Hypertrophic Cardiomyopathy (HCM): New insights into Coronary artery remodelling and ischemia from FFRCT

Stephanie L Sellers; Tim A Fonte; Rominder Grover; John Mooney; Jonathan Weir-McCall; Karen Pl Lau; Anesh Chavda; Charis McNabney; Amir Ahmadi; Philipp Blanke; Geoffrey W Payne; Darra T Murphy; Kevin Ong; Charles A Taylor; Jonathon A Leipsic

doi:10.1016/j.jcct.2018.08.002

Hypertrophic Cardiomyopathy (HCM): New insights into Coronary artery remodelling and ischemia from FFR_CT

J Cardiovasc Comput Tomogr. 2018 Nov-Dec;12(6):467-471. doi: 10.1016/j.jcct.2018.08.002. Epub 2018 Aug 15.

Authors

Affiliations

¹ Department of Radiology, St Paul's Hospital and University of British Columbia, Vancouver, Canada; Centre for Heart Lung Innovation, St Paul's Hospital and University of British Columbia, Vancouver, Canada.
² Heart Flow Inc, Redwood City, CA, USA.
³ Department of Radiology, St Paul's Hospital and University of British Columbia, Vancouver, Canada.
⁴ University of Northern British Columbia, Prince George, Canada.
⁵ Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, Canada.
⁶ Department of Radiology, St Paul's Hospital and University of British Columbia, Vancouver, Canada; Heart Flow Inc, Redwood City, CA, USA; Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, Canada. Electronic address: jleipsic@providencehealth.bc.ca.

PMID: 30139668
DOI: 10.1016/j.jcct.2018.08.002

Abstract

Introduction: Angina, myocardial ischemia, and coronary artery physiology in hypertrophic cardiomyopathy (HCM) are poorly understood. However, coronary computed tomography angiography (CCTA) with fractional flow reserve from CT (FFR_CT) analysis offers a non-invasive method for evaluation of coronary artery volume to myocardial mass ratio (V/M) that may provide insight into such mechanisms. Thus, we sought to investigate changes in V/M in HCM.

Methods: A retrospective analysis was performed on 37 HCM patients and 37 controls matched for age, sex, and cardiovascular risk factors; CCTA-derived coronary artery lumen volume (V) and myocardial mass (M) were used to determine V/M. FFR_CT values were calculated for the left anterior descending (LAD), left circumflex (LCx) and right coronary (RCA) arteries as well as the 3-vessel cumulative FFR_CT values.

Results: HCM patients had significantly increased myocardial mass (176 ± 84 vs. 119 ± 27 g, p < 0.0001) and total coronary artery luminal volume (4112 ± 1139 vs. 3290 ± 924 mm³, p < 0.0001) that resulted from increases in segmented luminal volumes of both the left and right coronary artery systems. However, HCM patients had significantly decreased V/M (23.8 ± 5.9 vs. 26.5 ± 5.3 mm³/g; p = 0.026) which was further decreased when restricting V/M analysis to those HCM patients with septal hypertrophy (22.4 mm³/g, p = 0.01) that was mild-moderately predictive of HCM (AUC = 0.68). HCM patients also showed significantly lower nadir FFR_CT values in the LCx (0.87 ± 0.06 vs. 0.91 ± 0.06, p = 0.02), and cumulative 3-vessel FFR_CT values (2.58 ± 0.18 vs. 2.63 ± 0.14, p = 0.006).

Conclusions: HCM patients demonstrate significantly greater coronary volume. Despite this, HCM patients suffer from decreased V/M. Further prospective studies evaluating the relationship between V/M, angina, and heart failure in HCM are needed.

Keywords: Computed tomography angiography; Coronary remodelling; FFR(CT); Hypertrophic cardiomyopathy; Ischemia; V/M.

MeSH terms

Adult
Aged
Cardiomyopathy, Hypertrophic / diagnostic imaging*
Cardiomyopathy, Hypertrophic / physiopathology
Computed Tomography Angiography*
Coronary Angiography / methods*
Coronary Stenosis / diagnostic imaging*
Coronary Stenosis / physiopathology
Coronary Vessels / diagnostic imaging*
Coronary Vessels / physiopathology
Female
Fractional Flow Reserve, Myocardial*
Humans
Male
Middle Aged
Predictive Value of Tests
Retrospective Studies
Severity of Illness Index
Vascular Remodeling*
Ventricular Remodeling