Emergency Physicians Are Able to Detect Right Ventricular Dilation With Good Agreement Compared to Cardiology

Right Ventricular "Bubble Time" to Identify Patients With Right Ventricular Dysfunction

STUDY OBJECTIVE

We propose a novel method of evaluating right ventricular (RV) dysfunction in the emergency department (ED) using RV "bubble time"-the duration of time bubbles from a saline solution flush are visualized in the RV on echocardiography. The objective was to identify the optimal cutoff value for RV bubble time that differentiates patients with RV dysfunction and report on its diagnostic test characteristics.

METHODS

This prospective diagnostic accuracy study enrolled a convenience sample of hemodynamically stable patients in the ED. A sonographer administered a 10-mL saline solution flush into the patient's intravenous catheter, performed a bedside echocardiogram, and measured RV bubble time. Subsequently, the patient underwent a comprehensive cardiologist-interpreted echocardiogram within 36 hours, which served as the gold standard. Patients with RV strain or enlargement of the latter found on an echocardiogram were considered to have RV dysfunction. Bubble time was evaluated by a second provider, blinded to the initial results, who reviewed the ultrasound clips. The primary outcome measure was the optimal cutoff value of RV bubble time that identifies patients with and without RV dysfunction.

RESULTS

Of 196 patients, median age was 67 year, and half were women, with 69 (35.2%) having RV dysfunction. Median RV bubble time among patients with RV dysfunction was 62 seconds (interquartile range [IQR]: 52, 93) compared with 21 seconds (IQR: 12, 32) among patients without (P<.0001). The optimal cutoff value of RV bubble time for identifying patients with RV dysfunction was 40 or more seconds, with a sensitivity of 0.97 (95% CI 0.93 to 1.00) and specificity of 0.87 (95% CI 0.82 to 0.93).

CONCLUSION

In patients in the ED, an RV bubble time of 40 or more seconds had high sensitivity in identifying patients with RV dysfunction, whereas an RV bubble time of less than 40 seconds had good specificity in identifying patients without RV dysfunction. These findings warrant further investigation in undifferentiated patient populations and by emergency physicians without advanced ultrasound training.

Point-of-care echocardiography of the right heart improves acute heart failure risk stratification for low-risk patients: The REED-AHF prospective study

OBJECTIVES

Validated acute heart failure (AHF) clinical decision instruments (CDI) insufficiently identify low-risk patients meriting consideration of outpatient treatment. While pilot data show that tricuspid annulus plane systolic excursion (TAPSE) is associated with adverse events, no AHF CDI currently incorporates point-of-care echocardiography (POCecho). We evaluated whether TAPSE adds incremental risk stratification value to an existing CDI.

METHODS

Prospectively enrolled patients at two urban-academic EDs had POCechos obtained before or <1 h after first intravenous diuresis, positive pressure ventilation, and/or nitroglycerin. STEMI and cardiogenic shock were excluded. AHF diagnosis was adjudicated by double-blind expert review. TAPSE, with an a priori cutoff of ≥17 mm, was our primary measure. Secondary measures included eight additional right heart and six left heart POCecho parameters. STRATIFY is a validated CDI predicting 30-day death/cardiopulmonary resuscitation, mechanical cardiac support, intubation, new/emergent dialysis, and acute myocardial infarction or coronary revascularization in ED AHF patients. Full (STRATIFY + POCecho variable) and reduced (STRATIFY alone) logistic regression models were fit to calculate adjusted odds ratios (aOR), category-free net reclassification index (NRI_cont ), ΔSensitivity (NRI_events ), and ΔSpecificity (NRI_nonevents ). Random forest assessed variable importance. To benchmark risk prediction to standard of care, ΔSensitivity and ΔSpecificity were evaluated at risk thresholds more conservative/lower than the actual outcome rate in discharged patients.

RESULTS

A total of 84/120 enrolled patients met inclusion and diagnostic adjudication criteria. Nineteen percent experiencing the primary outcome had higher STRATIFY scores compared to those event free (233 vs. 212, p = 0.009). Five right heart (TAPSE, TAPSE/PASP, TAPSE/RVDD, RV-FAC, fwRVLS) and no left heart measures improved prediction (p < 0.05) adjusted for STRATIFY. Right heart measures also had higher variable importance. TAPSE ≥ 17 mm plus STRATIFY improved prediction versus STRATIFY alone (aOR 0.24, 95% confidence interval [CI] 0.06-0.91; NRI_cont  0.71, 95% CI 0.22-1.19), and specificity improved by 6%-32% (p < 0.05) at risk thresholds more conservative than the standard-of-care benchmark without missing any additional events.

CONCLUSIONS

TAPSE increased detection of low-risk AHF patients, after use of a validated CDI, at risk thresholds more conservative than standard of care.

Right ventricular dysfunction in acute heart failure from emergency department to discharge: Predictors and clinical implications

BACKGROUND

Among acute heart failure (AHF) inpatients, right ventricular dysfunction (RVD) predicts clinical outcomes independent of left ventricular (LV) dysfunction. Prior studies have not accounted for congestion severity, show conflicting findings on echocardiography (echo) timing, and excluded emergency department (ED) patients. We describe for the first time the epidemiology, predictors, and outcomes of RVD in AHF starting with earliest ED treatment.

METHODS

Point-of-care echo and 10-point lung ultrasound (LUS) were obtained in 84 prospectively enrolled AHF patients at two EDs, ≤1 h after first intravenous diuresis, vasodilator, and/or positive pressure ventilation (PPV). Echo and LUS were repeated at 24, 72, and 168 h, unless discharged sooner (n = 197 exams). RVD was defined as <17 mm tricuspid annulus plane systolic excursion (TAPSE), our primary measure. To identify correlates of RVD, a multivariable linear mixed model (LMM) of TAPSE through time was fit. Possible predictors were specified a priori and/or with p ≤ 0.1 difference between patients with/without RVD. Data were standardized and centered to facilitate comparison of relative strength of association between predictors of TAPSE. Survival curves for a 30-day death or AHF readmission primary outcome were assessed for RVD, LUS severity, and LVEF. A multivariable generalized linear mixed model (GLMM) for the outcome was used to adjust RVD for LVEF and LUS.

RESULTS

46% (n = 39) of patients at ED arrival showed RVD by TAPSE (median 18 mm, interquartile range 13-23). 18 variables with p ≤ 0.1 unadjusted difference with/without RVD, and 12 a priori predictors of RVD were included in the multivariable LMM model of TAPSE through time (R² = 0.76). Missed antihypertensive medication (within 7 days), ED PPV, chronic obstructive pulmonary disease history, LVEF, LUS congestion severity, and right ventricular systolic pressure (RVSP) were the strongest multivariable predictors of RVD, respectively, and the only to reach statistical significance (p < 0.05). 30-day death or AHF readmission was associated with RVD at ED arrival (hazard ratio {HR} 3.31 {95%CI: 1.28-8.53}, p = 0.009), ED to discharge decrease in LUS (HR 0.11 {0.01-0.85}, p < 0.0001 for top quartile Δ), but not LVEF (quartile 2 vs. 1 HR 0.78 {0.22-2.68}, 3 vs. 1 HR 0.55 {0.16-1.92}, 4 vs. 1 HR 0.32 {0.09-1.22}, p = 0.30). The area under the receiver operating curve on GLMM for the primary outcome by TAPSE (p = 0.0012), ΔLUS (p = 0.0005), and LVEF (p = 0.8347) was 0.807.

CONCLUSION

In this observational study, RVD was common in AHF, and predicted by congestion on LUS, LVEF, RVSP, and comorbidities from ED arrival through discharge. 30-day death or AHF-rehospitalization was associated with RVD at ED arrival and ΔLUS severity, but not LVEF.

Comparison of Emergency Echocardiographic Results between Cardiologists and an Emergency Medicine Resident in Acute Coronary Syndrome

INTRODUCTION

Early detection of regional wall motion abnormality (RWMA) can be a reliable tool for rapid disposition of patients with acute coronary syndrome (ACS) in the emergency department. In this study, the diagnostic accuracy of point-of-care echocardiography performed by a trained emergency medicine resident was evaluated in comparison with board-certified cardiologists.

METHODS

A prospective, cross-sectional study was implemented on adult patients with ACS. A trained emergency medicine (EM) PGY-3 resident performed point-of-care echocardiography under the supervision of two cardiologists and the reports were compared with cardiologists as a reference test.

RESULTS

100 patients with the mean age of 54.1 ± 11.5 years were recruited (65% male). Based on Thrombolysis in Myocardial Infarction (TIMI) and History, EKG, Age, Risk factors, and troponin (HEART) scores, 43.0% and 25.0% of patients were categorized as low-risk for ACS, respectively. The absolute measure of agreement between cardiologists to determine ejection fraction (EF) was 0.829 (95% CI: 0.74-0.89) based on intraclass correlation coefficient (ICC) estimation. The measurements of agreement between specialists and the EM resident based on the analysis of Kappa coefficient were 0.677 and 0.884 for RWMA and pericardial effusion, respectively. Moreover, 25 patients were in the-low risk group according to the HEART score with an agreement rate of 92% for the lack of RWMA between the EM resident and cardiologists.

CONCLUSION

This study found acceptable agreement between the EM resident and cardiologists in assessing RWMA in different ACS risk groups. In addition, there was acceptable agreement between the EM resident and cardiologists in determining left ventricular ejection fraction (LVEF) and pericardial effusion.

Resuscitative Cardiopulmonary Ultrasound and Transesophageal Echocardiography in the Emergency Department

Resuscitative ultrasound describes point-of-care applications that provide diagnostic information, physiologic monitoring, and procedural guidance in critically ill patients. This article reviews the evaluation of ventricular function, identification of pericardial effusion and tamponade, evaluation of preload and fluid responsiveness, and hemodynamic monitoring, as some of the main applications where this modality can help emergency physicians during resuscitation of critically ill patients.