The FDA approved two types of devices for transcatheter aortic valve replacement (TAVR) after determining they were better than standard therapy for inoperable patients and an alternative to open surgery in high-risk patients. Nonetheless, this generally elderly patient population poses challenges and there are still potential missteps that could derail TAVR. Patient selection tools, 3D imaging and other approaches may minimize the likelihood of complications and poor outcomes occurring.
The frailty factor
Patient selection may not be the be-all, end-all for achieving good outcomes with TAVR, but it can go a long way toward maximizing the chances. Identifying those patients with severe aortic stenosis, whether inoperable or at high surgical risk, who truly will benefit from the procedure is critical to success. But given the patient population, physicians may wrestle with myriad clinical and patient factors when making their assessments.
“The centers and teams evaluating patients for transcatheter aortic valve replacement are recognizing more and more the complexity of these patients,” says Brian R. Lindman, MD, MSCI, of Washington University School of Medicine in St. Louis. “We have patients who we’re evaluating in their 80s and 90s who have multiple comorbidities. Not only that, in many cases they are frail.”
Valve options in the U.S.
The FDA so far has approved three transcatheter aortic valve replacement devices by two companies.
Sapien Transcatheter Aortic Valve
In PARTNER I (Placement of Aortic Transcatheter Valve), the pivotal trial for Edwards Lifesciences’ Sapien valve, patients in the inoperable cohort were a mean age of 83.1; 92.2 percent had New York Heart Association (NYHA) class III or IV symptoms; 21.2 percent had oxygen-dependent chronic pulmonary obstructive disorder; and 18.1 percent were considered frail (N Eng J Med 2010;363:1597-1607). The mean age for patients in Medtronic’s extreme risk trial for its CoreValve device was 83.2 years; 92 percent were NYHA class III or IV; 23.5 had severe lung disease; and many were frail (J Am Coll Card 2014;63:1972-1981).
“When we talk to these patients, it is clear that they don’t feel well but it is not so clear how much of their quality of life is influenced by their valvular stenosis,” Lindman says. “We are trying to weigh, does this patient have severe aortic stenosis as the dominant cause of their poor health status or is the dominant cause for their poor health status their clinical and geriatric comorbidities?”
Lindman and colleagues offer a framework for assessing TAVR candidates based on clinical risk stratification, geriatric risk stratification, expected clinical benefit and patient preferences and goals (J Am Coll Cardiol Intv 2014;7:707-716). Clinical risk factors—a very high Society of Thoracic Surgeons score, severe concomitant valve disease, comorbidities and the like—have been emphasized in the past but physicians may not recognize the importance of geriatric risk factors. Those include frailty, impaired mobility, disability, low muscle mass, cognitive impairment and mood disorders.
Frailty may be the tipping point between good and bad outcomes in some patients. Candidates may appear low risk for TAVR based on clinical factors but their frailty may leave them with little reserve during recovery, Lindman says. “We are recognizing more and more that these issues that fall under the umbrella of frailty are important to try to more objectively characterize so that we can better estimate and anticipate risk and potential benefit of these procedures.”
Looking beyond survival
Survival alone may not be the ultimate goal for patients seeking TAVR, some physicians argue. Very elderly patients may value quality of life over longevity, wishing to get the best out of their remaining time with family and friends. TAVR that extends life but at the cost of a poorer quality might seem a bad tradeoff. Physicians have reliable tools to navigate