August 25, 2010 (London, United Kingdom) — Results of the Balloon Pump–Assisted Coronary Intervention Study (BCIS)-1 study, showing no advantages to a strategy of elective intra-aortic balloon pump (IABP) insertion vs bailout usage in patients with severe left ventricular (LV) dysfunction and complex PCI, have now been published in the August 25, 2010 issue of the Journal of the American Medical Association .
|Dr Simon Redwood|
As previously reported by heartwire , the BCIS-1 results were first presented at the TCT 2009 meeting last September by senior author Dr Simon Redwood (King's College, London, UK). At the time, Redwood stressed that while the trial clearly supports the important role of IABPs in hypotensive patients, the results should serve as a wake-up call to physicians already convinced that IABPs are necessary in all patients with low ejection fractions facing complex procedures--something BCIS-1 clearly rejects. Nearly one year after those results were first released, Redwood now says that IABP use has dropped at his hospital and, he told heartwire , "anecdotally, other centers in the UK seem to be using it less."
Also commenting on the study for heartwire , first author on the published paper, Dr Divaka Perera (King's College, London, UK), also emphasized that the trial ran counter to the assumptions of many interventionalists.
"While we were still recruiting to BCIS-1, we conducted an email survey of 110 UK interventional cardiologists--ranging from low- to high-volume operators, with varying institutional PCI volumes--asking for their IABP strategies in three different scenarios: severe coronary disease plus poor LV function, moderate coronary disease plus poor LV function, and severe coronary disease plus good LV function. The majority said they would insert an IABP electively when undertaking PCI in patients with severe coronary disease and poor LV function. . . . When we presented the results of BCIS-1 at our national PCI meeting in January 2010, three months after TCT, very few seemed to opt for elective [use during] PCI, in a show-of-hands survey. I think practice in the UK is changing."
|Dr Divaka Perera|
But both Redwood and Perera pointed to "important" caveats.
"All cath labs, specifically those performing PCI, must have an IABP readily available," Redwood says. "They are still very useful, and cath-lab staff must remain conversant with their use. Having said that, now that this trial has been published, we anticipate that it will help to revise the current AHA/ACC guidelines for IABP use in PCI."
He also noted that investigators in BCIS-1 were all high-volume users in high-volume centers accustomed to dealing with the complex patients enrolled in the study. "If this trial had been performed in low-volume centers by low-volume users, the results, although speculative, may have been different," he said.
The published BCIS-1 results are nearly identical to those previously reported by heartwire . The trial randomized 301 patients to either elective IABP use or "no planned" IABP use, with bailout IABP permitted. To be enrolled in the study, all patients had to have an ejection fraction of <30% and extensive myocardium at risk (myocardial jeopardy score >8/12).
At hospital discharge or 28 days, major adverse cardiac and cerebral events (MACCE), the primary end point, as well as individual components of the end point, were not statistically different between the two groups. Major secondary outcomes, including mortality, complications, and length of stay, were also no different between the elective- and no-planned-IABP groups, with the exception of major procedural complications, which favored the elective group (1.3% vs 10.7%, p<0.001), and major or minor bleeds, which trended higher in the elective group (19.2% vs 11.3%, p=0.06). There was a nonsignificant 2.8% absolute difference in mortality favoring the elective-IABP group at six months, and the curves appeared to be diverging over the study period.
"We don't yet know whether the divergence in curves at six months is important, but we should have longer-term follow-up data in the next few months," Perera told heartwire .
In fact, it was this mortality difference that prompted investigators to continue to follow the study cohort over the longer term, Redwood said. "Although very speculative, it may be that LV function improved slightly more in the [elective]-IABP group, and this may result in a long-term slight reduction in mortality."
An Important Role to Play for Some
Rescue IABP insertion was needed in 18 patients (12%) in the no-planned group; 13 for procedural hypotension and one each for pulmonary edema and sudden vessel closure. "The fact that one in eight required bailout IABP is important," Redwood told heartwire . "Since TCT, we have done a post hoc comparison of those who needed rescue IABP vs those who got through PCI without needing an IABP. Those requiring bailout had more extensive coronary disease--a higher mean jeopardy score and a greater proportion with 'full' jeopardy--hinting that these patients may be at particularly high risk of complications," he said, although the study was not powered to look at subgroups. "[Since] it's not possible to definitively identify patients who are going to need a bailout IABP, we strongly recommend a standby IABP approach when doing such cases," he said.
No authors disclosed receiving commercial funding.
Heartwire from Medscape © 2010 Medscape, LLC
Cite this: Routine Balloon Pump Unnecessary for High-Risk/Low-EF PCI Patients: BCIS-1 - Medscape - Aug 25, 2010.