BackgroundPatient nonadherence to cardiac medications following acute coronary syndrome (ACS) is associated with increased risk of recurrent events. However, the prevalence of cognitive dysfunction and poor health literacy among ACS patients and their association with medication nonadherence are poorly understood.MethodsWe assessed rates of cognitive dysfunction and poor health literacy among participants of a clinical trial that tested the effectiveness of an intervention to improve medication adherence in patients hospitalized with ACS. Of 254 patients, 249 completed the Rapid Estimate of Adult Literacy in Medicine, Revised (REALM-R) survey, an assessment of risk for poor literacy, and the St Louis University Mental Status (SLUMS) exam, a tool assessing for neurocognitive deficits, during ACS hospitalization. We assessed if SLUMS or REALM-R scores were associated with medication adherence.ResultsBased on SLUMS score, 14% of patients were categorized as having dementia, and 52% with mild neurocognitive disorder (MNCD). Based on REALM-R score of ≤6, 34% of patients were categorized as at risk for poor health literacy. There was no association between poor health literacy and medication nonadherence. Of those with MNCD, 35.5% were nonadherent, compared to 17.5% with normal cognitive function and 6.7% with dementia. In multivariable analysis, cognitive dysfunction was associated with medication nonadherence (P=0.007), mainly due to an association between MNCD and nonadherence (odds ratio =12.2, 95% confidence interval =1.9 to 243; P=0.007). Cognitive status was not associated with adherence in patients randomized to the intervention.ConclusionCognitive dysfunction and risk for poor health literacy are common in patients hospitalized with ACS. We found an association between MNCD and medication nonadherence in the usual care group but not in the intervention group. These findings suggest efforts to screen for MNCD are needed during ACS hospitalization to identify patients at risk for nonadherence and who may benefit from an adherence intervention.