Spectrum and Clinical Significance of Systolic Function and Myocardial Fibrosis Assessed by Cardiovascular Magnetic Resonance in Hypertrophic Cardiomyopathy

• Published in: The American journal of cardiology Vol. 106; no. 2; pp. 261 - 267
• Main Authors: Olivotto, Iacopo, MD, Maron, Barry J., MD, Appelbaum, Evan, MD, Harrigan, Caitlin J, Salton, Carol, Gibson, C. Michael, Udelson, James E., MD, O'Donnell, Christopher, Lesser, John R., MD, Manning, Warren J., MD, Maron, Martin S., MD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 15.07.2010; Elsevier; Elsevier Limited
• Subjects: Adult; Biological and medical sciences; Cardiology; Cardiology. Vascular system; Cardiomyopathy, Hypertrophic - complications; Cardiovascular; Cardiovascular disease; Clinical medicine; Female; Heart; Heart rate; Humans; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Myocarditis. Cardiomyopathies; NMR; Nuclear magnetic resonance; Stroke Volume; Systole; Ventricular Dysfunction - diagnosis; Ventricular Dysfunction - etiology; Ventricular Remodeling; Myocardial fibrosis; Heart disease; Magnetic resonance; Hypertrophic cardiomyopathy; Medical imagery; Cardiovascular disease; Circulatory system; Cardiology; Myocardial disease; Nuclear magnetic resonance imaging
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/j.amjcard.2010.03.020

In hypertrophic cardiomyopathy (HCM), the clinical significance attributable to the broad range of left ventricular (LV) systolic function, assessed as the ejection fraction (EF), is incompletely resolved. We evaluated the EF using cardiovascular magnetic resonance (CMR) imaging in a large cohort of patients with HCM with respect to the clinical status and evidence of left ventricular remodeling with late gadolinium enhancement (LGE). CMR imaging was performed in 310 consecutive patients, aged 42 ± 17 years. The EF in patients with HCM was 71 ± 10% (range 28% to 89%), exceeding that of 606 healthy controls without cardiovascular disease (66 ± 5%, p <0.001). LGE reflecting LV remodeling showed an independent, inverse relation to the EF (B-0.69, 95% confidence interval −0.86 to −0.52; p <0.001) and was greatest in patients with an EF <50%, in whom it constituted a median value of 29% of the LV volume (interquartile range 16% to 40%). However, the substantial subgroup with low-normal EF values of 50% to 65% (n = 45; 15% of the whole cohort), who were mostly asymptomatic or mildly symptomatic (37 or 82% with New York Heart Association functional class I to II), showed substantial LGE (median 5% of LV volume, interquartile range 2% to 10%). This overlapped with the subgroup with systolic dysfunction and significantly exceeded that of patients with an EF of 66% to 75% and >75% (median 2% of the LV volume, interquartile range 1.5% to 4%; p <0.01). In conclusion, in a large cohort of patients with HCM, a subset of patients with low-normal EF values (50% to 65%) was identified by contrast-enhanced CMR imaging as having substantial degrees of LGE, suggesting a transition phase, potentially heralding advanced LV remodeling and systolic dysfunction, with implications for clinical surveillance and management.