STEMI time delays a clinical perspective

Authors: MJ de Boer F Zijlstra

Publish Date: 2015/07/18

Volume: 23, Issue: 9, Pages: 415-419

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Abstract

STEMI time delays have been introduced as a performance indicator or marker of quality of care As they are only one part of a very complex medical process one should be aware of concomitant issues that may be overlooked or even be more important with regard to clinical outcome of STEMI patients In this overview we try to summarise the most important onesVarious delays when treating patients with STElevation Myocardial Infarction STEMI with primary percutaneous coronary intervention PPCI ‘Healthcare system delay’ is the total delay from emergency medical service EMS call to PPCI ‘PCIrelated delay’ is the extra delay that one may use to perform PPCI and achieve effective reperfusion First Medical Contact either EMS call EMS arrival on scene or arrival at hospital according to regional STEMI system of care after reference 15The most commonly used parameters or indicators are the time from symptom onset till effective reperfusion total ischaemic time and the median doortoballoon time D2BT the latter supposed to represent the inhospital performance Besides D2BT is easily determined and it was quickly introduced as a measure of quality of care of STEMI patients The mean D2BT in our first study group of primary PCI patients in the early 1990s was only 61 min although this concerned patients who were also eligible for fibrinolytic therapy 2 Other issues sometimes addressed are calltoballoon time CTB time from FMC time from first ECG time to the catheterisation lab time to coronary angiography door1 to door2 time D1D2 time in case of interhospital transfer and so on All have their strong and weak points and often have to be registered in hectic situations and during offduty hours For a comprehensive overview of system delays in primary angioplasty field triage we refer to Fig 1 Furthermore different hospitals use different electronic health records with different databases or still have to operate without automated system files The prehospital phase data mostly from ambulances are usually stored separately This inevitably accounts for the lack of consistency of methods and data registration and makes comparison among and between hospitals and/or health care providers difficult However we need these data to improve our performance and ability to monitor all aspects of this complicated chain of medical care and to find ways for improvement not only of the PCI procedure itself but also its surrounding logistics Our suggestion would be to count system time delay from first ECG to the time of start of coronary angiography CAG both being easily obtainable and above all automatically stored in current practice As primary angioplasty is the preferred treatment in almost all candidates identified by prehospital triage or by direct presentation to hospitals we should not use the term ‘doortoneedle time’ anymore as was used in previous studies and surveys that concerned mainly patients who received fibrinolytic therapy 17International comparisons have demonstrated significant differences in infarct care organisation and outcomes between countries and national surveys have proven to be useful in improving the system and quality of care in STEMI patients 16 18 In many countries a substantial number of STEMI patients are not receiving any reperfusion therapy at all or receive it outside the guidelinerecommended timeframes and implementation of the best reperfusion therapy as recommended in the guidelines should be encouraged This includes efforts at reducing D2BT for STEMI patients undergoing primary angioplasty regardless of the clinical setting or health care regionSicker patients and patients with highrisk features undergo more delay 19 There may be large differences in baseline characteristics in the patients studied Prognostic factors including age comorbidities presence of diabetes previous myocardial infarction or congestive heart failure haemodynamic state on admission and infarct size are usually not reported but may result in differences in outcome 18 20 Above all if adjustment for these characteristics is applied time delay does not seem to be a significant determinant of outcome anymore

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