Variation in patients’ perceptions of elective percutaneous coronary intervention in stable coronary artery disease: cross sectional study

Although elective percutaneous coronary intervention can alleviate the symptoms of angina in patients with stable coronary artery disease, numerous studies and meta-analyses have shown that it does not prevent myocardial infarction or death, as compared with optimal medical treatment alone. Accordingly, the decision to proceed with percutaneous coronary intervention should involve a discussion with patients as to whether the benefits of improvement in symptoms outweigh the risks and costs, compared with medical treatments alone. 

Patients with a better understanding about treatments may be more involved in shared decision making, thus being more likely to receive care that is aligned with their goals and ensuring that practice variations in treatment for stable coronary artery disease result from patients’ rather than from physicians’ preferences. For patients to participate meaningfully in decision making about treatment for their stable coronary artery disease, a sound understanding of the benefits, risks and alternatives of elective percutaneous coronary intervention is essential.

Substantial evidence indicates that patients have a limited understanding of the benefits of elective percutaneous coronary intervention in stable coronary artery disease and believe that it is performed primarily to prevent heart attacks and improve survival. To date, no study has examined whether patients’ perceptions vary by the hospital where they are treated or as a function of the interventional cardiologist performing the procedure. Investigating sources of patient variation is extremely important in determining whether interventions and efforts to better educate patients should extend beyond targeting patient level factors alone, such as education, literacy and numeracy.

To tackle this gap in knowledge, these US-based investigators conducted a multicentre investigation in 10 US academic and community hospitals performing percutaneous coronary interventions between 2009 and 2011.

The understanding of patients with stable coronary artery disease of the benefits of elective percutaneous coronary intervention was examined to determine if patients’ perceptions varied across centres, across operators within a centre, or both. 

The subjects were 991 patients with stable coronary artery disease undergoing elective percutaneous coronary intervention.

The outcome measures were patients’ perceptions of the urgency and benefits of percutaneous coronary intervention, assessed by interview. Multilevel hierarchical logistic regression models examined the variation in patients’ understanding across centres and operators after adjusting for patient characteristics, using median odds ratios.

The most common reported benefits from percutaneous coronary intervention were to extend life (90%, n = 892; site range 80-97%) and to prevent future heart attacks (88%, n = 872; site range 79-97%). Although nearly two thirds of patients (n = 661) reported improvement of symptoms as a benefit of percutaneous coronary intervention (site range 52-87%), only 1% (n = 9) identified this as the only benefit. Substantial variability was noted in the ways informed consent was obtained at each site. After adjusting for patient and operator characteristics, the median odds ratios showed significant variation in patients’ perceptions of percutaneous coronary intervention across sites (range 1.4 to 3.1) but not across operators within a site.

Patients have a poor understanding of the benefits of elective percutaneous coronary intervention, with significant variation across sites. No sites had a high proportion of patients accurately understanding the benefits. Coupled with the wide variability in the ways in which hospitals obtain informed consent, these findings suggest that hospital level interventions into the structure and processes of obtaining informed consent for percutaneous coronary intervention might improve patient comprehension and understanding.