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Chronic angina substantially worsens patients’ quality of life1 2 and increases healthcare costs.3 Particularly now, in the post-ISCHEMIA era,4 relief of ischaemic symptoms should be a primary goal of percutaneous coronary intervention (PCI) for stable coronary artery disease (CAD). As such, the appropriateness of PCI most often hinges on the degree of symptom improvement achieved. In their Heart article, Yang et al compared the symptomatic benefit (using the 7-item Seattle Angina Questionnaire (SAQ-7) and Rose Dyspnea Score (RDS)) of patients with stable CAD who were treated with PCI that was judged as appropriate versus maybe appropriate.5 The authors found similar improvement in angina-related health status regardless of the appropriateness status of the PCI and concluded that the current Appropriate Use Criteria (AUC) do not discriminate well between the patients who will versus will not benefit from PCI. They argue that patient-reported outcome measures could be used to improve the current AUC by potentially identifying those patients more likely to benefit from PCI. I note three key conclusions from this paper.
Patients with more symptoms have greater symptomatic benefit from PCI
The authors found that patients who underwent an appropriate PCI had statistically similar symptom benefit compared with those who underwent a maybe appropriate PCI. In contrast, symptoms prior to PCI were the strongest determinants of symptom improvement post-PCI, meaning those patients with more symptoms were more likely to benefit symptomatically. I would argue that there is some evidence of greater symptomatic benefit in those who underwent appropriate PCI. The mean difference in SAQ summary scores between groups was greater than 6 points—greater than the treatment difference between revascularisation and medical therapy in both COURAGE6 or ISCHEMIA.4 The lack of statistical significance in the current study may be due to inadequate power, particularly as there was a greater improvement in RDS in the appropriate PCI group. However, the greater improvement in symptoms in those who underwent appropriate PCI was likely driven entirely by more frequent pre-PCI angina in this group. In fact, it was likely this increased angina burden that was one of the key reasons these PCIs were in the appropriate category (vs maybe appropriate). Thus, the conclusion that ischaemic symptom burden prior to PCI is a better discriminator for post-PCI improvement than the current AUC criteria still holds.
Patients’ symptom burden may be a better measure of appropriateness of PCI
The determination of the appropriateness of PCI in stable CAD per the current AUC is grounded on two potential benefits of revascularisation—symptom relief and reduction in ischaemic risk. The potential clinical benefit of PCI follows the argument that revascularisation reduces the risk of major adverse cardiovascular events for patients with higher risk anatomy or ischaemia. To make the case that pre-PCI patient symptom burden may be a better method of quantifying the appropriateness of PCI would imply that the degree of ischaemia on stress testing or the severity of anatomical CAD should not play a role in determining the appropriateness of revascularisation—an argument that has some support with the recent ISCHEMIA trial.4 While symptom burden may not be the only criteria to determine appropriateness of PCI, the trials thus far certainly support the assertion that symptom relief should be the primary driver of the decision for PCI. How the next round of AUC will consider the results of ISCHEMIA and whether or not to continue to include anatomy and ischaemia in the criteria (as potentially driving clinical outcomes) is not known. Regardless, understanding that symptom burden is at least an integral part of the assessment of appropriateness, it is imperative to quantify symptoms using a reliable, responsive, and valid patient-reported measure, which leads me to point #3.
Patient-reported outcome measures are needed to reliably assess patients’ symptom burden
The AUC use the Canadian Cardiovascular Society (CCS) classification system to quantify the patient’s symptom burden as a means of classifying the appropriateness of revascularisation.7 As the CCS is a physician’s estimation of the patient’s symptoms, it is vulnerable to errors in assessment and potentially even gaming. While we all believe our interview skills are superior and we can accurately estimate our patients’ angina, studies have repeatedly shown substantial inconsistency between physician-estimated and patient-reported burden of angina.8 9 In contrast to the CCS, the SAQ is a patient-reported measure that can validly and reliably assess the health status of patients with stable CAD (angina-related symptoms, functional limitations, quality of life). While the SAQ has established itself as an important outcome in clinical trials over the past two decades, health status measures have yet to be integrated into routine clinical care. In this current study, fewer than half of patients with stable CAD undergoing coronary angiography completed the baseline survey. While the reasons for non-participation were not provided, this speaks to some of the challenges of integrating patient-reported measures into clinical care. This may be even more challenging when we attempt to move the health status assessment upstream—prior to the decision to send the patient to the cardiac catheterisation laboratory—so these data can be available for shared decision making. In an ideal world, the SAQ-7 (and perhaps the RDS) would also be completed at follow-up after PCI, which could provide data about treatment success (perhaps as a quality metric) and guide the de-escalation of antianginal medications. However, to recognise these potential benefits, we must find a way to integrate these data into clinical practice.
Conclusion
In patients with stable CAD, the appropriateness of PCI hinges on whether or not revascularisation is likely to provide benefit to the patient—either in survival or quality of life. As more data emerge that the primary benefit (and some may argue the only benefit) of PCI in stable CAD is relief of ischaemic symptoms, we must make a greater effort to accurately capture patient-reported health status so as to engage in shared decision making prior to PCI. We have spent much time and effort in precisely quantifying the degree of ischaemia on stress imaging and burden of anatomical CAD on angiograms. The time has come to move beyond CCS to a more reliable, responsive, valid and patient-centred method to quantify patients’ ischaemic symptoms.
Footnotes
Twitter @arnoldgehrke
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Commissioned; internally peer reviewed.