Post-COVID myocarditis diagnosed by endomyocardial biopsy and/or magnetic resonance imaging 2–9 months after acute COVID-19

Purpose

To study clinical features of myocarditis and its possible mechanisms (including persistence of SARS-Cov-2 in the myocardium) in the long-term period after acute COVID-19.

Methods

Fifteen patients (8 male and 7 female, mean age 47.8±13.4, 24–65 years) diagnosed with postcovid myocarditis were included in the study. The diagnosis of COVID-19 was confirmed by positive PCR results in 40%, and seroconversion in all patients. The average time of admission after COVID-19 was 4 [3; 7] months, from 2 to 9 months. The diagnosis of myocarditis was confirmed by cardiac MRI in 10 patients and by right ventricular endomyocardial biopsy (EMB) in 6 patients. The PCR for cardiotropic viruses and PCR with immunohistochemical study for SARS-Cov2 detection were used. All patients had study for anti-heart antibodies (AHA), EchoCG, and Holter ECG. Coronary atherosclerosis was excluded in all patients over 40 years (7 coronary angiography, 4 cardiac CT).

Results

A clear association of the cardiac symptoms with a previous new coronavirus infection was noted in all patients. The symptoms started 1–5 months following COVID-19. MRI showed subepicardial and intramyocardial LGE, signs of hyperemia, increased T1 relaxation time, edema. AHA levels were increased 3–4-fold in 73%. Two variants of postcovid myocarditis were observed. 1. Arrhythmic variant (n=6) – newly developed frequent supraventricular or ventricular extrasystole, recurrent atrial fibrillation in the absence of systolic dysfunction. 2. Decompensated variant with biventricular heart failure (n=9): the mean LV EF was 34.1±7.8% (23 to 46%), LV EDD 5.8±0.7 cm, EDV 153.8±46.1 ml, pulmonary artery systolic pressure 40.7±11.2 mmHg. In one case, myocarditis was accompanied by IgG4- and ANCA-negative aortitis. SARS-Cov-2 RNA was detected in 4 of 5 myocardial biopsies (in one case the material in the study). The longest period of virus persistence after COVID-19 was 9 months. By using spike and nucleocapsid antibodies, coronavirus was detected in cardiomycytes and macrophages. Data of patients with morphologically proved myocarditis are presented in Table 1. Lymphocytic myocarditis was diagnosed and confirmed immunohistochemically (n=5); giant cell myocarditis with atrial standstill was detected in one more case (Fig. 1). Three patients had also signs of endocarditis, in two cases with parietal thrombosis.

Conclusions

COVID-19 can lead to the subacute and chronic myocarditis of varying severity. Post-COVID myocarditis manifests itself in two main clinical forms - isolated arrhythmias and systolic dysfunction with heart failure. Post-COVID myocarditis is characterized by prolonged persistence of coronavirus (up to 9 months in this study, in most patients with decompensated variant) in combination with high immune activity (high titers of AHA), which should be considered as the main mechanisms of its long-term course. Treatment approaches for such myocarditis require investigation.

Funding Acknowledgement

Type of funding sources: None. Table 1. Patients with EMB proved myocarditisFigure 1. The EMB in postcovide myocarditis

Subacute and chronic post-covid myoendocarditis: clinical presentation, role of coronavirus persistence and autoimmune mechanisms

Aim    To study clinical features of myoendocarditis and its possible mechanisms, including persistence of SARS-Cov-2 in the myocardium, in the long-term period following COVID-19.Material and methods    This cohort, prospective study included 15 patients aged 47.8±13.4 years (8 men) with post-COVID myocarditis. The COVID-19 diagnosis was confirmed for all patients. Median time to seeking medical care after COVID-19 was 4 [3; 7] months. The diagnosis of myocarditis was confirmed by magnetic resonance imaging (MRI) of the heart (n=10) and by endomyocardial biopsy of the right ventricle (n=6). The virus was detected in the myocardium with PCR; immunohistochemical (IHC) study with antibody to SARS-Cov-2 was performed; anticardiac antibody level was measured; and echocardiography and Holter monitoring were performed. Hemodynamically significant coronary atherosclerosis was excluded for all patients older than 40 years.Results    All patients showed a clear connection between the emergence or exacerbation of cardiac symptoms and COVID-19. 11 patients did not have any signs of heart disease before COVID-19; 4 patients had previously had moderate arrhythmia or heart failure (HF) without myocarditis. Symptoms of myocarditis emerged at 1-5 months following COVID-19. MRI revealed typical late gadolinium accumulation, signs of hyperemia, and one case of edema. The level of anticardiac antibodies was increased 3-4 times in 73 % больных. Two major clinical variants of post-COVID myocarditis were observed. 1. Arrhythmic (n=6), with newly developed extrasystole or atrial fibrillation without systolic dysfunction. 2. Decompensated variant with systolic dysfunction and biventricular HF (n=9). Mean left ventricular ejection fraction was 34.1±7.8 %, and left ventricular end-diastolic dimension was 5.8±0.7 cm. In one case, myocarditis was associated with signs of IgG4‑negative aortitis. SARS-Cov-2 RNA was found in 5 of 6 biopsy samples of the myocardium. The longest duration of SARS-Cov-2 persistence in the myocardium was 9 months following COVID-19. By using antibody to the Spike antigen and nucleocapsid, SARS-Cov-2 was detected in cardiomyocytes, endothelium, and macrophages. Five patients were diagnosed with lymphocytic myocarditis; one with giant-cell myocarditis; three patients had signs of endocarditis (infectious, lymphocytic with mural thrombosis).Conclusion    Subacute/chronic post-COVID myocarditis with isolated arrhythmias or systolic dysfunction is characterized by long-term (up to 9 months) persistence of SARS-Cov-2 in the myocardium in combination with a high immune activity. Endocarditis can manifest either as infectious or as nonbacterial thromboendocarditis. A possibility of using corticosteroids and anticoagulants in the treatment of post-COVID myoendocarditis should be studied.

Effectiveness of myocarditis therapy depending on the diagnosis approach (with or without myocardial biopsy)

Aim. To evaluate the effectiveness of myocarditis therapy depending on the diagnosis approach (with or without myocardial biopsy).

Material and methods. The study included 83 patients ≥18 years old with severe and moderate myocarditis (25 women and 58 men; mean age, 45,7±11,7 years), established by myocardial biopsy (group 1, n=36) or by a non-invasive diagnostic algorithm (group 2, n=47), for which immunosuppressive therapy (IST) was carried out. Inclusion criteria were left ventricular (LV) end-diastolic dimension >5,5 cm and ejection fraction (EF) <50%. An endomyocardial (n=31) or intraoperative (n=5) biopsy with a study of the viral genome and level of anticardiac antibodies were performed. Coronary angiography (29%), cardiac multislice computed tomography (75%), cardiac magnetic resonance imaging (41%), and 99mTc-MIBI scintigraphy (35%) were also carried out. The mean follow-up period was 3 years (36 [12; 65] months). The study was approved by the Intercollegiate Ethics Committee.

Results. The groups were completely comparable in age, baseline parameters (class III [2,25; 3] and III [2; 3] heart failure (HF); end-diastolic LV dimension, 6,7±0,7 and 6,4±0,7 cm; EF, 29,9±8,7 and 31,4±9,3%), the extent of cardiac therapy (excluding the administration rate of в-blockers — 94,4 and 78,7%, p<0,05) and 1ST (methylprednisolone in 91,7 and 89,4% of patients at a mean dose of 24 [16; 32] and 20 [15; 32] mg/day, azathioprine in 50,0 and 46,8% of patients at a mean dose of 150 mg/day or mycophenolate mofetil 2,0 g/day in 30,6% in group 1, hydroxychloroquine 0,2 g/day in 27,8 and 23,4%). Biopsy in group 1 revealed active/borderline (61/39%) myocarditis, in 8 patients — viral genome in the myocardium, including parvovirus B19 in 7 of them. Both groups showed a comparable significant increase in EF after 6 months up to 37,6±8,1 and 42,6±11,5% (p<0,001) and after 27 [12; 54] months up to 43,4±9,6 and 45,5±12,3% (p<0,001), as well as a significant decrease in HF class to 2 [1; 2] in both groups. An increase in EF by ≥10% was recorded in 70 and 72% of patients, respectively. The mortality rate was 13,9 and 12,8%. Taking into account the only transplantation in group 2, the death+transplantation endpoints reached 13,9 and 14,9% of patients (without significant differences between the groups).

Conclusion. In patients with severe and moderate myocarditis diagnosed with and without myocardial biopsy, the effectiveness of combined therapy, including IST, was comparable. If it is impossible to perform a biopsy, complex non-invasive strategy makes it possible to diagnose myocarditis with different probability rate and conduct an effective IST, the refusal of which mostly is not justified.

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