Abstract
Background: Platelet inhibition with dual antiplatelet therapy (DAPT) is an important component of medical management in patients with stable coronary artery disease (CAD). Dual antiplatelet therapy nonadherence is associated with increased mortality. Little is known about illness perceptions (IPs) surrounding the use of antiplatelet medications and whether they differ in stable CAD patients treated with medical and/or interventional approaches.
Objective: The aim of this study was to examine temporal changes in IP scores for patients with stable CAD and examine the influence of clinical and demographic variables, IP, and depressive symptoms on adherence to DAPT.
Methods: Patients (n = 180, 71.7% men; mean [SD] age, 65.1 [8.3] years) were recruited after coronary angiography and optimal medical therapy (OMT) (n = 90) or after percutaneous coronary intervention with initiation of OMT (n = 90). The Illness Perception Questionnaire-Revised and Patient Health Questionnaire-9 were administered at baseline and 30 days after treatment, with a response rate of 52.8% (n = 95) at 30 days. Adherence to DAPT (aspirin and thienopyridine) at 30 days was collected using a health history update.
Results: Patients with stable CAD experienced shifts in IP within the first 30 days after treatment. Patients treated with OMT demonstrated increased symptoms after treatment (timeline cyclical) and reduced beliefs in the level of control provided by their prescribed regimen (treatment control, t = 3.26, P = .002). Both groups demonstrated an increase in perceived understanding of illness (illness coherence subscale) from baseline to 30 days (percutaneous coronary intervention/OMT, t = -4.43, P < .001; OMT, t = -3.74, P = .001). Chronic IPs were associated with 5.7% increased odds for improved adherence to thienopyridine agents (B = 0.509, P = .009, Exp(B) = 1.66) and 5.6% increased odds for aspirin use (B = 0.265, P = .031, Exp(B) = 1.30). Depressive symptoms were predictive of adherence for thienopyridine medications (B = 0.509, P = .009, Exp(B) = 1.66).
Conclusions: Illness perceptions influence adherence to DAPT in patients with stable CAD. Understanding patterns in IP after treatment may help identify the best strategies to promote a tailored approach for improving adherence to DAPT.