..The present study aimed to assess the value of coronary artery calcium (CAC) for guiding aspirin allocation for primary prevention using 2019 aspirin meta-analysis data on CVD relative risk reduction (RRR) and bleeding risk
..Only 5% of MESA participants would qualify for aspirin consideration for primary prevention according to ACC/AHA guidelines and using >20% estimated ASCVD risk to define “higher risk”. Benefit/harm calculations were restricted to aspirin-naïve participants <70 years not at high risk of bleeding (N=3,540). The overall NNT5 with aspirin to prevent one CVD event was 476 and the NNH5 was 355. The NNT5 was also greater than or similar to the NNH5 among estimated ASCVD risk strata. Conversely, CAC≥100 and CAC≥400 identified subgroups in which NNT5 was lower than NNH5. This was true both overall (for CAC≥100, NNT5=140 vs NNH5=518) as well as within ASCVD risk strata. Also, CAC=0 identified subgroups in which the NNT was much higher than the NNH5 (overall, NNT5=1,190 vs NNH5=567).
Conclusions: CAC may be superior to the PCE to inform allocation of aspirin in primary prevention. Implementation of current 2019 ACC/AHA guideline recommendations together with the use of CAC for further risk assessment may result in a more personalized, safer allocation of aspirin in primary prevention. Confirmation of these findings in experimental settings is needed