You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

Background: Pulmonary embolism (PE) has been identified as one of the deadliest complications of coronavirus disease 2019 (COVID-19), especially in patients admitted to the intensive care unit (ICU). Western literature reminds us of the high prevalence of PE in COVID. Here, we report a series of 13 cases of PE diagnosed and managed at our hospital. Methods: Retrospective analysis of medical records of 13 cases of PE admitted at our hospital from February 1, 2020, to September 31, 2020, were done. Their clinical, laboratory, and radiologic data were assessed in detail. Results: Computed tomography pulmonary arteriography was used to make the diagnosis in eight patients (61.53%), and clinical findings with corroborative ultrasound and laboratory parameters were used to label PE in five patients (38.46%). Five patients were hemodynamically unstable, requiring thrombolysis with recombinant tissue plasminogen activator, and four patients (30.76%) suffered a fatal outcome. Conclusion: COVID-19 is a highly prothrombotic state, and all physicians should keep a high vigilance for PE. All hospitalized patients with COVID-19, especially those admitted in ICU, should be on prophylactic anticoagulation and, if there is any worsening, should be started on therapeutic regimen. Patients at the time of discharge should be switched to oral anticoagulation, which should be continued for at least 3-6 months.
["Case Report"]