Author + information
- Rosanna Tavella, BSc(Hons), PhD,
- Isuru Ranasinghe, MBBS, MMed (Clin Epi), PhD,
- Chris Zeitz, MBBS, PhD and
- John F. Beltrame, BSc, BMBS, PhD∗ ()
- ↵∗Basil Hetzel Institute for Translational Health Research, 28 Woodville Road, Woodville South, Adelaide, South Australia 5011, Australia
The recently published DUTCH PEERS (DUrable polymer-based sTent CHallenge of Promus Element Versus ReSolute Integrity; TWENTE II trial (1) utilizes an important endpoint for percutaneous coronary intervention (PCI) studies: “post-PCI angina.” We congratulate the authors for reporting this important outcome. This comparative effectiveness study evaluated 2 third-generation drug-eluting stents (DES) with respect to this patient-reported outcome measure (PROM). At 1-year follow-up, there was no difference between treatments, with over 80% of patients in both groups being angina-free. This compares favorably with other PCI studies reporting this PROM, including the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation) (2) (57%), SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) (3) (72%), and FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) (4) (79%) trials. If post-PCI angina is to become a commonly reported PROM, a better understanding of its determinants is required.
Variability in the post-PCI angina outcome may arise from differences in patient, angiographic, interventional, and measurement factors. Patient factors include risk factors such as diabetes (where angina sensation is impaired), the clinical presentation (post-PCI angina may be less common in acute coronary syndromes), and the baseline angina frequency. Angiographic and interventional factors that describe the extent of coronary artery disease and completeness of revascularization are also important. Whether it is a coincidental observation or an important determinant, the type of stent may be relevant because the COURAGE, SYNTAX, FREEDOM, and DUTCH PEERS studies represent a transition from bare-metal stents to first- and second-generation DES, respectively, with reports of increasing angina-free status at 12 months.
Measurement factors for the assessment of post-PCI angina are especially important and worthy of further consideration in interpreting the DUTCH PEERS study. First, ensuring that the measure is “patient-reported” rather than “clinician-reported” is important because these have been shown to differ (5). The empiric 4-graded scale used appears to be “patient-reported”; however, it is unclear whether the “mild, moderate, or severe physical effort” description was clinician-directed. As the major endpoint was “angina free,” this is of less importance in this particular discussion. A second consideration is the observation time course; that is, does “angina-free at 12 months” infer no pain over the entire 12 months or no pain in the month prior to the 12-month interval? The latter is often utilized, but it is unclear in the present study. Finally, has the DUTCH PEERS 4-category post-PCI angina scale been validated? The studies described previously (2–4) have utilized the Seattle Angina Questionnaire (SAQ), which has been shown to be reproducible in patients with stable angina, responsive to PCI, and validated with short-acting nitrate consumption. These characteristics need to be detailed for the DUTCH PEERS angina scale to assist with interpretation of the results. Furthermore, the SAQ was not used because it was too long; however, the short version (SAQ-7) would have been appropriate.
Thus, the future evolution of evaluating post-PCI angina requires the use of established validated measures as well as detailed documentation of the patient, angiographic, and interventional factors that may influence this important PROM. The measurement of this endpoint is fundamental and should be incorporated into all PCI studies, particularly because it is often the primary reason the patient initially sought medical attention.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2015 American College of Cardiology Foundation
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