HOD-Cardiology, Stanley Medical College and Hospital, Chennai
Today we have Dr. K. Khannan who is one of the senior and leading cardiologist from the City of Chennai. Currently, he is associated as an head and professor of cardiology from the Stanley Medical College, Chennai. So sir, it is a warm welcome on this particular show regarding the revolutionary talk on atrial fibrillation. So sir, regarding the arrhythmic disorders you must have found atrial fibrillation as the common arrhythmic disorder having the incidence rate around 30 to 33%, but the thing is that diagnosis and the screening is one of the biggest challenge regarding the atrial fibrillation. So in your practice, when you come across this kind of the condition how you will decide the strategy to diagnose or screen out the patients for AF.
Basically we look at atrial fibrillation as an arrhythmia. The two distinct challenges, one is it associated with the structural heart disease or not associated with structural heart disease. (01:00). These are the two broad criteria. If you have a structural heart disease, we look at its reversibility. Is it a reversible heart disease or an irreversible heart disease. For example, you have mitral regurgitation or valvular regurgitation, severe MR which is dilated atrium with thickening mitral valve, the atrium shrinks, heart rhythm becomes normal. These are reversible type, which have some structural evidence. The patients you have got irreversible cardiac conditions leading to atrial fibrillation. Those group of patients we have to plan for a life long anticoagulation. This way we look for structural heart disease. In a patient who has no structural heart disease, then the problem is depending on other factors we classify the scoring. The CHA2DS2 scoring and in the CHA2DS2 scoring we do that to assess what is the risk of going in for a stoke, because the major complication in atrial fibrillation is stoke. Then we also look at one the heart rates in atrial fibrillation (02:00). Is it controlled heart rate or is it an uncontrolled heart rate with atrial fibrillation. We look for the presence or absence of cardiac failure. We look at the age of the patient, we look at the overall echo parameters of increased size of atrium and then we decide on the duration, the drug we adopt and what is the advise we give to the patient. This is how we approach.
So definitely it is quite convenient and practical approach for the atrial fibrillation screening and diagnoses. Now if you talk about the management part, I think since last 60 years the drugs like vitamin K antagonist and oral antiplatelets are available, but now very recently the trend is going towards the change for the newer generation of oral anticoagulants. So in your practice you may have come across step by step from the OACs then to antiplatelets and then now the newer generation of oral anticoagulants. So what is your clinical experience by using these all three kind of the group of the drugs?
(03:00) Major problems, which we encounter with the vitamin K antagonist was the erratic INR levels in patients, we are not able to judge, which patient will have problems with INR and this often leads to discontinuation of treatment also. In many incidences we try to reduce and the doses are suboptimal and when you try to increase it, it will lead to bleeding and land in bigger problems, so erratic INR levels are the major issue when we treat with the vitamin K antagonist. But in the absence of structural heart diseases, structural heart disease is there, still there is evidence only for vitamin K antagonist. In the absence of structural disease, because of nonvalvular atrial fibrillation, the newer anticoagulants have definite superiority because one, effectiveness has been found to be equal or sometimes superior and second the side effect profile is very very negligible compared to the vitamin K antagonist and there is no need to monitor INRs.
Definitely, as of now in India, there are three NOACs available, first was dabigatran, then rivaroxaban and now apixaban as well. So if you come across all three NOACs in your practice then how will you differentiate, definitely there is no any head-to-head comparison of this trail, but again if you want to choose any molecule for different group of the patients for the atrial fibrillation then what you have prepared a criteria to select the NOACs.
Because initially the first drug which I put was dabigatran, which came into the market. So if you say frankly about the volume of patients I treated with dabigatran, will definitely be more than rivaroxaban or apixaban, but if you see the literature and the limited experience that we have with these two molecules, I will definitely say that at least on effectiveness basis and the convenience basis these two molecules have a definite role to play (05:00) and I think we will have to wait for some more time before we can give a full experience on these molecules.
Surely, surely so I think sir has given a very brief and very practical aspects regarding the role of NOACs in the stroke prevention atrial fibrillation. This atrial fibrillation is definitely is the major concern for society. The diagnosis and screening part is also a major issue. If you talk about older oral anticoagulants like vitamin K antagonist, they have such kind of ill effects like the poor INR monitoring and the high rate of the intracranial hemorrhage as well. Sir has mentioned very well that the NOACs, newer generation of our anticoagulants is the solution for this kind of side effects and about three kind of the NOACs are available, so in future when more data is coming and more experience then definitely in some segments they can cross over the use of the vitamin K antagonist (06:00). So I think with this discussion we are ending our discussion. Thanks a lot Dr. Khannan for providing your valuable and expert opinion. Thank you.