMR in G+/LVH- subjects.

Methods and Results—Forty sarcomere mutation carriers with normal echo wall thickness (< 12 mm or z-score < 2.5 in children) underwent concurrent CMR. Mean age was 21.7 ± 11.1 years, 55% were female). If LV wall thickness appeared non-uniform, the size and location of relatively thickened segments were noted. Late gadolinium enhancement (LGE) was assessed with CMR. Diagnostic agreement between echo and CMR was good (90%), although CMR measurements of LV wall thickness were ~19% lower than echo. Four subjects had mild hypertrophy (12.6-14 mm, ≤2 segments) appreciated by CMR but not echo. No subjects had LGE. During median 35-month follow up, 2 subjects developed overt HCM, including 1 with mild LVH by CMR at baseline.

Conclusions—Echo is unlikely to miss substantial LVH; however CMR identified mild hypertrophy in ~10% of mutation carriers with normal echo wall thickness. CMR may be a useful adjunct in HCM family screening, particularly in higher risk situations, or if echocardiographic images are suboptimal or suggest borderline LVH.