Setting up a stress echo service: best practice

Accuracy and Prognostic Value of Physiologist-Led Stress Echocardiography for Coronary Disease

BACKGROUND

We demonstrated that physiologist-led stress echocardiography (PLSE) is feasible for coronary artery disease (CAD) assessment. We sought to extend our work by assessing its accuracy and prognostic value.

METHODS

Retrospective study of 898 subjects undergoing PLSE (n=393) or cardiologist-led stress echocardiography (CLSE) (n=505) for CAD assessment using exercise or dobutamine. For accuracy assessment, the primary outcome was the ability of stress echocardiography to identify significant CAD on invasive coronary angiography (ICA). Incidence of 24-month non-fatal MI, total and cardiac mortality, revascularisation and combined major adverse cardiac events (MACE) were assessed.

RESULTS

Demographics, comorbidities, CAD predictors, CAD pre-test probability and cardiac medications were matched between the PLSE and CLSE groups. PLSE had high sensitivity, specificity, positive and negative predictive value and accuracy (85%, 74%, 69%, 88%, 78% respectively). PLSE accuracy measures were similar and non-inferior to CLSE. There was a similar incidence of individual and combined outcomes in PLSE and CLSE subjects. Negative stress echocardiography conferred a comparably low incidence of non-fatal MI (PLSE 1.4% vs. CLSE 0.9%, p=0.464), cardiac mortality (0.6% vs. 0.0%, p=0.277) and MACE (6.8% vs. 3.1%, p=0.404).

CONCLUSION

This is the first study of the accuracy compared with gold standard of ICA, and prognostic value of PLSE CAD assessment. PLSE demonstrates high and non-inferior accuracy compared with CLSE for CAD assessment. Negative PLSE and CLSE confer a similarly very low incidence of cardiac outcomes, confirming for the first time the important prognostic value of PLSE.

Safety and efficacy of physiologist-led dobutamine stress echocardiography: experience from a tertiary cardiac centre

Background

Dobutamine stress echocardiography (DSE) services have traditionally been medically led. In some UK institutions, DSE lists are led by physiologists with medical support. In our tertiary cardiac centre at New Cross Hospital (NCH), the DSE service was established by a consultant echocardiographer. Following intensive training and assessment, the Trust approved drug administration by named senior cardiac physiologists. We believe this is the first report of a cardiac physiologist-managed DSE service, including physiologist drug administration. We have assessed the feasibility, safety and validity of this physiologist-led DSE service.

Methods

Retrospective analysis of 333 patients undergoing stress echocardiogram for inducible reversible ischaemia, myocardial viability and valvular heart disease over 6 months. Patients’ case notes review after 18–24 months.

Results

Overall, 92% of all cases (306) were performed by physiologists. In 300 studies, dobutamine was administered. The majority of the referrals were for coronary artery disease (CAD) assessment (281). In 235 cases, the study was uncomplicated. Sixty-seven patients developed dobutamine-related side effects. In 16 cases, complications led to early termination of the study. In two cases, urgent medical review was needed. Of the 281 studies for CAD assessment, 239 were negative for ischaemia, 28 were positive and 14 inconclusive. In 5 out of 28 cases with echocardiogram, evidence of inducible ischaemia, coronary angiography revealed unobstructed coronary arteries.

Conclusion

This study demonstrates the safety and effectiveness of this practice and provides potential for the expansion of the physiologists’ role and physiologist-led DSE services in other hospitals.

Feasibility of physiologist-led stress echocardiography for the assessment of coronary artery disease

BACKGROUND

Physiologist-led stress echocardiography (PLSE) services provide potential for expansion of SE services and increased productivity for cardiologists. There are however no published data on the feasibility of PLSE. We sought to assess the feasibility, safety and robustness of PLSE and cardiologist-led stress echocardiography (CLSE) for coronary artery disease (CAD) assessment.

METHODS

Retrospective analysis of 898 patients undergoing PLSE or CLSE for CAD assessment using exercise or dobutamine stress over 24 months. PLSE involved 2 cardiac physiologists (exercise) or 1 physiologist plus 1 cardiac nurse (dobutamine). A cardiology registrar was present in the echocardiography department during PLSE in case of medical complications. CLSE involved 1 physiologist and 1 trainee cardiologist who analysed the study and reviewed findings with an imaging cardiologist. Sixteen-segment wall motion scoring (WMS, WMSI) analysis was performed. Feasibility (stressor, image quality, proportion of completed studies, agreement with imaging cardiologist analysis) and safety (complication rate) were compared for PLSE and CLSE.

RESULTS

The majority of studies were CLSE (56.2%) and used dobutamine (68.7%). PLSE more commonly used exercise (69.2%). Overall, 96% of studies were successfully completed (>14 diagnostic segments in 98%, P = 0.899 PLSE vs CLSE). Commencement of PLSE was associated with an increase in annual SE's performed for CAD assessment. Complication rates were comparably very low for PLSE and CLSE (0.8% vs 1.8%, P = 0.187). There was excellent agreement between PLSE and CLSE WMS interpretation of 480 myocardial segments at rest (κ = 0.87) and stress (κ = 0.70) and WMSI (ICCs and Pearson's r >0.90, zero Bland-Altman mean bias).

CONCLUSION

This to our knowledge is the first study of the feasibility of PLSE. PLSE performed by well-trained physiologists is feasible and safe in contemporary practice. PLSE and CLSE interpretation of stress echocardiography for CAD agree very closely.