Study Casts Doubt On Value Of Genetic Testing For Familial Hypercholesterolemia Reply

new study published online in the Lancet suggests that one of the main screening plans that relies on genetic tests will fail to identify a substantial portion of people with familial hypercholesterolemia.

Investigators from the UK and Belgium analyzed DNA from several cohorts of FH and non-FH patients. Their chief finding was that a large percentage of FH patients did not have one of the single genetic mutations known to cause FH. Instead, these patients, termed “polygenic,” were found to have variants in multiple genes, each of which had a small LDL-raising effect, but when combined resulted in LDL levels similar to those in people with known FH mutations.

According to one cholesterol expert: 

The take home is that genetic screening is not a panacea and that screening based on fasting ipids makes most sense. Indeed, I never understood genetic screening for this disease anyway, since the phenotype (hypercholesterolemia) is what kills people, not the genotype, the phenotype is readily available with a blood test, the disease is not immediately fatal (It takes years to develop), and treatment is based on the numbers. It is like asking for a gene test fro sickle cell anemia. You can look at blood and make the diagnosis.

Click here to read the complete story on Forbes.

 

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Model Finds High Cost For ECG Screening Of Athletes 2

A national program of ECG screening for U.S. athletes would save almost 5,000 lives over 20 years but would cost more than $50 billion dollars, according to a paper published in the Journal of the American College of Cardiology. The advisability of routine ECG screening for athletes has divided the experts: currently the ESC recommends ECG screening while the American Heart Association does not.

Israeli investigators developed a cost-projection model using data from a retrospective Italian study and based on population data derived from high school and college athletic associations and expense assumptions from Medicare. Currently there are more than 8.5 million student athletes. Over 20 years, the investigators predicted that a national screening program would result in 170 million ECG screenings and, based on an estimated 2% disqualification rate, 3.4 million disqualifications. This would cost between $51 and $69 billion dollars and save 4,813 lives, yielding a cost per life saved in the range of $10.6 to $14.4 million.

In an accompanying editorial comment, Antonio Pelliccia takes issue with the cost assumptions in the paper and maintains that pre-participation screening “should be priced as a package of preventive medicine program” rather than the more expensive individual diagnostic testing. He acknowledges that this “will require a change in the cultural attitude and current medical policy” in the U.S.

In a statement, the ACC said that automatic external defibrillators (AEDs) can be life saving “if used quickly on stricken athletes.” However, although AEDs are now commonly placed at sports venues and other public places, they “are only effective if actually used” and bystanders are often afraid to use them. “AEDs are life-saving,” said Joanne Foody, in the ACC statement. “While many fear they may cause more harm than good, it is not the case.”

Click here to read the ACC press release…

UK Study Casts Doubts On Value Of Type 2 Diabetes Screening Reply

The dramatic growth in type 2 diabetes has resulted in increased interest in screening programs. Now a new study published in the Lancet raises concerns that screening programs may not result in long-term improvement in outcomes.

In the ADDITION-Cambridge study, investigators in the UK randomized general practices to either screening or no screening.  The practices allocated to screening were further divided to either intensive cardiovascular risk reduction or standard care. The study population included more than 20,000 adults 40-69 years of age at high risk for undiagnosed diabetes.

3% of patients in the screening groups received a diagnosis of diabetes. After a median followup of 9.6 years, there were no significant differences between the screened population and the control group.

Rate per 1,000 person-years and hazard ratios for the no-screening and the screening group:

  • Mortality: 9.89 versus 10.50, 1.06 (CI 0.90-1.25)
  • CV mortality: 3.25 versus 3.30, 1.02 (0.75-1.38)

The authors proposed several explanations for the lack of benefit associated withs screening, including ad-hoc screening outside the practice setting in the unscreened group, patients who did not follow the screening program, and concurrent gains in identifying and managing other cardiovascular risk factors during the study period. In addition, the patient population in the study may have been a relatively healthy population with a lower prevalence of undiagnosed diabetes.

The authors concluded that “if population-based screening for diabetes is to be implemented, it should be undertaken alongside assessment and management of risk factors for diabetes and cardiovascular disease and population level preventive strategies targeting underlying determinants of these diseases.”

In a Lancet press release, senior author Simon Griffin said that “the benefits of screening might be smaller than expected and restricted to individuals with detectable disease.  However, benefits to the population could be increased by including the detection and management of cardiovascular risk factors alongside the assessment of diabetes risk, performing repeated rounds of screening, and improving strategies to maximize the uptake of screening.”

In an accompanying comment, Michael Engelgau and Edward W Gregg write that prevention programs should screen not just for diabetes but for high-risk individuals as well, though they note that this strategy “assumes that effective prevention programs are available to high-risk cases.” Further, the value of screening depends “on more than just mortality as an outcome,” and will need to include morbidity, quality of life, and costs.
Click here to read the Lancet press release…

Screening For AAA Comes Under Renewed Scrutiny And Criticism Reply

A 2007 Medicare initiative to increase AAA (abdominal aortic aneurysm) screening in appropriate patients failed to prevent AAA rupture or reduce all-cause mortality, according to a new study published in Archives of Internal Medicine. The larger implications of the study are unclear, but two accompanying papers, an invited commentary and a perspective, emphasize the darker side of AAA screening.

Jacqueline Baras Shreibati and colleagues examined the effect of the 2007 Screening Abdominal Aortic Aneurysms Very Efficiently (SAAAVE) Act which provided Medicare coverage for a one-time ultrasound screening for new Medicare patients who were men and who had a history of smoking or women with a family history of AAA. The SAAAVE Act was based on 2005 US Preventive Services Task Force recommendations.

Using Medicare data from 2004 to 2008, the investigators found a modest increase in AAA screening among eligible 65-year-old Medicare men during the study period, from 7.6% in 2004 to 9.6% in 2008. The SAAAVE Act resulted in no significant differences in the rates of AAA repair, AAA rupture, or all-cause mortality, they concluded.

In an invited commentary, Russell Harris, Stacey Sheridan, and Linda Kinsinger write that the evidence about AAA screening has changed since the 2005 USPSTF recommendations. In the past 10-15 years, they write, mortality from ruptured AAA has been cut nearly in half. AAA screening, they maintain, has had little to do with this change; rather, the change is more likely due to long term trends in the reduction of smoking prevalence and the incidence of MI.
Click to continue reading…

USPSTF Maintains Recommendation Against ECG Screening Of Asymptomatic Low-Risk Adults Reply

The  US Preventive Services Task Force (USPSTF) has reaffirmed its 2004 recommendation against ECG screening for asymptomatic adults who are already at low risk for coronary heart disease (CHD). The Task Force also concluded that there was insufficient evidence to assess the risks and benefits of ECG screening in asymptomatic people at intermediate- or high-risk for CHD. The report has been published in Annals of Internal Medicine.

For asymptomatic people at low-risk, the report concludes that additional information obtained from resting of exercise ECG tests would be unlikely to change their risk assessment or to improve their health outcomes. By contrast, the tests are associated with “significant possible harms,” most importantly related to “exposure to potential adverse effects of invasive tests.”

The USPSTF weighed the evidence of the risks and benefits of ECG screening, but it did not include the cost of ECG screening as part of its analysis. The Task Force also recommends that physicians “individualize decision making to the specific patient or situation.”

The USPSTF notes that their recommendations differ slightly from current ACCF/AHA guidelines which state that resting ECGS are “reasonable for cardiovascular risk assessment in asymptomatic adults with hypertension or diabetes.” In addition, an exercise ECG “may be considered for cardiovascular risk assessment in intermediate-risk asymptomatic adults (including sedentary adults considering starting a vigorous exercise program), particularly when attention is paid to non-ECG markers such as exercise capacity.”