New research shows that you don't have to have a blockage in your coronary arteries to be at high risk for a heart attack.
This is something doctors largely knew, but the new study of U.S. military veterans who had undergone tests for blockages provides data to back up instances of a condition known as non-obstructive coronary artery disease. "You do have some atherosclerosis, or hardening of the arteries - that lining of the artery. It's not enough to limit blood flow, and yet every once in a while, it can get worse in a big hurry and cause a heart attack," said Dr. Charles Orr, a cardiologist at St. Vincent Heart Center in Indianapolis.
Researchers looked at data from nearly 41,000 veterans who had an angiography between 2007 and 2012. It showed that even those who had non-obstructive heart disease had an increased risk of heart attack or death of up to 44-percent. Some doctors previously thought the risk of heart attack was minimal unless an artery was actually blocked. Orr compared it to a blockage in a water hose. "You have to have a pretty tight blockage in a hose before the water pressure is decreased. But you can have mild calcium or lime buildup, still have excellent flow, and yet it's not quite normal."
What's worse is that non-obstructive heart disease does not cause the same warning signs of a heart attack caused by blocked arteries. "They don't show up on treadmill stress tests, even if those were perfectly accurate - which they are not. The blood flow is not limited, so there is no chest discomfort, shortness of breath or fatigue," Orr said. What can happen, however, is a plaque deposit can break away inside an artery and cause a heart attack.
There is a screen that helps doctors see non-obstructive heart disease called the coronary calcium score. "It correlates with overall plaque burden, or how much atherosclerosis is present," Orr said. "It's better in people 55 or over." Orr says if such a test shows you do have some plaque buildup, you ought to begin taking preventative measures, such as taking an aspirin a day, lowering cholesterol and controlling your blood pressure.