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This post refers to

‘Self-monitoring of oral anticoagulation: systematic review and meta-analysis of individual patient data’ by Carl Heneghan and others of The Self-Monitoring Trialist Collaboration  that was published in The Lancet – 28 January 2012, Vol. 379, Issue 9813, Pages 322-334 http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(11)61294-4/abstract?rss=yes

I never wanted this to be a medico-political blog but it has been difficult to avoid given the barbs that have fired at cardiologists over the last few weeks. I’m sure there will be more to come…

Anyway, for now at least, it’s nice to get back to reading some science.

One of my mentors as a medical student, in fact the senior physician on my first medical rotation at medical school, was the diabetes expert Prof. Robert Tattersall. Undoubtedly, Tattersall’s major contribution to medicine was his work promoting home blood glucose monitoring for people with diabetes. In his book, Diabetes: The Biography, he hands most of the credit to Dr Clara Lowy of St Thomas’s who allowed a pregnant diabetic patient to monitor her own blood sugar at home using a machine loaned by the hospital. This might not seem extraordinary now but at the time, as recently as 1975, this was seen as ‘irresponsible and dangerous’ by many colleagues. Tattersall is too modest about his part in this revolution, neglecting to mention that he led the ‘Nottingham Group’ that in 1978 published their experience alongside that of Lowy, in Issue 8067 of The Lancet.

So this meta-analysis concerning self-testing and management of anticoagulation from Oxford, caught my eye. The findings are particularly relevant to patients with mechanical artificial heart valves. Although the risk of thrombo-embolic complications is low with modern mechanical valves self-management of anticoagulation appears to have a fairly dramatic effect in reducing this risk further, without any increase in bleeding. This didn’t translate into a reduction in mortality although the trend was in favour.

Despite being available for some years self management of anticoagulation has never really caught on, probably for a variety of reasons. In Australia cost has been a significant hurdle. Nevertheless, inertia amongst the medical community, similar to that experienced by Tattersall and Lowy has probably also played its part.

Given the bad press surrounding the new oral anticoagulant dabigatran, and the lack of a defined role in patients with mechanical valves, it seems that warfarin still has some years to run. The Last Cardiologist will be taking another look at the whole place of self management of warfarin for his patients, and particularly those with mechanical valves.

On the face of it, it is hard to see the exact motive behind Tony Webber’s spray that was published in the Medical Journal of Australia this week. Sour grapes at the DoHA in their failure to respond to some of his concern? Frustration that despite all that hard work as chair of the Professional Service Review Board he was unable to implement any real improvement in an inherently flawed system? Or just good old fashioned professional jealousy?

Either way, cardiologists were clearly in the firing line.

As others have been quick to point out, the position chairing the committee responsible for dealing with the worst cases of abuse of the Medicare system is perhaps not the best vantage point for taking an objective view of the functionality of the system as a whole. Furthermore, the cost of ‘waste’ quoted at $2-3billion per annum appears to be little more than Webber’s personal estimate based upon a calculation that he doesn’t care to share with the readership.

In fact, Dr Webber’s tilt at cardiologists seems a little misplaced. Whilst mourning the inability of Ms Roxon to arrange to cut the medicare rebate to ophthalmologists for cataract operations by 50% he simply ignores the fact that in the same budget cardiology practices and their patients were forced to absorb a 20% reduction in the rebate for cardiac catheterisation without any discussion, consideration or consultation. Add to that the fact that rebates for cardiac diagnostic imaging services such as echocardiography have not been indexed in the memory of most practising cardiologists (resulting in an effective cut of >40% compared to CPI) and his assertion that once rebates have been set they are never reconsidered seems at best baseless, and at worst a deception.

Whilst Webber goes to some lengths to point out that not all specialists abuse the Medicare system it’s unlikely that this is how his comments will be interpreted. At least not if the first round of associated newspapers headlines are concerned

Sydney Morning Herald – ‘Medicare rorts cost $3bn’

The Age – ‘Don’t let rorters undermine Medicare’

Fortunately, we were able to rely on the journalists from The Australian who weren’t able to see too much past the fact that…

‘…the safety net has been used to “subsidise cosmetic procedures such as surgery for ‘designer vaginas’…

Fundamentally, Webber’s comments are poorly written, randomly directed, lacking detail and unsubstantiated. In many ways it is surprising that the MJA even agreed to publish the article in this form. Perhaps even more disappointing is the total lack of even a suggestion of a solution. Without that it is likely that as Webber slides back into obscurity as a suburban Sydney GP his comments will follow him.

The list of esteemed national and international speakers who have been invited to deliver the named lectures at the 2012 Cardiac Society of Australia and New Zealand annual scientific meeting which will be held in August in Brisbane can now be found here and includes 

Renu Virmani (Gaithersburg, USA) delivering the RT Hall Lecture

Joseph Bavaria (Philadelphia, USA), the Victor Chang Memorial Lecture

Michael Stowasser (Brisbane, Aus), the Gaston Bauer Lecture, and

Linda Worrall-Carter (Fitzroy, Aus), the Cardiovascular Nursing Lecture

You can now see the full announced international faculty for the meeting.  Detailed biographies are included for each speaker. It is an outstanding line up for an Australian scientific meeting that includes the likes of Jay Cohn (University of Minnesota), Tom Marwick (Cleveland Clinic), Laura Mauri (Harvard), Carole Warnes (Mayo Clinic) and Richard Schilling (University of London).

Registration for the meeting opens in March but don’t forget that abstract submission is now open and  must be made before March 15th.

http://www.csanz2012.com/

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