Additional Study Information: *COVID Cohort* We are seeking patients that have had a pre-COVID heart CT scan (Coronary Computed Tomography Angiography) that was performed at Columbia University Irving Medical Center/NewYork-Presbyterian Hospital before March of 2020. For this study, half of patients will be required to have had COVID-19 symptoms (e.g., fever, cough, shortness of breath) and would have tested positive for COVID-19 (by an FDA-approved test). The other half will not have had a prior diagnosis of COVID-19. If you enroll in the study, you will be given a CT, asked to provide a blood sample as well as answer the study questionnaires, and get an ECG done. The total duration of the tests is 3 hours. It can be done in 1 or 2 study visits, whichever works best for your schedule. You will be compensated $100 after all tests are completed.