Measuring what matters: 5-years experience with patient-reported outcome measures in acute coronary syndrome patients

Introduction

Patient-reported outcome measures (PROMS) are recommended quality indicators to measure patients' perspectives of symptoms and quality of life. In ischaemic heart disease, the Seattle Angina Questionnaire (SAQ), Rose Dyspnoea Score and Patient Health Questionnaire are suggested. However, routine longitudinal measurements are under-utilised, due to lack of workflow integration, administrative burden and patient fatigue1. While recommended for 5-year collection after acute coronary syndrome (ACS)2, it is unclear if this is feasible and clinically meaningful.

Purpose

We investigated the feasibility and completeness of real-world PROMS collection in ACS patients for 5 years, analysing characteristics of those who did respond on follow-up. We compared PROMS across different interventions of percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and medical therapy only.

Methods

This was a prospective observational study. ACS admissions between Aug 2017-Jan 2021 were surveyed in-person, via phone or SMS. Due to manpower constraints, only SMS were used at 3-5 years. Intervention data was collected prospectively, mortality and readmissions via retrospective linkage to existing registries. Paired t-tests were used for PROMS and chi-square for binary variables.

Results

1673 baseline PROMS were submitted. 902 patients responded to at least one follow-up. They were younger (62 vs 65y, p<0.0001), had higher education (68.6% vs 58.2%, p<0.0001), more likely employed (60.3% vs 53.5%, p=0.006), and able to self-care (50.5% vs 41.6%, p<0.0001). Response rates peaked at 1 month (32.9%) and 1 year (32.0%), were 25-26% at 3 and 6 months, 13.5% at 2 years, and fell below 10% after 3 years, reaching 3% at 5 years.

Among responders who were recommended PCI or CABG, we compared those receiving either with those who chose medical therapy alone. 5-year mortality was significantly higher in the latter (Fig.1). At baseline, patients on medical therapy instead of CABG had slightly better angina frequency scores, though still in the monthly frequency range. Changes in SAQ, computed between baseline and latest scores, reached minimally clinically important difference (MCID) thresholds across all groups. Summary scores suggest significant improvements that peaked in the initial months and largely plateaued over time (Fig.2). However, those on medical therapy had significantly smaller improvements in physical limitation compared to PCI and angina frequency compared to CABG.

Conclusion

SAQ appeared to differentiate some aspects of patient-reported quality of life amongst ACS patients receiving different therapies. While possible to collect PROMS over 5 years, attrition affects the long-term conclusions. Majority of PROMS improvements occurred in the initial months. As long-term collection after ACS is challenging, more real-world studies are needed to justify its collection for longer-term clinical management.Figure 1.PROMS and clinical outcomesFigure 2.5-year PROMS across groups