Simply put, coronary artery disease is the buildup and obstruction of an artery of the heart because of deposits of cholesterol and fat within the artery. A blocked artery limits the flow of the blood supply to the heart muscles, which in turn could cause heart-related problems and, in severe cases, death.
When a person has coronary artery disease (CAD), he will have an episode referred to as "angina," which includes discomfort, pain, tightness or pressure in the chest. Other symptoms include nausea, vomiting, heartburn, profuse sweating, shortness of breath, as well as pain in the arm, back, neck or jaw. Highly susceptible to this condition are males (females are said to be protected by hormones but the risk starts closing in after menopause), those who have hypertension, diabetics, smokers, those who are overweight and those with a family history of the disease.
"Coronary artery disease is the single most important killer in the world, especially in developed countries," declares Dr. Tan Huay Cheem, a senior consultant cardiologist of the National University Hospital of Singapore, who was in town recently for the Annual Scientific Sessions in Cardio-Pulmonary Medicine organized by the Philippine Heart Center Medical Alumni Society Inc. in connection with the Philippine Heart Center’s 29th anniversary.
"Next to cancer, CAD is the No. 2 killer in Singapore, which is a cause for about 25 percent of mortality among Singaporeans every year," says Dr. Cheem, president of the Singapore Cardiac Society.
According to recent studies, CAD affects "five million people worldwide and an estimated 1.28 million Filipinos have varying degrees of CAD, with heart-related diseases being the No. 1 cause of death among Filipinos."
In Dr. Cheem’s experience, heart attacks can happen at any age. His youngest patient, he says, is 21 years old and the oldest, 100 years old. "Fifteen percent of people in Singapore who suffer from heart attacks are less than 45 years old. Most people who develop this disease at a young age are either smokers and have a family history," he says.
Dr. Fabio Enrique Posas, chairman of Cardiovascular Research of the Heart Institute of St. Luke’s Medical Center, notes that drug abuse is one of the leading factors of heart attacks among young Filipinos in the 22-28 years age bracket. He adds that most individuals who develop heart attacks never had symptoms, which makes awareness about the disease, having a healthy lifestyle, and regular medical checkups important practices to follow.
"It’s the job of our health care system to educate individuals to recognize risk factors and look for physicians who could provide the necessary care," says Dr. Posas.
As the saying goes, prevention is better than cure, and this both doctors couldn’t emphasize enough. Besides, they point out that coronary artery disease is a progressive disease, meaning don’t bet on being completely cured. The best that medical science can do is to prevent the disease from worsening either via a bypass surgery or using the latest state-of-the-art technology.
"What we can do is make people’s lives better, decrease their symptoms, improve their functions and also improve the quality of life," says Dr. Posas.
There was a time when bypass surgery was the only answer to many a CAD patient’s woes. A heart bypass involves sewing in a blood vessel taken from either the chest or leg to the heart to "bridge over the blockage." With the advent of new technology, patients could opt for less severe methods of treatment such as angioplasty. Balloon angioplasty is one such treatment involving the insertion of a balloon between a clogged artery. The inflated balloon then pushes the fatty plaque back against the artery wall to allow normal blood flow once again. An expandable stent, a wire mesh tube, may also be inserted and acts as a scaffold to hold the plaque against the artery walls.
"This concept of dilating a blocked artery was conducted by Swiss physician Andreas Gruentzig, but the greatest breakthrough came in 2000 with the first ever drug-eluting stent," says Dr. Cheem.
The problem with stents, says Dr. Cheem, is that after six months, there is a big chance for the artery to become narrow again. The reason? It seems that implanting a stent causes injury to the vessel wall and whenever there is an injury, scar tissues form, or what doctors term as restenosis. "When you have excessive scar formation, which happens to 30-40 percent of patients, this causes a renarrowing of the artery, thus limiting blood flow once again," explains Dr. Cheem.
With the introduction of drug-eluting stents, such as the Cypher Sirolimus-eluting Stent, the chances of restenosis are greatly reduced. A drug-eluting stent is equipped with a "medicine-coated mesh tube that props open clogged arteries and releases a drug designed to help keep scar tissue from forming and re-clogging the arteries."
"Three to four months later, the stent is no longer there for the body has already incorporated it into the vessel wall," points out Dr. Posas.
Unlike a bypass, which could take hours, a simple angioplasty could be over in 10-15 minutes, with the patient fully conscious. Although this can be done multiple times, Dr. Posas says that this is no excuse for one to revert to his unhealthy lifestyle. Successfully done, angioplasty enables a patient to go back to his usual functions.
Like all new treatments, the cost of a drug-eluting stent could be a bit steep, compared to having a bypass surgery. But in the long run, spending a bit more for this procedure could be more cost-efficient than having to spend for all those medicines to control the symptoms. However, drug-eluting stents are not a replacement for bypass surgery as these two procedures could complement each other. For instance, a patient who once had a bypass and has suffered a renarrowing could opt for angioplasty next time or, if the arteries are severely damaged, bypass is the best choice.
Dr. Cheem says, "People always worry about three things – efficacy of the treatment, safety of the device and cost." So far, he adds, he hasn’t heard of any side effects among patients who were implanted with the drug-eluting stents three years ago.
As far as Dr. Posas is concerned, the country’s educational system plays a vital role in making people aware of the symptoms of CAD, and having physicians who can recognize these symptoms and realize that these patients can indeed be helped, especially with the latest drug-eluting stents, decreases the incidence of mortality among CAD patients.