We are going to discuss very important issue today of coronary artery disease. It has been increasing rapidly in India.Any particular reason why at this point of time our country is facing so much of issues with coronary artery disease?
So we know from the data that over the few decades the incidence of coronary artery disease has risen three to four times in the rural areas and about five times in urban areas. More worrying is the fact that more and more younger people in our country have significant incidence of heart disease. They are generally in the prime of their life, they are breadwinners and heart attack at that age devastates not only these people but their entire families, because they are the source of livelihood. As the incidence of coronary arter disease increases, the incidence of heart failure also is going up in our country and the reason for that is that there is a greater survival because of wide spread availability of coronary care units. We have a very high incidence of diabetes in our country. The environmental factors, that is pollution and the lifestyle changes like obesity, smoking, junk food, these are gradually increasing in our country. All these combine to increase the incidence of coronary artery disease and by virtue of a combination of factors higher incidence of heart failure in our country.It is estimated by the WHO that by the year 2020 heart diseases will overtake infectious diseases as a primary cause of motility in our country. It is worrying because we are nowhere close to eradicating infectious diseases and if heart failure overtakes or coronary artery disease overtakes that you can imagine the magnitude of the problem that we are going to face over the next couple of decades.
Sir, you pointed out heart failure as one of the most important reasons which is going to be a killing factor for the patients who have coronary artery disease and eventually develop an LV dysfunction and subsequently leading to heart failure.Beta blockers have been the mainstay of therapy in coronary artery disease secondary prevention. At one point of time they were contraindicated or people at least used to think that they should not be given in patients with heart failure, but over a period of time they revolved and they also form the mainstay of management in heart failure as well. Any particular point would you like to tell to the physicians how they should be using beta blockers therapy in patients with heart failure and coronary artery disease?
I will talk about beta blockers in heart failure. As the knowledge about the pathophysiology has gradually evolved, we have moved away from the concept of simple pump failure to neurohormonal activation being a major factor in propagation of heart failure and we know that catecholamines have a significant role in increasing the incidence. The adaptive responses gradually become maladaptive and they have an adverse effect on heart failure. Therefore beta blockers and renin angiotensin aldosterone antagonism, these are the two mainstays of heart failure therapy. Used judiciously they result in a significant, not only symptomatic improvement, but also result in reverse remolding and thereby improve LV functions, decrease mortality and morbidity over a course of time. It is important to use beta blockers very judiciously. If somebody comes to us with acute heart failure, it is important initially to achieve a euvolemic state and once that particular state has been achieved, then one should introduce beta blockers in gradually increasing doses. It depends upon the heart rate and the blood pressure, the presence of any pulmonary disease in deciding how we should be initiating beta blockers,but the general rule is that you start slowly, may be metoprolol say about 6.25 mg twice a day or something equivalent. At present there are three beta blockers which are approved for treatment of heart failure, that is metoprolol succinate, carvedilol and bisoprolol.So use any of these with which you are comfortable. Also simultaneously ACE inhibitors or angiotensin receptor blockers have to be used and one should gradually over at an interval of one to two weeks, depending upon pulse and blood pressure of the patient keep on increasing the dose till you reach the doses which have been recommended by guidelines. The doses are available in literature.If you cannot reach those doses, at least try to reach as close to those doses as possible because they are the once which give the best possible results over a long-term period.
Sir, you mentioned about three drugs metoprolol, carvedilol and bisoprolol and of course the users can choose based on their preferences,but any studies or data which shows superiority of one over the other or any particular indication in which one has to be preferred or one has to be avoided?
Not really. These studies have shown nearly identical results with all the three of them.Different cardiologists have different experience with beta blockers, so important thing is to use a beta blocker and to use it in the guideline recommended dose and try to reach the maximally tolerated dose. You can use any of them with which you are comfortable.
Any particular timeframe or time the beta blockers have to be given or any particular reasons when they should be stopped, for example if the heart failure is worsening is there a need to stop it or titrate it or down.
So duration of beta blockers given the fact that by and large heart failure is a permanent disease in a person, beta blocker therapy has to be continued permanently unless there is a contraindication. Contraindication or the reasons for stopping would be if somebody develops hypotension or if there is bradycardia or heart block or if somebody has severe bronchospasm. In those situations it may require a temporary discontinuation and reintroduction of beta blockers once the particular conditions which necessitated their stoppage has disappeared or has been resolved.If somebody presents to us with a severe heart failure and the person has been on beta blocker, one has to use their own judgment and initially may require either down titration or even stoppage of beta blockers for a particular period of time till acute heart failure has been resolved. But it is again important that once a euvolemic state has again been achieved to reintroduce the beta blockers and again up titrate them to the required dose.
Any newer therapies which are coming in heart failure would you like to mention about that?
There are a number of things, some are new some are not so new, but they are not used so often. For example, in patients with heart failure and left bundle branch block, CRT or cardiac resynchronization therapy with implantable cardioverter-defibrillator is a modality which is expensive but grossly underused in our country. So if these patients have left bundle branch block, there is a significant improvement in their symptoms, in their quality of life and even in their longevity if they get a cardiac resynchronization therapy in which you put in a pacemaker where one lead is in the left ventricle and one in the right ventricle so that both of them contract simultaneously and improve cardiac output. ICDs or implantable cardioverter defibrillators are a great method of preventing sudden cardiac death in these patients, the incidence of which is close to 10% per year. In any person with heart failure it is very important to exclude reversible causes and primary of them being a coronary artery disease. Ever so often we find that somebody has come with heart failure and after controlling if you do their angiogram you find a significant coronary artery disease with a large amount of myocardium which can be salvaged with revascularization either with angioplasty or bypass surgery. There have been instances where they have been extremely gratifying results by the use of these techniques. There is a new drug called neprilysin inhibitor which is being mentioned as a game changer in patients of heart failure. At present we use renin angiotensin aldosterone antagonism as one arm of therapy, beta blockers another arm of therapy. There is a third group called natriuretic peptides which have all the beneficial effects. Until now we did not have any therapy which have shown to improve results by utilizing this arm and the reasons for that are multiple, I will not go into details, but this new compound which has come neprilysin inhibitor was recently tried in a large study called paradigm trial and showed dramatic results in improving mortality and morbidity. This is the only non-malignancy drug which has been given expedited approval by FDA has also been approved by European Union and is likely to become available in the Western world towards the end of this year. Hopefully this drug should come next year also in our country and this has shown nearly 22 to 25% mortality and morbidity reduction over and above the standard of care therapy which is available today, which is a huge number.
Thank you so much sir. One final question. exercise is also concerned in heart failure patients.Any particular advice you would give to physicians to advise to their patients on exercise in patients with heart failure.
All too often we find that patients when they get heart failure they either stop exercising or even some of their physicians may advise them not to exercise. It is not a great idea. We know that exercise promotes heart health and they can start with whatever they can tolerate. After the heart failure has been controlled they should start walking. Walking is a great exercise for them and gradually keep increasing it to the limit of their tolerance. Doing regular exercise improves cardiovascular functions and also improves the person's general health and it is highly recommended.
Thank you so much sir. Thank you for taking out time and discussing on very important topic today with us. Thank you sir.