NEW YORK (Nov. 9, 2007) -- In 9 out of 10 cases, a burst abdominal aortic artery is quickly fatal for its most common victim: elderly males. A new study -- the largest yet performed -- now confirms that women over 65 with a history of smoking or heart disease are also at high risk for an abdominal aortic aneurysm (AAA) -- supporting the notion that they should also receive ultrasound screening to help spot and correct the dangerous condition.
The findings, reported in the Journal of Vascular Surgery, challenge current recommendations on AAA screening issued by the United States Preventive Services Task Force. Those guidelines recommend that screening only be performed -- and reimbursed by Medicare -- for men aged 65 to 75 who have ever smoked.
The Task Force ruled against screening for older women, citing a lack of evidence to support the cost-effectiveness of such a move.
"That left us scratching our heads," says the study's senior author, Dr. K. Craig Kent, chief of vascular surgery at NewYork-Presbyterian Hospital, the Greenberg-Starr Professor of Surgery at Weill Cornell Medical College and professor of surgery at Columbia University College of Physicians and Surgeons. "We know that AAA kills up to 30,000 Americans each year, with the ratio of males to females at about 4 to 1. But that still means that thousands of American women will die from this type of event each year. We wanted to discover whether certain subgroups of women might be at especially heightened risk and therefore benefit from screening."
An AAA occurs when a bubble-like swelling occurs in a portion of the aorta, the major artery that carries blood from the heart through the abdomen to the lower body. As this 'bubble' swells over time, the artery wall can thin out and rupture.
Ruptures can occur suddenly and typically prove fatal. In fact, 85 percent of people who suffer a ruptured AAA die before making it to the hospital, and only half of the 15 percent who do receive hospital care survive the attack.
"That's why detecting these aneurysms early and monitoring or repairing them is crucial," Dr. Kent says.
But right now, doctors are actually being advised against providing their female patients with the 10-minute ultrasound test that could spot the problem. The noninvasive test itself is relatively inexpensive (about $40) and is often bundled with other diagnostic screens.
In the new study, Dr. Kent and colleagues recruited 17,540 patients from 100 hospitals and clinics spread across the United States. Overall, the cohort included 10,012 women over the age of 65 (average age 69.6 years) and 7,528 men over the age of 60 (average age 70).
Patients were questioned as to their demographics, history of smoking and medical histories. They also underwent conventional AAA ultrasound screening.
Overall, AAA showed up in 291 (3.9%) of the men and 74 (0.7%) of the women -- similar to the usual rate. But certain subgroups of women fared much worse. For example, women over age 65 were more than four times as likely to have this type of aneurysm than women younger than 65, and that risk grew by 10 percent with every added year of age.
Women with a history of smoking, or a history of heart disease (i.e., a prior heart attack or coronary bypass) faced triple the risk of AAA, the researchers found.
Any combination of the above risk factors boosted a woman's odds of AAA by up to six-fold, the team found.
"The bottom line, in terms of the cost-effectiveness of screening older women, is that these tests are probably not useful for the general population, but are certainly warranted for women over 65 with risk factors such as smoking and a history of heart disease," Dr. Kent says. "In fact, having just one of those risk factors alone may also indicate a need for screening, based on a discussion between the patient and her doctor."
"We hope that this data provides the evidence that the Task Force and others in the field have needed to push for screening of AAA in at-risk females," Dr. Kent says. "Women can also benefit greatly from this data, as they decide with their doctors whether or not testing is right for them."
Patients enrolled in the study were screened through the Stroke and Aneurysm Vascular Evaluation (SAVE) Program, which is sponsored and funded by medical device maker Medtronic Inc., of Minneapolis, and conducted by Life Line Screening, Cleveland.
|Contact: Emily Berlanstein|
New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College