New research, new techniques, new hope
India Today Health Special brings on board the countrys leading physicians and surgeons to let you know about the next wave of whats new.
Heart disease continues to be the leading cause of illness and death in India and indeed across the world. But researchers are labouring on many fronts to find new ways to understand and treat this serious disease. What has changed: from lab bench to the bedside? India Today Health Special brings on board the countrys leading physicians and surgeons to let you know about the next wave of whats new.
Looking into the Future
Dr Naresh Trehan
Chairman and Managing Director, Medanta-The Medicity, Gurgaon
Recent advances are focused on the need to make cardiac surgery less invasive and painful, with shorter hospital stay and quicker return to productive life. New technologies are evolving to deal with conditions that were once considered inoperable.
As innovations in surgical techniques advance, incisions on the chest become smaller: from cutting only the upper or lower part of the sternum (breastbone) to entering the chest cavity through an incision between the ribs, thus avoiding cutting any bone at all. This means faster recovery and better outcome.
And a range of conditions can be treated: from multivessel bypass surgery, valve replacements to repair of certain kinds of holes in the heart. Port access surgery, in which three small incisions are made on the chest wall and surgery is carried out using 'keyhole technique', is relatively new. It requires special training and good hand-eye coordination as the surgery is carried out looking at the picture projected on a TV monitor.
A revolutionary method, though not yet widely available, is robotic surgery, where the surgeon mans a robot in a room next to the patient's, or at a remote site. Incisions are made on the chest through which robotic arms, holding instruments, are passed in. As the image is magnified, it can be very precise.
With newer diagnostic techniques, patients previously considered inoperable can benefit. For instance, the PET scanner can identify heart muscle which apparently looks dead and non-functional but can be revived once blood supply is restored. Sometimes, the heart muscle suffers severe injury but can recover if given time.
Support devices called ventricular assist devices (VAD) are now available to help a patient tide over that critical period. For advanced heart failure, VADs are being miniaturised-enough to be implanted inside the body. They take over the function of the heart and allow patients to go about their daily activities.
Finally, there is the exciting field of stem cell and gene therapy. One's own stem cells, capable of forming any tissue in the body, are isolated from the bone marrow, processed, and injected into the heart-either during surgery or through catheters.
Attempts are also being made to grow heart valves outside the body through tissue engineering, so that damaged valves can be replaced by artificial valves grown from the patient's own tissues. Preliminary attempts are also being made to grow sheaths of heart muscles, to replace damaged heart muscles. The next couple of decades will, hopefully, see revolutionary treatment modalities, bringing greater benefits to greater number of patients.
The Importance of Dietary Diversity
Dr K. Srinath Reddy
President, Public Health Foundation of India (PHFI)
Coronary heart disease (CHD) results from blockages in arteries that supply blood to the heart. Fat deposition leads to build-up of plaques, which grow large and obstruct blood flow. Even smaller plaques can become unstable, crack open and initiate formation of blood clots. Clinical manifestations range from angina (chest pain) on exertion, unstable angina (even at rest or minimal effort) or a heart attack.
That people of Indian origin are highly vulnerable to CHD was observed as early as the 1950s. Studies have also shown a rising rate of CHD, with a disturbing feature of heart attacks striking a decade earlier than in the West. This led to the speculation that Indians are 'genetically' susceptible to CHD. With the INTERHEART study, which compares risk factors of CHD in 52 populations across the world, it is now proved that the same set of nine risk factors-including unhealthy diet, physical inactivity and tobacco consumption-that explain CHD risk globally are also applicable to Indians.
Dyslipidemia (abnormal blood fat levels or patterns), high blood pressure (HBP) and tobacco consumption are major contributors to CHD. Indians also tend to have higher proportion of body fat and less lean muscle mass, compared to Caucasians or Africans.
Further, the fat tends to accumulate prominently in the abdomen (central adiposity). This is associated with resistance to the action of insulin on muscles, leading to abnormal handling of blood glucose and higher incidence of diabetes. A fatty liver can cause insulin resistance in seemingly lean persons.
Blood fat patterns in Indians are often characteristic of insulin resistance: even when total cholesterol level is not high, protective HDL (high-density lipoprotein) fraction is low, the plaque-causing LDL (low-density lipoprotein) is high. Even in LDL, the particularly harmful 'small dense' component is elevated in persons with central adiposity and insulin resistance.
Triglycerides (TG), another fat variety, and a high ratio of TG:HDL are now known to be a good surrogate marker for high levels of small dense LDL, which is difficult to measure. This risk marker is particularly relevant to Indians and is linked to high dietary intake of sugar or refined carbohydrates.
Recent evidence shows that while trans-fats are harmful, because they markedly raise the LDL:HDL ratio, sugar raises the TG:HDL ratio. Refined carbohydrates are stripped of the protective effect of fibre and rapidly raise blood sugar levels. The modern Indian diet confers a high risk for these reasons.
How do we effectively prevent something as multifactorial as CHD? Eat healthy, be physically active and stay away from tobacco. Dietary diversity is important; fruits and vegetables must be on the 'high' list while sugars, starches and polished cereals on the 'low'. Early detection and treatment of HBP, diabetes and dyslipidemia are vitally important to prevent their progression to CHD. When they co-exist, even at modest levels, the risk is compounded. Family history of premature CHD is a red flag.
Most drugs needed for CHD are available in India: aspirin, statins, ACE inhibitors to beta-blockers. A combination of healthy living and efficient health services can prevent CHD in most Indians, without the need for such magic bullets.
Technology's Healing Touch
Dr Ramakanta Panda
VC & MD, Asian Heart Institute, Mumbai
First up, a story. There is a small town in Italy, Limone sul Garda. In the 1970s and 1980s, researchers at the University of Milan discovered that a gentleman from that town had high levels of LDL (bad cholesterol) and triglycerides-yet no sign of any cardiac disease.
Perplexed, they tested the town's 1,000 inhabitants and discovered 40 people had high cholesterol and no heart disease. The researchers then discovered that all 40 people had common ancestors. And a mutant protein, now famously called Apolipoprotein AI Milano, was present in all 40 inbred people who had defied all logic. Today, Apolipoprotein A is associated with a decreased risk of heart attack, stroke and arteriosclerosis.
Not all of us are so lucky. Cholesterol deposits could well mean cardiac conditions, angioplasty and bypass surgery. And then there are the mechanical problems that affect the valves. Heart valve disease is one of the common forms of heart disease affecting people.
The four heart valves-mitral, aortic, tricuspid and pulmonary-ensure that blood flows in one direction through the heart. Heart valve disease occurs when either the valve is narrowed (thus reducing the amount of blood flow to the body), called valve stenosis, or is leaking (thus producing extra load on heart), called valve regurgitation. Heart valve disease occurs largely as a result of ageing. Most sufferers are in their late 50s when diagnosed. And more than one in 10 people over age 75 have it. Yet few patients-and even doctors-are aware of the disease. And the symptoms can easily be mistaken for ageing or lung disorders.
There is no doubt that we have come a long way from the beginning of valve surgery in the last 62 years. Thanks to all the medical innovations since the 1960s, today even 70-plus patients are considered for the surgery.
All the new innovation and research are now directed towards three things: reducing the amount of cut; repairing rather than replacing; improving the longevity of tissue valve. The latest innovation to reduce the size of the cut is TAVI or Transcatheter Aortic Valve Implantation, where a new valve mounted on a balloon at the tip of a catheter is inserted through the groin and guided to the diseased aortic valve. Another cutting-edge research, still in the animal experiment stage, is on an artificial self-healing valve.
Initially a tissue valve is washed of all dead tissue and cells, leaving behind only the scaffolding of the valve on to which the cells that make the blood vessels are seeded.
Such an artificial valve, when implanted into the valve position, has been found behaving like a natural valve with ability for self-healing. Thus living tissue valves can be placed in a minimally invasive manner and not only do they have the potential to function well but also to self-heal.
Medicine for me is about hope, healing and excellence. All advancements in technology are a way to save more lives that we are capable of saving. And to make sure that people lead a better life.
Heartening Innovations
Dr Ashok Seth
Chairman, Fortis Escorts Heart Institute.
The last 50 years have seen fascinating developments in the treatment of heart diseases.
In non-surgical treatment of heart, the progress has been so unbelievable that some of the procedures that were performed even 20 years ago look crude and outdated now. The era of excitement took off in 1977, when Andreas Gruentzig, a young German radiologist studying in Zurich in Switzerland, opened an artery blockage in a patient non-surgically and under local anaesthesia with balloon angioplasty for the first time.
I was fortunate to get my training in Interventional Cardiology in the early 1980s, just as these exciting times took off. And I feel privileged to have taken part in and witnessed the rapid progress and pioneering spirit in non-surgical treatment of heart disease, especially in the Asia-Pacific region.
We can now treat multiple blockages of arteries of the heart without surgery. We can effectively treat heart attacks and prevent deaths. We can replace diseases of the valves of the heart safely and effectively through small cuts on a conscious patient in the cath lab, with a patient returning to full activity within two-three days.
As we look into the future, the medical world seems almost like a 'wonderland', considering the rapid pace at which the science is progressing to conquer the disease processes of the heart. Treatment is becoming less invasive, more safe, more effective. Solutions are expected for some heart problems which in the past were considered untreatable. Here are some of the new and futuristic technologies which may benefit a large number of patients. First on my list are bioresorbable stents. When arteries get blocked by cholesterol deposits, heart attacks can occur.
One of the widely used treatments involves angioplasty, where small spring-like devices made of stainless steel and coated drugs-drug-eluting stents-are inserted to remove the blockage and keep the arteries open. But having a piece of metal in the heart arteries throughout life has some disadvantages, including the fact that the patients have to be on blood thinning tablets constantly.
There are now 'stents' which are made of plastic-like material that after opening the arteries gradually dissolve and disappear in about two years, leaving the artery totally normal. This fascinating and revolutionary treatment was first used in India at the Fortis Escorts Heart Institute in October 2010, as part of a study. Since December 2012 onwards, after approval in India, these bioabsorbable stents are in regular use and benefiting a large number of patients.
Another new treatment under investigation is Renal Denervation Therapy, for patients of high blood pressure. In this, nerves to the kidney are interrupted by microwave catheter. The patient can be discharged the very next day. Another innovative device is the leadless pacemaker that doesn't require electric leads to be inserted into the chamber of the heart and hence less chances of complications.
Another life-saving device, the subcutaneous ICD system, has been approved for patients at risk of sudden cardiac death due to life-threatening ventricular arrhythmias (irregular heartbeat) and who do not require a pacemaker: the S-ICD lead is implanted along the rib cage and breastbone.