This is a spontaneous report from a contactable consumer, based on information received by Pfizer (manufacturer control number: license party for apixaban (ELIQUIS). This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of SUBCLAVIAN VEIN THROMBOSIS (Active thrombosis of central left subclavian vein), ARTERIOSCLEROSIS (Intimal arterial calcifications) and PULMONARY ARTERY DILATATION (Enlarged main pulmonary artery) in 78-year-old female patient who received apixaban (Eliquis) tablet for Cerebrovascular accident prophylaxis. The patient's past medical history included Hypertension, Bradycardia-tachycardia syndrome, Pacemaker insertion (cardiac), Anemia, Arthritis, Blood transfusion (without reported diagnosis), Cataract, Depression, Obstructive sleep apnea syndrome on 20-Jun-2019, Allergy (Cephalexin, Penicillin, Demerol HCL [meperidine], Hydrocodone, Metoprolol, and Ace inhibitors) and Nonsmoker. Concurrent medical conditions included Alcohol use (I glass of wine with dinner usually). Family history included Congestive heart failure (Mother), Hypertension (Mother, father), Cataract (Mother, sister, Brother), Stroke (Father, sister), Type 2 diabetes mellitus (Father, sister, paternal grand mother and paternal grand father), Cervical cancer (sister) and Ovarian cancer (sister). Vaccination history included: Covid-19 vaccine (Dose-1, MANUFACTURER UNKNOWN), for COVID-19 immunization. On 22-Oct-2020, the patient started Eliquis (Oral), 5 milligram twice a day. Further treatment periods at the same dose started on 11-Mar-2021. On 31-Mar-2021, 5 months 9 days after starting Eliquis, the patient experienced SUBCLAVIAN VEIN THROMBOSIS (seriousness criterion medically significant), ARTERIOSCLEROSIS (seriousness criterion medically significant) and PULMONARY ARTERY DILATATION (seriousness criterion medically significant). Eliquis(Oral) was interrupted due to event. At the time of the report, SUBCLAVIAN VEIN THROMBOSIS was resolving and ARTERIOSCLEROSIS and PULMONARY ARTERY DILATATION outcome was unknown. Patient was taken off Eliquis to have an epidural for unknown reason. Patient was put back on Eliquis and experienced a blood clot around heart. Eliquis stopped temporarily for transluminal epidural steroid injection bilateral L4-5, procedure done on 10-Mar-2021. Treatment of acute thrombosis of central left subclavian vein was Eliquis discontinued, transitioned to warfarin. Patient presented to ED on 31-Mar-2021 reporting discomfort in her left shoulder that has been intermittent in nature after receiving her second COVID vaccine in late February. On the day of presentation, she awoke with a swollen hand and forearm and was found to have DVT on imaging. Patient started anticoagulation after presenting with left upper extremity discomfort was found to have a rapid tachyarrhythmia consistent with a flutter and started on Eliquis. She had a pacemaker implanted for management of Tachybradycardia syndrome. She tolerated this well. She got her last Covid vaccine in late Feb-2021 in her right arm. She was off her Eliquis for a planned periprocedural hold while she was getting in epidural injection on 10-Mar-2021. She was off Eliquis from 07-Mar-2021 to 11-Mar-2021 and she developed acute left upper extremity swelling and pain around the time of 30-Mar-2021 and presented to the ER on 31-Mar-2021. Since that time, she has been on Lovenox subcutaneous twice daily and had significant improvement in her symptoms of pain and swelling in her left upper extremity. She reported that the medication is expensive but is affordable. She can dose appropriately but understandably does not like giving herself injections. Patient denies chest pain, shortness of breath, fevers, sweats, chills. She was up to date on her age-appropriate cancer screening with a colonoscopy and mammogram in the fall. She has had some abnormalities in her pancreas has been followed by serial MRIs last of which was performed in Jan-2021 shows stability. 12-point review of systems were negative. DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 03-Aug-2020, Colonoscopy: 2 2 to 3 mm polyps in the transverse colon and ascending colon removed with a jumbo cold forceps, 3 4 to 5 mm polyps in the transverse colon and ascending colon resected, otherwise normal. On 13-Oct-2020, Mammogram: no mammographic evidence of malignancy BI-RADS 2. On 28-Jan-2021, Magnetic resonance imaging pancreas: Stable multifocal pancreatic cystic foci largest measuring 8 mm. On 31-Mar-2021, Blood alkaline phosphatase (42-98 international unit per litre): 133 international unit per litre, Blood pressure measurement: 150/78, Blood sodium (136-144 millimole per litre): 135 millimole per litre, Body temperature: 98.2 degree fahrenheit, Computerised tomogram thorax: thrombus central left subclavian vein, intimal arterial calcifications, enlarged main pulmonary artery, incidental accessory spleens, Heart rate: 70 units not specified, Oxygen saturation: 99 percent and Ultrasound scan: left arm-occlusive venous thrombosis central left subclavian vein no upstream thrombosis. For Eliquis(Oral), the reporter did not provide any causality assessments. Doctor thought that the blood clot was from the Eliquis. Patient received apixaban for atrial fibrillation. Follow-up (13Oct2021): This is a follow-up spontaneous report from a contactable nurse, based on information received by Pfizer (manufacturer control number:. This case was split from master case Unknown for a female patient took BNT162B2 and experienced Musculoskeletal discomfort. Follow-up attempts completed. No further information expected.