What test would NOT be performed for a suspected myocardial infarction?

A complete blood count (CBC) is primarily used to assess overall health and to detect a variety of conditions, such as infections, anemia, and some blood disorders. While a CBC can provide useful information about the patient’s general health status and can help identify any concurrent issues, it is not a specific test for diagnosing myocardial infarction (MI).

In contrast, an electrocardiogram (ECG) is a crucial diagnostic tool for MI as it can identify characteristic changes in the heart's electrical activity that occur during an infarction. Troponin levels are highly specific and sensitive markers for myocardial injury, making them essential for confirming the diagnosis of MI. A chest X-ray may also be performed to rule out other causes of chest pain, such as aortic dissection or pneumothorax, and to assess the heart size and pulmonary conditions.

Thus, while CBC can provide supplementary information about a patient's overall health, it does not aid in the direct diagnosis of myocardial infarction, making it the least relevant choice among the options provided.