Balloon-Pump Assisted Coronary Intervention Study - BCIS-1

Description:

Data from nonrandomized studies had indicated that elective intra-aortic balloon pump (IABP) use in patients with ejection fraction (EF) <30% undergoing elective percutaneous coronary intervention (PCI) (high-risk PCI) is associated with better outcomes. The current trial sought to evaluate the efficacy and safety of elective IABP insertion prior to high-risk PCI versus conventional treatment (with no planned IABP use).

Hypothesis:

Elective IABP use would be associated with a lower major adverse cardiac event (MACE) rate at hospital discharge or 28 days, as compared with conventional treatment (with no planned IABP use).

Study Design

  • Randomized

Patients Enrolled: 301
NYHA Class: Class III/IV: 69%
Mean Follow Up: 6 months
Mean Patient Age: 71 years
Female: 21
Mean Ejection Fraction: 23.6%

Patient Populations:

  • Impaired LV function (EF ≤30%)
  • Extensive myocardium at risk:
  • BCIS-1 Jeopardy Score >8
  • Target vessel supplying occluded vessel, which supplies >40% of myocardium

Exclusions:

  • Cardiogenic shock
  • Acute MI <48 hours before
  • Planned staged PCI within 28 days
  • Complications of acute MI, such as ventricular septal defect, severe mitral regurgitation, or intractable VT/VF
  • Contraindication to IABP
  • Planned staged procedure within 28 days
  • Bleeding diathesis or warfarin therapy
  • Active internal bleeding
  • Allergy to aspirin, clopidogrel, glycoprotein IIb/IIIa inhibitors
  • Thrombocytopenia
  • Pregnancy

Primary Endpoints:

  • MACE at hospital discharge or 28 days (all-cause mortality, MI, revascularization, CVAs)

Secondary Endpoints:

  • Six-month mortality
  • Procedural complications
  • Prolonged hypotension OR
  • Ventricular tachycardia/ventricular fibrillation (VT/VF) requiring cardioversion OR
  • Cardiac arrest requiring cardiopulmonary resuscitation/ventilation
  • Bleeding complications
  • Vascular complications
  • Procedural success
  • Duration of hospital stay

Drug/Procedures Used:

Routine IABP use versus bailout IABP use only. IABP was removed 4-24 hours after PCI.

Concomitant Medications:

The use of abciximab was recommended, administered as a 0.25 mg/kg bolus followed by intravenous infusion at 0.125 μg/kg/min for 12 hours. This was used in about 41.0% of the patients during the procedure. On discharge: aspirin (99%) and clopidogrel (99%) was administered.

Principal Findings:

A total of 301 patients were enrolled, 151 to IABP and 150 to conventional therapy. Baseline characteristics were fairly similar between the two groups. About 33% of the patients had diabetes, and 74% had a history of prior myocardial infarction (MI). About 69% of the patients had New York Heart Association class III/IV symptoms, and 47% had Canadian Cardiovascular Society class III/IV angina. The majority of patients had a high jeopardy score, with the mean being 10.4 (range 8-12). The mean number of lesions per patient was 2.1, and about 28% had evidence of left main disease. Crossover to IABP was noted in 12% of the patients who were in the conventional therapy arm.

There was no difference in the primary endpoint of MACE at 28 days between the IABP and conventional therapy arms (15.2% vs. 16.0%, hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.51-1.76; p = 0.85). This included MI (12.6% vs. 13.3%, p = 0.85), and cerebrovascular accident (CVA) (1.3% vs. 0%). Other outcomes such as all-cause mortality at 6 months (4.6% vs. 7.4%, p = 0.32), procedural success (93.9% vs. 93.0%), and length of stay (median 2 days in each arm) were similar between the two arms. Procedural complications were significantly lower in the IABP arm (1.3% vs. 10.7%, p < 0.001), although access site complications (3.3% vs. 0%, p = 0.06) and all bleeds (19.2% vs. 11.3%, p = 0.06) tended to be more frequent in the IABP arm. The most common periprocedural complication was prolonged procedural hypotension, which necessitated IABP insertion in all affected patients in the conventional therapy group.

Two-year follow-up: All-cause mortality at 2 years (median 51 months) was significantly lower in the IABP arm at 2 years (27.8% vs. 38.7%, HR 0.66, 95% CI 0.44-0.98; p = 0.039). Information on other outcomes at 2 years such as MI, cardiovascular death, and CVA was not available.

Interpretation:

The results of this trial indicate that the routine use of IABP in patients with low EF undergoing high-risk PCI is not associated with a significant difference in MACE or mortality at 28 days. There was a lower risk of procedural complications, especially prolonged procedural hypotension necessitating emergent IABP use, but a higher risk of access site complications and bleeding in the IABP arm.

Recently, similar results have been noted for the use of IABP in high-risk ST-elevation MI patients presenting with cardiogenic shock, and undergoing PCI. It is unknown if the use of other support devices such as Impella would be associated with better outcomes in this high-risk cohort.

Interestingly, at 2 years, there seemed to be a mortality benefit with prophylactic IABP use in these patients. The mechanism of this benefit is not clear. Both periprocedural infarction/outcomes and completeness of revascularization were similar between the two arms, and thus, unlikely to be major contributors. It is possible that these findings are due to statistical chance, and will need to be confirmed in larger, well-powered trials, given the importance of this topic.

References:

Perera D, Stables R, Clayton T, et al., on behalf of the BCIS-1 Investigators. Long-Term Mortality Data From the Balloon Pump-Assisted Coronary Intervention Study (BCIS-1): A Randomized, Controlled Trial of Elective Balloon Counterpulsation During High-Risk Percutaneous Coronary Intervention. Circulation 2013;127:207-12.

Presented by Dr. Divaka Perera at ACC.12 & ACC-i2 with TCT, Chicago, IL, March 24, 2012.

Perera D, Stables R, Thomas M, et al. Elective intra-aortic balloon pump counterpulsation during high-risk percutaneous coronary intervention: a randomized controlled trial. JAMA 2010;304:867-74.

Presented by Dr. Simon Redwood at at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2009), San Francisco, CA, September 25, 2009.

Keywords: Shock, Cardiogenic, Myocardial Infarction, Stroke, Follow-Up Studies, Heart Failure, Hypotension, Confidence Intervals, Intra-Aortic Balloon Pumping, Angioplasty, Balloon, Coronary, Diabetes Mellitus


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