Senior Cardiologist and Physician
Manoria Heart and Critical Care Hospital, Bhopal
Sir, before starting our discussion, can you highlight some important points in your written book on monograph on atrial fibrillation. What is the key message that you want to drive.
This monograph is basically written to physicians so that they can understand atrial fibrillation, how to assess the ischemic risk, how to assess the bleeding risk, when to initiate the anticoagulants, when to use the newer anticoagulants, and there are many subset of atrial fibrillation, each subset is also highlighted, so it is a very compact book on atrial fibrillation and each chapter is decorated with highlights so that if you do not have time, you can just see the highlights and you will be aware of the key issues in atrial fibrillation.
So definitely sir, atrial fibrillation as you rightly mentioned is one of the very critical disease, is the commonest arrhythmic disorder worldwide and you also mentioned that it is at (01
If you have sustained atrial fibrillation, it will not be missed by any good physicians, but on many occasions atrial fibrillation is paroxysmal that may last for seconds, minutes, and some of these patient develop stroke. Previously when stroke used to be developed an echocardiogram was normal, no other tests showing any cause of atrial fibrillation, they were categorized as cryptogenic stroke, but now with prolonged monitoring we know that if you suppose monitor ECG for seven days or five days, many of the so called cryptogenic stroke are in realty paroxysmal atrial fibrillation and that has produced this stroke, so one of the test before we label any patient as cryptogenic (02
Sir, rightly mentioned, and you also mentioned that stroke is one of the major complication of atrial fibrillation. It remains four to five times higher chance of risk of a stroke when the patient has atrial fibrillation.
No. It depends on the cause of atrial fibrillation. Suppose it is valvular atrial fibrillation, the risk of stroke is 17 times compared to non-valvular it is five times the normal individual. So, if you are having a valvular atrial fibrillation which is seen in 50% of the Indian atrial fibrillation, the stroke risk is very very high and optimum anticoagulation is mandatory. Whereas if it is non-valvular atrial fibrillation, which is a dominant scenario in the West and not in India, the (03
So regarding the prevention of a stroke in atrial fibrillation, so far there is anti-thrombotic treatment is available, anti-platelets, oral anticoagulants, so what is your experience as of now, usage of these kind of conventional oral anticoagulants and anti-platelets in stroke prevention.
See, if you provide optimum anticoagulation, the risk of stroke can be minimized at least by two-third or more. The problem with atrial fibrillation is many physicians are scared of the bleeding complications of the anti-coagulants, but they should be well versed with the subject and then there will be no issue. For example, if you want to initiate an oral anti-coagulant, you have to calculate the ischemic risk, means what is the risk of stroke. The Chad Vas Score is superior compared to the conventional Chad Score because it is more sensitive, so all these scores are given in any book or on the net and it takes hardly (04
Definitely sir, you have mentioned very correctly that VKAs are older and standard drugs, but still they have some practical challenges like INR monitoring, food drug interaction, and thus the patient has a double-edged stroke kind of condition, high risk of stroke, and high risk of ICH and in place of that newer generation of oral anti-coagulants like Apixaban, Rivaroxaban, and Dabigatran they have a chance to replace these kind of treatment. So, sir what is your experience that of this all three NOACs, how can we can put individually in some group of the patients. (07
See, if your relation or friend is taking an anti-coagulant like warfarin, you will understand the limitation. What is the problem with warfarin, always you have to keep the eye in between 2 and 3. He is always walking on a tight rope trying to balance the efficacy and safety of the drug. Today his INR is safe point, he goes to a restaurant takes something, he drinks, food items, I think there is a big list of the drugs and drug-to-drug interaction, food-to-food and some many that despite all precautions the INR will fluctuate and the pharmacokinetics and pharmacodynamics of warfarin are highly unpredictable. Some dose in different individual will produce different effect, same dose in the same individual will produce different effect over different period of time, so the variable pharmacokinetics, the variable pharmacodynamics and narrow therapeutic range. If you cross the range above 3, bleeding, below 2 stroke, the third risk because of these dietic restrictions, the patient is in a real mess. If he goes for a party, he goes for marriage, he is all the time looking at what to eat, what not to eat, and despite that things change and then (08
Definitely sir, you have rightly mentioned. This is just the last question for you sir. You have three NOACs, Apixaban, Rivaroxaban, and Dabigatran. You already mentioned dabigatran is certainly (12
</b>See everything is very simple. There will never be head-to-head trials, so you will say Dabigatran is superior, what is the data. The data will never come, so selection of this agent is very simple. If you have a patient who has a high ischemic risk and a low bleeding risk when the ischemic Chad Score is high, bleeding risk is plus/minus you will use Dabigatran in higher dose. Because Dabigatran 150 mg has the greatest power of reducing stroke. So, high ischemic risk, low bleeding, Dabigatran 150 mg. If you have a high ischemic risk and high bleeding because the most of the bleeding risk and the ischemic risk factors are same, then we will use Apixaban. Because Apixaban, the bleeding risk is minimal. The efficacy is just like warfarin (13
</b> Yes, obviously. It is not hypothetical, but it is a very rationale.
</b>We have the data, why using Apixaban because the bleeding is risk, GI bleed, why using Apixaban, Dabigatran increases the GI bleeding so that is why I am using and then GI bleed is easily manageable for all practical purposes. Unlike the head bleed intracranial, you will die. So, disadvantage with Dabigatran and Rivaroxaban, they increased GI, but Apixaban does not increase. To some extent it may decrease it.
</b>So, definitely, as Dr. Manoria has said very well that he has given very practical kind of the approach as to how the VKAs are available, but they have very wide kind of practical issues like monitoring of INR, PT monitoring, food drug interaction (15
The only thing when should we use warfarin. Now, warfarin has to be used if you have a valvular atrial fibrillation. The newer agents are not suitable at the moment. If the patient is very poor, you will have to use warfarin. If some patient is doing well with warfarin, suppose his INR is stable, no ischemic risk no bleeding, you may continue at risk, but keeping in mind that the intracranial bleeding is 50% more with warfarin. If the patient and physician interacts and then decide that this patient whose is very well controlled, wants to shift to newer agent because of fear of intracranial bleed and that will finish if your bleeding risk is high due to some reaction, then even if the patient is doing good, we will shift to a newer agent or (16
Also this is a well taken point that in which conditions the warfarin also can be used. Definitely it is very low cost available molecule and it has the own advantage in valvular conditions and as a part. So, thanks a lot Dr. Manoria for providing us your valuable time.