North Carolina Study Sparks Debate Over National PCI Trends

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The rates of diagnostic coronary angiography and coronary revascularization via percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery declined in North Carolina from 2003 to 2009, according to a study published online October 10, 2011, ahead of print in the American Heart Journal. However, relative rates of PCI to cardiac catheterization increased over the same period.

But experts disagreed over whether the study was reflective of, or contrary to, national trends.

Using data from the North Carolina State Medical Facilities Plan, W. Schuyler Jones, MD, of Duke University Medical Center (Durham, NC), and colleagues compared rates and variation in procedure use as well as relative rates of PCI to cardiac catheterization, CABG to cardiac catheterization, and CABG to PCI at 53 general acute care hospitals and academic medical centers throughout the state. Only hospitals that performed at least 25 cardiac catheterizations, 25 PCIs, and 25 CABGs each year were included.

Rates Decline for All Invasive

The absolute numbers of all procedures declined significantly over the study period. When results were adjusted for population growth, the decreases remained (table 1).

Table 1. Adjusted Procedure Rates per 100,000

 
Despite the decline, the relative rate of PCI to cardiac catheterization increased by 11%, while the relative rate of CABG to cardiac catheterization decreased by 13% and the relative rate of CABG to PCI decreased by 22%.

Hospital-level analysis showed evidence of significant variation in the relative rates of both PCI and cardiac catheterization (10%-90%, P < 0.05) and CABG to cardiac catheterization (5%-35%, P < 0.05).

Results Indicative of National Trends . . . or Not

Dr. Jones told TCTMD in a telephone interview that while he hypothesized the rates of procedure use would decrease, “we didn’t know that it would go down this much.” Because this study is the first to conduct hospital-level analysis, he said, “this is likely something that’s occurring around the country.”

He attributes the trends primarily to better medical therapy over the study time period. “Drug-eluting stents have helped decrease repeat use of PCI and potentially CABG,” he said.

However, Edward L. Hannan, PhD, of the University of Albany (Albany, NY), told TCTMD in a telephone interview that he was surprised that rates of PCI went down in North Carolina because rates in New York have increased, and that he would not expect national rates to mirror this study’s findings.

For cardiac catheterization and CABG rates, Dr. Hannan said he would expect declines over the study’s time period and into the future. “It’s not surprising that the ratio of CABG to PCI has gone down,” he said. “That’s certainly something that’s happening all over the place. I’m not surprised that the ratio of PCI to cardiac catheterization has gone up because there have been a lot more ad hoc PCIs done over that time period.”

Referring to research in 2007 stating that medical therapy worked as well as medical therapy plus PCI for patients with stable coronary artery disease, Dr. Hannan said PCI rates in New York declined around that time.

“There was also some adverse publicity about drug eluting stents and stent thrombosis that contributed to a decrease around that time as well,” he said. “But numbers in New York have started to climb back up again and were higher in 2009 than they were in 2003. So I’m not surprised that there was a decrease in that time period. I’m just surprised that in 2009 numbers are not bigger than the 2003 numbers.”

Inter-Hospital Variability Striking

In addition to the overall rate changes, Dr. Jones said he was interested to see the significant variation in the mode of revascularization used among the various hospitals analyzed. Attributing the inconsistencies in procedure rates to rates of cardiac catheterization, he said these differences could also be due to patient and operator characteristics, neither of which was studied in this instance.

“We’re not saying that Duke is the gold standard,” he said. “We’re just saying there’s a pretty substantial variation of hospitals outside the standard deviation – the 25th and 75th percentiles. . . . But if you’re outside the 25th or 75th percentile, you may say we need to look at this from a quality metrics standpoint.”

 

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Source:
Jones WS, Patel MR, Holleran SA, et al. Trends in the use of diagnostic coronary angiography, percutaneous coronary intervention, and coronary artery bypass graft surgery across North Carolina. Am Heart J. 2011:Epub ahead of print.

 

 

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