Determination of Aortic Stenosis Severity

It is well known that physical examination is a cornerstone in the evaluation of patients with cardiovascular disease. It is also known that a time-honored careful physical examination performed by an expert is very useful for triage, even when compared with pocket-size devices; Abe et al. have shown this in their article in the specific case of aortic stenosis.

However, medical skills on physical examination and medical availability to perform it are declining. As time goes on, there are fewer and fewer physicians who are really expert at examining patients with valvular or other cardiac diseases, and also fewer physicians with the time to do so. This happens because (1) physicians are becoming busier and busier, and history taking and physical examination are time-consuming tasks; (2) there also is decreased availability of time for bedside teaching; (3) as described above, technologic advances have changed the nature of practice and the approach to the cardiac patient, young physicians now rely more on new technology, so powerful, so cheap, so accessible at the bedside, so easy to use, and certainly with a quicker learning curve than physical examination; (4) physicians are also aware that physical examination is less accurate than an echocardiogram in the assessment of cardiovascular findings ; (5) convinced that all the answers will be revealed by tests, the patient him- or herself often does not see the value in being examined carefully and prefers to skip over history taking and physical examination (it is not uncommon for the patient, at the beginning of a consultation visit, simply to throw copies of his test results on the physician’s desk, without any discussion).

So it comes up as a natural feature, a reflection that the times have changed, that the value of imaging provided by pocket-size devices is rising as physical examination skills are declining. Younger physicians and other caregivers are now using pocket-size devices just as older physicians used to rely on their stethoscopes. Moreover, the ability to “see” the heart rather than to deduce what it would look like by listening, seems a valuable, rational, and attractive tool. The advent and availability of powerful imaging methods has probably, in some way, made the bedside examination in 2013 less crucial, and it seems that the press to “do more and to do it faster” sometimes makes physicians rush through the physical examination because imaging studies are going to be ordered anyway.

One of the take-home messages on this topic is that, not surprisingly, in a patient suspected of having aortic stenosis, a careful bedside examination by a skilled cardiologist is, even in the era when pocket-size devices are available, still very effective in discriminating between aortic stenosis of moderate-severe degree versus mild or trivial aortic stenosis. In addition, in the assessment of possible aortic stenosis (and perhaps of other valvular disease or other cardiac condition), when the examiner is not skilled at evaluating the severity of valve disease, a rapid and relatively easily applied point-of-care method of imaging, such as using a pocket-size device, might add confidence to examination findings or might even provide incremental information.

Use of Pocket-Size Echocardiography Devices at the Point of Care

How do these devices change the way we work? What are the consequences of their spread and dissemination for our clinical practice and also for the health care system? According to the work of Abe et al. , if good-quality images of the aortic valve are obtained, then the severity of aortic stenosis can be accurately predicted based on the leaflet motion score, and these data may be used to triage patients for further evaluation.

This strategy of workflow integration of pocket-size devices, when using them as a triage method to select which patients need complete and detailed studies with high-end machines, seems attractive and has already been suggested. Pocket ultrasound scanners must be seen not as a replacement for, or as a competitor to, full-service state-of-the-art echocardiography machines. On the contrary, they promise to be a way to improve triage and to achieve a more-accurate clinical diagnosis by decreasing the number of unnecessary conventional studies in overcrowded echocardiography laboratories while increasing the number of adequate studies in these laboratories (by increasing the time available to perform the more time-consuming and advanced echocardiographic procedures, reducing waiting lists for echocardiographic examinations, saving health care resources, and improving cost-effectiveness ratios).

Whether this approach and optimistic strategy will prove to be robust enough to survive is likely to depend on several factors, taking us back to some of the initial controversial issues named above:

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  Is the image quality good enough for clinical decision making in daily clinical practice? Is this still a controversial issue, or has the original discussion moved on? Specifically, will it work in difficult-to-scan populations, e.g., patients who are obese and patients with pulmonary disease (being useful to remember on one hand that the United States and Western countries lead the world in the greatest increase in body mass index and, on the other hand, that it has been previously shown that high-end machines are more accurate than hand-held scanners when ultrasound examination quality is poor ).

  
  
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  Will this strategy work with less-experienced operators? Is the learning curve for using these devices so rapid that this technology can be used widely by nonexperts or only by a few with considerable preexisting experience? This takes us back again to the issues of expertise, training, and certification.

  
  
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  Will it work in a wide range of clinical settings, for instance, in the emergency department and in intensive care units, where the stressful environment, time constraints, and difficulty of image acquisition increase the probability of potentially catastrophic and dangerous errors, especially in inexperienced hands?

So, this triage method must not simply be taken for granted, but it must be fine-tuned by taking into account the quality of the acoustic window, the expertise of the operator, and the environment where these devices are to be used. In addition economic issues cannot be ignored. In environments that work on a fee-for-service basis, how will pocket size scanners enter in the real-world arena? If the nonreimbursed pocket-size examinations really were to decrease the number of echocardiography laboratory examinations, then the laboratory profits would also decrease, which makes these devices victims of their own success.

In our opinion, physical examination, pocket-size devices, and high-end echocardiography machines must be seen as allies not as competitors. We do not believe that one method replaces another; instead, each approach has an important role:

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  Physical examination is a time honored and valuable tool that, together with medical history information, contributes not only to strengthen the physician-patient relationship but also to formulate an individualized, integrated, humanistic, and accurate clinical diagnosis that no complementary diagnostic technique can provide. Its crucial role must not be forgotten or denied, and the cardiologic community must make serious educational efforts to keep the skills of this art alive. Clinical assessment and clinical diagnosis often reflect an enormous amount of knowledge acquired during years and years at the bedside, sometimes during a lifetime of experience, and are the cornerstone of the humanity and quality of medicine, and the core business of our medical profession.

  
  
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  High-end echocardiography machines will obviously stay at the top of the pyramid and be used to perform comprehensive diagnostic studies of patients previously evaluated by using clinical or clinical plus pocket-scanner triage, providing high-quality morphologic and functional data that document the presence and clarify the severity of a wide range of cardiovascular diseases.

  
  
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  Pocket-size ultrasound instruments have the potential to introduce substantial changes in the way that clinical cardiology is performed in routine practice. They are certainly very useful at the point of care, when the examiner is not skilled or available to clinically evaluate the severity of valve disease (increasingly more frequent nowadays), or when physical examination findings are inconsistent or uncertain. These miniaturized scanners that fit in our white coat pocket may provide incremental information, even when physical examination findings are carefully obtained and evaluated. The best use of this technology may rely on a fine-tuned triage strategy, by selecting those patients who need to be sent to the echocardiography laboratory for a comprehensive examination, with theoretical clinical and economic benefits to all the participants in this process. However, the real impact of these changes must be the subject of further investigation.

A final word about training and expertise, relevant factors that may limit the potential spread of use of these devices. These machines are so cheap, so powerful, and so easy to use that their dissemination among noncardiologists is an inevitable and irreversible process, with a potential danger of misdiagnosis by nonexpert users. To prevent this, medical authorities should define rules regarding reimbursement or nonreimbursement, and medical schools and echocardiographic societies should develop new educational concepts. As cardiologists, it is our role to lead and guide this process.

About one decade ago, the American Society of Echocardiography published a position paper on hand-carried ultrasound devices (which covered only the class of portable ultrasound machines), and, 2 years ago, the European Association of Cardiovascular Imaging (formerly known as the European Association of Echocardiography) published a general position statement on the use of pocket-size imaging devices. It is about time to review these documents and to discuss in depth some of the unanswered hot topics mentioned above. It is urgent to define guidelines and to implement strategies and systems for routinely adding a point-of-care ultrasound cardiovascular examination for patients with known or suspected cardiovascular disease. It is also essential to discuss the roadmap for the future: is it feasible, and, most important, is it desirable that these devices include full standard echocardiographic functionalities, including spectral Doppler? These questions will have to be addressed, discussed, and answered. The times they have a’ changed. The future is here, and it is in our hands. The future is in our white coat pockets.