Handheld Ultrasound: Accurate Diagnosis at a Lower Cost?

JACC: CARDIOVASCULAR IMAGING

VOL. 7, NO. 10, 2014

ª 2014 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION

ISSN 1936-878X/$36.00

PUBLISHED BY ELSEVIER INC.

http://dx.doi.org/10.1016/j.jcmg.2014.07.008

EDITOR’S PAGE

Handheld Ultrasound: Accurate Diagnosis at a Lower Cost? Thomas H. Marwick, MD, PHD, MPH,* Y. Chandrashekhar, MD,y Jagat Narula, MD, PHDz

C

ardiovascular

has

cardiology fellows, emergency department physi-

changed little since the 19th century, but

physical

examination

cians, and surgical intensive care unit staff members

medical practice, in the meantime, has

to gather HHU information as an adjunct to the phys-

changed substantially. The diseases we treat, the cir-

ical examination (4–6). HHU is a part of clinical

cumstances of patient evaluation, the ages and

training at many medical schools, and as these stu-

comorbidities of patients, the availability of diag-

dents graduate and move through the workforce,

nostic testing, and the implications of missed diagno-

the reign of the stethoscope will be seriously threat-

ses in an era of effective therapy all pose challenges.

ened (7). Some would say this change is overdue.

The traditional bedside diagnostic method is a sub-

The report by Mehta et al. (8) in this issue of iJACC

jective process that is strongly operator dependent,

confirms the value of HHU as a diagnostic tool, but

has both low interobserver and test-retest consis-

it takes us in a new direction as well. One conse-

tency, and can be hard-copied, stored, and transmitted

quence of the limitations of physical examination is

to others only incompletely and with difficulty (1).

its indiscriminate replacement by laboratory testing,

In addition to its fundamental limitations, the pro-

leading to an expensive and inefficient process of

cess is often performed poorly, with a high error

“rarely appropriate” testing on high-end echocardio-

rate (2). In contrast, diagnostic imaging has marched

graphic machines. What if HHU were the prelude to

on with a strong evidence base that is subjected to

such testing? In this study, HHU was performed using

repeated scrutiny and testing; we can detect the path-

a pocket-sized, battery-operated device (VScan, GE

ophysiologic analogs of jugular venous distention,

Healthcare, Little Chalfont, United Kingdom) that

gallops, pulmonary crackles, and pericardial function

provides B-mode and color Doppler images but no

rubs, all bastions of the physical examination that

spectral Doppler data. The investigators studied 250

could not be obtained from testing in a former era.

patients referred for echocardiography for the inves-

In addition, imaging provides other information that

tigation of common indications (cardiac function,

physical examinations cannot, and this incremental

murmur, stroke, arrhythmias, and some miscella-

information has important therapeutic implications.

neous indications). Cardiologists completed a report

Although limited to 2-dimensional and color Doppler

(including suggestions for additional testing) after

imaging, handheld ultrasound (HHU) devices provide

physical and HHU examination. HHU correctly iden-

high image quality, and previous work has shown the

tified 117 of 142 patients with abnormal findings on

diagnostic content of studies performed with these

standard

systems is analogous to that of high-end ultrasound

correctly identified by physical examination (82% vs.

systems (3,4). Previous studies have documented

47%, p < 0.0001). Predictably, this was most marked

the ability of medical students, medical residents,

in patients with significant valve disease (71% vs.

echocardiography,

compared

with

67

31%, p ¼ 0.0003). The investigators went on to examine the implications for further testing; this was From the *Menzies Research Institute Tasmania, Hobart, Australia;

suggested in 89 patients after physical examination,

yUniversity of Minnesota School of Medicine, Minneapolis, Minnesota;

at least one-third more than after HHU (p < 0.0001).

and the zIcahn School of Medicine at Mount Sinai, New York, New York.

In addition to these findings, which are consistent

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Marwick et al.

JACC: CARDIOVASCULAR IMAGING, VOL. 7, NO. 10, 2014 OCTOBER 2014:1069–71

Editor’s Page

T A B L E 1 Where Should HHU Go in the Future?

Existing Data

Future Needs

How to Progress

Repeat testing

Limited data

Addition of spectral Doppler quantification, automation

HHU design improvement

Incidental findings

HHU more accurate than physical examination

Does it matter? Can we recognize findings as incidental and stop further investigations? Could additional irrelevant data be harmful (anxiety, cost of downstream testing)?

RCT with hard endpoints

False positives

HHU finds more information than physical examination

How does the clinician integrate these findings? If physical examination findings are inconsistent, they are ignored. Are clinicians prepared to do this with HHU? Are the legal implications of disregarding results the same?

RCT with hard endpoints

True positives

HHU finds more true abnormalities than physical examination

Would these have been found anyway during course of normal strategies? How did knowing them change practice and outcomes?

Studies comparing strategies

HHU ¼ handheld ultrasound; RCT ¼ randomized controlled trial.

with previous research, these investigators under-

the identified findings might not have necessitated

took cost modeling to show that the complete

clinical decisions because of the patient’s age and

(initial evaluation plus downstream) cost of the

comorbidities. Thus, a cost-effectiveness model (eval-

HHU-based evaluation was $644.43, compared with

uation of cost against survival or quality of life after

$707.44 for the evaluation based on the physical

reasonable decisions about management) could be

examination. These results are analogous to those of

more

Greaves et al. (9), who performed an evaluation of

Although less critical for replacing a physical exami-

HHU

informative

than

the

cost-utility

model.

in

nation, some redesign of these devices may improve

157 consecutive inpatients. In that study, the sensi-

confidence in the diagnostic process. The availability

tivity and specificity of HHU for the prediction of

of spectral Doppler would facilitate the clinical eval-

normal results and normal left ventricular function

uation of heart failure with preserved ejection frac-

were, respectively, 74% and 96%, and 81% and

tion and aortic stenosis, the prevalence of which is

100%. Greaves et al. (9) calculated that HHU

rapidly increasing. Similarly, easier image archiving

screening before inpatient echocardiography would

would be helpful. Finally, the training aspect must be

have reduced their echocardiography department’s

considered, especially in countries where sonogra-

work load by 29%, with a saving of approximately

phers rather than cardiologists are involved in image

and

full

echocardiographic

evaluation

£150 per patient.

acquisition. Although the efficacy of HHU with

In the current era of attention to appropriate use

training greatly improved the clinical diagnostic skills

and cost of testing, the results of the HHU testing are

of medical students and junior doctors, over and

interesting in that they might improve selection of

above history, physical examination, and electrocar-

patients for definitive, laboratory echocardiography.

diographic findings in some studies (5,6,11), this has

The performance of inappropriate testing remains

not been a uniform finding (12). A model in which

stubbornly high (between 10% and 20%) (10), reflect-

HHU supports incomplete and possibly inaccurate

ing a cohort of patients in whom clinicians consider

physical examination is different from a model in

that testing might be useful even if the indication for

which HHU is a gatekeeper to the echocardiography

testing is rarely appropriate. When funding is likely to

laboratory. The extent of the training required may

be tied to appropriate use, the use of HHU might

not be trivial (13), and these imaging skills may not be

provide a triage process for the definitive test. This

uniformly attainable (14). However, the editors of

study is an important step forward, but we may need

iJACC believe strongly that as HHU becomes an

more evidence to justify the desertion of the current

important part of medical education, and residents

referral process. The modeling presented by Mehta

routinely use HHU in day-to-day clinical practice, the

et al. (8) shows us the cost of evaluating the patient

training aspect will become moot.

rather than informing management—or changing

Subsequent studies should provide further assess-

outcome. The threshold for further investigation may

ment of cost-effectiveness, perhaps by randomizing

differ by individual and by region, reflecting physician

patients and examining not only subsequent costs

preference as well as local practice patterns. Some of

but also outcomes. The existing evidence is based on

Marwick et al.

JACC: CARDIOVASCULAR IMAGING, VOL. 7, NO. 10, 2014 OCTOBER 2014:1069–71

Editor’s Page

studies comparing physical examination with HHU,

use spreads to most medical specialties, and machine

using a full echocardiographic machine as the arbiter

costs decrease, more specialty societies will create

of “truth.” This has served us well in terms of

guidelines and training pathways in ultrasound use.

defining the accuracy of imaging with HHU, questions

Primary care clinicians are likely to increasingly

about training and operator ability, and possibly cost

use focused examinations to gain immediate and

utility; what is not clear is whether the extra findings

management-changing information about their pa-

obtained with HHU are clinically significant, whether

tients. In the meantime, cardiologists who trained in

they need to be acted upon, and whether doing

a former era may recognize that the incorporation of

so changes outcomes. We now need answers to a

HHU may return physical contact to the cardiology

different series of questions (Table 1); the endpoints

consultation, as doctors spend more time at the

should be comparing strategies and outcomes, not

bedside, reversing a secular trend that spans several

the performance of HHU against physical examina-

decades (15,16). Perhaps the wider adoption of HHU

tion, with the referee being findings from a full-

will have an added benefit on the patient-doctor

fledged system.

relationship.

Irrespective of its merits in the decision-making process for test selection, the paper by Mehta et al.

REPRINT REQUESTS AND CORRESPONDENCE: Dr.

(8) acts as a timely reminder of the value of HHU. The

Jagat Narula, Icahn School of Medicine at Mount

growth of HHU is likely, irrespective of the cost-

Sinai, One Gustave L. Levy Place, Mailbox 1030,

effectiveness of the use of the devices, as portable

New York, New York 10029. E-mail: jagat.narula@

ultrasound is adopted in medical education. As its

mountsinai.org.

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