Suspected heart attack; Severe Chest and arm pain; Severe Chest and Arm pain; The injection site became hot to the touch; Itching injection site; Painful Injection Site; Hard to the touch; Raised red spot on the injection site; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of MYOCARDIAL INFARCTION (Suspected heart attack), CHEST PAIN (Severe Chest and arm pain) and PAIN IN EXTREMITY (Severe Chest and Arm pain) in a 52-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 025B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 12-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 19-Apr-2021, the patient experienced VACCINATION SITE INDURATION (Hard to the touch) and VACCINATION SITE ERYTHEMA (Raised red spot on the injection site). On 20-Apr-2021, the patient experienced VACCINATION SITE WARMTH (The injection site became hot to the touch), VACCINATION SITE PRURITUS (Itching injection site) and VACCINATION SITE PAIN (Painful Injection Site). On 21-Apr-2021, the patient experienced MYOCARDIAL INFARCTION (Suspected heart attack) (seriousness criteria hospitalization and medically significant), CHEST PAIN (Severe Chest and arm pain) (seriousness criterion hospitalization) and PAIN IN EXTREMITY (Severe Chest and Arm pain) (seriousness criterion hospitalization). The patient was hospitalized from 21-Apr-2021 to 22-Apr-2021 due to PAIN IN EXTREMITY, and then on 21-Apr-2021 due to MYOCARDIAL INFARCTION. On 27-Apr-2021, VACCINATION SITE WARMTH (The injection site became hot to the touch), VACCINATION SITE PRURITUS (Itching injection site), VACCINATION SITE INDURATION (Hard to the touch), VACCINATION SITE ERYTHEMA (Raised red spot on the injection site) and VACCINATION SITE PAIN (Painful Injection Site) had resolved. On 29-Apr-2021, MYOCARDIAL INFARCTION (Suspected heart attack), CHEST PAIN (Severe Chest and arm pain) and PAIN IN EXTREMITY (Severe Chest and Arm pain) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 21-Jan-2021, Echocardiogram: normal (normal) normal. On 21-Jan-2021, Electrocardiogram: normal (normal) results. On 21-Jan-2021, Myocardial necrosis marker: raised Raised. On 21-Jan-2021, Oxygen saturation: normal (normal) normal.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.       On 21-Apr-2021, the patient had severe chest and arm pain. She went to the emergency room. The ER doctor suspected a heart attack. She was hospitalized overnight under observation and was released the next day.  No relevant concomitant medications were provided.  No treatment information was provided.  Company Comment: Very limited information regarding the events (Myocardial infarction) has been provided at this time. However, based on the current available information and temporal association between the use of the product and the start date of the event (chest pain, pain in extremity and others), a causal relationship cannot be excluded. Additional information regarding medical history, concomitant medications, levels of troponin (I or G) are required for further evaluation.; Sender's Comments: Very limited information regarding the events (Myocardial infarction) has been provided at this time. However, based on the current available information and temporal association between the use of the product and the start date of the event (chest pain, pain in extremity and others), a causal relationship cannot be excluded. Additional information regarding medical history, concomitant medications, levels of troponin (I or G) are required for further evaluation.