38 False activation for primary percutaneous coronary intervention is not a benign phenomenon

Abstract

Introduction: Primary percutaneous coronary angioplasty (PPCI) is the preferred reperfusion option for an acute ST elevation myocardial infarction (STEMI). Since 2005 24/7 PPCI is the first line treatment for an acute STEMI in our centre. 93% of patients are direct admissions by London Ambulance but a proportion (up to 20%) do not fulfil the diagnostic criteria for STEMI and are termed "false activations". Data on the outcome of this cohort is limited. Aim: To review the clinical outcome of patients presenting to our centre with false activation PPCI. Method: From January 2008 until October 2010, we identified 209 false PPCI activations defined as incomplete diagnostic criteria for acute STEMI: absence of STEMI: management and outcome 871 chest pain and/or ECG features (ST elevation or new LBBB). Data was collected via a "false activation" database together with review of case records. Results: 165 cases had complete data. Mean age was 67 with 71% male and 29% female. Mean length of stay was 4 days (range 1-33). 71% presented with chest pains and 29% had no chest pains, but had dyspnoea, palpitations or syncope. The ECG abnormality was non-specific ST-T changes in 22%, 19% LBBB, 15% left ventricular hypertrophy, 14% fixed ST elevation or Q waves, 10% early repolarization, 8% RBBB and 12% other ECG changes. The final diagnosis was non-ST elevation acute coronary syndrome (NSTEACS) in 19%, sepsis in 19% and congestive heart failure (CHF) in 15%. 8% stable angina and 7% syncope. Musculoskeletal or non-cardiac chest pains in 8% and 7% respectively. Pulmonary embolism in 2% and in 5% a gastric cause was diagnosed. 14% had other cardiac problems; arrhythmia, dilated cardiomyopathy, hypertension, pericarditis, pericardial effusion and late presentation STEMI. 15% had other diagnoses. Mean follow-up was 18.7 months during which 21.5% of false activation admissions died (n=45). 25% (n=11) died during index admission and 33% (n=15) died within 30 days of admission. Overall 30 day mortality for false activations was 7.2%, which is higher than the overall PPCI mortality of 6.0% (including cardiogenic shock) [p=0.008] and 3.3% (excluding shock) [p<0.0001] in our centre. 49% of deaths were cardiac, 29% sepsis and 22% other causes. The mean age for this group was 83. Conclusion: Patients presenting with false PPCI activation have a high observed mortality. This is probably due to co-morbidities, including occult cardiac disease. Thus, false PPCI activation is not a benign phenomenon and masks underlying significant disease. Robust pathways are required to minimise delay in further investigations and a need for risk stratification for NSTEACS presentations.