As 20th Century Swedish diplomat and author Dag Hammarskjöld suggests, an appropriate fixed point can serve as a guide, and maybe a goal, toward which to direct our actions. And interventional cardiology gains HORIZONS[-AMI] of its own in which to provide the appropriate course of care for cath lab procedures through the ever-burgeoning plethora of randomized, prospective trials.
The biggest winner of the 2009 Transcatheter Cardiovascular Therapeutics (TCT) conference in San Francisco last week was the sheer number of well-constructed randomized controlled trials, producing results upon which clinicians can rely and base their practices.
The second biggest winner of TCT09 was drug-eluting stents (DES). The data that emerged from SPIRIT IV, HORIZONS-AMI and others have truly begun to quell many of the fears that arose concerning DES-associated stent thrombosis in 2006. While SPIRIT IV, the largest DES randomized, head-to-head DES trial, found a statistically significant superiority for Abbott’s Xience V DES compared with Boston Scientific’s Taxus Express DES, both had exceptionally low stent thrombosis rates at one year (0.29 vs. 1.06 percent, respectively).
And, at two years with 3,602 STEMI patients, HORIZONS-AMI found that the Taxus Express DES showed significant reductions in ischemic target lesion revascularizations and target vessel revascularizations with no evidence of late catch-up, compared with a Taxus bare-metal stent (BMS). Interestingly, the study also showed that the BMS arm actually caught up to DES for incidents of stent thrombosis—each at 4.1 percent at two years of follow up.
In response, Abbott’s CMO Dr. Chuck Simonton told Cardiovascular Business News that “this year’s TCT represents the most positive moment [for drug-eluting stents] since the 2006 scare.”
Even in patients with more complex disease sets, like chronic total occlusions, DES was found to be safe and effective with a low rate of acute complications.
However, some caveats still remain for DES, particularly in stenting diabetics and dual-antiplatelet therapy. Many presentations and debates at TCT09 tackled the question of length for dual-antiplatelet therapy duration after PCI with DES. No definitive answer exists, because the DAPT randomized controlled trial—the only trial powered to answer that question—was launched at last year’s TCT.
One final word on prospective trialing, COGENT appears to have dispelled concerns about combining proton pump inhibitors and clopidogrel, which were previously linked to adverse events in previous, highly publicized observational studies. Dr. Shamir R. Mehta, MD, who conducted COGENT’s commentary, said, "these findings show how people can be completely mislead by observational data.”
Hammarskjöld also said that there is a “point at which everything becomes simple and there is no longer any question of choice.” Unfortunately, the practice of interventional cardiology isn’t so simple, and the horizons are ever evolving with the emergence of new technologies and procedures, but for now, the wealth of data from these trials will serve as practice guideposts.
On these topics, or others, feel free to contact me.