Cardiac magnetic resonance findings in acute and post-acute COVID-19 patients with suspected myocarditis

Abstract

Introduction: Cardiac injury is commonly reported in COVID-19 patients, resulting associated to pre-existing cardiovascular disease, disease severity, and unfavorable outcome. Aim is to report cardiac magnetic resonance (CMR) findings in patients with myocarditis-like syndrome during the acute phase of SARS-CoV-2 infection (AMCovS) and post-acute phase (cPACS).

Methods: Between September 2020 and January 2022, 39 consecutive patients (24 males, 58%) were referred to our department to perform a CMR for the suspicion of myocarditis related to AMCovS (n = 17) and cPACS (n = 22) at multimodality evaluation (clinical, laboratory, ECG, and echocardiography). CMR was performed for the assessment of volume, function, edema and fibrosis with standard sequences and mapping techniques. CMR diagnosis and the extension and amount of CMR alterations were recorded.

Results: Patients with suspected myocarditis in acute and post-COVID settings were mainly men (10 (59%) and 12 (54.5%), respectively) with older age in AMCovS (58 [48-64]) compared to cPACS (38 [26-53]). Myocarditis was confirmed by CMR in most of cases: 53% of AMCovS and 50% of cPACS with negligible LGE burden (3 [IQR, 1-5] % and 2 [IQR, 1-4] %, respectively). Myocardial infarction was identified in 4/17 (24%) patients with AMCovS. Cardiomyopathies were identified in 12% (3/17) and 27% (6/22) of patients with AMCovS and cPACS, including DCM, HCM and mitral valve prolapse.

Conclusions: In patients with acute and post-acute COVID-19 related suspected myocarditis, CMR improves diagnostic accuracy characterizing ischemic and non-ischemic injury and unraveling subclinical cardiomyopathies.

Keywords: COVID-19; arrhythmia; cardiac magnetic resonance; infarction; myocarditis.

FIGURE 1

CMR of a 58‐years‐old woman presenting for acute chest pain 10 days after COVID‐19 diagnosis. ECG showed ST elevation in the anterior leads. Echocardiography showed diffuse hypokinesia with depressed ejection fraction (35%). High‐sensitivity cardiac troponin T (hs‐cTnT) was severely elevated (13′722 ng/L, normal value <14 ng/L). The patient underwent ICA in the suspicion of ST‐elevation acute myocardial infarction, which however showed normal coronary arteries. After 16 days, the patient underwent CMR to identify the etiology of myocardial damage, which showed transmural edema of the right ventricle free wall in STIR images (arrows in A) corresponding to transmural LGE (arrows in B and C), suggesting acute myocarditis. The diagnosis was confirmed with endomyocardial biopsy documenting necrotizing myocarditis.

FIGURE 2

Esemplyfing case of COVID‐19 related acute myocarditis. A 46‐years‐old male patient presented to the ED for fever, cough, and diarrhea. ECG showed mild ST elevation in the anterior leads. Echocardiography showed diffuse biventricular hypokinesia with depressed ejection fraction (30%). High‐sensitivity cardiac troponin T (hs‐cTnT) was severely elevated (730 ng/L, normal value <14 ng/L). A nasopharyngeal swab resulted positive for SARS‐CoV‐2 infection. The patient underwent ICA in the suspicion of ST‐elevation acute myocardial infarction, which however showed normal coronary arteries (A and B). After 11 days, the patient underwent CMR to identify the etiology of myocardial damage, which showed focal patchy areas of edema in STIR images and T2 map (arrows in C and E) involving the infero‐lateral and inferior mid‐ventricle walls associated with diffuse alteration of T2 values, as for subtle diffuse edema associated (F). In site of hyperintensity on STIR images, were also evident patchy subepicardial areas of LGE (arrows in D) associated to increased native‐T1 values (G and H) and corresponding areas of increased ECV (arrow in G and values in I). CMR was suggestive for myocarditis which was confirmed with endomyocardial biopsy.

FIGURE 3

Exemplifying case of COVID‐19 associated acute coronary syndrome. A 58‐years‐old male patient presented to the ED for resting chest pain, mild dyspnea, and convulsive syncope. Electrocardiogram showed inverted T waves in the lateral leads. Echocardiography showed normal contractility with preserved ejection fraction. Initial high‐sensitivity cardiac troponin T (hs‐cTnT) was mildly elevated (16 ng/L, normal value <14 ng/L), with no significant change at 1 h. A nasopharyngeal swab resulted positive for SARS‐CoV‐2 infection, thus establishing the diagnosis of COVID‐19 associated to non‐ST elevation acute coronary syndrome (NSTE‐ACS). The patient then underwent chest CT for lung parenchyma evaluation, showing a moderate interstitial pneumonia with typical pattern for COVID‐19 (figure A), and invasive coronary angiography (ICA), showing total occlusion of left circumflex artery (arrow in B), promptly treated with stenting, and proximal occlusion of right coronary artery (arrowheads in C). After six days, the patient underwent CMR showing focal edema in STIR images in the infero‐lateral basal wall (arrow in D) associated to subendocardial LGE (arrows in E), confirming the diagnosis of acute myocardial infarction in the territory of left circumflex artery.

FIGURE 4

CMR images of an 80‐years‐old male patient presenting to the ED for persisting chest pain two months after COVID‐19 pneumonia. Electrocardiogram showed no signs of ischemia. Echocardiography showed normal contractility with preserved ejection fraction and circumferential pericardial effusion. High‐sensitivity cardiac troponin T (hs‐cTnT) was mildly elevated (45 ng/L, normal value <14 ng/L) with no significant increase at 1 h. The patient then underwent CMR, which showed a significant circumpherential pericardial effusion (thickness 1.5 cm) (arrows in A) associated with significant thickening of the pericardial layers (4 mm) characterized by marked increased intensity on both STIR (arrows in B) and LGE images (arrows in C), suggesting active essudative pericarditis.

FIGURE 5

CMR images of a 38‐years‐old male patient presenting for chronic exertional dyspnea and palpitation seven months after resolution of mild COVID‐19. Echocardiography showed normal contractility with preserved ejection fraction. High‐sensitivity cardiac troponin T (hs‐cTnT) was slightly elevated (27 ng/L, normal value <14 ng/L) before CMR. CMR showed absent edema in STIR images (A) and at T2 mapping (C and D) and a small subepicardial area of LGE in the infero‐lateral basal wall (arrows in B) associated to native T1 and ECV values elevation (arrows in E‐F and G‐H, respectively), suggesting healed myocarditis.