In the past two decades, published research has suggested that the prevalence of thoracic aortic disease (TAD) has tripled. This finding is largely attributable to the growing elderly population and increased physician awareness. Historically, physicians and surgeons often believed that TAD was a rare condition that was only to be considered as a diagnosis when patients were extremely ill or deceased. Additionally, imaging technologies have improved significantly, especially in the last decade. They have become less expensive and more accessible in hospitals across the United States. As a result, more cases of TAD are being detected than ever before.
A New Scientific Statement
The American Heart Association (AHA) has released a review of recent research related to descending TAD with a specific focus on open versus endovascular approaches to repair. The goal of the AHA statement, which was published in the June 2010 issue of Circulation, was to review current approaches and their associated outcomes so that physicians have the data they need to utilize evidence-based recommendations for treating patients with TAD. “We now realize that the current prevalence figures are likely the most accurate we’ve ever seen and are significant,” explains John S. Ikonomidis, MD, PhD, a co-author on the AHA statement. “They underscore the importance of the advances in the knowledge that we have with regards to the causes, diagnostics, and treatment strategies for TAD.”
“If physicians have patients with descending TAD, they should refer them to cardiovascular surgeons with specific expertise in the area of TAD”
With the increase in information on open and endovascular treatment of TAD, it is important to provide physicians with a better understanding of the pathophysiology of the disease process. The AHA statement also reviews the current outcomes and potential technical pitfalls associated with the available therapies. Two previous statements have outlined guidelines for the diagnosis and management of TAD. Dr. Ikonomidis says the new AHA statement sets itself apart from these previous statements because it focuses specifically on the descending thoracic aorta and on the current results of open surgical repair, endovascular approaches, and medical management. The statement also addresses overall risk assessments and complications associated with TAD (Table 1).
A Look at Various Approaches
In the past, the gold standard treatment for TAD has been open surgical repair because of the wealth of data available on long-term results. While high-volume aortic centers have seen significant improvements in morbidity and mortality rates and positive outcomes following surgical repair, a less invasive, endovascular approach has become more appealing in recent years. The endovascular approaches offer promising results, especially for older patients and those with comorbid illnesses, because many of these people are unsuitable for conventional open repair. “Thoracic aortic aneurysms (TAA) are more common as people age,” says Dr. Ikonomidis. “The use of endovascular repair may provide a good alternative to traditional surgical repair for these individuals.” The AHA statement provides recommendations for surgical intervention in patients with TAA (Table 2).
The AHA scientific statement notes that the durability of endovascular repair of the thoracic aorta remains largely unproven and more research is necessary. There has yet to be a prospective randomized trial comparing open and endovascular thoracic aortic repair that provides long-term durability data, Dr. Ikonomidis says. The FDA has approved three thoracic-aortic endografts that have demonstrated good durability 5 years after implantation. However, long-term data on the true durability characteristics of these devices is lacking. “The original deployment of these devices was in older patients who weren’t good candidates for open surgical repair,” says Dr. Ikonomidis. “Many of these patients died before the devices were in long enough for the necessary follow-up. These devices have only recently been used in a patient population that is likely to live long enough for adequate tracking. Continued follow-up of these patients is critical to determining how well they perform over the long haul.”
More to Come
According to Dr. Ikonomidis, the most recent AHA scientific statement is designed to assist physicians in making evidence-based treatment decisions, improve how patients are managed, and establish which patients should be referred onto specialists. “A referring physician should use the document, learn characteristics of patients presenting with descending TAD, and understand the different options that are available, including open repair, endovascular repair, and medical management,” he says. “If physicians have patients with descending TAD, they should refer them to cardiovascular surgeons with specific expertise in the area of TAD, especially if they’re unsure of the appropriate treatment options. In the future, we’re hoping more research will emerge on the causes of TAD as well as on the long-term efficacy and safety of endovascular approaches.
JonN