CardioExchange Archive

In 2006, the Occluded Artery Trial (OAT) showed no benefit of routine PCI in patients with persistently occluded infarct-related arteries that were identified at least one day after an MI. According to a recent study, led by Judith Hochman, OAT has had minimal impact on clinical practice. We asked Hochman and two other experts why OAT has not affected practice. Here are their answers:

Judith S. Hochman (study author, NYU): OAT did not affect practice for various reasons. First, many physicians and patients don’t want to let go of the intuitive belief that an open artery is better than a closed artery, and many third-party payers continue to reimburse for the late procedure. Second, OAT has often been misunderstood. Some observers don’t appreciate the consistent lack of benefit of PCI for all subgroups of OAT patients with occluded infarct-related arteries: proximal LAD occlusion, across ejection fractions, high-risk patients, presence of viability (directly measured or assessed by an increase in EF), enrollment within the earliest time window (24 to 72 hours post-MI), and for a small subset who received drug-eluting stents. Finally, some have criticized the conclusions of the OAT investigators and guideline writers, citing a meta-analysis that, although it appropriately pooled OAT’s findings with data from smaller trials of PCI for stable patients with total coronary occlusion post-MI, inappropriately combined those data with findings from studies of completely different patients who have an open, stenosed artery with possible severe ischemia and symptoms post-MI. When we examine the ACC NCDR database in the future, I hope to see a large decrease in the use of PCI for patients like those in OAT, as this information is further disseminated.

Eric R. Bates (U. Michigan): This analysis appears to involve PCI for chronic total occlusions, not OAT patients. The OAT hypothesis was essentially this: Revascularization of an infarct artery to an infarct zone without major ischemia improves outcome by changing LV remodeling, electrical stability, or future collateral circulation. To test that hypothesis, the patients would have to be within 28 days of MI and fulfill the OAT inclusion and exclusion criteria. The article and the NCDR CathPCI registry did not identify infarct arteries; record symptoms or exercise test results; detail duration of target-artery occlusion; or describe indications for PCI.

Glenn Levine (Baylor): Unfortunately, it is human nature to embrace studies that affirm our preconceived notions or current practice patterns, and to be more recalcitrant in accepting and incorporating into daily practice study results that contradict them. Assuming the CathPCI Registry analysis truly represents the patients studied in OAT, which it appears to do, it is disappointing that practice patterns have not changed as a result of the study and subsequent published guidelines. The purpose of clinical trials, particularly when there is uncertainty or true equipoise, is to facilitate our charge as physicians to make decisions that are best for the patients we have taken an oath to care for. We should embrace the results of well-conducted trials, such as OAT, that answer important scientific questions, as well as practice guidelines based on those trials, regardless of our preconceived notions or current practice patterns. Performing procedures with no demonstrated benefit — or at least the potential for harm — is not consistent with appropriate patient management.

What are your thoughts about why OAT has not affected clinical practice? Will the new study have an impact?