Appropriate use of transesophageal echocardiography at a primary care medical center.

In response to the increased rate of cardiovascular imaging studies being performed annually and to encourage a rationale use of cardiovascular imaging, the Appropriate Use Criteria (AUC) for Echocardiography was established in 2007, with an update in 2011 [1–11]. These criteria defined a standard set of procedural indications for performing echocardiography and classified each indication as being appropriate, uncertain, or inappropriate [2,3]. A number of medical centers have used these AUC to assess their own utilization of transesophageal echocardiography (TEE). Whereas many studies have taken place at tertiary centers where patients are referred for cardiac consultation, none to our knowledge has been conducted at a primary care hospital where patients come for medical care on their own accord. The majority of our patients are relatively young and indigent, and they typically rely upon our hospital rather than seek medical care elsewhere. The objectives of this study were three-fold: 1) to evaluate whether the procedural indications for TEEs at our primary care institution differed from previous studies given the different characters of our patient population, 2) to determine whether TEEs conducted on our patient population complied with the most recent AUC criteria, and 3) to assess whether performing these TEEs impacted the downstream management of our patients. Medical records from 412 consecutive patients who underwent TEEs at Truman Medical Center, a large city-based primary care hospital, during a 4-year period (January 2007–December 2010) were retrospectively reviewed. Clinical demographics included patient's age, sex, race, procedural indication, TEE findings, and findings from prior transthoracic studies. TEE results were reviewed by a board-certified cardiologist (DGC), and appropriateness scores were assigned according to the 2011 AUC [3]. Results were further evaluated for a) no abnormalities, b) abnormal findings related to valvular structure, function, and intracardiac thrombi or masses, and c) clinically important abnormal findings that were not noted on prior imaging studies or were newly identified. Regarding bacteremia, important TEE abnormal findings included intracardiac vegetations not previously seen on transthoracic echocardiography (TTE), or significant interval changes from a prior TTE. For TEEs performed to evaluate a cardiac source of emboli (CSE) or atrial fibrillation/flutter (A-fib/flutter), important abnormal findings included left atrial appendage thrombi or thrombi elsewhere within the heart. In order to simplify data analysis, we regrouped the 15 different TEE clinical indications defined by the 2011 AUC into 5 broad categories: 1) evaluation of possible bacteremia, 2) evaluation of a possible CSE, 3) evaluation of A-fib/flutter to make clinical decisions regarding cardioversion, 4) evaluation of cardiac valvular structure and function prior to surgery, and 5) other (such as poor visualization of the heart by TTE). Of the 412 consecutive patients, 170 (41.0%) were female and 242 (59.0%) were male, ranging in age from 18 to 94 (mean age of 53 years). This population was 49.5% African American, 40.0% Caucasian, 7.3% Hispanic, and 3.2% had mixed racial backgrounds. The largest group of patients (38.4%) at our institution had TEEs performed for evaluation of bacteremiawith an organism considered high risk for endocarditis: Staphylococcus (76.9%), Streptococcus (11.1%), Enterococcus (6.5%), and various organisms (5.4%). Of these 158 patients, 50 (31.6%) weremanaged with hemodialysis. Following bacteremia, TEEs were performed for evaluating valvular structure and function (24.7%), identifying a potential CSE (19.4%), and deciding upon cardioversion for patient with A-fib/flutter (13.3%). All 412 procedures reviewed in this study were classifiable by the 2011 AUC. Of procedures performed, 388 (94.1%) were “appropriate”, 6 studies (1.5%) were “uncertain”, and 18 studies (4.4%) were “inappropriate”. As shown in Table 1, TEEs identified important abnormal findings in 12.7% of the bacteremic patients, 6.4% of patients evaluated for CSE, and in 23.6% of the patients with A-fib/flutter. Of the 20 bacteremic patients with important abnormal findings, one-half were on hemodialysis. Our study population differed from those previously reported in several ways. First, our study took place at a primary care hospital where the relatively younger, mainly indigent population rarely seeks preventative medical care. Additionally, the largest subgroup of TEEs performed in our study was ordered for the clinical indication of bacteremia at a substantially higher rate (38.4%) than that seen in other studies. Only 18% of the patients studied by Ogbara et al., 10.5% of the patients studied by Aggarwal et al., 10.0% of the patients reported by Rao et al., and none of the patients evaluated by Alquarqaz et al. had bacteremia as a primary clinical indication for performing TEEs [1,4,5,8]. Perhaps the unusually high percentage of bacteremia seen at our center reflects the fact that many of our patients have end stage renal disease (on dialysis) and/or intravenous drug abuse, predisposing them to bacteremia. The remaining clinical indications for TEEs at our facility were in fact similar to tertiary medical center studies, but the relative proportions of each indication differed from those previously reported, differentiating our patient population from the others. Despite the different