Study Looks at Differences in PCI Outcomes at Teaching vs. Non-Teaching Hospitals

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While general outcomes including mortality after percutaneous coronary intervention (PCI) are similar in teaching and non-teaching hospitals, vascular complications are more frequent at teaching hospitals, where less-experienced physicians are often involved in the procedure, according to a study published online July 29, 2013, ahead of print in the American Heart Journal. On the other hand, rates of emergency coronary artery bypass graft (CABG) surgery are lower at those centers.

Hitinder S. Gurm, MD, of the University of Michigan (Ann Arbor, MI), and colleagues looked at 89,048 patients who underwent PCI at 31 Michigan hospitals—teaching (n = 30,870) and non-teaching (n = 58,178)—from January 2007 to January 2009. Teaching hospitals were defined as those with trainee involvement in more than half of PCIs, with teaching status granted by national accreditation agencies.

Difference in Complications, Not Mortality

In-hospital mortality did not differ between hospital types, nor did rates of contrast-induced nephropathy, nephropathy requiring dialysis, stroke or TIA, in-hospital MI, transfusion requirement, or GI bleeding. However, vascular complications were more common at teaching hospitals, specifically rates of arteriovenous fistula, hematoma requiring transfusion, pseudoaneurysm, and thrombosis (P < 0.01 for all). On the other hand, the risk of emergency CABG was lower (adjusted OR 0.63; 95% CI 0.49-0.83; P = 0.0009; table 1), as was the risk of MACE.

Table 1. Procedural Complications




P Value





Vascular Complications



< 0.0001

Emergency CABG








Lastly, the use of vascular closure devices was greater at non-teaching compared with teaching hospitals (41.7% vs. 21.9%; P < 0.0001).

Teaching vs. Non-Teaching Not Most Important Differentiator

In a telephone interview with TCTMD, Dr. Gurm said he did not “expect to see any differences in survival because PCI has become a fairly advanced science and people follow good protocols.” However, the increased risk of vascular complications seen at teaching hospitals “seems obvious” because less-experienced residents and fellows are involved in the procedures.

“What was surprising is that emergency bypass was higher at the non-teaching hospitals,” he continued. “I don’t have a good explanation for that.”

The study reflects slightly older data, Dr. Gurm observed, and the recent uptick in adoption of radial PCI should improve outcomes going forward. “It’s possible that once radial access becomes more prevalent, this difference between teaching and non-teaching hospitals for vascular complications might go away,” he said. “Radial patients hardly ever get vascular complications. [And when] they do, they are not as big a deal as with femoral patients.”

Overall, the results are good for both kinds of hospitals, and “patients shouldn’t have to worry if it’s a teaching or non-teaching hospital,” Dr. Gurm said, adding that patients should focus on the outcomes of the specific hospital.

Harlan M. Krumholz, MD, SM, of the Yale University School of Medicine (New Haven, CT), agreed. In a telephone interview, he told TCTMD that “we should get past using these broad categories of comparison for hospitals and dig more deeply into what it is about specific hospitals that allow them to excel and others to lag behind.”

The problem with using teaching vs. non-teaching as characteristics for comparison “is that these [are] broad categories and there’s a lot of overlap,” he said. Because a hospital is a teaching institution does not mean that it will have higher rates of vascular complications, Dr. Gurm explained, “it just means on average.

“The new paradigm has to be to try to understand what specific institutions are doing. . . . There is substantial heterogeneity, and to lump [teaching hospitals] all together is to neglect the nuances that really distinguish them,” Dr. Gurm continued. “My hunch is that it goes far beyond whether they are teaching or not. It goes into their internal culture, their policies and practices, and that takes a combination of quantitative and qualitative research to understand.”

AMI-Only Outcomes Could Shed More Light

Edward L. Hannan, PhD, of the University at Albany (Albany, NY), told TCTMD in a telephone interview that he would have been interested in seeing other outcomes assessed, including longer-term mortality in the subset of AMI patients, because of their higher overall risk.

The exact definition of a teaching hospital might also cause some confusion, Dr. Hannan said. “I know it’s a fairly standard definition, but there can be differences that may vary [from] 1 state to another. If you’re a teaching hospital, the degree to which the residents actually perform the procedure could vary quite a bit.”

Dr. Gurm said that trainees at his institution practice using a simulator before participating in live procedures. “We hope that will reduce vascular complications,” he said. “We are also making a bigger push for more radial use at teaching hospitals.”

Study Details

An institution was deemed a teaching hospital based on:

  • The presence of an American Medical Association accredited residency program
  • Resident-to-bed ratio of 0.25 or higher
  • Membership to the Council of Teaching Hospitals
  • The presence of cardiology fellows who were scheduled to rotate through the catheterization laboratory and participated in at least 50% of PCIs performed during their rotation

Patients at teaching hospitals had significantly higher baseline serum creatinine than patients at non-teaching hospitals. The median time from admission to discharge per case was 2 days, regardless of hospital classification. There was no clinically relevant difference in total contrast load. Fluoroscopy time was higher at teaching hospitals (18.1 vs. 12.8 minutes; P < .0001). Prior to PCI, patients at teaching hospitals were more likely to be taking clopidogrel, statins, and ACE inhibitors or angiotensin receptor blockers.


Sandhu A, Moscucci M, Dixon S, et al. Differences in the outcome of patients undergoing percutaneous coronary interventions at teaching versus non-teaching hospitals. Am Heart J. 2013;Epub ahead of print.



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  • Dr. Gurm reports receiving research funding from Blue Cross Blue Shield of Michigan and the National Institutes of Health.
  • Drs. Krumholz and Hannan report no relevant conflicts of interest.