Acute Myocardial Injury and Rhabdomyolysis in COVID-19 Patients: Incidence and Mortality.

Background Myocardial injury has been defined as an elevated troponin level. The frequency of acute myocardial injury of hospitalized coronavirus disease 2019 (COVID-19) patients ranges from 7% to 36%. COVID-19 patients with cardiovascular disease (CVD) have a four-fold higher risk of mortality (odds ratio, 4.33; CI 95%, 3.16-5.94). In COVID-19 hospitalized patients' study showed mortality rate was 18.5%. Rhabdomyolysis is considered as muscle necrosis and the release of intracellular muscles elements and enzymes into blood. In one of retrospective cohort study of COVID-19 hospitalized patients, incidence of rhabdomyolysis was 16.7%. Materials and methods This retrospective observational study consisted of 413 COVID-19 hospitalized patients. Patients with rhabdomyolysis was defined as creatine kinase level greater than 1,000 U/L and acute myocardial injury was defined as serum high-sensitivity troponin-T for males greater than 30 ng/l and for female greater than 20 ng/l. The primary outcome was in-hospital mortality of COVID-19 patients with acute myocardial injury and rhabdomyolysis.  Results The incidence of acute myocardial injury and rhabdomyolysis in hospitalized COVID-19 patients was 23.9% (99) and 15.7% (65), respectively. The mortality rate of in hospitalized COVID-19 patients who developed acute myocardial injury (28.3%) was significantly higher in comparison to patients who developed rhabdomyolysis (13.8%). Discussion The binding of SARS-CoV-2 virus to the angiotensin-converting enzyme 2 (ACE2) is a critical step in the pathophysiology in patients with COVID-19. There may be diverse direct and indirect mechanisms of acute myocardial injury in COVID-19 including ischemic injury, hypoxic injury (MI type 2), direct viral myocarditis, stress cardiomyopathy and systemic cytokine storm. Musculoskeletal injury may be caused by direct viral myositis or indirectly by host immune hyperinflammatory cytokine storm response that leads to skeletal muscle fiber proteolysis and fibrosis. Conclusions Acute myocardial injury and rhabdomyolysis were underreported in COVID-19 patients. The incidence and mortality of acute myocardial injury are higher than that of rhabdomyolysis in COVID-19 hospitalized patients. The outcome was worse in COVID-19 patients with severe acute myocardial injury. Patients with acute myocardial injury and rhabdomyolysis may get benefits from rehabilitation programs.