CathPCI Shows About Half of US PCI Centers Are Low Volume

Reed Miller

October 19, 2012

TEMPLE, Texas — A large number of the facilities performing PCIs have a lower annual procedure volume than what is recommended in the national guidelines, according to a new report from the CathPCI Registry of the National Cardiovascular Data Registry (NCDR) [1].

The lead author of the report, Dr Gregory J Dehmer (Texas A&M University College of Medicine, Temple), told heartwire , "As delivery of PCI in the US continues to change and . . . we look to developing more efficient models and systems of care, not only for patients with STEMI but other conditions, [the centers' PCI volume] will be a topic of considerable discussion over the next several years."

The latest data from the CathPCI registry, published online October 17, 2012 in the Journal of the American College of Cardiology, includes data from about 85% of US cath labs. The report has information from 1 110 150 patients undergoing only diagnostic cardiac catheterization and another 941 248 undergoing PCI.

The data reveal that from January 2010 through June 2011, almost one-third of the facilities reporting to the registry performed 200 PCIs or fewer annually and represented 12.4% of the PCI procedures included in this data sample. On-site cardiac surgery was not available in 83% of these facilities.

The NCDR is a national treasure, and a national treasure is not something to put in a box and keep secret. Dr. John Smith

Nearly 49% of the facilities included in the report performed 400 or fewer PCI procedures annually, while 89% of the facilities performing PCI without on-site surgery had an annual PCI case volume under 400.

In the report, Dehmer et al explain that "although data showing a relationship between case volume and outcomes are mixed and uncertain," the 2011 American College of Cardiology Foundation/American Heart Association guidelines on coronary intervention recommend that PCI should ideally be performed at centers that do at least 400 of these procedures annually and have on-site bypass-surgery capability. The guidelines indicate that an annual PCI volume of 200 or fewer may be untenable. "Unless they are geographically isolated--which is not very many in the United States--you ought to reevaluate whether your facility needs to keep doing PCIs, because [200 annually] is getting down very low," Dehmer said. However, the CathPCI report shows a slight increase in the percentage of all US PCIs being performed at these sub-200 centers, from 4.0% to near 4.5% from the beginning of 2010 to mid-2011.

Database Is a Treasure Trove

The reported CathPCI data "give you a snapshot; here's what is really happening in our country as far as all of these metrics with the use of PCI," Dehmer said. "The NCDR [is] a national treasure . . . and a national treasure is not something to put in a box and keep secret. We need to put the information out there and let people benefit from it."

The paper by Dehmer et al also points out that 70% of the patients undergoing angioplasty and stenting presented with an MI or other acute symptoms, 18% had stable angina, and 12% had atypical symptoms or no angina. The average door-to-balloon time for patients presenting with an ST-elevation MI was 64.5 minutes when the patient first came to a PCI-capable hospital and 121 minutes if they had to be transferred.

Despite the growing enthusiasm for transradial catheter access, over 90% of procedures are still done with femoral access. Only 8.3% of diagnostic tests and 6.9% of angioplasty and stenting procedures were transradial in this registry.

Imaging Data Does Not Suggest Overuse

Among the patients undergoing only a diagnostic catheterization, almost 50% had either no coronary disease or nonobstructive CAD, but, the authors point out, coronary stenosis of less than 50% can be associated with unstable coronary syndromes, and roughly 10% of patients with STEMI are found to have normal coronary arteries, so "a finding of less than 50% stenosis in a large number of patients does not automatically indicate an overuse of diagnostic angiography facilities."

Stress testing and other imaging prior to PCI is "another area that's been under a lot of active comment and active research," Dehmer said. The CathPCI study found that around a third of patients who underwent PCI had a stress test or imaging study and about 46% of the patients who had a diagnostic cath only without PCI underwent stress or imaging tests. About 82% of these additional tests were stress myocardial perfusion tests. Computed tomography represented less than 3% of the imaging tests. "When those technologies came out, it was thought--probably more by regulators than anyone else--that physicians would use these in excess, [with] patients exposed to a lot more radiation and [incurring] the costs of these sophisticated tests, and a lot of them would end up having angiography anyhow," Dehmer said. "But the numbers here are surprisingly low, and that's comforting to me, in a sense, because it says that the cardiology community has not gone overboard in ordering these tests."

Lower-Risk Patients Get More Post-PCI Imaging

In a separate paper published online October 16, 2012 in Circulation: Cardiovascular Imaging, Dr Daniel Mudrick (Duke University, Durham, NC) and colleagues report on the patterns of noninvasive stress tests and invasive coronary angiography after PCI [2].

By linking the CathPCI registry data with longitudinal Medicare claims data for 250 350 PCI patients undergoing PCI from 2005 to 2007, Mudrick et al found that stress testing and invasive angiography is common in older patients after PCI, and yet patients with higher-risk features at baseline were less likely to undergo post-PCI testing. Only 9% of patients referred for stress-testing after PCI underwent revascularization within 90 days.

Between two months post-PCI and the end of follow-up (the median was two years) about 60% of patients had another test. About 82% of these patients' first test was a stress test, while the rest were coronary angiography. Clinical factors associated with a higher likelihood of not getting a downstream test included older age, male gender, heart failure, diabetes, smoking, and renal failure. About 15% of patients who underwent a stress test first after their PCI also underwent angiography within 90 days. About 49% of these patients underwent revascularization, while 53% of patients whose first post-PCI test was angiography underwent revascularization (p<0.001).

Dehmer reports have no relationships relevant to the contents of this paper to disclose; disclosures for the coauthors are listed in the paper. Mudrick et al had no disclosures.