Should non-interventional cardiologists stop doing coronary angiography?

I was at the autumn meeting of the British Cardiovascular Intervention Society (BCIS) today in Blackpool. One of the speakers raised this question. There wasn’t much debate or discussion and I guess this might be because the audience was full of interventional cardiologists. But the speaker was thinking forward to future not so far away when this question might asked more and more.

The coronary angiogram was once seen as the gold standard for the assessment of coronary artery stenosis. NICE chest pain guidelines recommend angiography as the first line investigation where the likelihood of coronary artery disease us high and this results in about 250,000 angiograms being performed every year in the UK. Of course we all know, or should know, that an angiogram is not done to make a diagnosis of angina. That diagnosis based on the clinical history, rather the angiogram is done to define the pattern of coronary artery disease and to make recommendations regarding potential revascularisation or further management. So if the reason for doing the angiogram is to plan further management is it reasonable that this procedure should only be done by cardiologists with a specialist interest in coronary artery disease management namely interventional cardiologists?

In 2013 about a quarter of a million angiograms were performed in the UK, many of these by non-interventional cardiologists and cardiology trainees. At present the trainees have to learn how to do a coronary angiogram and be signed off as competent to perform this procedure independently.  The number of procedures requires is not stated and the assessment based on competency. Once they become a consultant many cardiologists like to continue performing angiography as it is a commonly requested test and they wish to continue performing the procedure in the private sector. I think that is necessary to carry out at least 100 angiograms per year to maintain competency and less than this the skill level probably declines. There was once a time that the junior registrars performed all of the angiography in a hospital with the consultants getting on with the intervention. Fortunately this has changed and in my practice I directly supervise and teach all my trainees in the catheter laboratory and every case is attended and reported by myself. Having personally performed more than 5000 coronary angiograms and interventional procedures I firmly believe that procedural experience enables the cardiologist to undertake the procedures safely, rapidly and to be able to deal with all eventualities. It is rare for experienced operators to fail in vascular access or to be able to complete the procedure successfully. The fact that the interventional cardiologists can proceed to angioplasty may also improve patient safety if a complication occurs especially if the angiogram is taking place on a site where they are the only cardiologist present.

But there is more to my argument that just operator experience or safety. Interventional cardiologists have woken up to the realisation that eyeballing a coronary angiogram might not be the best way to assess the significance of a narrowing. For years we have had the idea that the percentage stenosis is so important. Is the lesion 50% or 70%? This terminology should be abandoned and replaced by description of whether the lesion is significant (i.e. flow-limiting) or non-significant, at least with respect to the need for interventional treatment of stable angina.

This leads us to the growing body of data derived from functional assessments using pressure wires which prove that the “Wire is mightier than the eye”. In the RIPCORD study, the recommendation for medication, angioplasty or cardiac surgery changed in 30% of cases when pressure wire data was available in addition to the angiogram. This is of huge important if you’re the patient and your cardiologist has just told you that you should have coronary bypass surgery. What if their eyeball assessment was wrong and actually all you needed was a stent or worse still just some medication? Although the RIPCORD study is not a randomised trial and it doesn’t have clinical outcome data it does illustrate vividly the importance of functional assessment of coronary lesions in making an accurate diagnosis.The argument then follows that if there is a need for pressure wire assessment shouldn’t the diagnostic angiogram be carried out by an interventional cardiologist who is trained to make these measurements.  An interventional cardiologist has been trained to pass wires down the coronary arteries safely and therefore should be the person performing the procedure. Patients currently being treated by non-interventional cardiologists might have this important assessment denied to them by lack of training, experience or an outdated reliance on the eye-ball assessment of coronary disease.

It is also possible that because interventional cardiologists are performing intervention that they in fact be better at lesion assessment. This could include the use of non-traditional views to assess difficult things such as ostial disease.  Also having performed many pressure wire measurements the interventional cardiologist has an inbuilt feedback which may in fact improve their calibration and eyeball assessment of coronary lesions.

The interventional cardiologist also has a better idea of whether revascularisation is possible and the potential pitfalls. One patients three vessel disease is not the same as another patients and should not immediately lead to a reflex surgical referral especially if the Syntax score is low.  Importantly the patient treated by an interventional cardiologist has the option to proceed to coronary intervention at the same time as the angiography. This might be if there is an urgent clinical situation or a catheter induced complication or more commonly if the patient prefers to have definitive treatment on the same occasion as the diagnostic test. Although ad hoc angioplasty is discouraged by the European Society of Cardiology in some situations where the patient has ongoing angina, a positive stress test, is already on 2 anti-anginal medicines and has a type A critical stenosis in one single vessel there is little to discuss and proceeding at the same time as performing the angiogram saves the patient from having two invasive procedures.

The interventional cardiologist also provides the patient with continuity of care for both diagnostic and interventional procedures and their expert knowledge and practical experience of the pros and cons of different methods of revascularisation is likely to be greater.  It may be that non-interventional cardiologists have a bias to recommend medical therapy rather than angioplasty, which may not always be appropriate. Interventional cardiologists may also tend to be more up-to date with new techniques such as the use of the radial rather than the femoral artery, the management of chronic total occlusions and therefore be in a position to offer the patient treatments which non-interventional cardiologists are not familiar with.

The decision about the scope of a doctor’s practice often resides with their employing institution or them as an individual. However I believe patients should be better informed about the doctors that are treating them. I have put a lot of detailed information about my practice on the web including information about volumes and my views on angiography and angioplasty. I don’t see that very often from other cardiologists and until very recently with the publication of the BCIS angioplasty data by individual operator gaining any specific information about a cardiologists practice as a member of the public was virtually impossible. It is often surprising how rarely patients ask the question: How many of these procedure have you done? What is your success rate? What is you complication rate? There is an assumption that if you are doing the procedure you know what you are doing.

I would welcome your comments on this. As we move towards more functional assessment and a debate about whether pressure wire assessment should be incorporated into diagnostic coronary angiography this question is going to be raised more and more.

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