In patients with coronavirus disease 2019 (COVID-19), cardiovascular involvement occurs frequently. Myocardial injury with elevated troponin levels is described in patients hospitalized with COVID-19¹ and seems to be associated with outcome.² The origin of myocardial injury can result from ischemia due to thrombotic coronary obstruction but can also include other causes such as heart failure, pulmonary embolism, tachycardia, and sepsis.³ Obviously, an infection of the myocardium with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is another alternative for elevated troponin. Next to elevated biomarkers for cardiac injury, myocardial dysfunction determined by echocardiography is also reported in up to 70% of hospitalized patients.⁴ This makes cardiac involvement during COVID-19, which manifests primarily as a pulmonary disease, likely.

Background: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used to treat cardiogenic shock. However, VA-ECMO might hamper myocardial recovery. The Impella unloads the left ventricle. This study aimed to evaluate whether left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO was associated with lower mortality. Methods: Data from 686 consecutive patients with cardiogenic shock treated with VA-ECMO with or without left ventricular unloading using an Impella at 16 tertiary care centers in 4 countries were collected. The association between left ventricular unloading and 30-day mortality was assessed by Cox regression models in a 1:1 propensity score–matched cohort. Results: Left ventricular unloading was used in 337 of the 686 patients (49%). After matching, 255 patients with left ventricular unloading were compared with 255 patients without left ventricular unloading. In the matched cohort, left ventricular unloading was associated with lower 30-day mortality (hazard ratio, 0.79 [95% CI, 0.63–0.98]; P =0.03) without differences in various subgroups. Complications occurred more frequently in patients with left ventricular unloading: severe bleeding in 98 (38.4%) versus 45 (17.9%), access site–related ischemia in 55 (21.6%) versus 31 (12.3%), abdominal compartment in 23 (9.4%) versus 9 (3.7%), and renal replacement therapy in 148 (58.5%) versus 99 (39.1%). Conclusions: In this international, multicenter cohort study, left ventricular unloading was associated with lower mortality in patients with cardiogenic shock treated with VA-ECMO, despite higher complication rates. These findings support use of left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO and call for further validation, ideally in a randomized, controlled trial.

Early diagnosis of acute myocardial infarction (AMI) in patients presenting with acute chest pain improves clinical outcome. Moreover, rapid exclusion of AMI is important to triage patients in view of limited resources in the emergency department. Measurement of cardiac troponin levels, as a marker of myocyte necrosis, is essential for diagnosing AMI.¹ Compared with sensitive troponin assays, high-sensitivity troponin assays enhance the accuracy and speed of the diagnosis,^1-4 improve outcome, and are cost-effective.⁵