COVID-19 Myocarditis and Severity Factors: An Adult Cohort Study
Authors: Ma Kun-Long , Liu Zhi-Heng , Cao Chun-Feng , Liu Ming-Ke , Liao Juan , Zou Jing-Bo , Kong Ling-Xi , Wan Ke-Qiang , Zhang Jun , Wang Qun-Bo , Tian Wen-Guang , Qin Guang-Mei , Zhang Lei , Luan Fu-Jun , Li Shi-Ling , Hu Liang-Bo , Li Qian-Lu , Wang Hai-Qiang 
Published: March 2020

Background

Notwithstanding the clinical hallmarks of COVID-19 patients were reported, several critical issues still remain mysterious, i.e., prognostic factors for COVID-19 including extrinsic factors as viral load of SARS-CoV-2 and intrinsic factors as individual’s health conditions; myocarditis incidence rate and hallmarks.

Methods

Demographic, epidemiologic, radiologic and laboratory data were collected by medical record reviews of adult hospitalized patients diagnosed as COVID-19. Cycle threshold (Ct) value data of real-time PCR (RT-PCR) were collected. The time duration was from 21 January to 2 March, 2020. Pulmonary inflammation index (PII) values were used for chest CT findings. Multivariate logistic regression analysis was used to identify independent severity risk factors.

RESULTS

In total, 84 hospitalized adult patients diagnosed as COVID-19 were included, including 20 severe and 64 nonsevere cases. The viral load of the severe group was significantly higher than that of the non-severe group, regardless of the Ct values forNorORF1abgene of virus (all p<0.05).Typical CT abnormalities was more likely existing in the severe group than in the nonsevere group in patchy shadows or ground glass opacities, consolidation, and interlobular septal thickening (all p<0.05). In addition, the PII values in the severe group was significantly higher than that in the nonsevere group (52.5 [42.5-62.5] vs 20 [5.0-31.6]; p<0.001). Amongst 84 patients, 13 patients (15.48%) were noted with abnormal electrocardiograms (ECGs) and serum myocardial enzyme levels; whereas 4 (4.8%) were clinically diagnosed as SARS-CoV-2 myocarditis. Multivariable logistic regress analysis distinguished three key independent risk factors for the severity of COVID-19, including age [OR 2.350; 95% CI (1.206 to 4.580); p=0.012], Ct value [OR 0.158; 95% CI (0.025 to 0.987); p=0.048] and PII [OR 1.912; 95% CI (1.187 to 3.079); p=0.008].

Interpretation

Three key-independent risk factors of COVID-19 were identified, including age, PII, and Ct value. The Ct value is closely correlated with the severity of COVID-19, and may act as a predictor of clinical severity of COVID-19 in the early stage. SARS-CoV-2 myocarditis should be highlighted despite a relatively low incidence rate (4.8%). The oxygen pressure and blood oxygen saturation should not be neglected as closely linked with the altitude of epidemic regions.

Research in context

Evidence before this study

We searched Pubmed on March 15, 2020 using the terms (“COVID-19” OR “novel coronavirus” OR “2019 novel coronavirus” OR “2019-nCoV” OR “pneumonia” OR “coronavirus”), AND “Myocarditis” OR “Cycle threshold (Ct)” OR “Altitude”. We found that one article analyzed the risk factors affecting the prognosis of adult patients with COVID-19 in terms of survivorship, without considering Ct values as extrinsic factors. Moreover, there are no reported studies on viral myocarditis caused by COVID-19 and the relationship between the altitude and COVID-19.

Added value of this study

We retrospectively analyzed the clinical data, Ct values, laboratory indicators and imaging findings of 84 adult patients with confirmed COVID-19. Three key-independent risk factors of COVID-19 were identified in our study, including age [OR 2.350; 95% CI (1.206 to 4.580); p=0.012], Ct value [OR 0.158; 95% CI (0.025 to 0.987); p=0.048] and PII [OR 1.912; 95% CI (1.187 to 3.079); p=0.008]. Amongst 84 patients, 13 patients (15.48%) were noted with abnormal electrocardiograms (ECGs) and serum myocardial enzyme levels; whereas 4 (4.8%) were clinically diagnosed as SARS-CoV-2 myocarditis. Moreover, altitude should be considered for COVID-19 severity classification, given that oxygen partial pressure and blood oxygen saturation of regional patients vary with altitudes.

Implications of all the available evidence

Three key-independent risk factors of COVID-19 were identified, including age, PII, and Ct value. The Ct value is closely correlated with the severity of COVID-19, and may act as a predictor of clinical severity of COVID-19 in the early stage. SARS-CoV-2 myocarditis should be highlighted despite a relatively low incidence rate (4.8%). The oxygen pressure and blood oxygen saturation should not be neglected as closely linked with the altitude of epidemic regions.