sexta-feira, 22 de julho de 2011

Abnormal carotid IMT results change physician, but not patient, behaviors - from theheart.org

Madison, WI - Abnormal findings on an office-based carotid ultrasound test results in physicians changing their use of aspirin and cholesterol-lowering medications, including setting more aggressive lipid and blood-pressure targets [1]. Patients, on the other hand, failed to make changes to their diet or increase physical activity levels, and in some instances, even failed to quit smoking, despite an increased awareness of their cardiovascular-disease risk.

"This isn't a randomized clinical trial, and obviously that's a weakness," senior investigator Dr James Stein (University of Wisconsin School of Medicine, Madison) told heartwire. "But the most interesting finding in this study is that the results of the carotid ultrasound didn't really affect the patients. We know that when doctors see abnormalities on a calcium scan or carotid ultrasound, they are very inclined to do things, like prescribe aspirin and have more aggressive targets for cholesterol and blood pressure. We also know that patients say they're going to do all kinds of things, but after one month in this trial those intentions were already extinguished."

The results of the study are published in the July 2011 issue of the Journal of the American Society of Echocardiography.

Increased carotid intima-media thickness (IMT) and the presence of carotid plaque are independent predictors of future cardiovascular-disease events, and carotid ultrasound screening has been recommended as a tool to help risk prediction, particularly in intermediate-risk patients, such as those with a 6% to 20% risk of MI or coronary heart disease over 10 years. The devices have also become more widespread in clinical practice—some of today's inexpensive carotid ultrasound systems are handheld—and are being used by nonsonographer physicians to identify increased carotid IMT and carotid plaque.


Community-based practices

In the present study, led by Dr Heather Johnson (University of Wisconsin School of Medicine, Madison), the researchers identified 355 subjects who underwent carotid ultrasound screening at five nonacademic community practices in the US. Patients were >40 years of age and had at least one cardiovascular disease risk factor. Of these subjects, 75% had an abnormal result on the carotid ultrasound, defined as carotid IMT >75th percentile or the presence of carotid plaque.

For the physicians, an abnormal finding on the ultrasound resulted in a change in the LDL-cholesterol target for the patient. In one-third of the patients with abnormal results, the physicians decreased the LDL-cholesterol target from 130 mg/dL to 100 mg/dL and decreased the LDL-cholesterol goal from 100 mg/dL to 70 mg/dL in another 21% of patients. Similarly, for those with an abnormal result, the doctors altered systolic blood-pressure goals from 140 mm Hg to 130 mm Hg. Physicians were also more likely to prescribe aspirin in patients with an abnormal ultrasound result. Overall, 26% of patients were started on aspirin, while 10% had increases in the baseline aspirin dose.

LDL-cholesterol and systolic blood pressure targets were not changed in patients with normal carotid ultrasound results, while just three subjects with a normal ultrasound were prescribed aspirin.

For the patients, the presence of an abnormal carotid ultrasound predicted intentions to change health-related behaviors. For example, these patients stated they would attempt to achieve their exercise goals and to change their diet to lower LDL-cholesterol levels, such as decreasing saturated-fat intake. In the small group of smokers, they also stated an intention to quit smoking. At 30 days, however, just 34% of patients increased their exercise frequency and just 37% lost weight. The presence of an abnormal ultrasound result did not predict the increase in exercise frequency or weight loss.

"The very act of screening people heightens their attention to health-related behaviors," said Stein. "It makes perfect sense to doctors that if you show somebody a picture and you scare them they'll be motivated to change their behavior. But really, motivation is on the doctor's side. There is ample evidence now showing that a one-time intervention really doesn't last very long, and this study showed that, too."

Stein told heartwire that physicians need to be humble and realize that patient psychology is more complicated than efforts to scare them into change. He said that patients appear to change their behavior, such as losing weight or eating healthily, only if they feel these changes are possible for them. Regardless of the risk, patients tend to simply avoid their physician or ignore their advice, if they feel the changes are impossible.

"The only thing that seems to work is case management, where you have repeated encounters with the healthcare system," said Stein. "Patients get feedback on their progress, you help them solve problems, and you work with them through setbacks. These are the only things that have been shown to work in terms of changing patient behaviors. We need a systems-based approach to make sure that patients are coming in for screening and rescreening, to make sure they are complying with their medication and have more encounters with the healthcare system. And it doesn't have to be doctors—it could be nurses, exercise physiologists, or dieticians. People who can really give them the guidance

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