One-Quarter of Diagnostic CAD Catheterizations Deemed Inappropriate in NY State

Download this article's Factoid (PDF & PPT for Gold Subscribers)

 

Twenty-five percent of diagnostic catheterizations performed in New York State between 2010 and 2011 for suspected coronary artery disease (CAD)—or over 2,200 patients—would be considered inappropriate according to criteria developed by multiple cardiology societies over the past 3 years. Results from a statewide database review were published online January 28, 2014, ahead of print in Circulation: Cardiovascular Interventions.

Researchers led by Edward L. Hannan, PhD, of State University of New York (Albany, NY), used the New York State Cardiac Diagnostic Catheterization Database to identify 3,986 patients who underwent diagnostic cath for suspected CAD in 2010 and 2011, retrospectively rating their procedures as inappropriate, uncertain, or appropriate.

Dr. Hannan and colleagues applied appropriate use criteria published online May 9, 2012, in the Journal of the American College of Cardiology. The criteria were developed by an expert panel representing the American College of Cardiology Foundation and the Society for Cardiovascular Angiography and Interventions, in collaboration with multiple relevant professional societies.

Only One-Third Judged Appropriate

In the study, which encompassed 18 nonfederal New York hospitals, the authors found that 24.9% of diagnostic cath procedures given to patients with suspected CAD were inappropriate, while 39.8% were uncertain, and 35.3% were appropriate.

Inappropriate diagnostic cath was more likely to occur in:

• Patients ≤ 55 years of age (P < 0.001)
• Women (P < 0.001)
• Current tobacco users (P = 0.03)
• Patients without:
  • Diabetes (P < 0.001)
  • Hypercholesterolemia (P < 0.001)
  • Hypertension history (P < 0.001)
  • Angina symptoms (P < 0.001)

• Patients with:

• Congestive heart failure (P < 0.001)
• Renal failure (P = 0.01)
• Low risk or no stress test results (P < 0.001)
• Low global risk score (P < 0.001)

Patients with payers that were private, Medicaid, or “other” had inappropriateness rates of 25%. New York was also subdivided into 5 geographic regions, with inappropriateness rates ranging between 22% and 31%.

Patients who were rated as inappropriate fit into 3 general scenarios:

• No previous stress test/asymptomatic/low or intermediate global CAD risk (57% of all inappropriate diagnostic caths; n = 1,270)
• No previous stress test/symptomatic/low pretest probability (7%; n = 163)
• Previous stress test with low-risk findings/asymptomatic (36%; n = 807)

Thus, roughly two-thirds of patients whose diagnostic caths were rated as inappropriate lacked stress tests and had either low/intermediate global CAD risk or low pretest probabilities.

Meanwhile, patients who were rated as appropriate were:

• Symptomatic with no previous stress test but had high pretest probabilities of CAD (47.2% of all appropriate diagnostic caths)
• Symptomatic with intermediate-risk stress tests (36.7%)
• Patients with high-risk stress tests, regardless of symptoms (16.1%)

Hospital, Operator Appropriateness

The median hospital appropriateness rate was 30.5%, with a median inappropriateness rate of 28.5%. There was a correlation between hospital diagnostic cath volume and inappropriateness of the procedure (P = 0.15).

Among the 92 operators in the study with diagnostic cath volumes of at least 25 per year, the median appropriateness rate was 33.2%, with a median operator inappropriateness rate of 24.6%.

According to the authors, suspected CAD patients who received diagnostic cath with no prior noninvasive testing were rated as inappropriate if they were asymptomatic with either a low or intermediate global risk score or if they were symptomatic with a low pretest probability of CAD.

“It is notable that 50.7% of all patients who could be rated had no stress tests before [diagnostic cath], and 31.5% of patients with no stress test results were rated as inappropriate for [diagnostic cath],” the authors state. “These patients comprised 64% of all patients with suspected CAD who were rated as inappropriate for [diagnostic cath]. The vast majority of these patients (89%) were asymptomatic with low or intermediate global CAD risk scores.”

An important limitation of the study, they stress, is that the appropriate use criteria were published after its time frame, “so no referring physicians had the opportunity to use the criteria in determining which patients to refer for [diagnostic cath],” they write. In addition, 3,266 patients (27%) could not be rated due to missing information. “In the unlikely event that all of these patients with missing information were appropriate for [diagnostic cath], the inappropriateness rate would have dropped from 24.9% to 18.3%,” Dr. Hannan and colleagues point out.

Inappropriate May Not Equal Unnecessary

In an e-mail communication with TCTMD, Sunil V. Rao, MD, of the Duke Clinical Research Institute (Durham, NC), noted that ‘inappropriate’ is not always the same as ‘unnecessary.’

“All unnecessary PCI is inappropriate, but not all inappropriate PCI may be unnecessary,” he said, adding that regardless, “the data are quite clear that the rate of adverse outcomes is very low even with rare inappropriate PCI. That is one of the major limitations of [appropriate use criteria].”

Nevertheless, the rate of inappropriate PCI will likely never reach zero, Dr. Rao noted. “We have to be very careful here. There likely will be a certain rate of rarely appropriate PCI (the appropriate use criteria document says this explicitly),” Dr. Rao said. “And I don’t think we should focus on eliminating ‘inappropriate’ PCI or on gaming the system to make the rate zero. What we should be focusing on is overall PCI quality and preventing unnecessary PCI from being performed.”

The focus, he stressed, should be on “delivering PCI to the patients who really need it.”

 

---

Source:
Hannan EL, Samadashvili Z, Cozzens K, et al. Appropriateness of diagnostic catheterization for suspected coronary artery disease in New York State. Circ Cardiovasc Interv. 2014;Epub ahead of print.

 

Disclosures:

• The study was funded in part by the New York State Department of Health.
• Drs. Hannan and Rao report no relevant conflicts of interest.

 

Related Stories:

• Consensus Document Outlines Guidelines for Cardiac Cath Use
• Consensus Document Updates Practice Standards for Cath Labs
• SCAI Publishes Cath Lab Best Practices