National Venous Screening Program Update Unveils Risks

BY MARK S. LESNEY

Increasing national interest in educating individuals about the devastating effects of venous disease has led to a dramatic rise in the number of centers volunteering to participate in the second annual National Venous Screening Program, according to Dr. Robert B. McLafferty, who presented an update and detailed statistical analysis at the Vascular Annual Meeting.

The National Venous Screening Program (NVSP) was developed to provide "a free, comprehensive national screening program" to the public that would "educate, identify, and empower those individuals at risk from VTE."

Screening results in the 2007 analysis indicated that 40% of participants were at low risk, 22% were at moderate risk, 21% were at high risk, and 17% were at very high risk if placed in a situation conducive to VTE.

Over 4,000 physicians from the American Venous Forum, the American College of Phlebology, and the Society for Vascular Surgery were invited to participate in the 2006-2007 screening. Of these, 164 physicians requested materials, with 83 finally completing screening and returning data, up from 17 the year before. These 83 physicians were located in 40 states; a total of 2,234 individuals were screened.

The NVSP instrument, administered by the American Venous Forum, includes instruction information for individual surgeons to run their own screening event. This involves alerting potential patients, obtaining demographics from those who attend, and assessing a patient's VTE risk and their venous-specific quality of life (QOL). The demographic data obtained by the physicians and provided to the NVSP coordinating center in Baltimore showed that the mean age of the individuals screened was 60 years (ranging from 17 to 93), with 77% being female and 80% white; the mean body mass index (kg/m2) was greater than 29. A total of 40% of individuals screened were current or previous smokers; 24% were taking antiplatelet therapy, and 4% were taking warfarin, reported Dr. McLafferty, a professor of vascular surgery at Southern Illinois University, Springfield, and colleagues from other institutions.

The participants this year stated that the most common reason for attending the NVSP was that it was free (60%); the second most common reason was their varicose veins (42%). The QOL assessment indicated that 17% of individuals had a combined total score for all 11 questions of "very limited" or "impossible to do."

In 1994, the American Venous Forum produced a consensus document for the classification and grading of cardiovascular disease on the basis of clinical manifestations (C), etiologic factors (E), anatomical distribution of involvement (A), and underlying pathophysiologic findings (P). In this CEAP classification, a patient in class 0 has no evidence of disease, and a patient in class 6 has an active leg ulcer.

In the analysis of the NVSP for 2006-2007, the overall percentages for CEAP classes 0-6 for the participants were 29%, 29%, 23%, 10%, 7%, 1%, and 0.5% respectively, according to Dr. McLafferty.

The percent distribution of venous reflux in the 2,234 individuals analyzed showed that the 37% had reflux in one or more segments, and 5% had obstruction in one or more segments. Distribution of reflux was most common in the saphenofemoral venous junction, followed by the common femoral vein and the popliteal vein. For obstruction, the popliteal artery had the highest percentage, followed by the common femoral vein and the saphenofemoral vein.

The clinically relevant, significant analyses coming out of the 2006-2007 National Venous Screening Program results showed that obstruction was significantly higher in nonwhites (9%) vs. whites (4%); in diabetics (9%) vs. nondiabetics (5%); in those with hypertension (6%) vs. those without (2%); and in those taking warfarin (12%) vs. those not taking it (4%). Overall, 35% of those screened had a high or very high risk of VTE, and approximately 25% were rated as moderate to severe ("bothered/limited") in venous QOL assessment, according to Dr. McLafferty and his colleagues.