Friday, July 13, 2018

Cardiovascular Disease: Risk Assessment with Nontraditional Risk Factors

Cardiovascular disease is the most common cause of death among adults in the United States. Treatment to prevent CVD events by modifying risk factors is currently informed by the Framingham Risk Score, the Pooled Cohort Equations, or similar CVD risk assessment models. If current CVD risk assessment models could be improved by adding more risk factors, treatment might be better targeted, thereby maximizing the benefits and minimizing the harms.

Detection - The USPSTF found adequate evidence that adding the ABI, hsCRP level and CAC score to existing CVD risk assessment models may improve calibration, discrimination and reclassification. The USPSTF chose to review these 3 nontraditional risk factor because prior evidence reviews identified them as the most promising to improve on existing CVD risk assessment tools.

Benefits - The USPSTF found inadequate evidence to assess whether treatment decisions guided by ABI, hsCRP level, or CAC score test results, when added to existing CVD risk assessment models, lead to reduced incidence of CVD events or mortality.

Potential Harms – Testing for hsCRP level and the ABI is noninvasive, and there is little direct harm from the tests. Harms of testing for CAC score include exposure to radiation and incidental findings on computed tomography of the chest, such as pulmonary nodules, that may lead to further invasive testing and procedures. Abnormal test results may lead to further testing, procedures, and lifelong medication use without proof of benefits but with expense and potential adverse effects for the patient. Psychological harms may results from reclassification into a higher-risk category for CVD events.

Current Practice – Only 1 of the risk assessment models currently used in the United States, the Reynolds Risk Score, incorporates hsCRP level into its risk calculation. A number of guidelines, including those from the American College of Cardiology and the American Heart Association, recommend considering hsCRP level, the ABI, or CAC score to clarify treatment decisions for patients whose risk assessment is borderline or unclear using a traditional risk assessment model.

Screening Tests – The Framingham Risk Score and, more recently, the Pooled Cohort Equations have both been documented to overestimate and underestimate risk in some persons. Therefore, identification of additional tests (for nontraditional risk factors) that could improve risk prediction, including the ABI, hsCRP, and CAC score, is of interest.

The ABI is the ratio of the systolic blood pressure at the ankle to the systolic blood pressure at the brachial artery. A value of less than 0.9 indicates peripheral artery disease.

High-sensitivity C-reactive protein is a serum protein involved in inflammatory and immune responses. Testing for hsCRP level involves a single blood sample, and the test is widely available.

Coronary artery calcium score is obtained by computed tomography, which measure the calcium content of the coronary arteries.

My Take:
When you read this do you come to the same conclusion as the USPSTF? I don’t. When I measure serum lipids, I also run a hsCRP. It’s part of my basic profile.

The ABI is a simple examination process with no cost, that’s a “no-brainer.”

The CAC does have some cost (under $200) and radiation risk (much less than the routine chest x-ray performed on entry to every hospital in the US). I don’t run this test often but will, as the ACC and AHA suggest, use it with borderline cases. I typically recommend it prior to a cardiac stress test which runs about $6,000.

The Bottom Line:
The real problem is that the current models basically use age and cholesterol levels to find that virtually everyone over the age of 45 is a risk and needs statin drugs. That is not prevention, that’s medication of the masses.

Take all these risk assessment tools, then improve your lifestyle with diet, exercise and nutritional supplementation. Repeat the tests and note the improvement – that’s prevention.

Source: July 10, 2018 US Preventive Services Task Force (USPSTF)

No comments:

Post a Comment

Comments Await Approval Before Posting