Dear Dr. Roach: I am an 81-year-old man (5 feet, 2 inches tall at 122 pounds) in good health, except that I have Type 2 diabetes. My A1C level has been in the range of 6.3% to 6.8% for the past five years with the help of metformin. Five times a week, I walk on a treadmill for 15 minutes (about a mile) with 25 minutes of stretching exercises, and I don’t have any chest pain or shortness of breath.

A couple of my friends in similar situations took the nuclear stress test (due to age and diabetes); one ended up with two stents, and another underwent triple bypass surgery. Neither had any prior symptoms due to the blockages.

So, I decided to see a cardiologist for the first time in my life. He recommended the nuclear stress test just to rule out any possible blockages. The test was over in less than 15 minutes, and all came out normal. However, he also recommended the calcium score test.

I talked to my primary care physician, and he said that he recommends the calcium score test first. If it indicates a problem, then he recommends the stress test afterward. Should I take the calcium score test even though the result of my stress test was normal?

— K.

Answer: A stress test and a CT calcium score are both ways of evaluating a person for blockages in the arteries of the heart. The likelihood of having blockages for a man with diabetes at age 81 is high.

Most authorities don’t recommend screening tests, and many cardiologists recommend treating you as though you already had blockages in your arteries. They’ll prescribe the appropriate medications, which are effective in reducing your risk of heart attack and death. However, there are some situations where screening is reasonable.

A stress test and a calcium score test are complimentary tests. The stress test looks for changes in blood flow to the heart at rest and during exercise, which indicates a high likelihood of a blockage. The “nuclear” part refers to a radioactive dye that enhances the ability of the test to make the diagnosis, compared to a “regular” stress test that just looks at the electrocardiogram. However, a stress test can’t detect very small blockages that don’t affect blood flow but still have the ability to rupture and cause a heart attack.

The calcium score looks for calcium in the wall of the cardiac blood vessels. Most blockages, especially in someone your age, contain calcium; however, not all calcified blood vessels have blockages. A negative calcium score is a very good predictor that a heart attack is unlikely.

The combination of a stress test and a calcium score test gives more information than either one does separately. The downside of a CT calcium score is a modest additional dose of radiation, in addition to the financial cost. In your case, if the calcium score wasn’t zero, most experts will recommend medication, such as a statin and an aspirin, to reduce your risk, in addition to even more stringent advice on diet, exercise, and maintaining excellent blood sugar and blood pressure levels.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.