Potential Impact of the 2019 ACC/AHA Guidelines on the Primary Prevention of Cardiovascular Disease Recommendations on the Inappropriate Routine Use of Aspirin and Aspirin Use Without a Recommended Indication for Primary Prevention of Cardiovascular Disease in Cardiology Practices: Insights From the NCDR PINNACLE Registry.

Background: Aspirin is recommended in patients with atherosclerotic cardiovascular disease for secondary prevention. In patients without atherosclerotic cardiovascular disease and not at high 10-year risk, there is no evidence aspirin reduces adverse cardiovascular events and it could increase bleeding. The 2019 American College of Cardiology/American Heart Association Guidelines on Primary Prevention of Cardiovascular Disease state that aspirin may be considered for primary prevention (class IIb) in patients 40 to 70 years that are at higher risk of atherosclerotic cardiovascular disease and that routine use of aspirin should be avoided (class III:Harm) for patients >70 years. We examined the frequency of patients on aspirin for primary prevention that would have been considered unindicated or potentially harmful per the recent guideline where aspirin discontinuation may be beneficial.

Methods: To assess the potential impact, within the National Cardiovascular Disease Registry Practice Innovation and Clinical Excellence Registry, we assessed 855 366 patients from 400 practices with encounters between January 1, 2018 and March 31, 2019, that were receiving aspirin for primary prevention. We defined inappropriate use as the use of aspirin in patients <40 or >70 years and use without a recommended indication as use of aspirin in patients 40 to 70 years with low, borderline, or intermediate 10-year atherosclerotic cardiovascular disease risk. Frequency of inappropriate use and use without a recommended indication were calculated and practice-level variation was evaluated using the median rate ratio.

Results: Inappropriate use occurred in 27.6% (193 674/701 975) and use without a recommended indication in 26.0% (31 810/122 507) with significant practice-level variation in inappropriate use (predicted median practice-level rate 33.5%, interquartile range, 24.1% to 40.8%; median rate ratio, 1.71 [95% CI, 1.67-1.76]).

Conclusions: Immediately before the 2019 American College of Cardiology/American Heart Association Guidelines on Primary Prevention of Cardiovascular Disease, over one-fourth of patients in this national registry were receiving aspirin for primary prevention inappropriately or without a recommended indication with significant practice-level variation. These findings help to determine the potential impact of guideline recommendations on contemporary use of aspirin for primary prevention.