Final answer:
Regular exercise does not contribute to coronary ischemia; it is beneficial for cardiovascular health by reducing the risk of plaque formation and blockage of coronary arteries. Therefore, the correct option is 3.
Step-by-step explanation:
The factor among the options that does NOT contribute to the partial or complete blockage of the coronary arteries causing coronary ischemia is regular exercise. High blood pressure, high cholesterol levels, and smoking are all factors that can lead to the development of coronary artery disease by contributing to the buildup of plaque, a process known as atherosclerosis. In contrast, regular exercise is a preventive measure that improves cardiovascular health and reduces the risk of plaque formation. Hence, regular exercise is beneficial and does not contribute to the blockage of coronary arteries.