The Association of Elevated Levels of LDH and CK-MB with Cardiac Injury and Mortality in COVID-19 Patients

Background: A new type of beta-coronavirus, named acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused coronavirus disease 2019 (COVID-19). Although COVID-19 is primarily associated with respiratory symptoms, cardiovascular complications can also occur. Herein, we aimed to evaluate whether the serum levels of enzymes related to cardiac injury, lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB), may associate with the mortality of COVID-19 patients to provide new insights to enhance clinical care. Methods: Based on hospital information systems (HIS) and patient records, we have retrospectively extracted laboratory findings of 159 patients with confirmed COVID-19 disease. The data of LDH and CK-MB of patients were defined as the day onset when the patients were admitted to the hospital. Results: The average age of all patients was almost 62 years old; the mean age in dead patients and recovered patients were 70 and 55 years old, respectively. The average aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine phosphokinase (CPK) values were 91.74, 66.20 U/L, and 268.24 U/L, respectively in all patients. The average LDH was 758.69 U/L, and CK-MB was 39.87 U/L in all of the COVID-19 patients. Among all 140 patients, laboratory results revealed that 121 (86.4%) patients had an elevated LDH level. In total, for 159 patients, the results indicated that 114 (71.69%) patients had an elevated CK-MB value. The average LDH value in dead patients was 1012.22 U/L, while in recovered patients was 545.20 U/L (P<0.0001). Also, the average CK-MB level in dead patients was 60.84 U/L, while in recovered patients was 35.17 U/L (P=00.0026). Conclusion: Elevated levels of LDH and CK-MB following COVID-19 disease increase the risk of death in these patients.