Clinical utility of guideline-based echocardiography: a prospective study of outpatient referral patterns at a tertiary care center

Genesis of improved quality in imaging through a national Australian echocardiography registry

Background

Despite rapid technological advances and growth, quality in imaging has not received the focus seen elsewhere in cardiovascular medicine, resulting in significant gaps between guidelines and practice. Contemporary echocardiography practice requires comprehensive real-time data collection to allow dynamic auditing and benchmarking of key performance indices. The American College of Cardiology (ACC) proposed additional data standardisation, structured reporting identifying key data elements and imaging registries. In the absence of an Australian echocardiography registry, we developed a national clinical quality registry (GenesisCare Cardiovascular Outcomes Echo Registry). We hypothesised that measurement and local reporting of data would improve compliance of echo studies with quality guidelines and hence their clinical value.

Methods and results

We prospectively collected data on 4 099 281 echocardiographic studies entered directly into a central electronic database from 63 laboratories across four Australian states between 2010 and 2021. Real-time auditing of key data elements and introduction of quality improvement pathways were performed to maximise completeness and uniformity of data acquisition and reporting. We compared completeness of key data element acquisition (AV peak velocity, left ventricular ejection fraction, E/e’, LA area, rhythm, RVSP) by time and state using de-identified data. Key performance outcomes benchmarked against the aggregated study cohort and international standards were reported to individual sites to drive quality improvement. Between 2010 and 2014 there were significant improvements in data completeness (72.0%+/-26.8% vs 86.8%+/-13.5%, p=0.02), which were maintained to 2020. In addition, interstate variability fell for both EF and E/e’ (p<0.002).

Conclusions

This large-scale collaboration provides a platform for the development of major quality improvement initiatives in echocardiography. Introduction of local quality assurance programmes via a unified national data set significantly improved the completeness of reporting of key echo quality measures. This in turn significantly improved the quality of, and reduced the interstate variability of, echo data. Developing a centralised database allowed rapid adoption nationally of local quality improvements.

Pretest probability of a normal echocardiography: validation of a simple and practical algorithm for routine use

BACKGROUND

Management of increased referrals for transthoracic echocardiography (TTE) examinations is a challenge. Patients with normal TTE examinations take less time to explore than those with heart abnormalities. A reliable method for assessing pretest probability of a normal TTE may optimize management of requests.

AIM

To establish and validate, based on requests for examinations, a simple algorithm for defining pretest probability of a normal TTE.

METHODS

In a retrospective phase, factors associated with normality were investigated and an algorithm was designed. In a prospective phase, patients were classified in accordance with the algorithm as being at high or low probability of having a normal TTE.

RESULTS

In the retrospective phase, 42% of 618 examinations were normal. In multivariable analysis, age and absence of cardiac history were associated to normality. Low pretest probability of normal TTE was defined by known cardiac history or, in case of doubt about cardiac history, by age>70 years. In the prospective phase, the prevalences of normality were 72% and 25% in high (n=167) and low (n=241) pretest probability of normality groups, respectively. The mean duration of normal examinations was significantly shorter than abnormal examinations (13.8 ± 9.2 min vs 17.6 ± 11.1 min; P=0.0003).

CONCLUSION

A simple algorithm can classify patients referred for TTE as being at high or low pretest probability of having a normal examination. This algorithm might help to optimize management of requests in routine practice.

Comparison of the 2006 and 2010 cardiac CT appropriateness criteria in a real-world setting

BACKGROUND

Coronary CT angiography (CCTA) is a relatively new technique whose role has yet to be fully defined. The initial appropriateness criteria (AC) guidelines published in 2006 have already been revised. There is paucity of data on the effect of the AC on the use of CCTA at academic centers and none for the private sector.

METHODS

All CCTA studies ordered at one institution (a large community hospital with internal medicine and cardiovascular training programs) from 2006 to 2008 were retrospectively evaluated, and the ordering indications were categorized per the published AC for both 2006 and 2010.

RESULTS

There were 384 studies, of which 243 were included in this study. The majority of the studies were ordered for chest pain (67.1% of patients). A significant proportion of studies (43.2%) were classified as inappropriate on the basis of the 2006 published criteria. Uncertain indications made up 39.1%, and appropriate indications were a minority. There was a significant regrading of appropriateness using the 2010 guidelines. Inappropriate testing remained similar at 48.1%, but uncertain cases decreased to only 2.8%, while appropriateness increased to 49.0% (P = .0001 for trend).

CONCLUSIONS

The updated 2010 AC guidelines for CCTA resulted in a significant reclassification of the indications for ordering CCTA from the previous 2006 guidelines. This shift in the AC reflects increased familiarity and confidence with this new technology across the imaging community. A large proportion of CCTA studies were ordered for inappropriate indications using both sets of criteria. Further research and enhanced education are needed to disseminate the appropriate role of CCTA in cardiovascular imaging.

Near real-time echocardiography teleconsultation using low bandwidth and MPEG-4 compression: feasibility, image adequacy and clinical implications

We assessed the feasibility, image adequacy and clinical utility of a tele-echocardiography service which combined video compression with low-bandwidth store-and-forward transmission. Echocardiograms were acquired by a hospital geriatrician, compressed and transmitted using both near real-time (urgent) and delayed (pre-programmed) protocols via an Internet connection to the notebook PC of a remote cardiologist. Clinical utility was evaluated as a change in therapeutic management. During a one-year period, 101 tele-echocardiography consultations were successfully performed (feasibility = 100%) on 95 patients (age 22-95 years), admitted with cardiovascular or neurological diagnoses (24% of the consultations were urgent). In total, 4617 files (1.4 GByte of data) were transmitted, 2669 of which were short video clips. On average, 46 files (13.8 MByte) were transmitted (mean duration 10 min) at each examination. Consultations (both urgent and pre-programmed) were clinically useful in 83% of examinations. Logistic regression analysis showed that both a low left ventricular systolic function and the examination indication were determinants of clinical utility. The transmitted images were considered adequate for diagnosis in 100% of the pre-programmed teleconsultations. Tele-echocardiography using MPEG-4 video compression is a feasible, adequate and clinically useful tool for telemedicine.

Application of appropriateness criteria in outpatient transthoracic echocardiography

BACKGROUND

Appropriateness criteria were applied to outpatient transthoracic echocardiographic (TTE) studies.

METHODS

Indications were rated as appropriate, inappropriate, or unclassifiable, considering provider-stated indications, previous TTE studies, symptom changes, and patient-stated indications. Clinically important new or unexpected findings were recorded.

RESULTS

Of 368 TTE studies, 206 (56%) were appropriate, 31 (8%) were inappropriate, and 131 (35%) were unclassifiable. Appropriateness was not correlated with patient or provider demographics. In 288 cases with prior TTE studies, there were 92 (32%) important new findings and 63 (22%) unexpected findings, of which 20% were from inappropriately ordered and 31% from unclassifiable TTE studies. Appropriateness was not associated with new (odds ratio, 1.23; 95% confidence interval, 0.48-3.18) or unexpected (odds ratio, 1.15; 95% confidence interval, 0.38-3.52) findings. Provider type and level of training were not correlated with new or unexpected findings.

CONCLUSIONS

Many indications for TTE studies were unclassifiable. A high percentage of inappropriately ordered TTE studies yielded important information. Care must be taken in judging the value of TTE studies solely on the basis of appropriateness criteria.