Appropriate Use of PCI Studied

July 5, 2011—Paul S. Chan, MD, et al published a study in the Journal of the American Medical Association to quantify the proportion of percutaneous coronary interventions (PCIs) classified as appropriate, of uncertain appropriateness, and inappropriate for acute as well as nonacute indications (2011;306:53–61). The investigators concluded that approximately all PCIs for acute indications could be classified as appropriate, whereas only approximately half of PCIs performed for nonacute indications could be classified as appropriate.

As the investigators noted, more than 600,000 PCIs are performed annually in the United States at a cost exceeding $12 billion. PCI exposes patients to the risks of periprocedural complications, as well as longer-term bleeding and stent thrombosis. The investigators also stated that recent trials in stable patients without acute coronary syndromes have shown that PCI compared with medical therapy may provide only a modest population-average improvement in symptom relief.

The study included data from more than 500,000 patients in the National Cardiovascular Data Registry undergoing PCI between July 2009 and September 2010 at 1,091 hospitals in the United States. The appropriateness of PCI was determined using multisociety appropriate-use criteria for coronary revascularization, which were published by Manesh R. Patel, MD, et al in the Journal of the American College of Cardiology (2009;53:530–553). These criteria were jointly developed by six professional organizations to support the rational and judicious use of PCI. Dr. Patel is also an investigator in the current study.

Results were stratified by whether the procedure was performed for an acute (ST-segment elevation myocardial infarction [STEMI], non-STEMI, or unstable angina with high-risk features) or a nonacute indication.
 


Of the 500,154 procedures classified, 103,245 (20.6%) were for STEMI, 105,708 (21.1%) were for non-STEMI, 146,464 (29.3%) were for high-risk unstable angina, and 144,737 (28.9%) were for nonacute elective indications. Based on the appropriate-use criteria definition for acute procedures, 355,417 PCIs (71.1%) were for acute indications and 144,737 (28.9%) were for nonacute indications. Heart attack comprised 58.8% of all acute procedures. High-risk unstable angina comprised 41.2% of acute procedures.
 


The researchers found that 98.6% of acute PCIs were classified as appropriate, 0.3% were classified as uncertain, and 1.1% were classified as inappropriate. Overall, 50.4% of nonacute PCIs were classified as appropriate, while 38% were for uncertain indications and 11.6% were for inappropriate indications. In general, compared with procedures classified as appropriate and uncertain, inappropriate PCIs were more likely to occur in patients with no angina, low-risk noninvasive stress testing results, or suboptimal antianginal therapy.
 


There was substantial hospital-level variation in the proportion of inappropriate procedures for nonacute indications. Hospitals in the lowest quartile had inappropriate PCI rates of 6% or lower. The rate of inappropriate PCI was > 16% among hospitals in the highest quartile. Analysis of the data suggested an 80% greater likelihood of patients with identical clinical characteristics receiving an inappropriate PCI at one randomly selected hospital as compared with another.
 


“Collectively, these findings suggest an important opportunity to examine and improve the selection of patients undergoing PCI in the nonacute setting,” stated the investigators. “Better understanding of the clinical settings in which inappropriate PCIs occur and reduction in their variation across hospitals should be targets for quality improvement.”