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					A scan 
					of calcium deposits inside the arteries can help doctors 
					deduce how long the patients likely to live, a new study has 
					found. The test, called a coronary calcium scan, uses a 
					regular CT scan to look for calcium deposits in the three 
					major arteries that carry blood away from the heart, lead 
					author said. People with the largest amounts of calcium in 
					their arteries carry an early death risk that's six times 
					greater than those with no calcium deposits, researchers 
					found in a 15-year study of nearly 10,000 patients. "If 
					people had no calcium or very small amounts, we were able to 
					track over a very long time that they actually had a very 
					outstanding survival," she said. Calcium deposits develop as 
					a response to plaque formation along the artery walls, she 
					added. These plaques, which are caused by blood cholesterol, 
					build up over time and cause arteries to narrow, leading to 
					heart disease as the heart works harder to pump blood 
					through the body. If a plaque bursts, a blood clot can form 
					on its surface, blocking blood flow and causing a heart 
					attack. If the clot breaks free, it can flow into the brain 
					and cause a stroke. To prevent plaques from bursting, the 
					body tries to harden them by depositing calcium salts over 
					and around them, lead author said. Doctors learned in the 
					1990s that these calcified plaques show up on CT scans, and 
					can be used to determine whether a person is suffering from 
					hardening of the arteries, she said. Up to now, however, 
					there's been little evidence showing that a calcium scan can 
					provide a solid assessment of a person's long-term health 
					risk, the study authors said. Most studies involving these 
					scans have a follow-up of five years or less. In this new 
					study, doctors referred 9,715 healthy patients in the 
					Nashville area between 1996 and 1999 to a cardiology 
					outreach screening program provided by the military's 
					Tricare Healthcare System. The patients underwent a calcium 
					scan, and also provided a detailed history of their heart 
					risk factors. Researchers then tracked the participants for 
					roughly 15 years, taking special note of the 936 patients 
					who died. Analysis revealed that the risk of premature death 
					steadily increased with the amount of calcium deposits found 
					in a person's major arteries. Patients with small levels of 
					arterial calcium had a 68 percent increased overall risk of 
					death, compared to those with no calcium deposits at all. 
					But people with the largest calcium deposits in their 
					arteries had a death risk six times greater than those with 
					no calcium. The results of a calcium scan can be reassuring 
					for people with few or no calcium deposits, and can provide 
					people with high calcium levels with added impetus to take 
					better care of themselves, lead author added. "It can be a 
					very potent motivator," she said. People with many calcium 
					deposits can improve their long-term prospects by eating 
					right, exercising, and taking medication to treat heart risk 
					factors such as high blood pressure, elevated blood 
					cholesterol and type 2 diabetes, she said. Lead author 
					thinks calcium scans ultimately could become part of a 
					person's regular physical exam, as common as blood 
					cholesterol tests. |