Conditions afflicting the blood vessels of the heart, also known as coronary artery disease or ischemic heart disease, currently affect 16.3 million Americans. Approximately 1.3 million new and recurrent cases occur annually, and a little over 40 percent of these involve women.
Although the mortality rate from coronary artery disease has declined by 34 percent over the last 10 years, ischemic heart disease remains the leading single cause of death in the United States and is responsible for one of every 4.8 deaths. Women in particular seem more vulnerable to the consequences of coronary artery disease. Recent statistics suggest that 1 in 3 women has some form of cardiovascular disease and that women represent 52.6 percent of all cardiovascular deaths. In fact, women are almost twice as likely to die from cardiovascular disease as from all forms of cancer combined. Moreover, 23 percent of women age 40 and older who have an initial heart attack die within one year compared to 18 percent of men. In part because women have heart attacks at older ages than men, they are more likely to die from them within a few weeks.
Like any muscle, the heart needs a constant supply of oxygen and nutrients to carry on its vital function. These nutrients are carried by the blood in the coronary arteries. Coronary artery disease most commonly occurs when cholesterol accumulates within the wall of the coronary arteries. This process, termed atherosclerosis, leads to the formation of cholesterol plaque that can gradually cause narrowing of the coronary arteries, thus decreasing the supply of oxygen to the heart. If not enough oxygen-carrying blood reaches the heart, the heart may respond with pain called angina. Under certain circumstances a cholesterol plaque may rupture and lead to the formation of an occlusive blood clot that completely cuts off the supply of oxygen-carrying blood to the heart, thus resulting in a heart attack.
The classic presentation of a heart attack involves chest pressure that may radiate to the neck or to the left arm. However, many people (especially women) do not experience these classic symptoms. Some may experience indigestion discomfort, which may be naturally attributed to acid reflux. Others may only experience sharp pains or even shortness of breath, which may unknowingly be attributed to other medical conditions. Women, and particularly diabetic women, are more likely to develop non-classical symptoms of a heart attack. Consequently, they are less likely to see a doctor for further evaluation and treatment, and when they do see a doctor, they are more likely to present later in the course of their symptoms. This may partially explain the increased cardiovascular mortality rate observed in women.
The diagnosis of a heart attack is typically made by specific blood tests as well as characteristic electrocardiographic (EKG) changes. Once a heart attack has been diagnosed, time is of the essence in treatment; the adage that “time is muscle” is particularly important in this situation since the earlier that treatment can be initiated the greater the amount of heart muscle that can be saved. The cornerstone of therapy is aspirin, which may reduce the risk of dying from a heart attack by up to 35 percent. Most hospitals across the United States will additionally treat heart attacks with clot-busting medications, called thrombolytics, to break up the causative blood clot in an effort to restore blood flow to the heart. Until recently, this was the primary modality of therapy at most centers. Unfortunately, thrombolytic therapy is not always successful and in some cases may increase the risk of major bleeding complications. Many hospitals now have the capability to treat heart attacks with angioplasty, also referred to as percutaneous coronary intervention (PCI).
Angioplasty first involves performing a diagnostic heart catheterization, a non-surgical and minimally invasive procedure intended to visualize the coronary arteries and localize the blockage responsible for the heart attack. Once the blockage has been identified, a small guiding wire is carefully positioned in the affected artery to serve as a “rail” onto which a balloon can be loaded and subsequently advanced to the site of the blockage. The balloon is then inflated to a high pressure, thus pushing the blockage aside and restoring blood flow through the artery. In most situations, the procedure is completed by deploying a stent at the original site of the blockage. A stent is a metal scaffold that helps keep the artery open and reduces the risk of re-narrowing of the coronary artery compared to balloon angioplasty alone. Although current stents are permanently incorporated into the coronary artery, newer bioresorbable stents are under development that will allow angioplasty to be performed without leaving permanent evidence of the procedure. Performed promptly, angioplasty can improve survival from a heart attack beyond that attributable to thrombolytic therapy.
The mainstay of treatment after a heart attack focuses on risk factor modification to reduce the risk of recurrent events. The principal targets of therapy include high blood pressure, high cholesterol, diabetes mellitus, smoking cessation, weight loss and exercise. Guidelines have been established by the American College of Cardiology and the American Heart Association with respect to target goals. With strict adherence to the guidelines, the risk of recurrent events can be reduced by up to 65 to 70 percent. Overall, vigilance is the key to successful outcomes.
Chandhiran Rangaswamy, M.D., F.A.C.C., is with Louisville Heart Specialists, The Physician Group at Jewish Hospital & St. Mary’s HealthCare. He earned an undergraduate degree from Speed Scientific School at the University of Louisville and his medical degree from the U of L School of Medicine. He completed his training in internal medicine at the Cleveland Clinic Foundation and received additional specialty training in general and interventional cardiology at the University of Michigan. Dr. Rangaswamy is a full-time faculty member at U of L. He is board certified in internal medicine, cardiovascular disease and interventional cardiology. He is a member of the American Heart Association and a Fellow of the American College of Cardiology. He can be contacted at 502-581-1951.