blood clot in his left leg from his ankle to his growing/ blood clots in his lungs; E frac now is only 29%/heart had an e-frac of only 10%; hard time breathing; it was hurting him; This spontaneous case was reported by a nurse and describes the occurrence of THROMBOSIS (blood clot in his left leg from his ankle to his growing/ blood clots in his lungs), EJECTION FRACTION DECREASED (E frac now is only 29%/heart had an e-frac of only 10%), DYSPNOEA (hard time breathing) and PAIN (it was hurting him) in a 35-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 008b21-2a and 036a21a) for COVID-19 vaccination.     Concomitant products included METFORMIN, METOPROLOL, SPIRONOLACTONE (ALDACTONE [SPIRONOLACTONE]) and LISINOPRIL for an unknown indication.   On 20-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 16-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. In May 2021, the patient experienced THROMBOSIS (blood clot in his left leg from his ankle to his growing/ blood clots in his lungs) (seriousness criteria hospitalization and medically significant), EJECTION FRACTION DECREASED (E frac now is only 29%/heart had an e-frac of only 10%) (seriousness criterion hospitalization), DYSPNOEA (hard time breathing) (seriousness criterion hospitalization) and PAIN (it was hurting him) (seriousness criterion hospitalization). The patient was hospitalized on 31-May-2021 due to DYSPNOEA, EJECTION FRACTION DECREASED, PAIN and THROMBOSIS. The patient was treated with SACUBITRIL, VALSARTAN (ENTRESTO) for Clot blood, at an unspecified dose and frequency and APIXABAN (ELIQUIS) for Clot blood, at an unspecified dose and frequency. At the time of the report, THROMBOSIS (blood clot in his left leg from his ankle to his growing/ blood clots in his lungs), EJECTION FRACTION DECREASED (E frac now is only 29%/heart had an e-frac of only 10%), DYSPNOEA (hard time breathing) and PAIN (it was hurting him) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In May 2021, Ejection fraction: 29 % heart had an e-frac of only 10%.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Medication patient had  improved , if not per the doctors patient would have died Patient never had COVID. The symptoms were ongoing.Patient was now in heart failure medication Entresto, Eliquis because of the blood clots. Caller was unsure about regular prescript medication of the patient as patient had to change it.. Patient to the ER on May 31st. AE cause patient to went to intensive care. Patient had to stay in Eliquis at least until Dec 9 2022  Patient received treatment in intensive care or  would have died per the doctors.  Company comment: This spontaneous case concerns a 35 year old male patient with no reported medical history, who experienced the unexpected serious (hospitalization, medically significant) AESI of Thrombosis; unexpected serious (hospitalization) events of Ejection fraction decreased, Dyspnoea and Pain, about 45 days after receiving the second dose with mRNA-1273 vaccine in the COVID-19 vaccination series. The patient received the first dose with the same vaccine, about 27 days ago with no reported adverse events. Patient felt abnormal and was taken to ER. Patient had a blood clot in his left leg, blood clots in his lungs and his heart had an ejection fraction of only 10%. He was having difficulty in breathing and was then admitted to intensive care unit. No further information on risk factors, indications for the concomitant drugs, detailed clinical course, further investigations and treatment details of the events was available in the report. The events were not resolved. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 35 year old male patient with no reported medical history, who experienced the unexpected serious (hospitalization, medically significant) AESI of Thrombosis; unexpected serious (hospitalization) events of Ejection fraction decreased, Dyspnoea and Pain, about 45 days after receiving the second dose with mRNA-1273 vaccine in the COVID-19 vaccination series. The patient received the first dose with the same vaccine, about 27 days ago with no reported adverse events. Patient felt abnormal and was taken to ER. Patient had a blood clot in his left leg, blood clots in his lungs and his heart had an ejection fraction of only 10%. He was having difficulty in breathing and was then admitted to intensive care unit. No further information on risk factors, indications for the concomitant drugs, detailed clinical course, further investigations and treatment details of the events was available in the report. The events were not resolved. The benefit-risk relationship of mRNA-1273 is not affected by this report.