乌鸦传媒

Although prescription rates for statins increased between 2007 and 2018, statins continue to be underused in older adults with atherosclerotic cardiovascular disease (ASCVD), a recent study has found.¹

In a list of top 10 take-home messages, clinical practice guidelines issued by the American College of Cardiology/American Heart Association (ACC/AHA) in 2018 recommended that individuals with clinical ASCVD be treated with high-intensity or maximally tolerated statin therapy to decrease their levels of low-density lipoprotein cholesterol (LDL-C).²

However, after similar guidelines were issued in 2013, a subsequent study, published in 2019, found that statin use in the U.S. didn鈥檛 increase and that more than 40% of individuals ages 40 years and over with a history of ASCVD weren鈥檛 on statin therapy.³ The same study also identified gender and ethnic-based disparities in statin use. A new study therefore aimed to evaluate current trends and disparities in statin use among older adults with ASCVD.

Tapping a large patient database

鈥淯sing data from a large multispecialty outpatient care organization in Northern California, we sought to evaluate temporal statin prescribing patterns and predictors of guideline-concordant statin prescription [use] in a multiethnic population of older adults with ASCVD,鈥� wrote Gabriela Spencer-Bonilla, MD, MSc, of the Stanford University School of Medicine, Stanford, Calif., and her colleagues in the Journal of the American Geriatrics Society.

Patients (N=24,651) in this retrospective longitudinal study were older than 75 years of age, had ASCVD, and recorded 鈮�2 outpatient visits within 2 consecutive years. These criteria were also used to select a cohort of patients ages 65 to 75 years old.

Patients reported their own smoking status and demographics information. Comorbidities, which included diabetes, hypertension, heart failure, malignancy, dementia, and renal disease, were identified via International Classification of Diseases (ICD) codes. Total cholesterol and LDL-C were measured closest to and within at least 1 year of the index date, and again 30 days following the start of statin therapy. Body mass index was categorized as underweight (<18.5 kg/m²), normal (18.5 to <25 kg/m²), overweight (25 to <30 kg/m²), and obese (鈮�30 kg/m²).

Prescription information was derived from the patient鈥檚 last visit during the study period. Statin intensity was categorized as high, moderate, or low according to ACC/AHA guidelines, and nonstatin, lipid-lowering prescriptions were also recorded.

Who鈥檚 more likely to use statins for ASCVD?

Of the study participants, nearly half (48%) were women, and 62%, 13%, 5%, and 1% were non-Hispanic white, Asian, Hispanic, and black, respectively. Coronary artery disease (CAD) was followed by cerebrovascular disease as the most frequent indications for statin therapy. More than half (56%) of the patients were overweight or obese; 4% were underweight. The most common comorbidity was hypertension (68%), followed by renal disease (46%), malignancy (28%), diabetes (26%), heart failure (18%), and dementia (10%).

Less than half (42%) of the patients were prescribed statin therapy, with 36% receiving moderate-to-high-intensity statin therapy, after patient data were pooled across years. The moderate-to-high-intensity statin prescription rate for secondary ASCVD prevention increased from 35% in 2007 to 45% in 2018. However, compared with the cohort of patients ages 65 to 75 years, rates remained 13% lower for those >75 years (odds ratio 0.87, 95% confidence interval 0.85 to 0.89).

Among patients older than 75 years, women and patients with heart failure, dementia, or who were underweight were found to be less likely to receive moderate-to-high-intensity statin therapy. Asian patients and those with >9 prescription medications were more likely than non-Hispanic whites to receive moderate-to-high-intensity statin therapy. Finally, patients with CAD were found to be less likely than patients with other forms of ASCVD to receive moderate-to-high-intensity statin therapy.

The study鈥檚 authors observed that the lower rates of statin use in women and in patients with specific comorbidities reflected prior studies鈥� findings. However, the decreased likelihood of patients with CAD to receive statin therapy compared with patients with other ASCVD forms was a novel finding. The authors hypothesized that this may be due to the later stages in which cerebrovascular disease and peripheral artery disease are diagnosed, a point at which statin therapy is more consistently implemented. Another proposed hypothesis was the stability of symptoms that often accompany CAD when it鈥檚 entered as a code during patient evaluation.

Future implications of statin underuse

Dr. Spencer-Bonilla and her colleagues found that, despite the statin prescription increase over time, fewer than half of patients received prescriptions for moderate-to-high-intensity statin therapy. 鈥淔uture studies will need to unpack reasons for statin under-prescription and generate evidence tailored to improving guideline-recommended statin use in the growing population of older adults with ASCVD,鈥� the authors wrote.¹

The investigators also acknowledged the study鈥檚 limitations, which involved an insured cohort with regular healthcare, thereby potentially limiting generalizations to other patient populations. Additionally, the study didn鈥檛 discern de novo high-intensity statin therapy from low-to-moderate or high-intensity therapy. Measures of patients鈥� function and mobility, which may affect statin prescriptions, were also not included.

鈥淭his represents an opportunity to decrease gaps in guideline adherence for this high-risk patient group,鈥� study author Fatima Rodriguez, MD, MPH, of the Division of Cardiovascular Medicine at Stanford University, told 乌鸦传媒. 鈥淔or secondary prevention, we know that elderly patients benefit from statins鈥攑erhaps to an even greater extent than younger patients鈥攂ut there remain significant patient-, provider-, and system-level barriers to use of these lifesaving medications.鈥�

Published: May 25, 2021