Which of the following would be considered a contraindication to cardiac rehabilitation?

A resting diastolic pressure of 115 mm Hg is recognized as a contraindication to cardiac rehabilitation because it indicates significant hypertension that could pose serious risks during physical activity. When diastolic pressure is elevated above normal levels, it can lead to increased workload on the heart and potential cardiovascular complications. In a rehabilitation setting, monitoring heart rate and blood pressure is crucial, and such high levels of diastolic blood pressure suggest that the patient's cardiovascular system may not be adequately prepared for the stress of exercise, thereby increasing the risk of adverse events.

Conversely, while a resting systolic pressure of 185 mm Hg is also elevated and should be monitored, it is not as absolute a contraindication as the diastolic pressure scenario. Similarly, a resting ST segment displacement of 1 mm and stable angina can be relevant clinical considerations, but they do not prevent participation in cardiac rehabilitation if managed appropriately. Stable angina may indicate an underlying coronary artery condition; however, it can often be addressed within a rehabilitation program under careful supervision. Thus, elevated diastolic blood pressure stands out as a clear contraindication due to the associated higher risk of acute cardiovascular events during rehabilitation efforts.