Heart of the matter
A heart attack is usually treated through conventional norms: Medicines, angioplasty or bypass grafting. GOUTAM GHOSH assesses the pros and cons of another option restructuring the left ventricle.
Dr. Janardhan Reddy doing an off-pump coronary bypass grafting.
TILL recently, cardiologists and cardiac surgeons were confident that they knew every cell of the roughly 500 gm organic pump: the heart. With the cardiopulmonary bypass (CPB, the heart-lung machine) the heart could be stopped (using cardioplegia) for bypass grafts to bypass the occlusions (blocks) of important coronary arteries and restore the blood supply to the myocardium (the heart muscle).
In the 1990s, mechanical stabilisers offered a relatively tremor-free field for the surgeon. Experts were happy that working on a beating heart would minimise the CPB risks (tiny blood clots, called microemboli, that caused havoc in the brain). The off-pump coronary artery bypass grafting is a standard procedure now, but the heart that beats over 378 lakh times a year still springs surprises. The surgeon often discovers truths after opening up a heart that a sophisticated investigation failed to record.
It is easy to preach an ideal way of life, but there is no ideal lifestyle that can rule out myocardial infarction (MI) called heart attack. It affects the rich and the poor alike. What happens at worst after a heart attack is obvious and the victim, if alive, hopes to reach a hospital quickly. Even then will the specialists help immediately?
Standard procedures are expensive. A private hospital, despite good intentions, will expect the patient to pay. A stent (a coated metal pipe placed at the spot of occlusion) costs about Rs. 60,000; a week's stay in intensive care unit costs around Rs. 30,000. Add the cost of investigations and you will reach a total close to Rs. 1,50,000. Given that corporate and speciality hospitals need to survive if not thrive, the consultants cannot be blamed for making sure the patient can pay.
A Government hospital is no better. Bribes are expected but the hospital may not have a stent or an artificial valve. "Government hospitals are the only place a poor person can turn to. At a teaching hospital the aim is to teach the techniques, and a student gets hands-on experience. So the patient's welfare is compromised, no matter how marginally," said a surgeon. The reality is, those who get attention are those who can pay so the number actually getting cardiac care is less than the number needing it.
Specialists say that MI happens when the myocytes (heart cells) are deprived of oxygen and nutrients beyond their tolerance limit. Usually an acute MI predicts future degeneration of the myocardium. Acute MI cases are usually handled according to some golden norms: cardiologists prescribing medicines; or using angioplasty to flatten the plaques that cause the stenosis (narrowing of the vessel); or planting a stent in the diseased coronary artery; or bypass surgery where the stenosis or occlusion (blockage of the blood vessel) is severe and cannot be corrected with medicines.
Bypass grafting in many cases merely slows down the process that leads to congestive heart failure (CHF). "Currently 4.9 million people in the U.S. are affected (by heart failure), 5,50,000 new cases are diagnosed each year, and $24.3 billion is incurred annually in related health care costs... " (Current Problems in Cardiology, March 2003).
"The database in our country is patchy so we depend on the U.S. figures," said Dr. K. R. Balakrishnan, head, department of cardio thoracic surgery, Sri Ramachandra Medical College, Porur, Chennai though "India has the highest number of CHF cases now,'' said Dr. C. Narasimhan, cardiologist from Hyderabad at the recent ``International Update on Heart Failure" at Sri Ramachandra Medical College.
The CHF patients have few options. Either the failing heart has to revitalise itself miraculously or the patient has to wait for a transplant. Many surgeons still hesitate to consider left ventricle (LV) restructuring. This chamber pumps oxygenated blood at a pressure of 120mm of mercury (nearly double the atmospheric pressure) to force blood up against gravity. The fear of losing a patient while restructuring the LV ranks high in most surgeons' minds.
Heart specialists across the world now agree that transplants (from brain-dead patients) are hardly an option. The primary reason is the excess demand for donor hearts. Though a heart transplant sounds more impressive than a kidney transplant, the process is so complex tissue compatibility, immunosuppressant to prevent organ rejection by the body's defence mechanism and more and there are so few donor organs that most of the CHF patients will have died by the time a hospital gets an organ. There is on-going research to design a total artificial heart and on using stem cells to replace myocytes.
Relief after a heart transplant to a patient suffering from related organ failures kidney or liver failure because of a diseased heart may be marginal. And a sudden painful death is likely but drugs can prevent this, it is claimed. Though heart transplants have traditionally grabbed media attention (as did Dr. Christiaan Barnard of South Africa first on a human recipient), a transplant seems unpromising. Dr. Balakrishnan said, "So far there have been around 35 heart transplants in our country." But how good does a recipient feel? Does the quality of life improve noticeably after the transplant?
Obviously, if patient welfare is a priority, a transplant cannot be an immediate option. There are expensive ventricular assist devices (VAD) that promise to keep the patient going till a donor heart is found. But VADs are not a feasible option for most Indian patients. The only immediate option is to restructure the LV.
The few surgeons in the world who restructure the LV (to exclude the diseased LV section that cannot contract anymore) or correct LV aneurysm (bulging of the LV wall because the fibrous patch becomes deadweight to the healthy myocardium) claim an impressive success rate.
Forget about statistics and claimed success rates. Even if one end-stage heart failure patient lives beyond the few months' deadline that cardiologists predict solemnly, the restructuring procedure is worthy (in terms of cost-effectiveness and the years of life that patients gain) of being practised in the over-equipped heart care centres around the world.
In India, LV restructuring is done at several centres, but the highest number happens in Chennai that accounts for over 95 per cent of such cases. Most of these patients have been living well for two to six years after the surgery, according to the data available.
The trend has been for a surgeon to wait for a diseased heart to reach the end stage defined as New York Health Association (NYHA) Class IV symptoms when transplant is the only option before he corrects it. Surgeons say that if there is a noticeable ischemic patch on the LV and there is occlusion of the coronary arteries, the surgeon needs to restructure the LV before the bypass grafts, instead of just grafting. "The prognosis for such patients will be better than those with bypass grafts alone," said some cardiac surgeons.
It is intuitively clear that those with far less organ-failure associated complications after an acute MI and whose LV is restructured (if the ischemic zone is localised in a single contiguous patch) along with bypass grafts will play a more fulfilling innings in life than those whose hearts are restructured only after they have been issued a death warrant by their cardiologists but who live long after the LV restructure surgery.
The procedure is even more warranted in LV aneurysm cases. That a ventricular septal (the muscular wall between the right and the left ventricles) rupture or the free wall (LV wall that is not a part of the septum and contracts freely during the pumping action) rupture could kill a patient instantly warrants this restructuring procedure if septal or free wall weakness is detected early.
That the number of LV-restructured survivors baffles those who swear by conventional wisdom of leaving the LV alone is beside the point. Though puzzles still remain such as sudden deaths of people whose coronary arteries hardly have 20 per cent occlusion and whose LVs are good, what matters is to do what is best for the patient.
Long way to go
THE recent "International Update on Heart Failure", on March 19-20, 2004 at Sri Ramachandra Medical College, Porur, Chennai ended on a positive note: that an increasing number of CHF patients are getting the care they need. Obviously, much more needs to be done.
Dr. Kushagra Kataria, University of Miami School of Medicine, insisted that off-pump coronary artery bypass grafting "is a safe option in end-stage heart disease" and outlined how the Acorn Cardiac Support Device (like a cone made of fish net) reshaped a bulging heart like shoving a water-filled balloon into a small conical chamber which then pumped well. But it did not seem the device significantly improved the recipient's lifespan. The story has been the same, no matter how impressive the devices.
The LV reshaping devices are yet to get U.S. Food and Drug Administration approval for clinical trials. In India, one device was tried on 27 patients at a private heart care centre in Delhi a point that researchers from the developed countries hailed. The absence of rigorous control of medicine trials in India is a boon to the West, particularly the U.S. After the drugs and devices are fine-tuned they are tried clinically in the U.S. "Trial elsewhere can cut the outlays for prolonged research," said a cardiologist.
Dr. Randas Batista, the surgeon who believes in partial ventriculectomy (cutting off the diseased part of the LV to give it a conical shape), said "The human heart is conical because it has to pump against gravity. A fish heart is almost spherical just as a whale's (a mammal) is. But a giraffe's heart is more conical than ours because it has to pump blood to reach its head that is at a greater height."
"A diseased heart remodels itself to meet the demands of the body. But progressive remodelling is an adverse sign of heart failure," said Dr. Fernando A. Lucchese of Brazil. The CHF patients can hope for a brighter future if a total artificial heart is designed. The comparison of ventricular assist devices and specific drugs indicate a symbiosis between industry and cardiac care giving system. If drug and device use is industry-driven, it cannot promise to be patient friendly.
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