SAVR Outcomes Improve Even as Population Ages

When it comes to performing complex valve surgery, experience is important – and Cleveland Clinic surgeons are among the most experienced in the world.

Aortic valve disease is the most common acquired valvular disease in elderly patients, with 5 percent of patients over age 80 diagnosed with aortic valve disease, according to Lars Svensson, MD, PhD, Chairman of the Sydell and Arnold Miller Family Heart & Vascular Institute at Cleveland Clinic.

As 77 million baby boomers retire, Dr. Svensson says the number of patients seeking treatment for this disease will increase. Despite the increase in the proportion of higher risk patients – defined mainly by advanced age, pulmonary function and kidney function contributions to the Society of Thoracic surgery (STS) Risk Model – Dr. Svensson notes that mortality rates are decreasing for surgical patients.

In a study of outcomes after surgical aortic valve replacement (SAVR) in 141,905 patients who underwent isolated primary SAVR from 2002 to 2010, researchers found that nearly 80 percent of patients have outcomes superior to the STS predicted risk models. Early results from the most recent patients showed further improvement in medium- and high-risk patients.

The reason? Advancements in preoperative assessment, intraoperative expeditious and advanced surgical techniques, and intensive postoperative care all contribute to improved SAVR outcomes in these elderly patients.

“We had to take on patients in research studies we hadn’t always operated on in the past,” Dr. Svensson explains. “As we did that, we had to step up our ability technically to deal with more complex operations, and also deal with a much larger geriatric population. We had to learn to deal with fragile tissues in fragile patients, get them through the more technically demanding operations, and handle poor nutritional reserve. These were all important factors to address.”

Dr. Svensson noted that mortality rates for isolated aortic valve procedures performed at Cleveland Clinic in the last four years proved considerably better than STS data.

“We pretty consistently run a risk of death one-quarter to one-third of the expected mortality rate from the STS calculations,” he says, adding that the average STS hospital site performs 23 aortic valve procedures annually, while the average U.S. surgeon performs eight. In contrast, Cleveland Clinic surgeons perform about 2,600 mitral and aortic valve operations annually. “When it comes to doing complex valve surgery, experience is very important.”

For the last four years the respective mortality rates for isolated aortic valves, irrespective of risk, have been 0.6 percent, 0.4 percent, 0.7 percent and 0.5 percent. For the first five months it is 0.6 percent. Back in 2006, Cleveland Clinic surgeons started the first two studies in the United States on a new percutaneous valve procedure through the groin and chest wall. The results of these types of procedures proved extremely good in some categories of patients.

Dr. Svensson says Cleveland Clinic surgeons and cardiologists made great advances in percutaneous aortic valve techniques, including valve in valve. This is relevant to younger patients who typically ask for biological valves to avoid blood thinners. The second surgery involves potentially placing a new valve within the previously implanted valve. Cleveland Clinic surgeons are now also doing these types of procedures for mitral valves.

Another promising option Dr. Svensson has researched for 14 years involves placing a balloon in a leaking mitral valve. He says early human studies are promising.

Other studies are looking at replacing the mitral valve in patients with severe mitral valve disease by using stented valves. This is a similar technology used for aortic valves that involves using a wire mesh tube containing valve leaflets to replace the old valves. Dr. Svensson says the procedure is more complicated for mitral valve replacement, but it’s an ongoing area of research.