By Annette M. Boyle
HOUSTON — Heart disease is the No. 1 killer of women veterans, yet they remain undertreated for high cholesterol, one of the main risk factors for cardiovascular disease.
“This may represent a gap in providers’ understanding of the benefits of statins for women, particularly for those with cardiovascular disease,” said Salim Virani, MD, PhD, cardiologist at the Michael E. DeBakey VA Medical Center, an investigator at the Center for Innovations in Quality, Effectiveness and Safety and an assistant professor at the Baylor College of Medicine in Houston.
Previous studies have found that female patients with cardiovascular disease (CVD) are less likely to have low density lipids (LDL-C) of less than 100 mg/dL. That target was, until late 2013, the level of LDL the American College of Cardiology and the American Heart Association recommended physicians try to achieve in patients with cardiovascular disease.
The current guidelines eschew a specific target, instead recommending that all patients with CVD receive a high-intensity statin therapy.
But Virani and his colleagues found in a study published in the American Journal of Cardiology that women veterans with cardiovascular disease are undertreated by this measure as well.1
“Female veterans with diagnosed heart disease or a history of stroke are 32% less likely to receive statins and less likely to receive high-intensity statins than male veterans,” he told U.S. Medicine.
The researchers analyzed data from 972,532 patients receiving care in 130 VHA facilities from Oct. 1, 2010, to Sept. 30, 2011. All the patients had diagnoses of coronary heart disease, peripheral artery disease or ischemic stroke. Of the patients, 13,371 were female and 959,161 were male.
They found that 57.6% of women received any statin therapy and 21.1% received a high-intensity therapy, compared with 64.8% of men on any statin therapy and 23.6% of men taking high-intensity statins.
All of the cholesterol measures were higher for women with CVD than for men. Mean LDL levels for women were 99 mg/dL compared with a mean for men of 85 mg/dL. Other measures also were higher by 25 mg/dL for total cholesterol, 6 mg/dL for triglycerides, 9 mg/dL for HDL-C and 15 mg/dL for non-HDL-C in female patients than in male patients.
The proportion of women veterans receiving statins also varied significantly by facility, from a high of about 71% to a low approaching 35%. For high-intensity statins, the range was greater, with a high of nearly 40% and a low of about 7%.
The lower rates of women veterans on statins may be due to some confusion about the effectiveness of the therapy in this population.
“Providers could think that statins are less beneficial in women compared to men,” Virani said. “This remains controversial in primary prevention of CVD (i.e., those that do not have a history of heart disease or stroke), but in the secondary prevention population, statins in general have been shown to be equally efficacious in both men and women.”
Some other factors potentially could contribute to the lower rate of statin use in women. Female veterans in the study were on average younger, had lower prevalence of diabetes and hypertension and were less often white. A higher percentage had peripheral artery disease.
In general, women had a higher overall illness burden. While women had more primary care visits, they saw a physician less often than men and received more care from nurse practitioners or physician assistants.
The study also did not examine the impact of patient preferences or the experience of side effects in the disparity in the receipt of any statin or high-intensity statins. Previous studies have not reported a significant difference in the experience of side effects between men and women, however.
Overall, the rate of statin therapy in the study population indicates a need for greater awareness among physicians of the recommendation that all patients with cardiovascular disease take the drugs and more discussion with patients about the medications, Virani said.
A low overall rate of statin therapy has been “shown in other healthcare systems as well,” he added. “One should note that we are looking at whether a patient was on a statin at the time of their primary care visit. It is quite possible that some, if not all, of this could be related to non-adherence of statins when prescribed, either due to real or perceived side effects from statin therapy.”
Given that the cholesterol-lowering therapy has been shown to provide substantial benefit to patients with atherosclerosis, physicians should discuss those benefits with their patients with CVD and ensure they are taking the statins that are prescribed, Virani emphasized, pointing out, “Helping patients understand why they are taking this life-saving medication after a heart attack or stroke and what the risks/benefits of this medication are will help them better understand the reasons they are taking the medication and will likely improve the probability that they will continue to take this medication.”
The relatively low rate of statin use in patients with CVD has implications for quality measures, too, study authors noted, explaining, “Although current quality measures (including the ones used by the Department of Veterans’ Affairs) consider either LDL-C <100 mg/dL or statin use as acceptable measure of good quality of cholesterol care, our results indicate that, if performance measures were to move toward statin or high-intensity statin therapy use as an indicator of good quality of CVD care, then a large proportion of these patients (who previously met the performance measure based on LDL-C levels <100 mg/dL) would no longer meet this performance measure.”
1 Virani SS, Woodard LD, Ramsey DJ, Urech TH, Akeroyd JM, Shah T, Deswal A, Bozkurt B, Ballantyne CM, Petersen LA. Gender disparities in evidence-based statin therapy in patients with cardiovascular disease. Am J Cardiol. 2015 Jan 1;115(1):21-6.