The US Preventive Services Task Force (USPSTF) guideline on statin use for the primary prevention of cardiovascular disease (CVD) in adults1 has prompted substantial discussion among cardiovascular scientists and clinicians on the interpretation and use of evidence-based guidelines in clinical and public health practice. Recently, 4 other major guidelines on the use of statins in the primary prevention of cardiovascular disease in adults have been published and disseminated.2–5 As highlighted by Greenland and Bonow,6 despite numerous randomized clinical trials (RCTs), gaps in evidence persist and contribute to differences in recommendations issued by guideline writing groups.
The USPSTF evidence report summarized data from 19 clinical trials (71 344 patients) that evaluated the effects of statins versus placebo or no statins in adults aged 40 to 75 years without known CVD.7 Of note, most of the investigators enrolled participants based on an elevated low-density lipoprotein level (LDL-C), a diagnosis of diabetes, or at least 1 CVD risk factor. The use of low- or moderate-dose statins was associated with a reduced risk of all-cause mortality (pooled risk ratio [RR], 0.86 [95% confidence interval (CI), 0.80–0.93]), cardiovascular mortality (RR, 0.69 [95% CI, 0.54–0.88]), ischemic stroke (RR, 0.71 [95% CI, 0.62–0.82]), myocardial infarction (RR, 0.64 [95% CI, 0.57–0.71]), and a composite cardiovascular outcome (RR, 0.70 [95% CI, 0.63–0.78]).7 Noteworthy is that the proportion of cardiovascular disease events prevented (ie, the relative risk reduction) was similar across age, sex, race/ethnicity, lipid level, and other risk factor categories. On the basis of the findings of this evidence review, the Task Force recommends the initiation of low- to moderate-dose statin therapy for adults aged 40 to 75 years without a history of cardiovascular disease and who have 1 or more cardiovascular disease risk factors and a calculated 10-year cardiovascular disease event risk of 10% or greater using the Pooled Cohort Equations8 developed for use with the American College of Cardiology/American Heart Association (ACC/AHA) lipid treatment guideline.2 The USPSTF graded this as a B-level recommendation indicating that there is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial.1
The USPSTF also recommends that clinicians selectively offer low- to moderate-dose statins to adults aged 40 to 75 years without a history of cardiovascular disease and who have 1 or more cardiovascular disease risk factors and a calculated 10-year cardiovascular disease event risk of 7.5% to 10%.1 Particularly noteworthy is the recommendation that decision to initiate therapy in this population should reflect assessment of patients’ specific circumstances, as well as their preference for a potential small benefit relative to potential harms and inconvenience of taking a lifelong daily medication. Of note, cardiovascular disease risk factors included for both of these recommendations were potentially modifiable: diabetes, dyslipidemia, hypertension, or smoking. The Task Force concluded that evidence is insufficient to assess the balance of benefits and harms of initiating statin use in adults 76 years or older who are without a history of cardiovascular disease. Emphasis was placed on the need for additional research in this population of older adults. Importantly, the Task Force recognized that there is no direct RCT evidence to guide the choice of a specific CVD risk threshold for initiating statin treatment; however, available evidence suggests that the likelihood that patients will benefit from treatment is directly associated with their absolute baseline risk of experiencing a cardiovascular disease event.7 Finally, the Task Force clearly indicated that these recommendations do not apply to individuals with a very high cardiovascular disease risk such as those with familial hypercholesterolemia or a low-density lipoprotein cholesterol of 190 mg/dL or greater.1 The rationale is that these individuals were not included in primary prevention trials. Noteworthy in this context is the Task Force recommendation that these individuals should be screened and treated for dyslipidemia in accordance with clinical judgment.1
In contrast, the ACC and AHA recommend statin use for primary prevention in asymptomatic adults aged 40 to 75 years without a history of cardiovascular disease who have an LDL-C level of 70 to 189 mg/dL if they also have diabetes or an estimated 10-year cardiovascular disease event risk of 7.5% or greater,2 as determined by the Pooled Cohort Equations risk calculator.8 The ACC and AHA recommend fixed-dose statin therapy using either a high-intensity regimen (ie, daily dose reduces LDL-C level approximately ≥50%) or a moderate-intensity regimen (daily dose reduces LDL-C by approximately 30%–50%).2 Importantly, shared decision making with provider-patient discussion of risks and benefits was clearly emphasized before the initiation of moderate- to high-dose statin therapy.
A detailed discussion of the Canadian Cardiovascular Society recommendations,3 the UK National Institute for Health and Care Excellence guidelines,4 and the European Society of Cardiology and European Atherosclerosis 2016 guideline on the assessment and management of dyslipidemia5 is beyond the scope of this Prevention Column. Taken together, however, and as summarized by Greenland and Bonow,6 some intensity of statin therapy for high-risk patients (and patients similar to those examined in the RCTs) is critically important in cardiovascular disease prevention. Recent evidence suggests that many patients who would clearly benefit from statin therapy are not receiving treatment.9 In the absence of consensus (based on evidence) on risk thresholds, several guidelines (referenced herein) suggest the selective use of additional testing such as coronary artery calcium scoring to assist in treatment decisions.10 A common theme in all guidelines is the recommendation for additional research (trial evidence) regarding the initiation of statin therapy in older adults. Finally, and perhaps most importantly, all the guidelines emphasize the critical importance of clinical judgment, as well patient preferences/patient input in processes of clinical decision making and the essential role of healthy lifestyle behaviors in the prevention and management of cardiovascular disease.
Close scrutiny of the processes of development of these guidelines and the recommendations offered provides insights and implications for cardiovascular nursing practice. Although data from RCTs have been foundational to evidence-based recommendations for adults including those recently issued by the USPSTF, they do not represent the full spectrum of adult patients and cannot address all the questions that emerge in clinical practice. Thus, clinical judgment, central to the standards and processes of nursing practice, is essential in interpreting and applying guideline-based recommendations in clinical practice. Independent of the type of therapy for dyslipidemia and cardiovascular disease prevention, patient preferences for treatment are critically important considerations particularly in situations where limited evidence exists to support the initiation of treatment that has both risks and benefits and lifelong implications. Finally, although controversy regarding optimal pharmacological approaches to primary prevention exists, based on substantial evidence, there is consensus on the cardiovascular benefits of maintaining healthy lifestyle behaviors across the life course.
1. US Preventive Services Task Force. Bibbins-Domingo K, Grossman DC, Curry SJ, et al. Statin use for the primary prevention of cardiovascular disease in adults: US Preventive Services Task Force Recommendation Statement. JAMA
2. Stone NJ, Robinson JG, Lichtenstein AH, et al. American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2013 ACA/AHA guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation
. 2014;129(25 suppl 2):S1–S45.
3. Anderson TJ, Grégoire J, Hegele RA, et al. 2012 update of the Canadian Cardiovascular Society guidelines for the diagnosis and treatment of dyslipidemia for the prevention of cardiovascular disease in the adult. Can J Cardiol
4. JBS3 Board. Joint British Societies’ consensus recommendations for the prevention of cardiovascular disease (JBS3). Heart
. 2014;100(suppl 2):ii1–ii67.
5. Catapano AL, Graham I, DeBacker G, et al. 2016 ESC/EAS guidelines for the management of dyslipidaemias: the task force for the management of dyslipidaemias of the European Society of Cardiology (ESC) and European Atherosclerosis Society (EAS) developed with the special contribution of the European Association for Cardiovascular Prevention & Rehabilitation (EACPR). Eur Heart J
6. Greenland P, Bonow RO. Interpretation and use of another statin guideline. JAMA
7. Chou R, Dana T, Blazina I, Daeges M, Jeanne TL. Statins for prevention of cardiovascular disease in adults; evidence report and systematic review for the US Preventive Services Task Force. JAMA
9. Pavlovic J, Greenland P, Deckers JW, et al. Comparison of ACC/AHA and ESC guideline recommendations following trial evidence for statin use in primary prevention of cardiovascular disease: results from the population-based Rotterdam Study. JAMA Cardiol
10. Blaha MJ, Cainzos-Achirica M, Greenland P, et al. Role of coronary artery calcium score of zero and other negative risk markers for cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis (MESA). Circulation