Incremental diagnostic and prognostic value of contemporary stress echocardiography in a chest pain unit: mortality and morbidity outcomes from a real-world setting

BACKGROUND

Clinical assessment often cannot reliably or rapidly risk stratify patients hospitalized with suspected acute coronary syndrome. The real-world clinical value of stress echocardiography (SE) in these patients is unknown. Thus, we undertook this study to assess the feasibility, safety, ability for early triaging, and prediction of hard events of SE incorporated into a chest pain unit for patients admitted with acute chest pain, nondiagnostic ECG, and negative 12-hour troponin.

METHODS AND RESULTS

Accordingly, 839 consecutive patients who underwent clinical, ECG, and SE assessments within 24 hours of admission were assessed for feasibility, safety, impact on triaging and discharge, and 30-day readmission rate and were followed up for hard events (all-cause mortality and acute myocardial infarction). Of the 839 patients, 811 (96.7%) had diagnostic SE results. Median time to SE and median length of stay for normal SE patients (77%) were both 1 day. The 30-day readmission rate was 0.5%. During long-term follow-up of 27±11 months, 39 hard events (30 deaths and 9 acute myocardial infarctions) occurred. Kaplan-Meier estimates of hard events were 0.5% versus 6.6% in the normal versus abnormal SE groups, respectively, in the first year of follow-up (15 events in the first year). Among all prognostic variables, only abnormal SE (hazard ratio, 4.08; 95% confidence interval, 2.15-7.72; P<0.001) and advancing age (hazard ratio, 1.78; 95% confidence interval, 1.39-2.37; P<0.001) predicted hard events in multivariable regression analysis.

CONCLUSIONS

SE incorporated into a chest pain unit has excellent feasibility and provides rapid assessment and discharge with accurate risk stratification of patients with suspected acute coronary syndrome but nondiagnostic ECG and negative 12-hour troponin.

Implementation of echocardiographic contrast agents into clinical practice: a United Kingdom National Health Service Survey on behalf of the British Society of Echocardiography

AIMS

The administration of echocardiographic contrast agents has been shown to improve accuracy and be cost-effective in patients with suboptimal endocardial definition. We sought to investigate the implementation of contrast agents in clinical practice.

METHODS AND RESULTS

An electronic questionnaire was devised to determine the use of contrast ultrasound agents in clinical practice and sent electronically to echocardiography departments at each national health service hospital within the UK. Out of 198, 107 departments responded (54%). Out of 673,121 echocardiograms, 25,834 (3.8%) were performed with contrast. Out of 551 echocardiography machines, 358 (65%) were suitable for contrast use. Of the sonographers, out of 711, 112 (15.8%) could perform i.v. cannulation and 42 (5.9%) could administer contrast independently. The median time for an echocardiographic examination was 30 min (inter-quartile range 30-45 min). Significant predictors of contrast use were the presence of a consultant cardiologist with subspecialty training in echocardiography (odds ratio 8.7, P = 0.004), the presence of a stress echocardiography service (odds ratio 2.3, P = 0.004), and the presence of a physician during the day (odds ratio 3.0, P = 0.04). Reasons for impediment in administering contrast were staff training (34.6%), extra time required for a contrast study (29.9%), and the expense of contrast (18.7%).

CONCLUSION

The use of echocardiographic contrast agents within routine echocardiographic practice in the UK is limited to <4% of all transthoracic echocardiographic studies. Major barriers to the implementation of contrast use are the absence of cardiac imaging specialists directly supervising echocardiography departments and the training of sonographers to independently administer contrast.