Knowing "Cardiovascular Age" May Help Patients Get to Lipid Targets, Follow Medical Advice

November 28, 2007 — Simple ways of informing patients about their cardiovascular risk can make them more likely to adhere to medical advice and reach lipid goals, a new study suggests [1]. In particular, the easily understandable concept of "cardiovascular age" might strike a chord with patients, particularly those at the highest risk of developing cardiovascular disease (CVD) but who don't yet have overt symptoms.
"We've been doing this for many years at the McGill Cardiovascular Health Improvement Program," lead author on the study, Dr Steven A Grover (McGill University, Montreal, QC), told heartwire. "Over a dozen years ago we started showing patients what their risk profiles were and how much they were changing when they lost weight, exercised, or took drugs for their lipids. So we were quite convinced from our own personal experiences that this was a useful way to guide patients about the progress of their treatments, particularly for asymptomatic conditions like blood pressure and cholesterol, when you're trying to convince the patients that they need to embark on some sort of therapy, whether it's lifestyle or drugs, and yet they don't feel that anything is wrong and they certainly don't notice any differences when you make changes."
Grover and colleagues report the results of their 3053-patient Cardiovascular Health Evaluation to Improve Compliance and Knowledge Among Uninformed Patients (CHECK-UP) study in the November 26, 2007 issue of the Archives of Internal Medicine.
Percent risk and cardiovascular age
For the study, 230 primary-care physicians enrolled more than 3000 patients, of whom 2687 were still in the study after 12 months. All patients underwent risk-factor screening at baseline, which generated a one-page computer printout detailing their probability of developing cardiovascular disease. For people with preexisting CVD, this was calculated using a CV life-expectancy model; for people with no CVD, their risk estimate was expressed as a percent risk of developing CVD over the next eight years, using Framingham risk estimates, and as a CV life expectancy. As the authors describe, this second tool — validated in earlier studies — expresses a patient's risk as their "cardiovascular age," calculated as the patient's age minus the difference between his or her estimated remaining life expectancy, taking into account coronary and stroke risk and the average remaining life expectancy of Canadians of the same age and sex. Study participants were then randomized to either usual care or to be shown the computer printout with their risk-profile results. Over the subsequent 12 months, patients had their lipids and blood pressure measured and met with their physicians at three-month intervals throughout the year. All patients were regularly encouraged to meet and maintain their lipid goals, but only patients in the intervention group were shown their risk-profile printouts during the visits.
After 12 months and after adjustment for baseline lipid levels, patients who had been shown their risk profiles throughout the study had greater, statistically significant, reductions in low-density lipoprotein (LDL) cholesterol levels and total-cholesterol/high-density lipoprotein (HDL) cholesterol ratios, although the differences between the two groups were small. Patients who regularly saw their risk-profile changes were also more likely to reach their lipid goals — a finding particularly marked in patients who had the worst lipid profiles at baseline.
According to Grover, cardiovascular age was one of the strongest predictors of reaching lipid targets, even stronger than Framingham risk. "While we can't say definitively, the thing that came up the most strongly was age gap: in other words, how far was your cardiovascular age from your chronological age? There appeared to be a dose response: the bigger the age gap, the bigger the impact on risk profile. But when we looked at high, medium, or low risk by Framingham, the impact was less. The thing that really seemed to motivate patients was seeing this one line about their cardiovascular age."
Understanding cardiovascular risk
Two editorials accompanying the CHECK-UP study explore the nuanced problem of cardiovascular risk communication. According to Dr Rod Jackson and Sue Wells (University of Auckland, New Zealand) [2], the concept of managing risk, not risk factors, is poorly grasped by doctors, let alone patients. "Most physicians are still taught to diagnose and treat hypertension and hyperlipidemia, whereas risk-based approaches dispense with these entrenched yet clinically irrelevant diagnoses. Also, most treatments are designed to target individual risk factors, so it is difficult for physicians not to focus on measuring and treating blood pressure or blood lipid levels."
A major hurdle, however, is time; the time allotted in the CHECK-UP study to calculate cardiovascular risk and convey it to patients at regular intervals would be difficult for many busy physicians to invest. As such, computerized systems that link risk calculations to patient medical records can expedite the process. In New Zealand, they point out, the PREDICT computerized system is already doing this for 45,000 patients.
Jackson and Wells also suggest that Grover et al's concept of cardiovascular age will prove to be "the right metric to translate predicted cardiovascular risk into something meaningful to patients and physicians" and should be further explored.
In a second editorial [3], Dr Charles B Eaton (Brown University, Pawtucket, RI) points out that the CHECK-UP study also indirectly validates the role of regular physician visits. Indeed, the fact that the difference between the two study groups for the study end points was not larger than that reported by the authors might be due to the fact that even patients in the nonintervention group were in regular contact with a physician urging them to meet treatment goals. Still, Eaton notes, "only 45% to 66% of these high-risk cardiovascular patients had reached their respective lipid targets after one year, and thus, a large treatment gap still persisted."
Hope for the aging heart
Acknowledging the gap, Grover told heartwire that his study is at least a step in the right direction. He believes that finding new ways of involving patients is paramount. "We know for certain that the drugs that work well in clinical trials don't do nearly as well in real life. So clearly, the treatment paradigms for chronic asymptomatic medical conditions have to go beyond what we're doing now," he said. "In a chronic-care situation, patients become their own experts—they know what makes them better and what makes them worse. If we're talking about an asymptomatic condition, they know what behaviors bring their lipids under control and what behaviors make them go out of control. To engage the patient so that you can leverage that knowledge is potentially a very powerful instrument."
In fact, Grover thinks the notion of cardiovascular age also holds profound resonance for doctors. His group has offered cardiovascular-age assessments in the exhibition hall at Canadian Cardiovascular Society meetings for the past 10 years. "Health professionals come back year after year to see how their numbers are changing, which shocks me," he told heartwire. "I always believed health professionals would probably have a gut sense of how they are doing and really weren't interested. But that's really not the case at all; they'll line up to get it done."
Pfizer sponsored the CHECK-UP study. Some of the study authors have disclosed various financial relationships with Pfizer, Sanofi Aventis, AstraZeneca, and Orynx.
Drs. Jackson, Wells, and Eaton have disclosed no relevant financial relationships.
Sources
Grover SA, Lowensteyn I, Joseph L, et al. Patient knowledge of coronary risk profile improves the effectiveness of dyslipidemia therapy: the CHECK-UP study: A randomized controlled trial. Arch Intern Med. 2007;167:2296-2303.
Eaton CB. Using cardiovascular age equivalent to close the treatment gap for dyslipidemia. Arch Intern Med. 2007;167:2288.
Jackson R, Wells S. Prediction is difficult, particularly about the future. Arch Intern Med. 2007;167:2286-2287.