A total of 315 articles were retrieved using the search strategy. After screening by abstract and title, 52 articles were selected for full-text assessment. Of these, 46 articles were excluded as they were not relevant to research aims and objectives [Figure 1].
Study characteristics
All the studies were conducted in China in 2020 and all of them were original articles except for one case report of Cui, et al. (8). Among the original articles, all were retrospective studies except study by Huang, et al. (9) which was prospective, observational study. All the studies have categorized patients into two groups: non-ICU/non-critical/without myocardial injury/with normal cardiac Troponin group and ICU/critical/with myocardial injury/with elevated cardiac Troponin group. Wang, et al.(10) and Huang, et al. (9) defined acute cardiac injury as blood levels of hypersensitive troponin I above the 99th percentile upper reference limit (>28 pg/mL) or new abnormalities shown on electrocardiography and echocardiography. Xingwei, et al. (11) defined myocardial injury as blood levels of myocardial troponin ≥3 times the upper reference limit (34.2 ng / L). However, Chen, et al.(12) and Guo, et al. (13) defined myocardial injury as serum levels of troponin above the 99th percentile upper reference limit [Table 1].
Baseline characteristics and co-morbidities of the patients
The median age of the patients in all the studies was above 50 years, except in studies of Huang, et al.(9) (median age; 49 years) and Cui, et al. (8) (patient’s age; 55 days). In all studies, patients requiring ICU/critical care or patients with myocardial injury/elevated cardiac Troponin were older comparatively, except in study conducted by Huang, et al.(9) (median ages of patients in non-ICU and ICU groups were same). Male predominance was seen in all studies except studies of Cui, et al. (8) and Guo, et al. (13). All the studies have included the underlying co-morbidities of the patients [Table 2].
Cardiovascular complications associated with COVID–19
Wang, et al. (10) established that among the 138 patients, acute cardiac injury was seen in 10 (7.2%), shock in 12 (8.7%), and arrhythmia in 23 (16.7%) patients. ICU patients were more likely to have one of these complications than non-ICU patients (p < 0.001) [Table 3]. ICU patients demonstrated significantly high levels of creatine phosphokinase myocardial band (CPK-MB), cardiac troponin I (cTnI) and D-dimer. Similarly, number of patients who had procalcitonin levels >0.05 ng/mL were more in ICU group compared with non-ICU group (27 [75%] vs 22 [21.6%]) [Table 4].
Study conducted by Huang, et al. (9) found that among the 41 patients, acute cardiac injury was seen in five (12%) and shock in three (7%) patients. Acute cardiac injury (4 [31%] vs 1 [4%]) and shock (3 [23%] vs zero [0%]) were seen more commonly in ICU patients compared with non-ICU patients [Table 3]. Besides, ICU patients demonstrated significantly high levels of creatine phosphokinase (CPK), and D-dimer. Number of patients who had procalcitonin levels >0.05 ng/mL and cTnI >28 pg/mL (99th percentile) were more in ICU group compared with non-ICU group [Table 4].
Similarly, Chen, et al. (12) discovered that among the 150 patients, 22 (7.1%) patients had acute cardiac injury. In the same study, out of 24 patients in critical group, 15 (62.5%) had acute cardiac injury and 7 (5.6%) out of 126 patients in non-critical group had acute cardiac injury and the difference was statistically significant (p-value <0.001) [Table 3]. Hypersensitive C-reactive protein (hs-CRP), N-terminal-pro brain natriuretic peptide (NT-proBNP) and cTnI levels of the patients were significantly higher in critical care cases than in mild cases (p-value <0.001) [Table 4]. On univariate logistic regression analysis, critical disease status had a significant correlation with age, male gender, elevated NT-proBNP, elevated cTnI, elevated hs-CRP, hypertension, and coronary artery disease (all p<0.05). Multivariate logistic regression analysis revealed that elevated cTnI (OR = 26.909, 95%CI 4.086–177.226, p = 0.001) and coronary artery disease (OR = 16.609, 95%CI 2.288–120.577, p = 0.005) were the independent risk factors of critical disease status.
In study performed by Xingwei, et al. (11) among the 54 severe/critically severe patients, acute myocardial injury was discovered in 24 (44.4%) patients while 26 (48.1%) patients died during hospital stay. In-hospital mortality rate was significantly higher in myocardial injury group compared to the group without myocardial injury [75.0% (18/24) vs. 26.7% (8/30), p-value = 0.001]. In myocardial injury group, C-reactive protein (CRP) and NT-proBNP levels were also found to be significantly higher than those without myocardial injury (all p-value<0.01)
Cui, et al (8) has described a case report of acute cardiac injury in an infant infected with COVID–19 as suggested by elevated plasma levels of CPK-MB, and cTnI.
Guo, et al. (
13) discovered that among the 187 patients, 52 (27.8%) exhibited acute cardiac injury as indicated by elevated cardiac troponin T (cTnT) levels. During hospitalization, arrhythmias were seen in 11 (5.9%) patients. Patient with elevated cTnT levels had more frequent malignant arrhythmias compared with normal cTnT (9[17.3%] vs 2[1.5%]). The overall mortality was 23% (43 patients died) [Table 4]. The mortalities were 7.62% (8 of 105), 13.33% (4 of 30), 37.50% (6 of 16), 69.44% (25 of 36) for patients without underlying CVD and normal cTnT levels, with underlying cardiovascular disease (CVD) and normal cTnT levels, without underlying CVD but elevated cTnT levels, and with underlying CVD and elevated cTnT levels respectively. Elevated cTnT levels was seen more commonly in patients with underlying CVD compared with patients without CVD (36 [54.5%] vs 16 [13.2%]). A significant positive linear correlation of plasma cTnT levels with plasma hsCRP levels (β = 0.530, p< .001) and NT-proBNP levels (β = 0.613, p < .001) was also observed.