Background: Focused cardiac ultrasound (FCU) has been used to answer clinical questions. Chemotherapy-related cardiotoxicity (CRR) is an entity that requires serial echocardiography. It is unknown whether FCU can be used to screen for CRR using advanced practice providers (APPs). The goal of this study is to determine if FCU can be used to reliably evaluate left ventricular ejection fraction (EF) by an APP to assess for CRR.
Methods: The study was conducted at the Echo lab and the Oncology clinic. An Oncology APP was trained on the use of FCU and EF analysis. The APP was trained to obtained standard 2D views for EF assessment and on EF interpretation. The EF assessment was compared to sonographer echocardiogram on the same day. EF was assessed by a cardiologist and this was deemed to be the gold standard. The studies were all analyzed by two separate blinded cardiologists and the degree of correlation was analyzed. Linear regression modeling to analyze correlation between EF interpretation between all blinded observers and Bland Altman analysis was performed. Image quality was evaluated for all FCU images by a single blinded cardiologist and segmental endocardial border delineation was scored.
Results: A total of 91 patients were scanned in Phase I of the study. The correlation coefficient between cardiologists was r=0.93. The correlation between cardiologist and APP were r=0.79 and 0.76 respectively. For the images obtained by the APP, the correlation between the APP and cardiologists were =0.83 and re=0.78. The correlation between APP and EF gold standard was r=0.77. The correlation between experienced cardiologists interpreting the FCU images was r=0.87. All images were determined to be interpretable.
Conclusions: There was good correlation between cardiologists with respect to EF analysis. There was also good correlation between APP and cardiologists for EF analysis. Image quality from FCU was found to be good and acceptable for interpretation. This study demonstrates it is feasible to train an APP on obtaining images for EF analysis and they can be trained on EF interpretation with good correlation with experienced echocardiographers. We will evaluate outcomes associated with its use including delays to chemotherapy imposed by traditional echocardiography, cost to the health care system and patient-reported outcomes.