Is primary percutaneous coronary intervention still the superior reperfusion strategy?

Abstract

Thecurrent guidelines for themanagementof ST-segment elevation myocardial infarction (STEMI) recommend primary percutaneous coronary intervention (pPCI) as the preferred treatment strategy if it canbe conducted in a timely fashion by an experienced catheterization team.1 Because of the restricted availability of hospitals providing pPCI support 24 hours 7 days a week, the concept of STEMI networks with prearranged rapid transferprotocolsbetweencommunityhospitals and PCI-capable centers has been developed. The goal is toofferpPCI,which is currently considered the superior reperfusion therapy, to a maximum number of patients with STEMI. Although initial experiences with local STEMI networkswere encouraging, the transition from thrombolysis to PCI forpatientsadmittedtocommunityhospitals requiresclose follow-up because changes in delaysmayoffset the benefit of pPCI over thrombolysis. Therefore, the study by Vora et al2 in this issue of JAMA InternalMedicine from theNational CardiovascularDataRegistry is eagerlywelcome, providing important information on delays, reperfusion therapy selection, andoutcomes in a large community-based population. Vora et al focused on interhospital drive time as being an important, but variable, component in the chain of time, which lasts from the onset of pain until the initiationof reperfusiontherapy.Duringthepastyears, manyperiodshavebeendefined (whichmayhave led to some confusion); generally, they can be divided into patientrelateddelaysandsystem-relateddelays (Figure). The systemrelateddelay starts from the firstmedical contact,whichusually corresponds to the first hospital door time, and endswith the initiation of reperfusion therapy; it includes time to diagnosis, time for transfer to thePCI hospital, and time for preparation of the reperfusion therapy (thrombolysis or PCI). The good news is that the proportion of patients achieving a first hospital door-to-balloon (DTB) timewithin 120minutes (systemdelay) has almost doubled over approximately 5 years. This is most likely attributed to the implementation of awarenessprogramssuchas theAcuteCoronaryTreatmentand InterventionOutcomesNetworkRegistry–GetWith theGuidelines program. The bad news is that approximately half of all patients still do not achieve these recommended time targets. Therefore, continuous efforts should be made to improve these system-related delays. Improvement measures may include the public reporting of time-related quality indicators or the promotion of prehospital triage, with transfer of patients directly fromhome toPCI-capable hospitals, bypassing the nearest community hospitals. In addition, the appropriateselectionofpatients for reperfusiontherapywill alsohelp to achieve a higher proportion of patients with optimal delays. The article byVora et al2 demonstrates that,when the estimated drive time exceeded 30 minutes, half of the patients failed to achieve a first DTB time within 120 minutes; among someof these patients, fibrinolysismayhave been an equivalent ormore effective therapy. The current reluctanceof starting fibrinolysis is driven, at least in part, by the overwhelmingevidenceof the superiorityofpPCIover thrombolysis. This evidence has been subsequently incorporated into international guidelines.1However, theseguidelines arebasedmainly on studies that were conducted before the use of newer adjunctive pharmacotherapies or the application of routine invasive evaluationafter thrombolysis, bothofwhichhavebeen associated with better outcomes. More recent trials and registrieshave shown lowermortality rateswith fibrinolysis comparedwiththeirhistorical cohorts.3,4Formanysubgroups,pPCI is no longer superior to thrombolysis when consideringmortality rates.3,5,6 This was also evident in the study by Vora et al,which showed comparable adjustedmortality rates among patients with estimated drive times of 30 to 120minutes who were eligible for fibrinolysis or pPCI. The major drawback to the use of fibrinolysis remains an associated increased risk of bleeding complications. However, by using half-dose thrombolytic regimens and by planning the invasive evaluation beyond the 3-hour window following drug administration, the risk seems to decrease.6 Based on these recent findings, some will argue for a revival of thrombolysis in the management of patients with STEMI admitted to hospitals without PCI capability. However, medical appropriateness aims to provide the best treatment strategy for each patient. As such, all efforts should be made to try to achieve the shortest DTB time as possible because evidence shows that pPCI remains superior to fibrinolysis if theDTB time is 60minutes or less.3,7 If these strict time lines cannot be achieved, the selection of optimal reperfusion therapy remains a complex decision process that should take into account the following 4 factors. Related article page 207 Figure. Patient-Related Delay and System-Related Delay