January 14, 2008
Organized Medicine Warned on "Entrepreneurial” Guidelines
Professional medical societies should actively oppose legislative health care mandates that rely on clinical practice guidelines produced by “entrepreneurial activity,” a commentary in last week’s Journal of the American Medical Association argued. The article was triggered by the Screening for Heart Attack Prevention and Education (SHAPE) Task Force Report, which appeared in a Pfizer-funded supplement to the July 2006 American Journal of Cardiology.
The SHAPE guideline called for non-invasive screening for “subclinical atherosclerosis” through tests such as ultrasound or CT scans for all men 45 to 75 and all women 55 to 75 who are considered more than minimally at risk for a heart attack or stroke. Legislation has been introduced in Texas that would require insurance companies to cover the tests.
The SHAPE task force was created by the Houston-based Society for Heart Attack Prevention and Eradication, which was created in 2001 by Morteza Naghavi. He advises and receives research support from Pfizer, manufacturer of cholesterol-reducing Lipitor, and consults for and owns stock in Endothelix, which makes a fingertip thermal measuring device that purports to reveal heart attack risk. The FDA approved the device last November even though it has never been studied in a randomized clinical trial.
Naghavi was also the lead writer on the SHAPE guideline. Twelve of 26 co-authors disclosed ties to drug and imaging equipment manufacturers. While the others claimed they had no financial ties to "a corporate organization or a manufacturer of a product discussed in this supplement," many had industrial ties on related subjects or are radiologists, who have a financial stake in increasing the number of cardiac imaging tests.
In his commentary, University of Michigan law professor Peter Jacobson called on the American College of Cardiology (ACC) to convene a consensus panel to determine the objectivity and scientific efficacy of the SHAPE guidelines. Previous reviews have concluded CT scans for measuring atherosclerosis are not superior to other diagnostic tests and generate a high rate of false positive results.
After reviewing the conflicts of interest among the writers of the guideline, Jacobson called on organized medicine to develop criteria for acceptable clinical practice guidelines. "Only those guidelines that meet the criteria should be endorsed," he wrote. However, he opposed banning conflicts of interest on CPG-writing panels. "I'm dubious that it's possible to find an expert committee to draft guidelines that has zero conflicts of interest," he said.
This story first appeared in Integrity in Science Watch, a publication of the Center for Science in the Public Interest.
Both the American Heart Association Guidelines (Mieres et al 2005 and Budoff et al 2006) on the topic have concluded CT scans for measuring atherosclerosis ARE superior to traditional risk factors in stratifying risk. This was further confirmed by the American College of Cardiology Expert Consensus Document on coronary calcium scanning with CT, which was also endorsed by the American Heart Association, Soceity of Atherosclerosis Imaging and Prevention, and the Society of Cardiovascular CT.
Furthermore, there are virtually NO false positive results with calcium scanning. A positive calcium scan is associated with atherosclerosis (plaque in the coronary arteries) and this raises the likelihood of both heart attacks and strokes. This was recently confirmed by a large multicenter trial performed by the National instutes of health (Multi-Ethnic Study of Atherosclerosis)
The above comment is misleading as :
1. it does not define terms and confuses "atherosclerosis" which almost everyone has, particularly as we age, with clinical heart
disease (heart attacks and related mortality), which is much less common and the clinically important endpoint. While coronary calcium indicates the common finding of atherosclerosis, it does NOT mean there is clinically important heart disease (nor that there will EVER be clinically important heart disease). thus there are many false positives from CAC scans.
2. The Mieres et al statement states that data on CAC is limited and more data is needed, I have copied it below. In addition, there are NO studies that show that CAC testing leads to better outcomes. Traditional cardiac risk factors (Framingham risk score) can be treated to reduce cardiac risk, coronary calcium cannot be treated and leads to anxiety when identified, without any benefit to patients.
Mieres et al ---- “Summary Coronary Artery Calcification (CAC).
For the clinical indication of risk stratification in asymptomatic women, the available data are limited to a few
reports. Given the evolving literature since the last ACC/
AHA Expert Consensus statement current data indicate
that CAD risk stratification is possible in women. Specifically,
low CAC scores are associated with a low adverse
event risk, and high CAC scores are associated with a
worse event-free survival. Additional high-quality
data are needed from larger cohorts that specifically
address CAD outcomes in women to more precisely
establish female-specific CAC risk cut points and to more
precisely quantify the incremental prognostic value beyond
the measurement of conventional coronary risk
factors. Until then, consistent with recent consensus statements,
CAC testing for CAD risk detection should be
limited to clinically selected women at intermediate risk.”