Impact of gastrointestinal problems on adherence to low-dose acetylsalicylic Acid: a quantitative study in patients...

Low-dose acetylsalicylic acid (ASA; 75-325 mg) is a mainstay of therapy for patients at high risk of cardiovascular (CV) events. However, in some patients, such treatment is associated with upper gastrointestinal (GI) adverse effects, e.g. dyspeptic symptoms, peptic ulceration, and GI bleeding, that may interfere with adequate adherence to, and continuation of, low-dose ASA for CV protection.

The objective of this study was to explore the extent of, and drivers for, poor adherence to, and discontinuation of, low-dose ASA treatment for CV protection among a representative sample of patients in the US with GI problems.

An online questionnaire was completed by eligible US adult patients (aged ≥20 years) who had been recommended low-dose ASA by a healthcare professional for secondary CV prevention or high-risk primary CV prevention (defined as diabetes mellitus or three or more risk factors for CV disease) and had experience of upper GI problems. Participants were asked questions about their demographic profile, general health, and attitudes towards low-dose ASA use. Patients were classified as 'lapsers' if they reported no longer regularly taking low-dose ASA; patients were also asked if they ever took deliberate, short-term breaks from their low-dose ASA regimen ('breakers'). Statistical analysis was descriptive.

From 56 296 invitation emails that were sent out, 1007 questionnaires were completed in full and were eligible for the analysis. The main reason for ineligible responses was unread emails. Respondents had a mean age of 52 years and 59% were women. Some 57% of patients were categorized as being at high primary CV risk and 43% were categorized as secondary CV prevention patients. A total of 67% of all patients used ASA at a daily dose of 81 mg. Overall, 28% of patients were considered to be poorly adherent through lapsing and/or taking deliberate, short-term breaks, and those receiving low-dose ASA for secondary CV prevention were more likely to be poorly adherent than were high-risk primary CV prevention patients (32% vs 25%). Of the overall population, 15% were lapsers (12% of secondary and 18% of high-risk primary CV prevention patients). The most common spontaneously reported reasons for lapse of low-dose ASA therapy were contraindicated combinations of medications and 'stomach problems'. Deliberate, short-term breaks from treatment were reported by 19% of all patients (24% of secondary and 15% of high-risk primary CV prevention). The most common spontaneously reported reasons for breaks were 'stomach problems' and preparation for surgery. Overall, 88% of patients reported experiencing heartburn or acid reflux symptoms. Self-reported rates of GI problems were greater in secondary than in high-risk primary CV prevention patients.

Among the US cohort studied (i.e. low-dose ASA users with experience of upper GI problems), poor adherence to low-dose ASA treatment for both secondary and high-risk primary CV prevention was common.