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Day 3 began with the excellent Session 696: Battles in the Emergency Room over Management of Possible ACS. Pollack, Mueller, Hollander, Than et al covered most of the big questions in this area with all the strengths and weaknesses of clinical assessment, risk stratification, biomarkers and non-invasive testing, especially CT coronary angiography (CTCA) of course. Whilst there are many answers it’s also clear that many questions remain.

Christian Mueller, as you’d expect, provided a great overview of the benefits of the increasingly sensitive troponin assays in this context. What many people don’t realise is that none of the high sensitivity troponin assays available elsewhere have yet been approved for clinical use in the US. But it is very likely that they will be over the next 18 months and so there is quite intense interest in this now. Martin Than had sent the scene for all of this with much of our own data including the ASPECT and ADAPT studies along with what I think was the first look at the results of Louise Cullen’s highly sensitive troponin I data (which is now in press in the Journal of the American College of Cardiology).

The debate over CTCA has, I think, some time to run. Judd Hollander makes a compelling case for this as the ‘best test’ for ruling out coronary disease in patients with chest pain but then he works in a hospital where the test is available until 10pm each night and for four hours on Saturdays and Sundays!!!

And from there it was on to have our poster moderated…

It seemed quite appropriate for the meeting to kick off where it often all begins; with a troponin assay.

The opening session: High Sensitivity Troponin Assays Are Coming: How to Exploit the Benefits and Avoid the Pain was addressed by a ‘Who’s Who’ of work in this field including Fred Apple, Alan Wu, Alan Jaffe, David Morrow and James Januzzi. Along with that, pretty much everyone else who might have been included on the program was in the room anyway along with a strong contingent of interested representatives of the diagnostics industry. This was meeting session #601 but it was really Troponin 101, covering through from analytical issues, normal ranges, deltas and clinical use in the setting of acute and chronic disease states. It was great to see some of our work (ADAPT) alongside that of Christian Mueller’s group cited by David Morrow as the studies showing the direction this is all heading.

At the other end of the day I went along to session #625 CT Angiography in clinical use. This too was chaired by two of the luminaries in this field, particularly when concerned with the use of CT coronary angiography (CTCA) in the context of acute chest pain assessment; Udo Hoffmann from Boston and James Goldstein form Michigan. Again there wasn’t so much new here, but an excellent review of the state of the art. CTCA has a good case for being the investigation of choice to exclude coronary disease in patients at low to intermediate risk presenting acutely with chest but the burning question I hoped would have been answered is just how low is too low to need a complex test such as this? It seems that still no-one is either willing or able to answer this one just yet. It strikes me that this is one just crying out to be studied further…

So a good first day for those interested in chest pain and still time to meet up with many colleagues and friends. I haven’t been to the ACC meeting for many years and I’d really forgotten how good it can be.

So it does what it says on the can, and from an ergonomic point of view the VScan is a joy; it’s light, small, intuitive and user friendly. With the possible exception of battery life there seems little reason not to take it on the round.

But, and it is a big but, what is the point? Is this really good use of my time? Does it just look cool but achieve nothing? In short, are my patients going to get a better outcome if I use hand held echocardiography? These are all big questions and to be fair there is no way that I can do much more than even begin to address them. This is a blog, which after all is just unreferenced and shameless anecdote…

We used the VScan on 4 patients on the acute cardiology round. A mixture of clinical problems. What did we find?

Image quality

My view here has to be subjective because I don’t have another handheld machine to compare to. Comparison with a full function ultrasound cart would be like comparing apples and oranges. This isn’t a $250 000 ultrasound cart, but that aside, the 2D image quality is fair.

We used the machine four times in the CCU and the ED and in the patients we tried it on, who weren’t particularly challenging from an ultrasonic point of view, it was pretty easy to acquire useful views of the left heart structures from at least one acoustic window. The images were certainly adequate for assessing overall left ventricular systolic function, but there are no means of anything more than subjective quantification. A simple assessment of left valve morphology also seems quite feasible and in one case we appropriately identified significant aortic valve degeneration.

The images, for me at least, are a little dark and although display brightness is one adjustable parameter it didn’t seem to have a great effect. The gain setting is automated which is a drawback. Getting the workspace adequately lit helps but may be challenging given that the machine is likely to be used in an ambulatory setting (we had trouble getting low light at 1030am on Saturday morning in the ED.

Clinical Correlation

Much better publications than this one are now emerging on this question, so the reader is directed to these below.

However, anecdotally we felt that the VScan helped us to answer a few relevant clinical questions. I was confident reassuring one of my interventional colleagues about the absence of haemodynamically, significant mitral regurgitation in a patient who had undergone primary PCI for a STEMI and identifying new left ventricular dysfunction and severe mitral regurgitation in an oncology patient who had a normal echocardiogram two months ago. Significant aortic valve degeneration was accurately identified in another patient and wall motion abnormalities excluded in a chest pain patient in the ED. This covers all four patients that we scanned and all findings were subsequently corroborated on a conventional transthoracic study within 48 hours.

Where to now

It is intriguing now to consider where this technology is leading us.

As you can read from my comments, I am left in little doubt that this is a real and usable technical advance but it still leaves a whole lot of unanswered questions. I was surprised to find that Nelson Schiller, highly respected echo cardiologist from San Francisco, had written an editorial in the Journal of the American College of Cardiology, as far back as 2001 on Hand-held echocardiography; revolution or hassle?‘. His points were well made then although to have described the hardware then as hand-held was stretching the definition somewhat and since then the technology has moved on considerably in terms of miniaturisation and in other respects.

In cardiology practice I don’t think that the use of the device will be able to replace too many formal echocardiographic examinations (it didn’t in any of our patients) given that the data that is missing is perhaps greater than that acquired. Nevertheless, as a bridge to a formal study, for use out of hours and in unconventional clinical settings there is little doubt that hand-held echo can now start to find its niche.

Perhaps the biggest questions that will remain will be by whom and on whom this sort of machine can be safely and effectively used. The very favourable price point of this device will undoubtedly place this machine in many more hands than currently have access to full function echocardiography equipment, but this could be a double edged sword.  We have to remember that this machine will be used to image sick patients, in unfavourable surroundings and (to be fair) provides suboptimal and limited data. Add to that mix an inexperienced or untrained operator and the rest is obvious. We must be careful not to fall for some of the marketing hype; just because this machine looks like an iPod and costs about $10 000 doesn’t necessarily mean that accurate, cost effective and safe echocardiography has suddenly become a whole lot easier to deliver.

Conclusion

Paris, September 2011

Well with those last comments I can hear the knives being sharpened – yes, just another protectionist cardiologist looking after his patch…etc etc etc.

I’m very excited about this. I hope, and actually believe, that this really is the beginning of hand held echocardiography. I just hope it finds a good home. And remember it took Laennec over twenty years to convince the community to accept the stethoscope.

Links to Further Reading

The use of pocket-size imaging devices: a position statement of the European Association of Echocardiography. 

Diagnostic accuracy of a hand-held ultrasound scanner in routine patients referred for echocardiography – Prinz and Voigt – Abstract

The Future of Echocardiography – Tom Marwick

Having scored the first weekend of the year on-call I thought I would take along the new hand held echo machine on my rounds to brighten things up a bit.

We only took delivery of this unit just before Christmas so this was really my first opportunity to put it to use where I think it will be of value; not in the echo lab but out there on the rounds, and primarily in the CCU. In this post I’m just going to cover some of the practical aspects of the device itself and less to do with its clinical impact, which frankly I think is a little early to really assess anyway.

There is going to be a lot of debate, I anticipate, about what the appropriate role of these sort of machines will be and probably even more about who should be using them.  Again, in order to avoid courting controversy, I won’t be addressing that here (at least not in this post).

Finally, all these comments relate to the GE VScan – this is not the only machine on the market that could be considered to offer hand held echocardiography, but it’s the only one I’ve used. My comments here are therefore limited to that particular machine but are unbiased and I certainly don’t have any specific conflict of interest in relation to this post.

First impressions

This really is hand held echocardiography. There is no doubt that this machine offers to provide meaningful clinical information in a truly portable, battery powered unit. It is perhaps this more than anything else that makes this an exciting device.

The GE VScan hand held ultrasound

Somewhere in my memory is a black and white picture of the first echo machine in town and in fact it used to be still sitting in the corner of a research lab where I trained, at least until a few years ago. Imagine a unit about the size of a 19 inch server rack, floor to ceiling, with a circular oscilloscope screen of about 6 inch diameter and you roughly have the idea. I’ve no idea what you could see on the screen but I’m pretty sure it was probably just B mode echoes. Bear in mind that this was in use within the careers of my current senior colleagues and you get some idea of the technological advance that the VScan represents.

Ergonomics

Ergonomically, the device is easy to handle and use. The machine powers up on opening the hinged screen, a mechanism which feels robust and should be able to withstand a bit of use. In fact the whole unit, although very light, feels pretty robust – whilst you probably would get a few palpitations if you dropped it on the floor I suspect that it could take a few knocks – reassuring for a device that is clearly designed for use on the ‘front-line’. The transducer is light and feels ‘easy’ in the hand. This together with the very lightweight cable makes imaging pretty easy. It is very feasible, as in the marketing images, to have the transducer in one hand and the machine in the other.

Usability

The VScan was demonstrated to me a few months ago and I didn’t have time to look at the manual before taking it out on rounds this weekend. So the fact that I could use it at all is probably the best indication of the user-friendly nature of the device and its controls. I may not have been getting the best from the machine for this reason but the simple tasks that I needed – powering up, initiating a new study, 2D imaging, image capture, freeze frame, colour flow imaging etc -were all self explanatory without any help. It’s pretty obvious that the engineers of the VScan have taken some inspiration from the design of the iPod and the intuitive nature of the interface and controls must also be complimented. In fact, you come away thinking that if Apple designed a portable echo machine it just might….

Boot up and battery

The VScan in its desktop charging cradle

From cold it takes abut 20-30 seconds to boot from sleep to initiating a new study and imaging. That’s pretty much nothing for an ultrasonic unit.

I suspect battery life isn’t that great. After performing just two scans of less than five minutes on a fully charged machine the battery indicator was at around 50%. I’ve no idea what GE quote as battery life but I think if you were really using this as an extension of clinical examination on a lengthy round then it would become an issue. Having a docking station for recharging on the ward would obviously help to solve this.

Archive

The VScan archives to a removable memory card and images can be exported to proprietary GE software on a PC but at the moment there is no facility to export DICOM files and therefore no ability to integrate with an established echo PACS system. For that reason, in our lab at least there is no ability to integrate the machine with our existing image-review-report workflow.

Practical issues

A bottle of ultrasound gel

The VScan, even in its case, looks and feels so inconsequential that it’s pretty easy to put it down and forget where you’ve put it. I did the several times on a busy round. I recommend that your vigilant fellow/registrar is given the opportunity of making sure you don’t lose the unit and thereby giving you the option of having someone to share the blame when you do.

For this reason, and the fact that this looks like the sort of thing that could be fun at home, I expect the VScan to rapidly rise up the table of equipment items most likely to be stolen from the hospital.

Bear in mind that I am no expert here. These are purely my first impressions, hands on, in the real world. Any corrections or clarifications are most welcome.

Oh, and you need to take some ultrasound gel with you. A space in the bag for a small bottle would be good!

In Part II: Image quality, clinical correlation and thoughts on future use

You can find out and see more of the VScan at the GE website at http://vscanultrasound.gehealthcare.com/