Author + information
- Published online April 1, 2019.
- Edgar Argulian, MD, MPH∗ (, )
- Roberto Ramirez, MD,
- Steven Hobson, MD,
- Chirag Bavishi, MD,
- Abel Casso Dominguez, MD,
- Allison Selby, DO,
- Soheila Talebi, MD,
- Pedro Moreno, MD,
- Amir A. Ahmadi, MD,
- Jeroen J. Bax, MD and
- Jagat Narula, MD, PhD
- ↵∗Mount Sinai St. Luke’s Hospital, Icahn School of Medicine at Mount Sinai, 1111 Amsterdam Avenue, New York, New York 10025
Insonation using point-of-care ultrasound, specifically, a handheld device, has been recently proposed as the fifth pillar of bedside examination (1). Compared with standard physical examination, insonation-augmented physical examination offers significant advantages in detecting common cardiovascular conditions, including valve disease.
We conducted a prospective, controlled, and blinded observational study that compared standard physical examination with insonation-augmented physical examination using a handheld ultrasound device (VScan, General Electric, Wauwatosa, Wisconsin) for the diagnosis of left-sided valve disease. All study patients, both cases and control subjects, were identified in the echocardiography laboratory (Figure 1A). Cases had severe single left-sided valve disease that fulfilled the standard echocardiographic criteria for diagnosis of severe stenosis or severe regurgitation. Control subjects were patients without significant valve disease (no more than mild regurgitation and no evidence of stenotic valve disease), and they were matched to cases based on age (±1 year) and sex. Three independent blinded observers were cardiology fellows with equivalent levels of training: >1 year of training in clinical cardiology, including at least 4 weeks of formal training in echocardiography. Standard physical examination was conducted by the observer, and findings were recorded by the research personnel at bedside using a standardized questionnaire. Subsequently, the observer used a handheld ultrasound device to confirm or refute their initial findings.
The study population consisted of 30 cases and 30 age- and sex-matched control subjects (Figure 1A). The mean age of study patients was 68 years (range 37 to 91 years), and 40 (67%) were men. The mean body mass index for cases was 27.3 kg/m2, and for control subjects, it was 26.4 kg/m2 (p = 0.59). Overall, 110 examinations were performed by 3 independent blinded observers. The decision tree for all observations is shown in Figure 1B.
Compared with the gold standard of comprehensive echocardiography, standard physical examination correctly identified 50% of severe valve disease (overall sensitivity: 50%), most of which was confirmed by insonation (85%). In contrast, among 26 valve disease observations missed by conventional physical examination, 15 (58%) were correctly identified after insonation. The overall sensitivity of insonation-augmented physical examination for single severe left-sided valve disease was 71%. The overall specificity of both standard physical examination and insonation-augmented physical examination was expectedly high (94% and 97%, respectively) (2). Numerically, insonation added to the standard physical examination in 18 of 110 observations (16%) and detracted from it in 6 of 110 observations (5%). Area under the curve analysis showed a significant difference between the receiver-operating characteristic (ROC) curves, which was explained by a 21% increase in sensitivity (p = 0.008). Interobserver agreement was estimated for observers with a sufficient number of observations; 29 patients were examined by observer #2 and observer #3. Kappa values were 0.55 for standard physical examination and 0.53 for insonation-augmented physical examination, and both indicated moderate agreement.
For regurgitant lesions, sensitivity of standard physical examination was 47% and specificity was 98%. Insonation-augmented physical examination yielded sensitivity of 83% and specificity of 95%. Area under the curve analysis showed a significant difference between the ROC curves, which was explained by a 36% increase in sensitivity (p = 0.0003). For stenotic lesions, sensitivity of standard physical examination was 56% and specificity was 88%. Insonation- augmented physical examination yielded sensitivity of 44% and specificity of 100%. Area under the curve analysis showed no statistically significant difference between the ROC curves (p = 0.14).
The benefits of insonation-augmented physical examination in the present study were driven by the improved detection of regurgitant lesions. Color Doppler examination typically allows rapid recognition of regurgitant lesions by careful inspection of the receiving chamber. In contrast, detection of stenotic lesions by bedside insonation relies on identifying the thickening, calcification, and restricted movement of the affected valves. Detection of flow turbulence by color Doppler can also be helpful. The ultrasound examination can be limited by insonation angles, and the findings might be confused with age-related valve sclerosis. The absence of spectral Doppler on a handheld device is a signification limitation in this regard, and insonation using spectral Doppler-capable devices may have a higher diagnostic yield (3).
This was a single-center study with a relatively small number of observations. The observers were cardiology fellows with equivalent levels of training. A study using attending cardiologists might yield different results but might also be confounded by nonuniform expertise in ultrasound examination.
In conclusion, insonation-augmented physical examination with current technology may offer significant advantages compared with the traditional physical examination in detecting severe regurgitant, but not stenotic, left-sided valve disease. Whether advances in technology will improve the diagnostic usefulness of insonation awaits further study.
Please note: GE Healthcare, Phillips Healthcare, and Valvehealth provided multiple handheld ultrasound units to Icahn School of Medicine at Mount Sinai as a part unrestricted educational grant to Dr. Narula. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2019 American College of Cardiology Foundation
- Narula J.,
- Chandrashekhar Y.,
- Braunwald E.
- Thomas F.,
- Flint N.,
- Setareh-Shenas S.,
- Rader F.,
- Kobal S.L.,
- Siegel R.J.
- Chamsi-Pasha M.A.,
- Sengupta P.P.,
- Zoghbi W.A.