Abstract P168: Primary Prevention of Cardiovascular Disease with Aspirin: Self-Reported and Validated Aspirin use in a Minnesota Community

Introduction: Aspirin (ASA) is recommended for the primary prevention (PP) of cardiovascular disease (CVD, defined as a first myocardial infarction or stroke) by the American Heart Association, Centers for Disease Control, and the U.S. Preventive Services Task Force. Rates of current ASA use for primary prevention of CVD are not well established. Furthermore, self-reported ASA use may be higher than actual use. We thus investigated self-reported and validated ASA use in a Minnesota population. Hypotheses: Current ASA use for primary prevention is low and self-report overestimates actual use. Methods: A population-based telephone survey was conducted of males 45-79 and females 55-79 years of age in a Minnesota community in 2012. Subjects were classified as PP or secondary prevention (SP) based on a history of CVD or previous cardiovascular procedures. Self-reported aspirin use was validated by measurement of serum thromboxane B 2 (sTXB 2 ), a stable metabolite of thromboxane A 2 , measured in a subset (n=54) using the Thromboxane B 2 EIA Kit (Cayman Chemical, Ann Arbor, MI) and reported as median (IQR). Results: A sample of 103 subjects (response rate 56%, age 64±9, 67% male) included both PP (n=74) and SP (n=29) cohorts. Risk factors were prevalent in both PP and SP groups: hypertension (41 vs 62%); diabetes (12 vs. 38%); hyperlipidemia (46 vs 76%); and current smoking (20 vs 23%). Daily aspirin use was reported by 37% of the PP vs. 76% of the SP groups. Within the PP group, most (96%) took aspirin to reduce the risk of CVD events. sTXB 2 levels were 165.6 (18.5, 250.1) ng/mL in aspirin non-users and were 2.8 (0.5, 12.0) ng/mL in self-reported aspirin users. A sTXB 2 cutpoint of 25 ng/mL to validate ASA exposure was associated with a sensitivity of 94% and specificity of 73%. Conclusions: Self-report of ASA use is a valid measure. Use is relatively low in a contemporary primary prevention population.