By Jim Atkinson
ABOUT TWENTY-FIVE YEARS AGO, I listened raptly to a group of young surgeons who were prophesying a time when hearts would be virtually bloodless. The most barbaric and common procedure at the time--open-heart, coronary-artery bypass grafting (CABG)--would become, they said, only slightly more serious than day surgery for an ingrown toenail through the wonders of fiber-optic imaging, microsurgical instrumentation, and lasers that could simply vaporize arterial blockages without a scalpel ever having to touch flesh. Given the pervasiveness of heart disease (our number-one killer, then and now) and the brutal trauma of open-heart surgery, this was big news. A quarter of century later, we're still waiting.
SO IF I BEGIN TO FEEL CHEST PAINS, I STILL HAVE TO GO IN AND BE "OPENED UP' LIKE MY DAD WAS?
Not necessarily. If the bad news about modern heart surgery is that we haven't been able to make it bloodless, the good news is that when the Big One visits, there are a lot more options to run through before being filleted like your dad was. To begin with, while he probably didn't know about his coronary-artery disease until he began to have angina (the chest pains that are an early symptom of it) or the real item, a heart attack, improved screening techniques--high-speed CT scans, MRIs, PET scans, stress echocardiograms--will allow many of us to elope out our problem long before a heart attack arrives. Individually, none of these technologies are anywhere near foolproof, but in aggregate they can fairly accurately separate those of us with an incipient heart-disease problem from those of us who, by virtue of good genes or clean living, don't seem to have a Big One in our future. This gives us a leg up on the problem that our dads didn't have. And though lifestyle adjustments--low-cholesterol and low-sodium diets, exercise, et cetera--haven't proved to be any magic bullet (half of all heart-attack mortalities are among people with normal cholesterol), deaths from heart disease have actually declined 60 percent since 1950, and the reason isn't simply open-heart surgery but cleaner living, particularly a 50 percent reduction in smoking.
BUT SUPPOSE CLEANER LIVING DOESN'T DO IT AND THE MRI'S KEEP SHOWING A PROBLEM. IS THERE ANYTHING MORE WE CAN DO ABOUT IT, SHORT OF OPEN-HEART SURGERY?
Yes. Let's say your latest scan shows a couple of arteries blocked by 70 percent and you've been suffering intermittent angina--a level of atherosclerosis that tends to call for serious intervention. In the old days, you'd be on the block and opened up, no question about it. But these days, you may have the option of one or more considerably less invasive and traumatic angioplasties--the minor surgery in which a balloon catheter is threaded up through an artery in your groin and then into one or more of your coronary arteries and expanded to compact the plaque and open the vessel.
True, the procedure has a checkered reputation. First heralded as a civilized alternative to open-heart bypass when it showed up on the scene in the late seventies, it quickly proved disappointing, since the rehabilitated vessels of almost half of all patients reclogged within six months to a year, necessitating another angioplasty and, in some cases, the dreaded open-heart surgery. But the widespread use of stents--tiny wire-mesh tubes that are inserted into the freshly expanded blood vessel to fortify it against renarrowing--over the past decade or so has not only restored angioplasty's reputation but also taken it to the top of many cardiologists' lists of potential treatments for all but the most advanced blockages.
According to the American Heart Association, heart patients who receive angioplasty plus stents these days have a 40 percent lower chance of needing an additional angioplasty or open-heart surgery than their fellow patients who underwent angioplasty with no stents back in the eighties. And according to the Cleveland Clinic Heart Center--named the best heart hospital in the nation by US News & World Report eight times in the past decade--angioplasties have become so reliable that the number of open-heart surgeries performed is expected to drop 5 to 10 percent per year over the next decade. Moreover, increased trust in angioplasty is encouraging its use preventively, which is to say, on those many patients who have serious coronary-artery disease but are not yet at Imminent risk of a heart attack. The idea of prophylactic surgery--actually getting your body rearranged in some fairly major way merely in anticipation of a life-threatening problem--may strike you as a little creepy. But one reason that heart disease remains our number-one killer is that its treatment has always been reactive. New and better imaging devices, coupled with a simple day surgery like angioplasty, allow cardiologists to treat the disease proactively, preventing both heart attacks and the gruesome open-heart surgery that they call for.
IF I'M BEYOND ANGIOPLASTY, I'M HEADED FOR THE SLAUGHTERHOUSE, RIGHT?
Well, you're going to have to be opened up, but there's a good chance it won't be as brutal as it was for previous generations of heart-surgery patients. Over the past decade, minimally invasive bypass surgery has quietly become one of the most important breakthroughs in the treatment of heart disease. There are three key innovations that have made minimally invasive approaches both more effective and easier on the patients.
- Surgeons finally figured out that harvesting the saphenous veins from the lower legs for the revascularization of clogged coronary arteries was counterproductive in two ways. One was that it tended to leave a lot of heart-surgery patients almost crippled; the other was that the venous tissue--generally weaker than arterial tissue because it carries blood back to the heart at a much lower pressure than it is carried out by the arteries--tended to reclog within ten or fifteen years, necessitating another open-heart procedure.
About ten years ago, surgeons discovered that simply pulling over a section of one or both internal mammary arteries was not only simpler but also provided much sturdier bypass tissue. And if more than two bypasses were required, the radial arteries of the arms could be used. "We can provide a quadruple bypass using only arterial vessels, and nearby ones at that," says Cleveland Clinic's chairman of cardiovascular surgery, Dr. Delos M. Cosgrove. "It leaves the patient's legs intact and lasts up to twenty years."
- In many surgeries, a full sternotomy--the infamous splaying open of the rib cage to get at the diseased heart--is not required. In some cases, a semisternotomy is sufficient, which may not sound much better but reduces recuperation time considerably. And another approach, known as heart-port surgery, requires no cracking of the chest at all but rather invades the pericardium, where the heart rests, by removing a rib or two and slipping in a fiber-optic camera, which gives the surgeon as good a view of the heart as he might have if the chest were opened up. The surgery is then performed with microsurgical instruments. Such minimally invasive techniques cut recuperation time in half, which is much easier on the patient and the finances of the health-care system. Unfortunately, the procedures themselves can still be at least as expensive--if not more so--than traditional CABG, and heart-port surgery is still considered inappropriate for some multi-vessel bypasses.
- Many bypass surgeries are now performed on a beating heart, meaning that the patient is not placed on the heart-lung machine, which, while eminently effective at breathing and circulating blood for the patient so that the surgeon can operate on a completely stilled heart, has been associated with postoperative blood clots and strokes and, worse, long-term neurological damage, especially memory loss. According to Cosgrove, studies of beating-heart versus heart-lung-machine or cardiopulmonary-bypass surgeries at his institution have yet to produce a definitive advantage for the more au naturel approach, but "there seems to be a slight advantage in lack of complications and recuperation time." And a study performed by a consortium of heart-treatment facilities known as the National Heart Surgery Study Group investigators found "there is an overall benefit in off pump surgery related to operative mortality and early complications--especially in patients traditionally considered high risk for CABG."
SO CARDIOLOGY HAS JUST GIVEN UP ON TAKING THE KNIFE OUT OF TREATING HEART DISEASE?
Certainly it's gone more slowly than my doctor buddies predicted, and perhaps with good reason. Though open-heart surgery is among the bloodiest of operations, It is also quite effective: It can give heart-disease patients another fifteen years of life or more, and the mortality risk of the operation itself is less than 2 percent. This has made a lot of surgeons reluctant to look beyond it too seriously, even though patient--and potential patients--continue to clamor for less-traumatic approaches.
But cheer up. Some reel advances may be just beyond the horizon. At the Texas Heart Institute in Houston, scientists have been pursuing a new schema of heart disease, one that eschews the idea that heart attacks are caused simply by an accumulation of cholesterol-based plaque in the coronary arteries--like a clogged drain--and asserts that they're caused more by an inflammation of some of that plaque, which causes it to rupture and then form a blood clot, which is the true evil-doer in the heart-attack process. Moreover, they've discovered that often the most "vulnerable" plaque is that which is contained in the thinnest blockages, leading to one of the enduring mysteries of heart disease: the fact that about half of all heart attacks occur in arteries where the plaque is blocking no more than 50 percent of the vessel. Given this scenario, they have reasoned, the key to preventing heart attacks is identifying which portions of artery walls are most prone to this sort of rupture and medically or surgically reducing or eliminating the threat.
Working with other scientists, Texas doctors James T. Willerson and Ward Casscells have figured out the most vulnerable plaques are those that are most inflamed, and the most inflamed tend to be hotter than normal tissue by about 3 to 5 degrees. So they've devised a special catheter rigged with microscopic thermometers that can be eased into the coronary arteries to identify the hot spots.
The catheter is now in clinical trials and is probably several years from being in your cardiologist's bag of tricks. And, of course, even when he does have it at his disposal, he won't necessarily know what to do about those hot spots that he discovers. It's tempting to think that if we could just take care of wherever it is that's causing the inflammation, we'd have the magic bullet for heart disease. The problem is, the more science learns about the inflammation process in coronary arteries, the more complicated things get The interior walls of arteries can be inflamed by cigarette smoke, the oxidation of LDL (bad) cholesterol, hypertension, high levels of homocysteine or C-reactive protein, and certain viruses and bacteria that may be living in your system asymptomatically. It's doubtful that even the most obsessive-compulsive dieter, exerciser, and cholesterol and blood-pressure checker could keep all those variables stabilized, particularly since in many cases they are mediated by genes, not behavior.
Some doctors see the answer in earlier and better-targeted use of stents and statins (cholesterol-lowering drugs, which also seem to have an effect on inflammation), but that sounds a bit timid. Willerson and other scientists think they may have struck upon a new approach that has to do with exposing the inflamed tissue to... lasers. Willerson's idea is that if vulnerable plaque can be pinpointed by a heat-sensing catheter, it can be melted away by simply heating it just a bit with a laser attached to the same catheter. And a California biotech concern, Pharmacyclics, is testing the combination of a drug treatment with the intense light of a laser to effect apoptosis, or cell suicide, of plaque cells.
AREN'T THERE PLANS FOR SOME KIND OF INJECTION OR PILL WE COULD TAKE TO MAKE THE PLAQUE GO AWAY?
Some scientists are indeed heading in that direction. Among the new approaches is something called "chelation therapy" for clogged arteries. Chelation is generally used as a detoxification process. A substance is introduced to the bloodstream to attract and bind, say, excess lead that might be in the bloodstream because of exposure or ingestion, to help with its removal. The thinking is that chelation might be able to collect and bind the calcium that holds together arterial plaque, thus causing its dissolution.
Of course, the most promising noninvasive approach for attacking the disease is gene therapy, but that is in an embryonic stage. The idea is that dysfunctional genes--whether they're inherited or the product of environmental exposures or lifestyle or the aging process--are the foundation of heart disease. So, as with cancer, once the offending genes can be identified and marked--in this case, any genes ranging from those that regulate synthesis of LDL cholesterol to those that manufacture C-reactive protein to those that are involved in the complex processes of inflammation or blood clotting--they simply can be replaced with new, perfectly functioning ones. Another approach, now in clinical trials, is the injection of genes that stimulate the growth of new blood vessels, which could provide a "natural bypass." Also being investigated is the infusion of fresh stem cells from the patient's own bone marrow into the damaged heart tissue--cells that can then transform themselves into new heart-muscle tissue. Finally, researchers in Houston have begun to develop a kind of vaccine against heart attacks based on a medication that would instruct the body to slow its production of certain blood-clotting agents, thus reducing the prospect of an artery-blocking clot
All these procedures are years away from practical use. But be brave. "People forget that tuberculosis was once treated by surgery," Cosgrove points out. "Then streptomycin came along and it could stop the disease, and then preventive health maintenance came along and the disease disappeared. I would expect this to be the course with heart disease."
Meaning that if you are under fifty today, your future heart attack might be totally prevented by, relatively speaking, a pinprick--the promised land of almost bloodless surgery.