A 52-year-old man with a history of hypertension presents to the emergency department with a 2-hour history of substernal chest pain that resolved 30 minutes before arrival. He is currently pain-free and hemodynamically stable. His 12-lead ECG is shown. The structure marked **B** in the diagram demonstrates symmetric deep T-wave inversion in V3. Which of the following best describes the clinical significance of this finding in the context of his presentation?