Determinants of Functional Mitral Regurgitation Severity in Patients with Ischemic Cardiomyopathy versus Nonischemic Dilated Cardiomyopathy

Authors

  • Dimitrios M. Konstantinou M.D., Ph.D.,

    Corresponding author
    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
    2. Heart Failure Care Group, Royal Brompton Hospital, London, United Kingdom
    • Address for correspondence and reprint requests: Dimitrios M. Konstantinou, M.D., Ph.D., Heart Failure Care Group, The Royal Brompton Hospital, SW3 6NP, London, UK. Fax: +442073518776;

      E-mail: D.Konstantinou@rbht.nhs.uk

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  • Klio Papadopoulou M.D., Ph.D.,

    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
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  • George Giannakoulas M.D., Ph.D.,

    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
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  • Vasilis Kamperidis M.D., Ph.D.,

    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
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  • Emmanouela G. Dalamanga M.D., Ph.D.,

    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
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  • Efthalia Damvopoulou M.D., Ph.D.,

    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
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  • Despina G. Parcharidou M.D., Ph.D.,

    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
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  • Theodoros D. Karamitsos M.D., Ph.D.,

    1. Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, United Kingdom
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  • Haralambos I. Karvounis M.D., Ph.D.

    1. First Department of Cardiology, AHEPA University Hospital, Aristotle University Medical School, Thessaloniki, Greece
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Abstract

Aims

Functional mitral regurgitation (MR) is prevalent among patients with left ventricular (LV) dysfunction and is associated with a poorer prognosis. Our aim was to assess the primary determinants of MR severity in patients with ischemic cardiomyopathy (ICM) and nonischemic dilated cardiomyopathy (DCM).

Methods and Results

Patients with functional MR secondary to ICM (n = 55) and DCM (n = 48) were prospectively enrolled. Effective regurgitant orifice (ERO) area, global LV remodeling, regional wall-motion abnormalities, and mitral apparatus deformity indices were assessed utilizing conventional and tissue Doppler echocardiography. ICM patients had more severe MR compared with DCM patients despite similar ejection fraction and functional status (ERO = 0.16 ± 0.08 cm2 vs. ERO = 0.12 ± 0.70 cm2, respectively, P = 0.002). Regional myocardial systolic velocities in mid-inferior and mid-lateral wall were negatively correlated with ERO in ICM and DCM patients, respectively. Multivariate analysis identified coaptation height as the only independent determinant of ERO in both groups. In a subset of ICM patients (n = 9) with relatively high ERO despite low coaptation height, a higher prevalence of left bundle branch block was detected (88.9% vs. 46.7%, P = 0.02).

Conclusions

Functional MR severity was chiefly determined by the extent of mitral apparatus deformity, and coaptation height can provide a rapid estimation of MR severity in heart failure patients. Additional contributory mechanisms in ICM patients include depressed myocardial systolic velocities in posteromedial papillary muscle attaching site and evidence of global LV dyssynchrony.

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