30% of bioprosthetic SAVR patients show valve degeneration within a decade
Bioprosthetic heart valves used in surgical aortic valve replacement (SAVR) procedures in the early 2000s demonstrated “satisfactory” durability, according to a single-center study published in the Journal of the American College of Cardiology. The rate of clinically significant structural valve degeneration (SVD) was 6.6 percent over a median 10-year follow-up, while 30.1 percent of patients exhibited subclinical SVD.
“Subclinical changes on echocardiography should probably alert clinicians about possible structural changes within the bioprosthesis warranting several considerations such as: 1) additional imaging tests to confirm/dismiss a more relevant SVD; 2) closer follow-up considering that the time period between subclinical and clinically relevant SVD remains unknown; and 3) a more aggressive therapeutic approach to address modifiable risk factors that promote atherosclerotic disease, which in turn may play a role in the progression of SVD,” wrote lead author Tania Rodriguez-Gabella, MD, with Quebec Heart and Lung Institute, and colleagues.
The researchers studied the long-term outcomes of 672 consecutive patients—61.5 percent male, mean age 72—who underwent SAVR with a bioprosthesis at their center from 2002 through 2004. Echocardiographic data was collected before hospital discharge and then again 10 years later in 87 percent of the patients still alive.
Sixty-four percent of all participants died within 10 years of follow-up, including 22.5 percent from cardiovascular causes. Older age, left ventricular dysfunction, atrial fibrillation, chronic obstructive pulmonary disease, greater body mass index (BMI) and diabetes were associated with an increased mortality risk.
The authors noted mortality rates were higher in their study than some other SAVR reports, likely because transcatheter aortic valve replacement (TAVR) wasn’t a popular alternative yet for the highest-risk patients when these procedures took place.
Higher BMI and the use of the Mitroflow valve (LinaNova, London) were independently associated with higher risks for clinically relevant SVD, which required aortic valve reintervention 83 percent of the time. The link between valve degeneration and higher BMI could be explained by lipoproteins triggering inflammatory responses in the cusps of valves, leading to calcification and deterioration, the authors wrote.
“The involvement of modifiable factors such as larger BMI and valve model in the process of SVD should stimulate further therapeutic efforts to improve valve durability,” they noted, adding the results should also be considered when evaluating long-term TAVR outcomes.
In an accompanying editorial, three cardiologists pointed out it is difficult to cut through the marketing hype of all the new valves coming onto the market and determine which ones are the most beneficial and why. Sometimes the data can’t keep up with the influx of new products, they noted, particularly when evaluating long-term issues like SVD.
“We are faced with rapid disruptive innovations in which novel devices can be used in clinical practice long before the real-world risk of SVD is apparent,” wrote Paul W.M. Fedak, MD, PhD; Deepak L. Bhatt, MD, MPH; and Subodh Verma, MD, PhD. “We must be prudent in our selection of a bioprosthesis—it is still a devilish disease. Therefore, it is imperative that we continually and objectively evaluate the long-term results of implanted aortic bioprosthetics.”
Considering most patients were of an advanced age and died before SVD was likely to become a problem, the editorialists said Rodriguez-Gabella et al.’s study demonstrated “an excellent durable result” for biological valves.
“The possible impact of the data for this rapidly emerging field of AVR is compelling,” they wrote. “As such, this study will serve as a critical benchmark for SAVR using a contemporary bioprosthesis. … Both patients and resource-challenged health care systems can benefit from the ‘one and done’ approach offered by a mechanical solution.”
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.