MATTERS OF THE HEART

By JEFFREY KLUGER AND MICHAEL D. LEMONICK

The heart may be fickle, but the science of keeping it healthy can be even more so. Every year experts come up with new insights into how to keep the cardiac system ticking. Sometimes the eurekas are justified, sometimes not. The annual meeting of the American Heart Association in Florida last week was so full of news it was hard to keep the breakthroughs straight. Here are the highlights:

WHEN GOOD CHOLESTEROL ISN'T

The "good cholesterol" you hope will turn up in your blood test has that name for a reason. More properly known as high-density lipoprotein (HDL), it can prevent the damage done by its evil twin, low-density lipoprotein (LDL). The latter clogs blood vessels by combining with oxygen to form a substance that sets off alarms in the immune system. White blood cells rush to attack it, and the whole mess forms into sticky globs called plaques that cling to vessel walls like mineral deposits in a water pipe. When these deposits break off and blood clots around them, the flow can shut off entirely, leading to heart attack or stroke.

HDL is good because it keeps LDL from combining with oxygen in the first place. But doctors at UCLA studying HDL in mice have found that when the immune system is under stress--after surgery, for example, or during a major infection--HDL stops producing an enzyme called paraoxynase and thus loses its antioxidant properties. When good cholesterol goes bad, moreover, it goes really bad. Not only does it stop protecting the body against LDL, but it also seems to goad the immune system into forming plaques even more quickly.

The new insight into what makes good turn bad might help doctors make good cholesterol even better. It may also point the way to better drugs and explain why aspirin helps prevent heart attacks. Besides its well-known action of thinning the blood and making clotting less likely, aspirin may also tone down the inflammation that leads to plaque formation.

ROLLING THE DICE

Living through a heart attack has always been something of a crapshoot, and now that seems almost literally true. According to a new study, patients experiencing cardiac arrhythmia have a better chance of surviving if the crisis occurs in a casino or even an airplane than in a doctor's office. The reason? Most doctors just aren't equipped to handle the problem.

Physician Mary Ann Peberdy of the Medical College of Virginia conducted a survey of 93 doctors' offices to determine how many of them had a heart defibrillator on hand. The answer turned out to be not many. Of the 51 offices that responded, only six had bothered to purchase the $3,500 piece of equipment, and only three had a nurse on staff trained in cardiac life support. By contrast, Las Vegas casinos--rarely regarded as oases of good health--are increasingly making it a point to have defibrillators and medical teams on-site at all times.

"Airlines are putting defibrillators on planes," says Peberdy, "and one Las Vegas casino recently saved three people with cardiac arrest." For the medical community, better cardiac preparedness could come relatively cheap. Last year Peberdy saw to it that all five buildings at her medical school were provided with defibrillators and teams of nurses trained to use them. The cost: about a nickel per paying patient.

DRILLING THE HEART WITH LASER BEAMS

When patients die of cardiac disease, the problem is often not that the heart has been denied blood but that it's been denied oxygen the blood carries. Lately, surgeons have experimented with a novel solution: drill some holes and let in some air.

In one of the most extensive tests of the technique to date, physicians at St. Vincent Hospital in Indianapolis, Ind., studied 160 patients suffering from angina, or heart-related chest pain. For about half the patients, they used traditional treatments, consisting largely of a complex menu of drugs. On the other half, they tried the new approach.

Opening the patients' chests, surgeons used a laser to sear dozens of 1-mm holes in the left ventricle, allowing blood to seep up from the pumping chamber and supply tissue with oxygen. Of the patients who received the surgery, 86% enjoyed a reduction in symptoms; of those who didn't, 12% improved. While the treatment is experimental, it could have a big impact: in the U.S., 100,000 people each year are driven to their beds--or their deaths--by angina.

GENETIC DETOUR

Once fatty plaque deposits have built to dangerous levels in blood vessels, standard treatments include bypass surgery--grafting detours around the blockages--or balloon angioplasty, in which deposits are squashed into vessel walls by a tiny expanding balloon. But doctors at St. Elizabeth's Medical Center in Boston have been testing a new, much less invasive therapy. They took eight patients with clogged vessels in their legs (a condition that can lead to gangrene and amputation) and injected them with genetic material--the same gene that governs blood-vessel growth in embryos. In 8 out of 10 blocked legs, blood flow improved, and in all but one of those, angiograms showed the improvement was due to new blood vessels that appeared at the site of the blockage, offering the blood a detour. The therapy may help some of the 200,000 Americans with severe leg-vessel problems--and if it helps heart vessels the same way, it could benefit the millions with coronary-artery disease as well.

A FISHY THERAPY AND A VEGGIE RED HERRING

There's little doubt that a diet high in meats and saturated fats can boost levels of bad cholesterol. What isn't so clear is whether the obvious alternative--a vegetarian diet--is the best way to keep the stuff to a minimum. A landmark study of East African Bantu people seemed to show that it wasn't: one group, which lived near a lake, ate huge amounts of fish and almost no meat; the other, which didn't, was vegetarian. The vegetarians, it turned out, had higher blood levels of lipoprotein "a," one of whose components is LDL, the bad stuff.

Still, a question remained. An individual's genetically determined blood chemistry is known to influence how much of this lipoprotein is present in the blood. Could it be that the vegetarians had bad chemistry to start with? The answer, it turns out, is no. A new analysis by a joint U.S.-Italian team shows that even when you correct for genetic differences, the fish eaters have an average 40% lower level of this particular lipoprotein. One study isn't definitive, of course. But it suggests that having that extra piece of red snapper can't hurt, and might even help.

AN OUNCE OF CARDIAC PREVENTION

It's not only people with significantly elevated blood fats who could benefit from treatment. New research suggests that even those with healthy blood might want to take aggressive steps to ensure that it stays that way.

In a sweeping study, more than 6,600 people with average total cholesterol of 220--just above the optimal 200--were placed on a cholesterol-lowering regimen of diet and exercise. Additionally, half took daily doses of the cholesterol drug pravastatin, while the other half took a placebo. After five years, the group taking the real drug was 36% less likely to have suffered a first heart attack and 33% less likely to have needed coronary bypass or angioplasty. What's more, their bad LDLs had fallen 25% while their good HDLs had risen 6%.

The results, though dramatic, have met with some skepticism. The study was funded by Merck & Co., which sells pravastatin under the name Mevacor. Regular Mevacor treatments can cost $1,200 a year, and with 8 million people in the U.S. having slightly elevated cholesterol, Merck could have a huge new market. For now, however, doctors are impressed, concluding that what's good for Merck could also be good for patients.

SEX UNDER PRESSURE

Tell most people that their health will suffer if they don't get their blood pressure down, and they respond with a shrug. But tell them their sex life will suffer? That gets their attention. In some men, blood-pressure drugs may lead to difficulty achieving erection and ejaculation, but few hypertensive women complain about sexual problems. According to a study by Bassett Healthcare in Cooperstown, N.Y., however, women with hypertension had a harder time achieving adequate vaginal lubrication and orgasm than women with normal blood pressure. Curiously, this was the case regardless of whether the hypertensive women took medication or not.

How blood pressure depresses sexual function is unclear; why men and women react differently to medication is murkier still. The only thing certain from the study is that with hypertension a leading cause of heart attack and stroke, the first priority is still to get the pressure down.

--By Jeffrey Kluger and Michael D. Lemonick