Background: Hypertension is a major cause of cardiovascular disease (CVD). In patients with hypertension, unawareness of the disease often results in poor blood pressure control and increases the risk of CVD. However, data in nationwide surveys regarding the proportion of unaware individuals and the implications of such on their clinical outcomes are lacking. We aimed to clarify the association between unawareness of being prescribed antihypertensive medications among individuals taking antihypertensive medications and the subsequent risk of developing CVD.Methods and Results: This retrospective cohort study analyzed data from the JMDC Claims Database, including 313,715 individuals with hypertension treated with antihypertensive medications (median age 56 years). The primary endpoint was a composite of myocardial infarction, angina pectoris, stroke, heart failure, and atrial fibrillation. Overall, 19,607 (6.2%) individuals were unaware of being prescribed antihypertensive medications. During the follow-up period, 33,976 composite CVD endpoints were documented. Despite their youth, minimal comorbidities, and the achievement of better BP control with a reduced number of antihypertensive prescriptions, unawareness of being prescribed antihypertensive medications was associated with a greater risk of developing composite CVD. Hazard ratios of unawareness of being prescribed antihypertensive medications were 1.16 for myocardial infarction, 1.25 for angina pectoris, 1.15 for stroke, 1.36 for heart failure, and 1.28 for atrial fibrillation. The results were similar in several sensitivity analyses, including the analysis after excluding individuals with dementia.
Conclusions: Among individuals taking antihypertensive medications, assessing the awareness of being prescribed antihypertensive medications may help identify those at high risk for CVD-related events.
Keywords: Awareness of being prescribed antihypertensive medications; Cardiovascular disease risk; Epidemiology; Hypertension; Preventive cardiology.