The Authors’ reply We appreciate the opportunity to comment on the reply to the counterpoint of our editorial.1 ,2 Admittedly, the comments were edgy, but the content was intended to be a scientific exchange regarding the interpretation of the European Society of Cardiology guidelines based on the best available evidence. Our position stems, in part, from a more regional than perhaps international perspective where guidelines are read by lawyers and politicians, who sometimes interpret statements out of context. Our mission was simply to address a prevalent confusion regarding ‘Percutaneous Coronary Intervention (PCI)-related delay’ and point out that in some paragraphs of the comprehensive 2012 European Society of Cardiology ST-Elevation Myocardial Infarction (STEMI) guidelines3 ‘PCI-related delay’ seems to be equated with ‘time from First Medical Contact (FMC) to Primary PCI (PPCI) delay’, since data addressing ‘PCI-related delay’ have been used to give recommendations concerning ‘FMC to PPCI delay’. In paragraph 3.5.2 the guidelines3 thoroughly discuss the paper by Pinto and colleagues4 (ref. 41 in the guidelines) and states: “Taking into account the studies and registries mentioned above, a target for quality assessment is that primary PCI (wire passage) should be performed within 90 min after FMC in all cases. In patients presenting early, with a large amount of myocardium at risk, the delay should be shorter (<60 min)”. Because the report by Pinto and colleagues4 addresses ‘PCI-related delay’ and not ‘FMC to PPCI delay’ the guideline engenders confusion regarding this particular point.

The recommendation in paragraph 3.4.1 in the guidelines3 stating: “If the reperfusion therapy is primary PCI, the goal should be a delay (FMC to wire passage into the culprit artery) of ≤90 min (and, in high-risk cases with large anterior infarcts and early presenters within 2 h, it should be ≤60 min) (ref. 40,41)” is not supported by the content of refs. 404 and 41,5 because the ‘FMC to PPCI delay’ is more than 120 min in refs. 404 and 41.5 We acknowledge that the authors of the reply to our editorial2 appreciate that the CAPTIM study (ref. 40)5 may not provide sufficient evidence to recommend ‘FMC to PPCI’ of <60 min. We are confident that our main proposal: “It is necessary to standardise and differentiate recommendations of “FMC to PPCI” depending on FMC being an Emergency Medical Service (EMS) call or a hospital arrival”, will become the norm. This point is crucial because STEMI systems of care focusing on prehospital diagnosis and field triage to PCI centres are developing throughout Europe.6 In the case of prehospital diagnosis using EMS systems, FMC equates with EMS call. In this case, typical delays are 10 min from EMS call to arrival on scene and 20 min on scene. The result is, that even with an ideal door-to-balloon delay of 30 min, it is impossible to achieve a ‘FMC to PPCI’ below 60 min for the majority of patients, since no time is left for transportation to the hospital. We agree wholeheartedly that this limitation in definition does not necessarily mean that fibrinolysis can be considered superior, but it highlights a recommendation for an unachievable and somewhat unsubstantiated goal for reperfusion time with hospital systems being ‘penalised’ for prehospital diagnosis. While not the intention, guideline recommended metrics, even if only offered to spur quality improvement and shorten reperfusion times, are often used as performance metrics defining the standard of care.

Even though the STREAM trial evaluated the issue,7 it is unclear whether patients with STEMI with a very short presentation delay would benefit more from prehospital fibrinolysis or with field triage to a PPCI centre, as recognised in the editorial to the STREAM trial,8 and recently stated in the National Institute of Health and Care Excellence (NICE) guidelines (guidance.nice.org.uk/cg167).9

As stated by the authors of the reply to our editorial, the text describes in detail the interpretation of studies evaluating the effect of ‘PCI-related delay’, offering <120 min as acceptable.3 Nevertheless, as we interpret figure 2 in the STEMI guidelines3 it is difficult to see that the guidelines are not suggesting a shorter metric. The recommendation among EMS presenters is fibrinolysis within 30 min of FMC if PPCI cannot be performed within 60 min of FMC in early presenters with large infarctions. This corresponds with a ‘PCI-related delay’ of 30 min and can be interpreted as ‘reducing the window of opportunity for PPCI’, particularly in systems with prehospital diagnosis.

Again, we consider the creation of STEMI guidelines to be a Herculean task and that the writing committee constructed a phenomenal product. We only suggest that the committee consider the issues raised in our editorial1 to avoid confusion as healthcare systems and clinicians attempt to devise STEMI systems of care that use regionalisation, pharmacoinvasive approaches and prehospital diagnosis.

The hitherto most elegantly formulated outline of this recommendation is actually found in the recently published NICE guidelines: Offer coronary angiography, with follow-on primary PCI if indicated, as the preferred coronary reperfusion strategy for people with acute STEMI, if primary PCI can be delivered within 120 minutes of the time when fibrinolysis could have been given.9