Abstract:
Background : In academic hospitals, cardiology fellows may be
the first point of contact for patients presenting with suspected STE
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 MI (AMI) when used by
fellows in training, its association with year of training in cardiology
fellowship, and its influence on clinical care.
Methods : This prospective study’s sample population was
comprised of patients who presented to Loma Linda University Medical
Center Emergency Department with suspected acute STEMI. On call
cardiology fellows performed bedside cardiac HHU at time of AMI
activation. All patients subsequently underwent standard TTE. The impact
of the detection of WMA on HHU in regards to clinical decision making,
including whether the patient would undergo urgent invasive angiography,
was also evaluated.
Results : 82 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 LVEF, and a concordance correlation coefficient
of 0.76 (0.65 - 0.84) for wall motion score index (WMSI). Patients with
WMA on HHU were more likely to undergo invasive angiogram during
hospitalization (96% vs 75%, p<0.01). The time interval
between performance of HHU to initiation of cardiac catheterization
(time-to-cath) was shorter in patients with abnormal vs normal HHU exams
(58 ± 32 minutes versus 218 ± 388 min, p=0.06). Lastly, among patients
who underwent angiography, those with WMA were more likely to undergo
angiography within 90 minutes 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 were associated with higher
rates of angiography as well as sooner angiography compared to patients
without WMA.
Keywords: Handheld ultrasound (HHU), cardiology fellow in training
(FIT), STEMI, wall motion abnormalities (WMA), left ventricular ejection
fraction (LVEF)