Atherotech has developed the VAPTM Test Case History Series to relate the experiences of clinicians who have adopted expanded cholesterol testing into their practices. For new and prospective users, these experiences provide important information about emerging heart disease risk factors and illustrate the benefits of the VAP Test as the new standard of care in cholesterol risk assessment.
The Florida Lipid Institute in Orlando, Florida, provides evaluation and management of lipid disorders and also has a highly regarded research program. Founded in 1987 by Paul Ziajka, M.D., Ph.D., a board-certified internist, the institute employs several certified registered nurse practitioners and researchers. The practice serves 4,000 patients in central Florida and is affiliated with the Orlando Regional Healthcare System.
Dr. Ziajka is a leading researcher in the field of expanded lipid testing and its role in the early diagnosis and treatment of coronary artery disease. He spends much of his time speaking to physician groups across the country about the value of expanded lipid testing. In 1998, Dr. Ziajka incorporated the VAP (Vertical Auto Profile) Cholesterol Test into his practice to replace the routine lipid panel and has ordered several thousand tests to date.
Limitations of the Routine Cholesterol Panel
Dr. Ziajka eliminated the use of the routine cholesterol panel in his practice because he found that it did not provide the comprehensive information he needed to accurately diagnose and treat patients. In fact, clinical trials, including those based on the Framingham Heart Study, validate Dr. Ziajka’s clinical experience showing that the routine cholesterol panel detects less than half of all lipid abnormalities.
“The sensitivity of the traditional lipid panel using the current criteria for identifying people at risk is about 40 percent in the American population,” he said. “In other words, 60 percent of Americans at risk for coronary events are not identified using the current criteria and
the traditional lipid panel. As a physician, this limited information means that you are flying half-blind. There are not many areas in medicine that you would consider 40 percent predictability state of the art.”
For more than four years, Dr. Ziajka has used the VAP Test for all his patients. The VAP Test goes beyond the measurements obtained using the routine cholesterol panel – HDL, calculated LDL, triglycerides, and total cholesterol – by providing direct measurements of HDL, LDL, and VLDL (very low-density lipoprotein), and also measuring other important lipoprotein subclasses, including Lp(a), HDL subtypes, and IDL (intermediate-density lipoprotein). The test also measures LDL pattern density – important because patients with small, dense LDL (Pattern B) have a four-fold increased risk of developing heart disease. Other known risk factors, including homocysteine, also are measured. This comprehensive information allows the VAP Test to identify up to 90 percent of at-risk patients – more than twice the detection rate of routine cholesterol tests.
The VAP Test also allows physicians to comply with the new National Cholesterol Education Program ATP III guidelines, which call for improved patient diagnosis and more aggressive treatment of heart disease and indicate that many patients who would benefit from treatment are not receiving it. Importantly, the guidelines discuss a number of emerging risk factors that are not measured by the traditional lipid panel but are measured by the VAP Test.
“The real value of the VAP Test is stratifying risk,” Dr. Ziajka said. “It’s taking someone who you may consider low risk and discovering that they’re high risk – finding that missing 60 percent that the regular lipid panel doesn’t pick up. On the flipside, if you’ve got a person you know is high risk, it helps you customize the treatment plan much more beneficially than you would with just a regular lipid panel.”
The VAP Test at the Florida Lipid Institute
According to Dr. Ziajka, there is a two-fold purpose for expanded lipid panels. “The first is identifying risk, which has a firm epidemiologic basis, and then a more anecdotal, but also important role in tailoring therapy,” he said. “There are studies that identify a population with a high serum Lp(a) as at increased risk for having heart disease, or two patients can have the same LDL level but one may be at increased risk based on particle size and density – small and dense versus large and buoyant.”
Dr. Ziajka said using the VAP Test has helped him uncover risk in patients who have had “normal” results from routine tests. “One female patient I saw had a terrible family history of heart disease,” he said. “Her regular lipid panel showed an LDL of 90 mg/dL. Her HDL was 60 mg/dL, her triglycerides were 100, and she looked perfect on paper. But after performing a VAP Test, we discovered her Lp(a) was 80 mg/dL – well over the desirable level of less than 10 mg/dL.”
The VAP Test also assists Dr. Ziajka in tailoring optimal cholesterol levels in his patients. “With the VAP Test, I can target people who I want to have an LDL goal lower than I would accept otherwise,” he said. “If patients are high risk with Pattern B, and I can’t shift particle size, I’ll certainly want to lower the LDL more aggressively. Or, if I’m unable to raise HDL, I’ll target the LDL between 70 and 80 rather than the NCEP guidelines recommendation of less than 100.”
Dr. Ziajka said that he uses VAP Test results to determine which form of therapy will be most appropriate for his patients, often leading him to combination therapy – a highly effective treatment option for shifting particle distribution and lowering Lp(a).
“The VAP Test results allow me to look closely at important subtleties that are critical in addressing therapy,” he said. “Before I used expanded labs, I had 5 percent of my people on combination therapy, where now I’ve got three-quarters of my patients on it. I think it’s critical to keep in perspective that the most important thing is to still lower the LDL, whether it’s Pattern A or B. Once that’s done, I add a niacin product to shift particle distribution, or I’ll add a drug like Tricor to lower triglycerides and Lp(a). I’ve even got people on triple therapy now, which was very unusual in the past.”
According to Dr. Ziajka, the VAP Test’s breakdown of lipid subfractions is vital in determining appropriate treatment options and reducing events. “The traditional LDL, as calculated at a regular lab, is a combination of the IDL, the real LDL, and the Lp(a),” he said. “That explains some variations in response to treatment, because IDL and Lp(a) don’t respond well to statin therapy.”
As an example of calculated LDL’s ambiguity, Dr. Ziajka referenced one patient whose cholesterol levels rose after undergoing a strenuous diet and exercise program. The 56-year-old female patient had no family history of heart disease and previously had been tested by her primary care physician with a routine lipid panel, which found her total cholesterol was 231, her LDL was 158, her HDL was 55, and her triglycerides were 90. The patient subsequently enrolled in a Pritikin-style diet and fitness program, where she ate only a 10 percent fat diet, exercised regularly, and took yoga classes. Two years later, her routine lipid panel found that her total cholesterol had jumped to 285, with her LDL rising to 180, her HDL to 63, and her triglycerides to a whopping 210.
At that point, the patient was referred to Dr. Ziajka, who performed a VAP Test. Results indicated that her IDL was 114 (the desirable level is <20) and that she was Pattern A/B. Based on the VAP Test results, Dr. Ziajka was able to give her a definitive diagnosis of Hyperlipoproteinemia Type III, or Broad Beta Disease – one of a rare group of inherited disorders of fat metabolism – and initiate a more effective treatment plan.
While data on IDL as a risk factor for premature heart disease are just beginning to emerge, early epidemiological data have shown that IDL is slightly more atherogenic than LDL. “This patient’s VAP Test results reinforce how the traditional lipid panel, using precipitation techniques, adds the real LDL, IDL, and Lp(a) into what is reported as LDL,” Dr. Ziajka said. “The key point here is that IDL does not respond like LDL to conventional lipid-lowering therapy. Statins or niacin used as monotherapy have very little effect on IDL.”
Dr. Ziajka referred this patient to a dietician, who restricted her carbohydrates and increased her fats to 35 percent of total calories, including 25 percent monosaturated fats. One month later, Dr. Ziajka performed a follow-up VAP Test, which showed that her IDL had dropped to 20, her triglycerides had dropped to 90, and her total LDL was reduced to 86. “In this case, we were able to reduce the patient’s IDL level by simple dietary changes,” he said. “However, if a follow-up VAP Test showed that the diet didn’t work, I would have considered a low-dose statin plus niacin or fibrates.”
VAP Test results also help Dr. Ziajka feel more comfortable about treating certain patients with potential risk factors less aggressively. “I’m often more comfortable developing a limited treatment plan, or sometimes even withholding treatment,” he said. “I have seen patients who are at borderline risk, like diabetics who have LDL that is close to normal, and the VAP Test helps us decide whether to treat or not. If we run a VAP Test on them and find they are Pattern A (large, buoyant LDL), I feel more comfortable leaving them alone.”
Monitoring Treatment
One of the most important uses of the VAP Test in his practice is to monitor patient progress – he regularly tests patients with the VAP Test to see how well therapy is working. “Whenever I’m starting therapy with a patient, it is to modify some or several aspects of their lipid profile,” he said. “The reason for me to monitor with the VAP Test is to see how they’re responding to the therapy. If I’ve simply made dietary changes with a patient, I may order another VAP Test in two months or even six months. If they are undergoing drug therapy, I will usually do another profile within 6-8 weeks to track their progress and make any necessary modifications.”
Conclusion
Since most of his patients are referrals, Dr. Ziajka said he strongly advises primary care physicians, including family practitioners and internists, to incorporate expanded lipid testing into their practices to stratify heart disease risk. “Physicians may wonder whether expanded lipid testing should be used as the first cholesterol test on all patients or only on higher-risk people,” he said. “What’s important to realize is that the value of the VAP Test is to identify risk, so if you already separate out low-risk people you’re losing half of the value of the test.”
Dr. Ziajka said he feels that because of the additional information the VAP Test provides, its use will continue to grow. “The use of the VAP Test is essential and is going to become increasingly common for two reasons,” he said. “The first issue is identifying people at risk –and I think it should be the cholesterol panel of choice. Secondly, the expanded lipid profile has an essential role in the custom design of therapy.”
Paul Ziajka, M.D., Ph.D.
Dr. Ziajka is founder and director of the Florida Lipid Institute and an assistant clinical professor in the Department of Medicine at the University of Florida at Gainesville. Dr. Ziajka is one of the nation’s leading researchers and speakers on the diagnosis and treatment of lipid disorders and the use of lipid subfractionation. He is a member of the American Heart Association’s Atherosclerosis Scientific Council and is a former board member of the Southeast Lipid Association. Dr. Ziajka also is the author of the book “Establishing and Managing a Private Practice Lipid Clinic.”