Provider Insider

Recommended prevention strategies

Fall 2017 | Issue No. 1

Secondary prevention recommendation:

Unless contraindicated, aspirin (81 mg daily) is recommended as a secondary prevention strategy in all patients with a history of atherosclerotic vascular disease. For patients with true aspirin allergy, clopidogrel can be utilized.

 

Evidence: Antithrombotic Trialists’ Collaboration (BMJ. 2002;324(7329):71).

  1. Meta-analysis of 195 randomized trials involving 135,000 patients with prior evidence of cardiovascular disease (e.g., prior or acute MI, prior or acute stroke or transient ischemic attacks [TIA], unstable angina, stable angina, peripheral artery disease, coronary artery bypass graft surgery, percutaneous coronary intervention, atrial fibrillation and valvular disease), produced the following results:
    • Significant reduction in the combined outcome of any “serious vascular event” by 22 percent:
      • Defined as nonfatal MI, nonfatal stroke or vascular death
    • Absolute effects of antiplatelet therapy on vascular events:
      • Previous MI—36 less events per 1,000 patients treated for a mean of 27 months
      • Acute MI—38 less events per 1,000 patients treated for a mean of one month
      • Previous stroke/TIA—36 less events per 1,000 patients treated for a mean of 29 months
      • Acute stroke—9 less events per 1,000 patients treated for a mean of 0.7 months
      • Other high-risk patients—22 less events per 1,000 patients treated for a mean of 22 months
    • No differences found in efficacy or safety between doses 75 to 150 mg/day and 160 to 325 mg/day.
  2. All major societal guidelines recommend aspirin for secondary prevention in patients with established vascular disease:
    • 2007 Diabetes Standards of Care
    • 2012 American College of Chest Physicians Antithrombotic Therapy and Prevention of Thrombosis guideline on the primary and secondary prevention of cardiovascular disease
    • 2011 American Heart Association/American College of Cardiology Foundation secondary prevention and risk reduction therapy
    • 2012 European guidelines on cardiovascular disease prevention in clinical practice

Primary prevention recommendation:

Evidence for the use of aspirin in primary prevention is not as conclusive as that of secondary prevention. The 2016 United States Preventive Services Task Force (USPSTF) recommends aspirin (81 mg) in adults aged 50 to 59 years who have a 10-year ASCVD risk of 10 percent or higher, are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years. This is a “Grade B” recommendation since there is high certainty the net benefit is moderate or there is moderate certainty the net benefit is moderate to substantial. The 10-year ASCVD risk calculations are made using the online ACC/AHA risk calculator.

 

The decision to initiate aspirin in individuals aged 60 to 69 years with 10-year ASCVD risk of 10 percent or higher should be made on an individualized basis. This is a “Grade C” recommendation since there is at least moderate certainty that the net benefit is small. Persons in this age group who place higher value on the potential benefits than the potential harms may choose to initiate low-dose aspirin.

 

The current evidence is insufficient to assess the benefits and risks for initiating aspirin for primary prevention in patients younger than 50 years old, as well as those 70 years of age or older. This is a “Grade I” recommendation since current evidence is insufficient to assess the balance of benefits and harms of the service. Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined.

 

2016 American Diabetes Association recommendation. Consider aspirin therapy (75 to 162 mg/day) as a primary prevention strategy in those with type 1 or type 2 diabetes who are at increased cardiovascular risk. This includes most men or women with diabetes aged > 50 years who have at least one additional major risk factor (e.g., family history of premature cardiovascular disease, hypertension, smoking, dyslipidemia or albuminuria) and who are not at increased risk of bleeding. This is classified as “Level of evidence C,” data from poorly controlled or uncontrolled studies, or conflicting evidence.