Prognostication in Refractory Angina
Editor's Note: Commentary based on Povsic TJ, Broderick S, Anstrom KJ, et al. Predictors of long-term clinical endpoints in patients with refractory angina. J Am Heart Assoc 2015;4(2): Epub Ahead of Print.
Refractory angina despite maximal medical therapy in patients without revascularization options is a frequent problem. Yet, this population has not been well defined in regards to long-term outcomes and risk factors for future adverse events. In the article, "Predictors of Long-term Clinical Endpoints in Patients with Refractory Angina," the investigators used single-center data to elucidate three-year outcomes and identify predictors and risk factors for mortality in clinically stable patients with advanced coronary artery disease (CAD) ineligible for revascularization.
Using the Duke Database for Cardiovascular Disease (DDCD), the investigators identified 1908 patients with advanced CAD ineligible for revascularization and class II to IV angina who remained clinically stable for at least 60 days following the index catheterization. Endpoints included three-year incidence of death, cardiac rehospitalization and a composite of death, myocardial infarction, stroke, cardiac rehospitalization and revascularization. A multivariable Cox regression model and Kaplan-Meier event rates were used to identify predictors and risk factors for mortality. Total rehospitalization costs over a three-year period were also determined.
The 3-year incidence of death, cardiac rehospitalization and a composite of death, myocardial infarction, stroke, cardiac rehospitalization and revascularization was 13.0%, 43.5% and 52.2%, respectively. Predictors of higher mortality included increasing age, multivessel CAD, diabetes, tobacco use and history of congestive heart failure (CHF), whereas angina class had no significant effect on the risk of mortality and prior coronary artery bypass graft surgery was protective. Total rehospitalization costs over a three-year period per patient were $10,185 in 2012 U.S. dollars.
Clinically stable patients with refractory angina despite medical therapy and without revascularization options have a modest risk of mortality overall, with those with multivessel CAD, depressed EF and history of CHF comprising a higher risk population. Rehospitalization for refractory angina is frequent, resulting in significant health care utilization and costs.
Multiple studies have examined patients with refractory angina; however, the reported long-term clinical outcomes of such patients have been variable, likely due to heterogeneity in the criteria used to define these patients. The current study robustly defines a cohort of patients with stable CAD and angina at the time of the index catheterization. The analysis is limited by lack of data on optimization of anti-anginal therapy and persistence of angina at follow-up. Nevertheless, the overall findings of the current study are similar to those of other cohort studies in this patient population. The current study suggests that although refractory angina does not result in a high rate of mortality (~4% per year), it does lead to significant health care utilization and costs. Patients with multivessel CAD, depressed EF and history of CHF comprise a higher risk population. Other clinical characteristics including increasing age, diabetes and tobacco use portend worse outcomes.
The current study identifies key clinical characteristics that may place patients with clinically stable refractory angina without revascularization options at higher risk of adverse outcomes and can assist clinicians in prognostication as well as identifying patients who warrant closer follow-up. The findings of this study also suggest that refractory angina results in high health care utilization and costs, emphasizing the need for focused efforts on optimizing care for this group of patients.
- Povsic TJ, Broderick S, Anstrom KJ, et al. Predictors of long-term clinical endpoints in patients with refractory angina. J Am Heart Assoc. 2015;4:e001287.
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