Surgical Backup for PCI Makes No Difference in Rates of Death, CABG

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Although guidelines recommend against performing percutaneous coronary intervention (PCI) at centers without on-site surgery facilities, a meta-analysis in the December 14, 2011, issue of the Journal of the American Medical Association suggests there is no increased risk of in-hospital death or need for emergency bypass at such hospitals. However, mortality rates were significantly higher at the hospitals with no surgical backup after adjusting for publication bias, leading the study authors to express concern.

For the study, researchers led by Mandeep Singh, MD, MPH, of the Mayo Clinic (Rochester, MN), compared PCI outcomes at centers with and without on-site surgery as reported in 15 studies published between 1995 and 2009.

Overall, 124,074 patients were included in the meta-analysis. For primary PCI in STEMI patients, there was no increase in the rates of in-hospital mortality or need for emergency coronary artery bypass graft (CABG) surgery at centers without on-site surgery facilities compared with those having such capabilities. A similar pattern was observed for nonprimary PCI (elective and NSTEMI; tables 1 and 2).

Table 1. Primary PCI Outcomes

Table 2. Nonprimary PCI Outcomes

However, after adjustment for publication bias, the mortality rate for nonprimary PCI was 25% higher at centers without on-site surgery compared with centers with on-site surgery (OR 1.25; 95% CI 1.01-1.53; P = 0.04).

Dr. Singh and colleagues conclude that additional outcome data are still needed, including rates and indications for urgent or emergency transfers, especially in patients undergoing nonprimary PCI at centers without on-site surgery.

In a random effects model, the odds ratio for emergency CABG surgery after primary or nonprimary PCI performed at sites without vs. with on-site surgery was 0.53 (95% CI 0.35-0.79) for primary PCI and 1.21 (95% CI 0.52-2.85) for nonprimary PCI.

In a subset analysis of 11 studies in which the study period included no years earlier than 1999, the odds ratios were similar to those in the primary analysis.

More Data Needed

The study authors say the results are relevant to patient care, especially since the 2006 guideline update to the ACC/AHA/SCAI guidelines for PCI do not recommend PCI for elective indications and give a class IIb indication for primary PCI at centers without on-site surgery. Given that the mortality rates for nonprimary PCI were approximately 25% higher at centers without on-site surgery, Dr. Singh and colleagues say “this finding is of concern, despite improved outcomes observed in recent years in studies from national registries in Europe and the United States.”

They acknowledge that most studies in the meta-analysis did not distinguish truly elective and low-risk PCI from higher-risk patients with unstable angina or non-STEMI or those needing rescue or facilitated PCI. In addition, indications for transfer, transfer rates, and outcomes for these patients were not universally reported and therefore were not included. Importantly, all but 1 study was observational. For more definitive conclusions, randomized trials by site (with or without on-site surgery) with inclusion of low-risk, elective PCI is needed, Dr. Singh and colleagues observe.

“More data for nonprimary PCI are required for definitive conclusions, especially data stratified on the basis of clinical and angiographic risk and operator or institutional PCI volumes, to better optimize the performance of PCI at centers without on-site surgery,” the study authors write. “Further work should identify processes that improve the safety and outcomes of nonprimary PCI performed at centers without on-site surgery.”

Judicious Use, Structured Protocols Vital

In an editorial accompanying the study, Scott Kinlay, MBBS, PhD, of the VA Boston Healthcare System (Boston, MA), points out that the meta-analysis spans a wide range of time periods beginning with the pre-stent era and continuing through the BMS era and well into the DES era.

“Despite outcomes differing substantially over these periods, the pooled estimates of in-hospital mortality and emergency CABG surgery for primary and nonprimary PCI are low in absolute terms,” he writes.

According to Dr. Kinlay, the meta-analysis bolsters prior studies showing that “patterns of judicious PCI use by operators in hospitals without CABG surgery leads to risks that are similar to those of hospitals with CABG surgery.”

He notes that the most recent PCI guideline, released in November 2011, avoids making recommendations about performing PCI in hospitals without CABG surgery.

“This omission reflects the residual uncertainty of expanding PCI to smaller more remote hospitals,” he writes. “Recommendations for annual PCI volume limit the spread of PCI services to smaller institutions but are largely based on data from the present era. Annual PCI volume may be less important than total lifetime number of PCI cases, which arguably reflects the experience an operator uses to recognize patterns of presentation or coronary anatomy that portend higher risk for emergency CABG surgery or death.”

But one of the most important issues, according to Dr. Kinlay, is that hospitals without CABG surgery have a structured program that features:

• Experienced operators and nursing staff
• Clear plans and agreements for rapid transport of patients to a facility with CABG surgery

Patient Benefit Questioned

However, in a telephone interview with TCTMD, Jeffrey W. Moses, MD, of NewYork-Presbyterian/University Hospital of Columbia and Cornell (New York, NY), took a decidedly different view, calling the 25% increase in mortality at centers without on-site surgery “very worrisome.”

“There is enough of a harbinger of a potential problem at this point that there should be a moratorium on doing this,” Dr. Moses said. “This is an idea whose time has come and gone.”

Although there are some geographic considerations in certain parts of the country that make it necessary for a small number of low-risk PCI procedures to be performed at a hospital without surgical backup, he observed that 90% of the population is within an hour of a PCI center.

“This concept of doing PCI at centers without adequate backup is being driven mainly by economics, by hospitals wanting to have that service available, but it isn’t in the best interest of patients,” he said. “It also goes against the concept of the ‘heart team’ approach because you cannot make rapid clinical decisions for the patient without all the experts at hand.”

Dr. Moses added that studies such as those included in the meta-analysis suffer from a key selection bias that makes it impossible to extrapolate to the PCI population as a whole or develop policy decisions.

“Essentially, there are certain patients we will not touch without surgical backup, so right there is an intrinsic bias in terms of [who is selected] for off-site PCI that they can’t correct for in any of these studies,” he said.

 

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Sources:
1. Singh M, Holmes DR, Dehmer GJ, et al. Percutaneous coronary intervention at centers with and without on-site surgery: A meta-analysis. JAMA. 2011;306:2487-2494.

2. Kinlay S. The trials and tribulations of percutaneous coronary intervention in hospitals without on-site CABG surgery. JAMA. 2011;306:2507-2509.

 

 

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