Primary PCI for STEMI — Pushing the Limits
The optimal management of patients with ST-elevation myocardial infarction (STEMI) has been the subject of ongoing clinical investigations for the past several decades. When it became apparent that primary angioplasty was not only feasible, but superior, to thrombolytic therapy in randomized clinical trials,1 there was universal adoption of primary percutaneous coronary intervention (PCI) for those centers that perform PCI. The belief that primary PCI was superior to thrombolytic therapy as the initial treatment of STEMI is so strong that many centers that previously administered thrombolytic therapy for STEMI have switched to triage for primary PCI centers for primary PCI, although definitive evidence supporting this strategy is lacking.
In this issue of the Journal, Aplin and colleagues2 present the results of a regionally implemented triage for primary PCI for STEMI experience. Acting as the hub of a wheel 100 miles in radius in central Minnesota, 25 hospitals which had previously administered thrombolytics were switched to primary PCI at St. Cloud Hospital, the PCI center, using helicopter transfer for the vast majority of patients (71%). This experience was notable for a median door-to-balloon (D2B) time of 110 minutes (mins) from the referral sites compared to only 56 mins at the PCI center. Primary PCI success was over 99% for both referral patients as well as those presenting to the PCI center itself, with the majority receiving drug-eluting stents. In-hospital outcomes appeared to be excellent, with low mortality rates of approximately 2% and 1-year mortality rates of 120 mins.
ACC/AHA guidelines have recently been updated describing the goals for patients presenting with STEMI at non-PCI-capable hospitals.3 These guidelines recommend that transfer for primary PCI in lieu of thrombolytic therapy should be considered if the door-to-needle time can be achieved in
The state of transfer of STEMI patients for primary PCI does not appear to be too dissimilar from the situation widely publicized several years ago when it became apparent that most primary PCI centers were not achieving D2B time in
In regard to the first issue, the results of the St. Cloud experience appear to be representative of a mature system delivering STEMI care using a referral to PCI center model. Although not specifically addressed by the authors, one would believe that the team responsible for overseeing the success of this program would have been able to overcome system-wide obstacles to faster transfer over the 4-year duration of this program. Given the similar D2B time (about 110–120 mins) from sites reporting their experience,4,5 it is unlikely that further efforts to achieve D2B times
One of the responses to this apparent dilemma from the proponents of transfer for primary PCI is the belief that the guidelines should use a D2B time of 120 mins as a goal for transfers, not 90 mins. Support for this is offered from two sources. First, the choice of
First, the clinical evidence supporting time dependence of reperfusion comes primarily from thrombolytic literature where occlusion to reperfusion times 60 mins, there is still a benefit of reperfusion therapy, but the relative benefit is reduced. Almost none of the patients undergoing primary PCI achieve reperfusion times of
However, the belief that the apparent similar outcomes of those achieving D2B times
As new information such as that described from the St. Cloud experience emerge and more centers migrate away from thrombolytics to transfer for primary PCI, the ACC/AHA guidelines will have to be reconsidered. The implications of wholesale transition to primary PCI, however, are potentially staggering to a health-care system already under fire for costs that are growing faster than any other segment of the economy. Use of a tiered approach with a pharmaco-invasive strategy for patients outside of a distance that prohibits achieving a transfer D2B time of 90 mins, and a primary PCI strategy for patients for whom a transfer D2B time of
From the Section of Cardiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina.
The author reports no conflicts of interest regarding the content herein.
Address for correspondence: Robert J. Applegate, MD, FACC, FSCAI, Section of Cardiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1045. E-mail: [email protected]
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