Authors: Expert: Michael J. Cowley, M.D., F.A.C.C.; Interviewer: Peter C. Block, M.D., F.A.C.C.

Complete author affiliations and disclosures are at the end of this activity.

 

More than 1,000,000 percutaneous coronary intervention (PCI) procedures are performed annually in the United States; worldwide, there are nearly 2,000,000 procedures done each year.^[1] With contemporary coronary stents and adjunctive pharmacotherapies (e.g., glycoprotein IIb/IIIa inhibitors, thienopyridines, and direct thrombin inhibitors), PCI procedural success is estimated to be about 95% today and emergency coronary artery bypass graft (CABG) surgery is required in fewer than 1% of cases (range: 0.2% to 0.5%).

Several hospitals with cardiac catheterization laboratories have developed PCI programs without on-site cardiac surgery. The strategy is to provide rapid transfer to a surgical center in the event of a complication. The argument made by these centers is that this approach is tantamount to providing on-site surgical backup support.^[2-5]

This approach is prevalent throughout Europe and other countries with a limited number of cardiac surgical programs. Indeed, the August 2005 PCI guidelines from the European Society of Cardiology do not even address on-site surgical backup. In the U.S., a recent survey indicates that PCI without on-site surgery is performed in 37 states with three additional states about to begin pilot projects of PCI without on-site surgery.

Individual programs have reported successful results in the United States. In the PAMI-No SOS study, for example, both on-site primary angioplasty and transfer groups had similar 30-day outcomes, but more rapid reperfusion was seen in the on-site group (Figure 1).^[2]

However, the overall U.S. experience may be less satisfactory. Wennberg et al. analyzed the Medicare database for a 3-year period from January 1999 to December 2001 (when stents and IIb/IIIa inhibitors were in widespread use).^[6] They identified 178 hospitals without on-site cardiac surgical facilities and 943 hospitals with on-site cardiac surgery that performed PCI during that period. After adjusting for baseline differences, they found similar mortality rates in patients who underwent primary PCI for STEMI (Figure 2).

For elective PCI, however, the adjusted mortality was 38% higher at hospitals without on-site cardiac surgery (Figure 2). This increased mortality was confined to low-volume hospitals that performed fewer than 50 PCIs per year. Among the 10% of hospitals without on-site cardiac surgery and an annual volume of >50 PCIs per year, the observed mortality for elective PCI was similar whether on-site cardiac surgery was available or not (adjusted odds ratio 1.04, 95% CI 0.76 to 1.41, p=0.83).

New guidelines for PCI published by the American College of Cardiology (ACC), the American Heart Association (AHA), and the Society for Cardiovascular Angiography and Interventions (SCAI) explicitly address the issue of on-site cardiac surgical backup for elective PCI as well as primary PCI for ST-segment elevation myocardial infarction (STEMI). The writing committee argued that rapid transfer strategies are unrealistic because they are logistically difficult to achieve and require that a critically ill patient be transported outside of a hospital environment, possibly without a physician in attendance. Furthermore, if an institution without cardiac surgery is sufficiently close to one that provides surgery to permit sufficiently timely transfer, the guidelines state there is little justification for not transferring the patient electively in the first place.

The guidelines writing committee stated that the Medicare analysis by Wennberg et al. is consistent with the concept that expansion of PCI services outside of large, full-service centers creates small, low-volume programs with inadequate infrastructure that are not able to perform PCI at the same level of sophistication and quality as a larger institution.

Therefore, the ACC/AHA writing committee concluded that performance of elective PCI in a setting without immediately available on-site cardiac surgery potentially compromises patient safety, exposing the patient "to a small but very real additional and medically unnecessary risk." Thus, the guidelines continue to support the recommendation that elective PCI should not be performed in facilities without on-site cardiac surgery.

The writing committee stated, "Mere convenience should not replace safety and efficacy in establishing an elective PCI program without on-site surgery. As with many dynamic areas in interventional cardiology, these recommendations may be subject to revision as clinical data and experience increase."

What about primary PCI for STEMI? The ACC/AHA guidelines acknowledge that primary PCI for patients with STEMI might be considered in hospitals without on-site cardiac surgery, provided that appropriate planning for program development has been accomplished, including appropriately experienced physician operators and a well-equipped catheterization laboratory. There should be a proven plan for rapid transport to a cardiac surgery operating room in a nearby hospital with suitable hemodynamic support capability for transfer.

 

In the April 18, 2006, issue of the Journal of the American College of Cardiology, David R. Holmes, MD, FACC, and colleagues at Immanuel St. Joseph's Hospital - Mayo Health System, reported on their experience in a 150-bed community hospital.^[7] The facility, in Mankato, Minnesota, is located 85 miles away from the nearest tertiary care facility in Rochester, Minnesota.

They developed a PCI program and started performing elective PCI and primary PCI for STEMI in March 1999 and March 2000, respectively. Main features of the program were cross-training and cross-credentialing of all operators, a telemedicine link for consultation, and strict protocols for case selection (Figure 3) and PCI program requirements.

Immediate access to emergency cardiac surgery was ensured with a tested transport protocol, which included access to three helicopters as well as ground ambulances for urgent patient transfer with intra-aortic balloon pump capability for hemodynamic support, if necessary. In rare circumstances during which inclement weather prohibited ambulance transport by air or ground, an elective PCI procedure was delayed or canceled. Transport times of less than 60 minutes were reliably achieved.

A total of 1,007 elective PCI and primary PCI procedures performed at the Immanuel St. Joseph's Hospital were matched one-to-one with those performed at St. Mary's Hospital in Rochester, Minnesota. Clinical outcomes (in-hospital procedural success, death, any myocardial infarction, Q-wave myocardial infarction, and emergency coronary artery bypass surgery) and follow-up survival were compared between groups.

Among 722 elective PCIs, procedural success was 97% at the Mankato community hospital compared with 95% at the tertiary facility in Rochester (p=0.046), with in-hospital death similar for both hospitals (Figure 4). The comparable procedural success rate among 285 primary PCIs for STEMI was 93% and 96% respectively (p=0.085), with in-hospital death slightly higher in the Mankato hospital (Figure 5). Importantly, no patients undergoing PCI at the community hospital required emergent transfer for cardiac surgery. Survival at 2 years' follow-up by treatment location was similar for patients with elective PCI and primary PCI.

The authors cautioned that the observed difference in procedural success, albeit statistically significant, may not be clinically relevant. A matched cohort analysis is not a substitute for a randomized controlled trial, and the authors acknowledged that their matching may not have adjusted for residual non-measured, non-quantified variables between the community hospital and tertiary care facility. Likewise, the majority of deaths observed at Immanuel St. Joseph's Hospital following primary PCI were not related to a procedural complication or absence of on-site cardiac surgery.

They concluded that efficacy and safety of performing elective and primary PCI are not simply related to the availability of on-site cardiac surgery per se; "rather, they are more likely associated with the staff, infrastructure, and processes to provide the service." To ensure optimal quality and clinical outcomes, they recommend standard prerequisites for developing a PCI program without on-site cardiac surgery (Figure 6).

"Our results should not be used to justify proliferation of low-volume PCI programs without on-site cardiac surgical capability," said the study authors. "Conversely, we believe that health care systems must determine how best to concentrate their cognitive and capital resources, including PCI programs, to provide the safest and highest quality of care to a population."

In this interview, Michael J. Cowley, MD, FACC, looks at the available data and addresses this controversy. Dr. Cowley is Immediate Past-President of the SCAI.

Guidelines

Smith SC Jr, Feldman TE, Hirshfeld JW Jr, et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol 2006;47:216-35. Full text available at: http://www.medscape.com/px/trk.svr?exturl=http://www.cardiosource.com/guidelines/guidelines/percutaneous/perc_PDF.pdf

 

Dr. Block: I'm here with Michael Cowley of the Medical College of Virginia to talk about angioplasty with or without cardiosurgical backup. Mike, this has been a hot topic and a problem for a number of centers. Data are emerging that there is little downside to this, particularly in the setting of acute MI. Where do we stand with this situation? And how are people reacting?

Dr. Cowley: Peter, this has been an emotional and controversial topic for a long time, although it is somewhat less so today. Still, I think there are issues about elective intervention without on-site surgery.

The most recent PCI guidelines, which were authored with ACC/AHA and SCAI, have endorsed primary intervention at centers without on-site surgery with certain conditions: if they have a well defined transport mechanism, if they have experienced operators, if they have experienced staff, and if they offer 24 hours a day/7 days a week coverage.

Given the data suggesting that primary intervention is better than fibrinolytic therapy when there will be a delay in transport, this is now reasonably well accepted in many communities and in many states.

Dr. Block: What about elective PCI?

Dr. Cowley: Elective intervention without on-site surgery is emerging in the United States, too. The new ACC/AHA guidelines still list this as a Class III indication; in other words, it is not recommended in the United States.

In other parts of the world this is much less of an issue. SCAI commissioned a task force to evaluate this topic and, in one of the surveys, 35 of 39 countries responding said this strategy of PCI without on-site surgical backup is utilized in about half of their centers performing PCI. In many countries, particularly in Europe, there are only a limited number of cardiac surgery programs. Therefore, these programs arose in high-volume centers with highly experienced operators and it has worked well.

The biggest issue today is whether or not centers without on-site surgery can have highly experienced operators and all the other necessary ingredients to make sure that excellent outcomes are achieved. There have been about 15 reports in the last 10 years looking at available data, usually single-center experiences or fairly small studies, and the data suggest favorable overall results associated with experienced physicians and careful case selection.

Dr. Block: Let's talk for a moment about transport in case of trouble. Do the sites in other countries have some plan in place so that they can take a patient who, though rare, gets in trouble and then deliver them to a surgical center in a hurry? Or is that not necessary?

Dr. Cowley: Most of the centers do have a relationship like that with a surgical center. Data tell us that urgent surgery is necessary in about 0.2% or 0.3% of cases, which is two or three out of 1,000; so, the transportation issue doesn't arise very often. Still, most of the hospitals in Europe and in the United States have such a transport plan in place.

Of interest, even though the guidelines consider PCI a Class III indication, at least in terms of elective angioplasty at a center without on-site surgery, this approach is being used in 37 of our 50 states. Among the 13 states where it's not being done, three have recently approved pilot projects to explore this approach. The new C-PORT II study will evaluate elective PCI and Georgia is one of the participating states; I think they have approved 10 centers to participate in this new study. Clearly, this is undergoing increased utilization.

Dr. Block: What percentage of patients is being treated without surgical backup? Do we know?

Dr. Cowley: Greg Dehmer looked through the NCDR database as part of an SCAI working group evaluation and found that of 450-some centers reporting their data in 2001 through 2003, 39 of them - about 9% - were centers without on-site surgery. The trends suggest that this is increasing; whether it's an increasing number of patients at the same centers without surgical backup, or more centers adopting programs without surgical backup, or both, is not entirely clear. Certainly this trend is continuing despite the recommendations from the guidelines.

Dr. Block: The C-PORT trial interests me, of course, being from Atlanta. This study should give us some information that may be a little less biased, while others think it is being set up to succeed so it won't tell us a lot. What's your thought on that?

Dr. Cowley: Study design is always a key factor. Data from smaller studies suggest this approach can be done safely if the operators are experienced and case selection is done very carefully. Several recent reports from the Mayo Clinic and Duke University showed very good results based on their satellite facilities. However, whether this can be generalized to a broader application is not clear.

In fact, Wennberg and colleagues looked at the Medicare database and evaluated results in centers with and without on-site surgery, with and without acute infarction patients. In the acute infarct population, primary PCI or rescue PCI results were similar whether on-site surgical backup was available or not. While some of these centers may not have had the experience level of the larger facilities with surgical backup, it may be that any added risk was offset by being able to take care of patients quickly without transferring them.

However, more disquieting, there was higher mortality and more adverse outcomes in the elective or the non-MI population among the centers that did not have on-site surgery. It appeared that this was predominantly in the lower-volume centers that did fewer than 50 Medicare cases a year. That goes along with other reports suggesting that operator experience is an important part of the outcomes seen. One of the real issues is whether centers without on-site surgery will sustain volumes that will allow optimal patient outcomes.

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