Risk assessment by acute bedside echocardiography prior to acute coronary angiography in patients with ST-elevation myocardial infarction: a feasibility study

Abstract

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Novo Nordisk Foundation. Background Early risk assessment by hemodynamic measurements in patients with ST-elevation myocardial infarction (STEMI) could be useful for early detection of patients at risk of developing hemodynamic instability after primary percutaneous coronary intervention (pPCI). Anterior STEMI patients have larger infarct size and may be of particular interest. Transthoracic echocardiography (TTE) is a quick, non-invasive, and available tool, however, evidence regarding the use of acute TTE prior to acute coronary angiography (CAG) is limited. Purpose To assess the feasibility of acute bedside hemodynamic assessment in the cath. lab. by TTE in addition to clinical examination, and blood samples in STEMI patients without CS at arrival in the cath. lab. Methods STEMI patients without CS at hospital arrival and treated with pPCI were included in the study during a five week period. Clinical examination (Killip class), blood sampling (lactate, troponin T (TNT), proB-type natriuretic peptide (proBNP), and focused bedside 2D TTE with Doppler were performed prior to the acute CAG. The TTE protocol was focused (approx. 5 minutes) on hemodynamic measurements, infarction related complications, and differential diagnoses e.g. aortic dissection. The TTE was performed during preparation for the acute CAG. Patients were stratified in anterior- vs. non-anterior STEMI based on the culprit artery and prehospital ECG. Feasibility was estimated by all of the following echocardiographic parameters; left ventricular ejection fraction (LVEF), left ventricular outflow tract (LVOT) velocity time integral (VTI), and right ventricular function (tricuspid annular plane systolic excursion (TAPSE)). Results A total of 60 STEMI patients (aged mean 63 years, 18% female) were included, and 47% had an anterior STEMI. No differences in baseline characteristics between the two groups were found including comorbidities, clinical parameters, and time from cath. lab. arrival to first wire over the culprit lesion (median (IQR) 28 (23; 38) vs 32 (24; 40) minutes). Admission biomarkers of blood glucose, lactate, and proBNP plasma concentrations were similar between the two groups. Whereas admission TNT were higher for patients with anterior STEMI (median (IQR) 110 (37; 449) vs. 37 (20; 94) ng/L, p=0.01). The feasibility of TTE-study protocol was 93%. Patients with anterior STEMI had lower LVEF (mean: 36±11 vs. 48±9%, p=0.0003; missing: n=0), and a trend to lower LVOT VTI (19 (6.4) vs. 22 (5.0) cm, p=0.06; missing: n=4). No difference in parameters of diastolic function or TAPSE (missing: n=0) were found. None of the included patients had echocardiographic visible complications related to the infarction. Conclusion Acute TTE is to a high degree feasible and does not delay time to acute revascularization in STEMI patients. Patients with anterior STEMI have significantly higher admission TNT levels, lower LVEF, and a trend to lower LVOT VTI compared with non-anterior STEMI patients.