Utility of Handheld Ultrasound Performed by Cardiology Fellows in Patients Presenting with Suspected ST-Elevation Myocardial Infarction.

Abstract

Background: In academic hospitals, cardiology fellows may be the first point of contact for patients presenting with suspected ST-elevation myocardial infarction (STEMI) or acute coronary syndrome (ACS). In this study, we sought to determine the role of handheld ultrasound (HHU) in patients with suspected acute myocardial injury (AMI) when used by fellows in training, its association with the year of training in cardiology fellowship, and its influence on clinical care.

Methods: This prospective study's sample population comprised patients who presented to the Loma Linda University Medical Center Emergency Department with suspected acute STEMI. On-call cardiology fellows performed bedside cardiac HHU at the time of AMI activation. All patients subsequently underwent standard transthoracic echocardiography (TTE). The impact of the detection of wall motion abnormalities (WMAs) on HHU in regard to clinical decision-making, including whether the patient would undergo urgent invasive angiography, was also evaluated.

Results: Eighty-two patients (mean age: 65 years, 70% male) were included. The use of HHU by cardiology fellows resulted in a concordance correlation coefficient of 0.71 (95% confidence interval: 0.58-0.81) between HHU and TTE for left ventricular ejection fraction (LVEF), and a concordance correlation coefficient of 0.76 (0.65-0.84) for wall motion score index. Patients with WMA on HHU were more likely to undergo invasive angiogram during hospitalization (96% vs. 75%, P < 0.01). The time interval between the performance of HHU to initiation of cardiac catheterization (time-to-cath) was shorter in patients with abnormal versus normal HHU examinations (58 ± 32 min vs. 218 ± 388 min, P = 0.06). Finally, among patients who underwent angiography, those with WMA were more likely to undergo angiography within 90 min of presentation (96% vs. 66%, P < 0.001).

Conclusion: HHU can be reliably used by cardiology fellows in training for measurement of LVEF and assessment of wall motion abnormalities, with good correlation to findings obtained via standard TTE. HHU-identified WMA at first contact was associated with higher rates of angiography as well as sooner angiography compared to patients without WMA.