High incidence of acute coronary occlusion in patients without protocol positive ST segment elevation referred to an open access primary angioplasty programme
- Andrew Apps1,
- Aseem Malhotra1,
- Jason Tarkin1,
- Robert Smith1,
- Tito Kabir1,
- Rebecca Lane1,
- Mark Mason1,
- Omar Ali1,
- Paula Rogers1,
- Winston Banya1,
- Mark Whitbread2,
- Charles Ilsley1,
- Miles Dalby1
- 1Department of Cardiology, Royal Brompton and Harefield NHS Foundation Trust, London, UK
- 2London Ambulance Service, London, UK
- Correspondence to Dr Miles Dalby, Department of Cardiology, Harefield Hospital, Hill End Road, Harefield, Middlesex UB96JH, UK;
- Received 8 February 2012
- Revised 23 January 2013
- Accepted 6 March 2013
- Published Online First 30 March 2013
Background Primary percutaneous coronary intervention (PPCI) programmes vary in admission criteria from open referral to acceptance of electrocardiogram (ECG) protocol positive patients only. Rigid criteria may result in some patients with acutely occluded coronary arteries not receiving timely reperfusion therapy.
Objective To compare the prevalence of acute coronary occlusion and, in these cases, single time point biomarker estimates of myocardial infarct size between patients presenting with protocol positive ECG changes and those presenting with less diagnostic changes in the primary angioplasty cohort of an open access PPCI programme.
Methods We retrospectively performed a single centre cross sectional analysis of consecutive patients receiving PPCI between January and August 2008. Cases were categorised according to presenting ECG—group A: protocol positive (ST segment elevation/left bundle branch block/posterior ST elevation myocardial infarction), group B: ST segment depression or T-wave inversion, or group C: minor ECG changes. Clinical characteristics, coronary flow grades and 12 h postprocedure troponin-I levels were reviewed.
Results During the study period there were 513 activations of the PPCI service, of which 390 underwent immediate angiography and 308 underwent PPCI. Of those undergoing PPCI, 221 (72%) were in group A, 41 (13%) in group B and 46 (15%) in group C. Prevalence of coronary occlusion was 75% in group A compared with 73% in group B and 63% in group C. Median 12 h postintervention troponin-I (25th–75th percentile) for those with coronary occlusion was significantly higher in group A patients; 28.9 μg/l (13.2–58.5) versus 18.1 μg/l (6.7–32.4) for group B (p=0.03); and 15.5 μg/l (3.8–22.0) for group C (p<0.001), suggesting greater infarct size in group A.
Conclusions A number of patients referred to an open access PPCI programme have protocol negative ECGs but myocardial infarction and acute coronary artery occlusion amenable to angioplasty.