The publication and presentation of the BARI 2D trial has triggered a battle that will surprise no one who observed the reception of COURAGE a few years ago.
On the one hand, the interventional cardiology community is doing its best to interpret the trial in a way that will dampen the impact of the trial on real world usage of PCI. On the other hand, more conservative cardiologists argue that the trial reinforces the major lesson from COURAGE that PCI is greatly overused in the US.
The interventional position was immediately staked out in a SCAI statement. While acknowledging that BARI 2D “is a useful and focused trial,” the SCAI press release argues for a limited application of the trial’s finding, noting that it “specifically applies to those with carefully controlled diabetes, multi-vessel but stable coronary artery disease (CAD), and few heart disease symptoms,” a population which represents “a very small subset of CAD patients with diabetes.”
SCAI states that “DES are the standard of care for diabetic patients undergoing angioplasty and stenting,” but that “many patients enrolled in the revascularization/PCI arm of BARI-2D received bare metal stents because DES were not available in the early years of this trial.” In addition, the sickest patients were excluded from the trial, and these patients “receive the greatest life-saving benefits from revascularization.”
Since the patients studied in BARI-2D faced only a small risk of death or heart attack to begin with, it stands to reason that revascularization would not show significant mortality benefits.
Responding to the SCAI statement, William Boden told CardioBrief that it was “predictable–dismissive and defensive,” and that it “overstated the benefits of DES.”
Sanjay Kaul responded in more detail to the SCAI statement:
- Drug eluting stents have not been shown to favorably impact hard outcomes of death or MI compared to bare-metal stents in either diabetic or non-diabetic patients. Thus, it is unlikely whether the exclusive use of DES in BARI 2D would have resulted in a different outcome.”
- Pre-randomization angiogram is a prerequisite to ensure that patients are eligible for randomization to either an initial strategy of intensive medical therapy or revascularization plus intensive medical therapy. It is, therefore, not a limitation of the trial.
- The mortality rate at 5 years averaged 12% or about 2.4% per year which is consistent with intermediate risk and is somewhat higher than the 1-2% annual mortality rates observed in several recent diabetes trials (ACCORD, VADT, DIAD). It is interesting to note that the mortality in BARI 2D is approximately 50% higher than that observed in the COURAGE trial (8%). Thus, the patients enrolled in BARI 2D do not appear to represent a low-risk population.
- The recommendation for screening for myocardial ischemia in asymptomatic diabetics was not supported in the recently published DIAD trial.
- What BARI 2D tells us is that intensive medical therapy without initial revascularization (especially PCI) can be implemented safely in most diabetic patients with stable CAD without incurring any disadvantage with respect to death or major cardiovascular events.
BARI 2D in the real world
What impact will BARI 2D have in the real world? Wachovia analyst Larry Biegelsen, who first called attention to the potential signficance of BARI 2D more than a month ago, predicts that BARI 2D will have a smaller effect on PCI volume than COURAGE:
“We do not expect the BARI 2D results to have as great of an impact on stent volume as COURAGE did. Recall, COURAGE reduced stent volume in the U.S. by about 10% in 2007, however, we expect BARI 2D to have less of an impact because: (1) BARI 2D essentially confirms the COURAGE results and (2) the patient population in BARI 2D represents a subset of the patient population in COURAGE, diabetes patients, who account for about 30% of total stent patients. Therefore, if BARI 2D were to have the same relative impact on stent volume as COURAGE did, we would expect about a 3% decline in stent volume in the U.S.”
You can request a copy of the Wachovia report by sending a message to: larry.biegelsen@wachovia.com).
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