Worsening stable angina is reclassified as which condition?

• A. Stable angina
• B. Unstable angina
• C. Myocardial infarction
• D. Variant angina

Answer: (B)

When angina becomes worse than the patient’s usual pattern, it shifts from stable to unstable. Stable angina is predictable, provoked by exertion, and relieved by rest or nitro. If the pain appears more frequently, lasts longer, occurs at rest, or is new in onset, this is unstable angina—an acute coronary syndrome reflecting more precarious coronary blood flow. Unstable angina indicates ongoing ischemia without evidence of myocardial necrosis yet, so troponin is typically not elevated. By contrast, a myocardial infarction would show troponin elevation due to heart muscle damage, and variant angina is caused by vasospasm with transient ECG changes rather than progression of atherosclerotic plaque. So worsening stable angina is best categorized as unstable angina.