It has been as quiet as a heartbeat, but every bit as steady: Over the past generation of patients, progress in cardiac care has been little short of revolutionary.
Doctors today not only can restore more patients to health, they can make those patients healthier than before and do it in less time. And in the past few years, advances have been breathtaking.
“Treatment of coronary patients has changed completely,” Dallas cardiologist Sam DeMaio says. “If you’re operating today on the basis of 1995 technology, then you’re completely out of the mainstream–almost in the Dark Ages.”
In the old days–say, 20 years ago–open-heart surgery patients could take several months to recover, says Dr. Clyde Yancy, a cardiologist on the faculty of the University of Texas Southwestern Medical Center at Dallas. “Now everything is very different,” says Yancy, a member of the local, state and national boards of the American Heart Association.
“If we can identify someone who’s had significant disease before there’s damage to their heart, we can restore those people to better than they were before surgery,” says Dr. Kevin Wheelan, co-chief of cardiology at Baylor University Medical Center.
Advances have taken place over a broad front including surgical techniques, medication and postoperative therapy.
In the operating room, bypass surgery and angioplasty remain the staple procedures. But refinements in both are delivering better results, sometimes dramatically so.
Angioplasty was introduced in the late 1970s. With the patient sedated, the doctor inserted a balloon-tipped catheter in the femoral artery near the groin. The probe was inched up through the artery into the chest, where the balloon was inflated to compress the fatty plaque blocking the artery. In 1990, doctors added blades as an alternative to balloons to scrape the arterial walls clean. Excimer lasers also came into use for the same purpose about the same time.
But no matter whether balloons, blades or lasers were used, a big problem remained: re-stenosis, or reclogging of the artery. The problem wasn’t new plaque; it was actually injury to the artery walls caused by the first procedure. The artery responded by producing new cells, and the growth narrowed the artery walls.
In 35 percent to 50 percent of patients, the arteries blocked up again within six months. Patients also could have an artery suddenly collapse, posing the risk of a heart attack and requiring emergency bypass surgery.
Then came stents in 1994, and everything changed. After clearing the blockage, the doctor inserted these tiny stainless-steel mesh cylinders, which acted as scaffolds to help keep the artery clear. Re-stenosis rates were cut virtually in half. Stents have been improved since then.
“Today, you have to have a good reason not to put a stent in somebody [during angioplasty],” DeMaio says. Along with the reduction in re-stenosis, he says, the incidence of artery collapse and other dire consequences has fallen to less than 0.5 percent.
New technology promises a further dramatic drop in re-stenosis rates. DeMaio is one of the researchers who for the past several years has been studying the use of radiation in angioplasty. Tiny pellets inserted for 15 to 20 minutes during the procedure emit gamma rays at the point of the arterial lesion, halting the growth of new cells. In the study of about 5,000 patients, re-stenosis rates again have been halved.
The approach is not without drawbacks. The radiation seems to increase the risk of having a blood clot block an artery and cause a sudden heart attack. Researchers also have found that the inside of the artery tends to grow more, not less, at the edges of the irradiated area.
However, another promising new approach is called percutaneous myocardial transluminal revascularization–a fancy name for drilling holes in the heart with a laser. Fifteen to 30 2 mm holes are drilled about 5 mm into the heart muscle. It damages the muscle cells, but with good results: The cells release growth factors that cause new arterial capillaries to form, boosting the heart’s blood supply.
PMTR, which can be done without opening the chest, is especially promising for patients with angina (chest pain) whose anatomy makes them poor surgical candidates. Doctors hope to have Food and Drug Administration approval to move PMTR from experimental to general use by the start of 2001, DeMaio says.
For patients who arterial blockage is too extensive for angioplasty, bypass surgery remains the chief option. However, it has been considerably refined too.
In the past, patients routinely went on a heart-lung machine. It keeps the blood circulating and the lungs going while the heart is stilled for surgery, but it’s hard on the cardiopulmonary system. Recovery takes longer.
That has changed. “We’re doing bypass now on a beating heart,” Yancy says. The bottom line, he says: “You can anticipate a 50 percent improvement in post-op recovery time plus better healing.”
Surgeons don’t even have to open the chest to do bypasses any more. If only one or two arteries must be bypassed, they can operate through a narrow incision by remote control.
