Discrepant Measurements of Maximal Left Ventricular Wall Thickness Between Cardiac Magnetic Resonance Imaging and Echocardiography in Patients With Hypertrophic Cardiomyopathy

OBJECTIVES: We sought to compare maximal left ventricular (LV) wall thickness (WT) measurements as obtained by routine clinical practice between echocardiography and cardiac magnetic resonance (CMR) and document causes of discrepancy.

METHODS: One-hundred and ninety-five patients with hypertrophic cardiomyopathy (median age, 52.8±15.1 years) who underwent echocardiography and CMR imaging within 6 months (median, 41 days; interquartile range, 16-97 days) were included. LVWT was assessed in parasternal long and short axis by 2-dimensional echocardiography and in short axis by CMR.

RESULTS: By Bland-Altman plot, mean maximal LVWT difference between echocardiography and CMR was 0.5 mm (95% confidence interval, -6.9, 7.8) with equal distribution of discrepancy along the full range of LVWT. Ninety-seven patients (49.7%) were identified to have intermodal measurement discrepancies ≥10%. In 7 patients (7.2%), reported measurement by CMR was inaccurate because of interpretation error. In 90 patients (92.8%), echocardiography underestimated (n=32; 33.0%) or overestimated (n=58; 59.8%) maximal LVWT. Underestimation was because of focal LV hypertrophy (n=10; 10.3%) or poor acoustic windows (n=22; 22.7%) while overestimation resulted from inclusion of right ventricular myocardium (n=37; 38.1%), LV trabeculations (n=5; 5.2%), papillary muscle (n=3; 3.1%), and apical-septal bundle (n=1; 1.0%), as well as imaging plane obliquity (n=7; 12.5%). In 31 (15.9%) patients, measurement discrepancy occurred at diagnostic or prognostic cut-offs.

CONCLUSIONS: Although maximal LVWT by echocardiography in general measured similar to CMR, discordance because of limitations in echocardiography technique was present in a significant subset of patients. As measurement of LVWT impacts diagnosis and sudden death management, CMR should be considered as part of routine evaluation of all patients with hypertrophic cardiomyopathy.

PMID: 28794137

Posted in Echo, Magnetic Resonance Imaging and tagged , .

2 Comments

  1. Editorial comment:
    Thick Walls, Thin Data: Measuring Left Ventricular Wall Thickness With MRI Versus Echocardiography
    Brian B. Ghoshhajra and Michael A. Fifer
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  2. Recent related article:
    Comparison of Maximal Wall Thickness in Hypertrophic Cardiomyopathy Differs Between Magnetic Resonance Imaging and Transthoracic Echocardiography.
    Bois JP, Geske JB, Foley TA, Ommen SR, Pellikka PA.
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