Patient awareness of serious consequences of non-adherence to antiplatelet therapy after coronary stenting Nikki L. Lee a , Cheuk-Man Yu b , Yat-Yin Lam b , Vivian W. Lee c , Bryan P. Yan b, ⁎ a Faculty of Medicine, University of Sheffield, Sheffield, United Kingdom b Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong c School of Pharmacy, The Chinese University of Hong Kong, Hong Kong article info Article history: Received 31 July 2012 Accepted 22 September 2012 Available online 8 October 2012 Keywords: Non-compliance Antiplatelet therapy Coronary stenting Patient awareness Self-reported adherence To the Editor: Premature discontinuation of antiplatelet therapy after percuta- neous coronary intervention (PCI) is common and a main predictor of late stent thrombosis which can lead to death and acute myocardial infarction [1,2]. Non-adherence to long-term medical therapy is affected by patients' knowledge about their condition, perceived benefits of therapy and awareness of consequences of non-compliance [3,4]. The impact of patients' understanding of the importance of antiplatelet therapy post-PCI as a mechanism for drug non-compliance is not known. Our study aims to assess patients' awareness of consequences of non- compliance with antiplatelet therapy after PCI and its impact on self- reported adherence. We retrospectively analyzed 393 patients who underwent PCI with stent implantation from the Care For Your Heart database in Hong Kong. Patients were inquired about their awareness of the risk of adverse cardiac events (including stent thrombosis, myocardial infarction and recurrent angina) or death from non-compliance with anti-platelet therapy after PCI by standardized phone interview. Patients who were non-compliant (defined as self-reported missing N 1 tablet per month or premature termination of prescribed regimen) were compared to compliant patients. Statistical analyses were performed using SPSS Ver.19 (SPSS Inc., Chicago, IL, USA) and 2-sided p-values b 0.05 were considered statistically significant. Of the 393 patients, 40.2% (n=158) were unaware that non- compliance with anti-platelet therapy was associated with risk of adverse cardiac events or death and 5.9% (n = 23) were non-compliant with prescribed antiplatelet therapy after PCI. Non-compliant patients were predominantly male (91.3%) with an average age of 67.0±0.9 years and 34.8% (n = 8) reported stopping their medication early without prior consultation with a doctor. Patients who were aware of the cardiac risks of non-compliance were significantly more likely to adhere to their anti- platelet regimen (odds ratio 8.07; 95% CI: 1.79–36.32, p b 0.01). More patients reported that their main source of information on cardiovascular health was from health talks (60.3%) and printed media (51.1%) than from their cardiologists (33.0%, p b 0.01). Paradoxically, 52.9% of patients who cited their cardiologist as the main source of information were unaware of the risks of non-compliance compared to 34.0% (p b 0.01) of those who cited sources other than their cardiologists. Patients who were aware of the cardiovascular complications of non-compliance were more likely to have multiple sources of information than a single source (52.9% vs. 27.4%, p b 0.01). Our results have shown that (1) patient awareness of the risks of non-compliance with antiplatelet therapy post PCI was suboptimal and was a predictor of non-compliance. And (2) patients who reported multiple sources of cardiovascular health information in addition to their cardiologist had better awareness of the risks of non-compliance. Recent studies have reported rates of premature discontinuation of antiplatelet therapy as high as 12.8% to 14.3% compared to 5.9% in our study [2]. However, the prevalence of non-compliance is likely under- estimated due to recall bias and self under-reporting [5,6]. Our findings demonstrated that well informed and knowledgeable patients are important determinants of adherence to therapy. Other studies have also shown that misconception and gaps in knowledge in disease is associated with inadequate preventive health behavior [3,4]. It is alarming to find that paradoxically, awareness and compliance of patients with cardiologists as their only information source was lower than those who had alternative sources of information such as printed media or health talks. The reason for this observation is unclear, although this may be reflective of the paternalistic medical culture commonly seen in Asia, where doctors adopt an authoritative approach with little explanation given to patients who are then expected to comply without questioning the doctor. This didactic approach to patient communication has been shown to produce poorer patient outcomes [7]. Other factors including brief consultation time due to overrun clinics, oversimplification or overload of information, and poor patient awareness of healthcare in general can also lead to ineffective knowledge transfer between doctor and patient. Although it may be a reflection of a health-seeking group, patients who reported information sources other than their cardiologist were the most compliant, suggesting that mass media may be a useful adjunct in healthcare promotion. This has been illustrated in a recent study which showed that exposure to mass media was associated with greater adherence to a healthy diet [8]. Patient awareness of the potential risks of non-adherence to antiplatelet therapy after coronary intervention is low. We envisage that increasing patient awareness of their risks and the importance of treatment should improve compliance and also empower them to participate in their own healthcare decisions. Nonetheless, for patients undergoing PCI, better patient education by healthcare providers of the dire consequences of non-compliance with antiplatelet therapy should be emphasized. The author(s) of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology. References [1] Grines CL, Bonow RO, Casey Jr DE, et al. Prevention of premature discontinuation of dual antiplatelet therapy in patients with coronary artery stents. A science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography and Interventions, American College of Surgeons and American Dental Association, with representation from the American College of Physicians. J Am Dent Assoc 2007;138(5):652–5. [2] Poh CL, Chan MY, Lau C, et al. Prevalence and predictors of premature discontinuation of dual antiplatelet therapy after drug-eluting stent implantation: importance of social factors in Asian patients. Intern Med J 2011;41(8):623–9. ⁎ Corresponding author at: Division of Cardiology, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong. Tel.: +852 2632 3846; fax: + 852 2637 3852. E-mail address: bryan.yan@cuhk.edu.hk (B.P. Yan). 278 Letters to the Editor