Which signs may indicate worsening angina?

The correct choice identifies key indicators of worsening angina. The increase in frequency, duration, or severity of anginal attacks suggests that the underlying cardiac condition may be deteriorating. Worsening angina could point to more significant myocardial ischemia, which needs prompt evaluation and management.

An increase in symptoms can imply that the heart's oxygen supply is inadequate to meet its demands, a potential warning sign that the patient may be at higher risk for more severe cardiovascular events. Regular monitoring of these symptoms is critical in managing patients with known coronary artery disease or angina.

In contrast, decreased exercise capacity, improved tolerance to stressful activities, or the disappearance of symptoms do not indicate the same level of concern regarding angina worsening. For instance, decreased exercise capacity might result from various factors, not necessarily linked to increased heart risks. Improved tolerance often suggests better management or adaptation and is a favorable sign. The disappearance of symptoms can indicate effective treatment or a remission in angina, further highlighting why these options do not represent signs of worsening angina.