Meta-analysis Confirms Safety of PCI without Surgical Backup


Survival after PCI appears to be unaffected by whether backup surgery is available on-site, according to a meta-analysis published online July 7, 2015, ahead of print in Circulation. Moreover, the equipoise holds true for both primary and nonprimary PCI.

Implications:  Meta-analysis Confirms Safety of PCI Without Surgical Backup

The “rationale for allowing nonprimary PCI to be performed in centers without on-site surgery is to enhance patient convenience and maintain continuity of medical care,” write Bon-Kwon Koo, MD, PhD, of Seoul National University Hospital (Seoul, South Korea), and coauthors. They advocate for further research into the effects of this strategy “on repeat revascularization, subsequent medical costs, and quality of life.”

The investigators identified 4 RCTs and 19 prospective observational or case-control studies involving more than 1 million patients that compared PCI at centers with and without surgical backup.

Eight studies enrolled exclusively patients who underwent primary PCI, 6 included only those receiving elective or urgent nonprimary PCI, and the rest evaluated all PCI patients but reported outcomes according to presentation. Overall, 133,574 patients (12.1%) underwent primary PCI for STEMI, with 15.6% of those procedures performed at centers without on-site surgery. In addition, 967,549 patients (87.9%) received PCI for conditions other than STEMI, with 6.1% performed at centers without surgical backup.

No Impact on Mortality, Emergency Surgery

There were no differences in rates of all-cause mortality or emergency surgery for either primary or nonprimary PCI regardless of whether centers had on-site surgery. Findings using an overall random-effects model were similar (table 1).

  Table 1. Pooled Outcomes According to the Presence of Surgical Backup

Because follow-up periods varied, separate pooled analyses were performed for mortality within and after 30 days. The availability of on-site surgery had no effect at either time point, regardless of whether PCI was primary or nonprimary.

In a meta-analysis that sorted trials chronologically, the strength of the pooled effect of all-cause mortality after primary PCI did not change between 1995 and 2014, despite evolution in practice patterns, revascularization methods, and adjunctive pharmacology. In contrast, after 2008, the mortality effect for nonprimary PCI shifted from greater risk at centers without on-site surgery to equivalent risk between the different settings.

In addition, findings regarding mortality were consistent across multiple subgroups.

Overall, rates of serious complications of PCI were low—except for cardiogenic shock at 4.6%—and did not differ between centers with and without on-site surgery.

Focus on Improving Primary PCI

According to the authors, the need for emergency surgery in the wake of PCI complications has declined from about 6.6% in the early days of balloon angioplasty to a fraction of 1% today, due to advances in technology, technique, and operator experience. Moreover, primary PCI has been shown to be superior to thrombolysis for treatment of STEMI, increasing demand for access to the procedure.

Several meta-analyses—including the current one—have now found the safety and efficacy of primary PCI to be similar at centers with or without on-site surgery, Dr. Koo and colleagues say. Thus, instead of mandated surgical backup for emergent PCI, the following strategies should be encouraged to improve outcomes:

  • Maintain the quality of care in individual PCI centers
  • Reduce total ischemic time
  • Improve community recognition of and response to cardiac events
  • Optimize posttreatment follow-up, including secondary prevention and cardiac rehabilitation

Nonprimary PCI Without Backup Trickier

The case for nonprimary PCI without onsite surgery is more problematic, the authors write, since it is not supported by the need for rapid access or a survival benefit. Current US guidelines give nonprimary PCI a class IIb recommendation, although they mandate stringent criteria for such a program. Thus, the advantages of expanding nonprimary PCI to centers without on-site surgery, such as more patient choice, greater convenience, and more continuity of care with local physicians, should be weighed against potential disadvantages, such as an incremental risk of life-threatening complications, they say.

Moreover, the investigators observe, data regarding clinical outcomes in centers without on-site surgery have been conflicting. For example, a large analysis of Medicare administrative data showed higher mortality among patients who underwent nonprimary or rescue PCI in hospitals without on-site backup. However, since the procedures were performed between 1999 and 2001, they do not represent contemporary PCI, the researchers add.

On the other hand, the recently published CPORT-E and MASS COMM randomized trials found that rates of all-cause mortality and emergency surgery after nonprimary PCI were unaffected by surgical backup, they note.

TVR Not Evaluated

The authors caution that they were unable to evaluate TVR due to the paucity of data and inconsistent reporting. While in the CPORT-E trial 9-month rates were higher in centers without vs with on-site surgery (P = .01), in the MASS COMM trial there was no difference between 12-month TVR rates regardless of surgery availability.

Dr. Koo and colleagues also acknowledge that the current meta-analysis precludes adjustment for patient-level and unmeasured confounders, such as operator experience, adequacy of medical therapy, and annual PCI volume. In addition, because most of the constituent studies categorized urgent PCI for NSTEMI as nonprimary PCI, the results may not represent outcomes for elective PCI for stable angina or silent ischemia. Finally, there was insufficient information to discriminate among methods of revascularization (ie, balloon angioplasty, BMS, or first- or second-generation DES).


Source: 
Lee JM, Hwang D, Park J, et al. Percutaneous coronary intervention at centers with and without on-site surgical backup: an updated meta-analysis of 23 studies. Circulation. 2015;Epub ahead of print.


Disclosures:

  • The study was supported by a grant from the Medical Research Collaborating Center of Seoul National University Hospital.
  • Dr. Koo reports no relevant conflicts of interest.


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Meta-analysis Confirms Safety of PCI without Surgical Backup

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