Case Report|Articles in Press

Dilated cardiomyopathy with anti-mitochondrial M2 antibody: A case series


      Patients with dilated cardiomyopathy (DCM) sometimes show anti-mitochondrial M2 antibody (AMA-M2) positivity. We aimed to compare the characteristics of DCM cases with and without AMA-M2, and to describe cases of DCM with AMA-M2 positivity.
      A total of 84 patients with DCM were analyzed. Six patients (7.1 %) were positive for AMA-M2. Of these six patients, five (83.3 %) had primary biliary cirrhosis (PBC) and four (66.7 %) had myositis. Patients with AMA-M2 positivity had more atrial fibrillation and more premature ventricular contractions than those without. Left and right atrial longitudinal dimensions were larger in patients with AMA positivity (left atrium, 65.9 mm vs. 54.7 mm, p = 0.02; right atrium, 57.0 mm vs. 46.1 mm, p = 0.02). Of the six patients with AMA-M2 positivity, three underwent cardiac resynchronization therapy with defibrillator implantation and three required catheter ablation treatment. Steroids were used in three patients. One patient died of unresolved lethal arrhythmia and another required re-hospitalization for heart failure; the remaining four patients did not have adverse events.
      Patients with DCM with AMA-M2 positivity had a higher affinity for PBC and myositis than those without, and are characterized by atrial enlargement and arrhythmias.

      Learning objective

      Patients with dilated cardiomyopathy sometimes exhibit anti-mitochondrial M2 antibody positivity. These patients are at higher risk for primary biliary cirrhosis and inflammatory myositis, and their cardiac disorders are characterized by atrial enlargement and various arrhythmias. The course of the disease up to the time of diagnosis and after steroid use varies, and the prognosis is poor in advanced cases.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of Cardiology Cases
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Berg P.A.
        • Klein R.
        Mitochondrial antigens and autoantibodies: from anti-M1 to anti-M9.
        Klin Wochenschr. 1986; 64: 897-909
        • Varga J.
        • Heiman-Patterson T.
        • Muñoz S.
        • Love L.A.
        Myopathy with mitochondrial alterations in patients with primary biliary cirrhosis and antimitochondrial antibodies.
        Arthritis Rheum. 1993; 36: 1468-1475
        • Hou Y.
        • Liu M.
        • Luo Y.-B.
        • Sun Y.
        • Shao K.
        • Dai T.
        • Li W.
        • Zhao Y.
        • Yan C.
        Idiopathic inflammatory myopathies with anti-mitochondrial antibodies: clinical features and treatment outcomes in a chinese cohort.
        Neuromuscul Disord. 2019; 29: 5-13
        • Maeda M.H.
        • Tsuji S.
        • Shimizu J.
        Inflammatory myopathies associated with anti-mitochondrial antibodies.
        Brain. 2012; 135: 1767-1777
        • Seferović Petar M.
        • Marija Polovina
        • Johann Bauersachs
        • Michael Arad
        • Ben Gal Tuvia
        • Lund Lars H.
        • et al.
        Heart failure in cardiomyopathies: a position paper from the Heart Failure Association of the European Society of Cardiology.
        Eur J Heart Fail. 2019; 21: 553-576
        • Yokokawa T.
        • Yoshihisa A.
        • Misaka T.
        • Sato T.
        • Kaneshiro T.
        • Oikawa M.
        • Kobayashi A.
        • Yamaki T.
        • Kunii H.
        • Takeishi Y.
        Anti-mitochondrial antibodies in patients with dilated cardiomyopathy.
        Intern Med. 2021; 60: 201-208
        • Konishi H.
        • Fukuzawa K.
        • Mori S.
        • Satomi-Kobayashi S.
        • Kiuchi K.
        • Suzuki A.
        • Yano Y.
        • Yoshida A.
        • Hirata K.I.
        Anti-mitochondrial M2 antibodies enhance the risk of supraventricular arrhythmias in patients with elevated hepatobiliary enzyme levels.
        Intern Med. 2017; 56: 1771-1779
        • Matsumoto K.
        • Tanaka H.
        • Yamana S.
        • Kaneko A.
        • Tsuji T.
        • Ryo K.
        • Sekiguchi K.
        • Kawakami F.
        • Kawai H.
        • Hirata K.-I.
        Successful steroid therapy for heart failure due to myocarditis associated with primary biliary cirrhosis.
        Can J Cardiol. 2012; 28 (515.e3-515.e6)