title: Regional Stress-Induced Ischemia in Non-fibrotic Hypertrophied Myocardium in Young HCM Patients.
abstract: The relationship between hypertrophy, perfusion abnormalities and fibrosis is unknown in young patients with hypertrophic cardiomyopathy (HCM). Since mounting evidence suggests causal relationship between myocardial ischemia and major adverse cardiac events, we sought to investigate whether (1) regional myocardial perfusion is decreased in young HCM patients and in individuals at risk of HCM, and (2) hypoperfused areas are larger than areas with fibrosis. HCM patients (n = 12), HCM-risk subjects (n = 15) and controls (n = 9) were imaged on a 1.5 T MRI scanner. Myocardial hypertrophy was assessed on cine images. Perfusion images were acquired during adenosine hyperemia and at rest. Maximum upslope ratios of perfusion (stress/rest) were used for semiquantitative analysis. Fibrosis was assessed by late gadolinium enhancement (LGE). Results are presented as median and range. Perfusion in HCM-risk subjects and in non-hypertrophied segments in HCM patients showed no difference compared to controls (P = ns). Hypertrophic segments in HCM patients without LGE showed decreased perfusion compared to segments without hypertrophy [1.5 (1.1-2.3) vs. 2.0 (1.8-2.6), P < 0.001], and hypertrophic segments with LGE showed even lower perfusion using a segmental analysis [0.9 (0.6-1.8), P < 0.05]. The extent of hypoperfused myocardium in HCM patients during adenosine exceeded the extent of fibrosis on LGE [20 (0-48) vs. 4 (0-7) % slice area, P < 0.05] and hypoperfused areas at rest (P < 0.001). Regional perfusion is decreased in hypertrophied compared to non-hypertrophied myocardium and is lowest in fibrotic myocardium in young HCM patients but does not discriminate HCM-risk subjects from controls. The stress-induced hypoperfused regions exceed regions with LGE, indicating that hypoperfusion precedes fibrosis and may be a more sensitive marker of diseased myocardium in HCM.
authors.affiliation: Department of Clinical Sciences, Clinical Physiology, Lund University Hospital, Lund University, Lund, Sweden. robert.jablonowski@med.lu.se.
authors.forename: Robert
authors.initials: R
authors.lastname: Jablonowski
authors.affiliation: Pediatric Heart Center, Lund University Hospital, Lund University, Lund, Sweden. Eva.Fernlund@med.lu.se.
authors.forename: Eva
authors.initials: E
authors.lastname: Fernlund
authors.affiliation: Department of Clinical Sciences, Clinical Physiology, Lund University Hospital, Lund University, Lund, Sweden. aletras@auth.gr.|Laboratory of Medical Informatics, School of Medicine, Aristotle University of Thessaloniki, Thessaloníki, Greece. aletras@auth.gr.
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Aletras
authors.affiliation: Department of Clinical Sciences, Clinical Physiology, Lund University Hospital, Lund University, Lund, Sweden. Henrik.Engblom@med.lu.se.
authors.forename: Henrik
authors.initials: H
authors.lastname: Engblom
authors.affiliation: Department of Clinical Sciences, Clinical Physiology, Lund University Hospital, Lund University, Lund, Sweden. Einar.Heiberg@med.lu.se.|Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden. Einar.Heiberg@med.lu.se.|Centre for Mathematical Sciences, Faculty of Engineering, Lund University, Lund, Sweden. Einar.Heiberg@med.lu.se.
authors.forename: Einar
authors.initials: E
authors.lastname: Heiberg
authors.affiliation: Pediatric Heart Center, Lund University Hospital, Lund University, Lund, Sweden. Petru.Liuba@med.lu.se.
authors.forename: Petru
authors.initials: P
authors.lastname: Liuba
authors.affiliation: Department of Clinical Sciences, Clinical Physiology, Lund University Hospital, Lund University, Lund, Sweden. Hakan.Arheden@med.lu.se.
authors.forename: Håkan
authors.initials: H
authors.lastname: Arheden
authors.affiliation: Department of Clinical Sciences, Clinical Physiology, Lund University Hospital, Lund University, Lund, Sweden. Marcus.Carlsson@med.lu.se.
authors.forename: Marcus
authors.initials: M
authors.lastname: Carlsson
mesh_terms: D000293:Adolescent; D000328:Adult; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D003287:Contrast Media; D005260:Female; D005355:Fibrosis; D005682:Gadolinium; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis*; D055414:Myocardial Perfusion Imaging; D009206:Myocardium / Q000473:pathology*; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: CMR; Fibrosis; Ischemia; Magnetic resonance imaging; Myocardial perfusion