Which of the following is a potential consequence of sudden discontinuation of antianginal medication?

Sudden discontinuation of antianginal medication can lead to rebound angina, which is a significant concern for patients managing angina pectoris or ischemic heart disease. Antianginal medications, especially those that help to regulate blood flow and oxygen delivery to the heart (like nitrates or beta-blockers), work to stabilize the cardiovascular system. When these medications are abruptly stopped, the body may experience a "rebound" effect that can lead to a resurgence of angina symptoms. This rebound angina occurs because the underlying issues that the medication was addressing return more severely, often resulting in increased frequency and intensity of angina episodes.

This is not to say that the other options are accurate in this context. For example, decreased risk of heart attack and improved exercise tolerance are not typically associated with stopping medications abruptly. Similarly, while blood pressure may change due to a variety of reasons, one would not expect it to lower immediately in a consistent or beneficial manner without the medication that helps regulate it. Hence, the specific and acute risk associated with stopping antianginal therapy is indeed the development of rebound angina.