The number of patients undergoing surgical aortic valve replacement (SAVR) to treat severe aortic stenosis (AS) has decreased dramatically in recent years, according to new research published by The Annals of Thoracic Surgery.[1] As one might expect, this is primarily due to the ongoing rise of transcatheter aortic valve replacement (TAVR), especially among patients 80 years old and older.
Clinical outcomes after SAVR are as strong as ever, however, and it remains a vital treatment for certain patient populations, including those with bicuspid aortic valves (BAVs).
The study’s authors explored data from more than 200,000 patients who underwent first-time SAVR for severe AS from 2012 to 2022. All data came from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS-ACSD).
Overall, annual SAVR volume decreased by a whopping 44.5% from 2012 to 2022. Over the course of the study, the number of patients younger than 65 years old undergoing SAVR actually increased by 13%. The number of SAVR patients between the ages of 65 and 79 dropped 60%, however, and the number of SAVR patients 80 years old or older dropped by 96%.
On the other hand, more patients with BAVs are being treated with SAVR than in the past. BAV patients now make up more than 45% of all patients who undergo SAVR. The number of BAV patients younger than 65 years old increased by nearly 50% and steady growth was also seen for all other age groups. BAV patients were less likely to present with diabetes, renal dysfunction or atrial fibrillation (AFib), researchers noted, and they faced lower risks of death or post-treatment stroke than traditional tricuspid aortic valve (TAV) patients.
“These findings suggest that future recalibrations of the STS-ACSD risk model should account for aortic valve morphology in predicting risk-adjusted outcomes, especially since BAV patients now comprise almost one-half of all patients undergoing SAVR,” wrote first author Christopher K. Mehta, MD, a cardiac surgeon with Northwestern Medicine, and colleagues. “In our sub-group analysis of patients without preoperative AFib or aortic root enlargement, the observed mortality and stroke rates remained excellent, especially for BAV patients.”
Mehta et al. highlighted why cardiologists and other members of the heart team may want to select SAVR over TAVR when treating patients with BAVs. It is unclear how effective a transcatheter approach is for these patients, they explained, making SAVR much easier to recommend when patients present with BAV AS.
“The role of TAVR as the initial treatment for BAV AS remains controversial and understudied, they wrote. “The long-term durability of TAVR valves is not yet elucidated and pivotal TAVR trials excluded patients with BAV. Bicuspid anatomy is heterogeneous with variable morphology, annular shape, degree of valvular calcium burden and amount of raphe calcification. Excess leaflet calcium, calcified raphes and left ventricular outflow tract calcification can increase the risk of periprocedural complications and midterm mortality. The increased rate of pacemaker implantation is also a limitation of TAVR.”
The researchers also noted that mortality rates remain low for patients after SAVR. The observed-to-expected (O/E) ratios based on STS-predicted mortality risks were 1.02 for patients younger than 65, 1.00 for patients aged 65 to 79 and 0.99 for patients 80 years old and older. BAV patients had consistently lower O/E ratios than TAV patients.
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Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.