Left Atrial Mechanics Assessed Early during Hospitalization for Cryptogenic Stroke Are Associated with Occult Atrial Fibrillation: A Speckle-Tracking Strain Echocardiography Study.

BACKGROUND: Occult atrial fibrillation (AF) is an important contributor to cryptogenic stroke, yet remains difficult to unmask at presentation. This study investigated the predictive value of left atrial (LA) mechanics by strain echocardiography during stroke hospitalization for the presence of AF as detected on early 30-day monitoring and routine clinical follow-up. METHODS: Left atrial mechanics were studied by strain echocardiography in a retrospective cohort of 191 patients with cryptogenic stroke and 30-day mobile cardiac outpatient telemetry poststroke to diagnose AF. After this, AF was diagnosed via routine clinical follow-up. The independent and incremental value of measures of LA size and mechanics (i.e., strain and strain rate in the reservoir, conduit, and booster pump phase) to predict AF on top of clinical characteristics was assessed. RESULTS: Of 191 patients, 15% (n = 28) developed AF, of which 10 were observed during 30-day mobile cardiac outpatient telemetry and 18 were observed at a median follow-up of 25 (interquartile range, 10-43) months. Median time from embolic stroke to strain echocardiography was 1 day (interquartile range, 1-2 days). Left atrial mechanics were significantly worse in AF (P < .05 for all), despite largely similar baseline cardiovascular risk profile. Booster pump strain rate was the strongest predictor for AF, independent of age, LA volume index, E/e', and reservoir strain (odds ratio = 2.88 per SD increase; 95% confidence interval, 1.29-6.41; P = .010). Adding LA strain reservoir strain and booster pump function significantly enhanced a multivariate model to predict AF. Freedom from AF was significantly lower in subjects with a booster pump strain rate (at stroke presentation) worse than -0.67 sec-1, as derived from receiver operator curve analysis (P < .001). CONCLUSIONS: Left atrial mechanics and particularly the LA booster pump function assessed early during hospitalization for cryptogenic stroke can identify patients at greater likelihood of future diagnosis of AF. These findings could in part relate to LA mechanical stunning after spontaneous cardioversion, which-when identified by early strain echocardiography-can inform further risk stratification and decision-making.

Educational intervention to reduce outpatient inappropriate echocardiograms: a randomized control trial.

OBJECTIVES: This study sought to prospectively study the impact of an appropriate use criteria (AUC)-based educational intervention on outpatient transthoracic echocardiography (TTE) ordering by physicians-in-training. BACKGROUND: AUC were developed in response to concerns about inappropriate utilization. It is unknown whether an educational intervention can reduce inappropriate outpatient TTE. METHODS: We conducted a randomized control trial in which physicians-in-training were randomized to an AUC-based educational intervention or a control group at an academic medical center in Boston, Massachusetts. The primary endpoints were the rates of inappropriate and appropriate TTE. RESULTS: For the cardiology physicians-in-training, the proportion of inappropriate TTE was significantly lower in the intervention than in the control group (13% vs. 34%, p < 0.001). As a corollary, the proportion of appropriate TTE ordered by the intervention group was significantly higher than that of the control group (81% vs. 58%, p < 0.001). The odds of ordering an appropriate TTE in the cardiology intervention group was 2.7 (95% confidence interval [CI]: 1.5 to 5.1, p = 0.002) relative to the control group. The internal medicine physicians-in-training ordered a small number of TTE overall, and there was a trend toward significant odds of ordering an appropriate TTE in the intervention group relative to the control group (odds ratio [OR]: 8.1, 95% CI: 0.95 to 69.0, p = 0.055). Six clinical scenarios accounted for 75% of all inappropriate TTE, with the 3 most common inappropriate indications being routine surveillance (<1 year) of known cardiomyopathy without a change in clinical status, routine surveillance of known small pericardial effusion, and routine surveillance of ventricular function with known coronary artery disease and no change in clinical status. CONCLUSIONS: In cardiology fellows with a high rate of ordering inappropriate TTE, an AUC-based educational and feedback intervention reduced the proportion of inappropriate outpatient TTE and increased the proportion of appropriate outpatient TTE. (Educational Intervention to Reduce Outpatient Inappropriate Transthoracic Echocardiograms; NCT01944202).