By Janna Jones Coleman
New trends in cardiac catheterization and the use of cardiac calcium scoring help cardiologists diagnose and treat cardiovascular disease. Well-Being spoke with the University of Mississippi Medical Center’s Dr. Cameron Guild, who is board certified in cardiovascular disease and interventional cardiology, to learn more about these techniques.
What’s New in Cardiac Catheterization
“Cardiac catheterization is most commonly used to evaluate heart arteries for blockage when there is compelling evidence that such might exist,” Dr. Guild explains. “A very small, hollow tube called a catheter is inserted through the skin through an artery and guided to the heart. Dye is injected into the arteries that supply the heart with blood to look for blockages.”
Cardiac catheterization can also measure pressures in the heart to help manage heart failure or evaluate for other disorders. Additionally it is used to cure or alleviate many of the conditions it diagnoses, such as opening blocked arteries, closing coronary holes and improving valve function.
In recent years, several small but significant improvements have led to increased safety in the procedure. Smaller devices are used to accomplish tasks that once required larger holes in the arteries. Closure devices have decreased the time spent holding pressure on the artery used as an entry point, and contrast agents are safer.
“However, the biggest game changer has been radial artery catheterization, which allows us to do most procedures formerly done through the groin through the wrist,” notes Guild. “This technology has been available for over a decade but has just recently been streamlined enough to avoid many of the challenges that complicated it in the past.”
Radial artery catheterization has benefits from both the patient’s and physician’s standpoints. Comfort is a major concern for patients, and access from a wrist artery causes minimal discomfort, as the artery is close to the skin’s surface. After the procedure, an inflatable wristband is used to stifle bleeding, and the patient is able to sit up or walk around.
“This is in stark contrast to groin access, where getting into the artery is often somewhat more uncomfortable, with prolonged holding of pressure on the site after the procedure to keep it from bleeding. Patients can also expect two to four (or more) hours of lying flat in bed to make sure the artery doesn’t start bleeding again,” says Guild.
Reduction in bleeding is the biggest benefit to radial access for doctors. While patients once stayed overnight to be monitored for bleeding complications, they can now be discharged later the same day following radial access catheterization.
Several factors help decide if catheterization will be done through wrist or groin access. Physicians who are more comfortable with performing cardiac catheterization through groin access often continue to do so. While over 90 percent of procedures can be performed via radial access, the groin approach is more appropriate when the equipment needed is too large for the wrist or if the patient’s arteries present certain anatomical challenges.
Coronary Calcium Scoring
Coronary calcium scoring uses a CT scan to measure the amount of calcium present in coronary arteries. The concept behind this technology is based on the fact that blockages, which form in the heart arteries, consist of calcium that has gradually become calcified by the body. The more blockages that one has, the more calcium will be present. The quantity of calcium found in a patient’s coronary arteries is compared to a similar age group of healthy people. A higher amount of calcium implies above average plaque buildup and an increased risk for heart attack.
The use of coronary calcium scoring has yet to gain widespread acceptance in diagnosing coronary artery disease. Doctors question whether the procedure is better able to predict future heart attacks than traditional risk factors, such as diabetes, age and hypertension. They also debate whether the results influence patient management. High calcium does not imply that severe blockages are present; the majority of plaque often lies outside the artery wall and does not reduce blood flow. However, higher amounts of calcium mean higher amounts of plaque, thus more opportunities for future blockages to form.
“Overall, cardiac CT scoring has been found by many to be a useful adjunct in predicting risk of heart attack (but not in diagnosing whether the heart arteries are blocked). It has yet to gain acceptance as a standard study in the routine evaluation of patients for coronary artery disease,” Guild said. “Like most new technology, it likely has a very useful application which will be better determined in the near future. Until then, we use it on a case-by-case basis.”
Cameron Guild, M.D., is a Jackson native. He attended medical school at University of Mississippi Medical School, completed his residency at Vanderbilt University and a fellowship in general and interventional cardiology at the Medical University of South Carolina in Charleston. Dr. Guild has been on staff at UMMC for six years. His special interests are in structural heart disease, coronary artery disease, and radial artery catheterization and intervention.