Zainal M. Hussain, MD, Cardiology
The Chester County Hospital and Health System
Published: February 11, 2013
Diabetes is fast becoming an epidemic. Its prevalence is largely being driven by obesity, which is also rampant in the United States. Diabetes and its associated complications, if left unchecked, will soon become the biggest killer of the 21st century.
According to data from the 2011 National Diabetes Fact Sheet, 25.8 million children and adults in the United States, or 8.3% of the population, have diabetes. Another 79 million people are prediabetic and at risk for developing the disease later. Adults with diabetes have a cardiovascular death rate that is up to four-fold greater than that of non-diabetics.
In the United States, it has been estimated that as many as 12.5 million diabetic patients may have coronary artery disease (CAD -- the progressive artery blockage that may eventually lead to heart attacks) but have no symptoms. In the absence of typical warnings such as chest pain, diabetic patients may suffer from reduced heart circulation more frequently than non-diabetics.
Chronically elevated blood sugar levels, insulin resistance, an abnormal amount of cholesterol and/or fat in the blood, high blood pressure, and cigarette smoking have all been associated with accelerated hardening of the arteries (atherosclerosis). Along with aggressive lifestyle modifications, diagnosis and risk assessment of diabetic patients with suspected CAD remains the key for prevention of cardiovascular complications.
A cardiac stress EKG is a well-established and inexpensive test for diagnosis and medical decision making; but adding either nuclear imaging or echocardiography creates even more accuracy in detecting obstructive CAD. An electron-beam CT scan to measure the amount of calcium in the coronary arteries is another way to assess the degree of blockage and therefore predict a cardiovascular event, such as a heart attack, as demonstrated in the research study called PREDICT (PRospective Evaluation of Diabetic Ischemic heart disease by Computed Tomography. The more calcium, the greater the risk.
In addition to CAD, diabetics more frequently have blockages in other arteries as well. Aggressive treatment with cholesterol -reducing drugs (such as statins), clot-preventing agents such as aspirin, as well as beta blockers and medicines called "ACE inhibitors" for high blood pressure remain the cornerstones of medical therapy in diabetic patients.
Many patients with CAD may eventually need treatment that restores blood flow through the arteries (also known as "revascularization") to reduce symptoms and improve overall survival. One-fourth of all coronary revascularizations performed in America are on diabetic patients, and the two usual options are Percutaneous coronary intervention (PCI) or coronary artery bypass grafting surgery (CABG). PCI opens arteries with a balloon or a metal stent placed via a catheter. In the past these procedures were often only temporarily effective, but over time the arteries might close again; thanks to the more recent and revolutionary innovation to add certain medications to the metal stents (turning them into "drug-eluting stents"), the chance of re-occlusion has been greatly reduced. CABG is open heart surgery that uses small sections of veins or other arteries to redirect blood flow around (that is, bypass) the obstructions. The choice of intervention depends on several parameters, such as clinical presentation (acute heart attack or stable CAD), coronary artery anatomy, heart muscle function, coexisting conditions and the patient's preference.
In summary, diabetes is a major risk factor for CAD that increases the risk of heart attack. Aggressive risk factor modification, early detection and appropriate treatment remain keys to preventing cardiovascular complications in people with diabetes.
This article was published as part of the Daily Local News Medical Column series which appears every Monday. It has been reprinted by permission of the Daily Local News.