Stephen Yau, 54, was an avid swimmer who covered 2,500 metres in the pool every day. But he was also a chain smoker with a history of high cholesterol and hypertension, which put him at high risk for coronary artery disease. This condition causes 68 per cent of heart-related deaths in Hong Kong.
Yau (name changed for reasons of patient confidentiality) was concerned about his health, and a close friend urged him to see Dr Albert Leung Wai-suen, a cardiologist, for a thorough check-up.
Given Yau's age, sex, lifestyle and medical history, Leung recommended a non-invasive CT coronary angiogram to assess the health of Yau's arteries. This allowed Leung to take a good look at the state of Yau's arteries with minimal risk. First Yau was intravenously given an iodine-containing contrast to make his blood vessels show up clearly under the scanners before images were taken of his coronary arteries.
According to the scan results, Yau's right coronary artery, which supplies oxygen-rich blood to the heart, was severely narrowed in two places. A hard substance called plaque, caused by the cholesterol, had adhered to the internal artery surface and caused his artery to narrow by 80 per cent in one place and 50 per cent in another. He had atherosclerosis, and the narrowed artery walls were reducing blood flow to his heart.
Yau was also in grave danger of a fatal heart attack. Lack of sleep, an angry outburst or even a mild illness - anything that stressed his body - could cause the plaque in the artery to rupture. If it did so and entered the blood stream, his body would form a blood clot in an effort to repair the damage caused by the ruptures. But the clot could completely block the artery instead. Given that the plaque-narrowed sites were so close to the root of the artery, any blockage would most certainly cut off blood supply to Yau's heart, starving it of oxygen and causing the heart muscle to stop working, Leung says.
Next Leung needed to look inside the lesions to confirm the severity of Yau's condition using a conventional coronary angiogram. Leung inserted a catheter into Yau's radial artery on his right wrist and worked it up to the affected coronary artery. Using a tiny probe in the catheter, Leung took cross-sectional images of the narrowed areas in the artery. The angiogram results confirmed the findings.