Confirmed asymptomatic
AVATAR, conducted at nine centers in seven countries in the European Union, randomly assigned 157 adults with severe AS by echocardiography and a LV ejection fraction (LVEF) greater than 50% to early SAVR or conservative management. They averaged 67 years in age, and 43% were women.
The trial excluded anyone with dyspnea, syncope, presyncope, angina, or LV dysfunction and anyone with a history of atrial fibrillation or significant cardiac, renal, or lung disease. The cohort’s average Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score was 1.7%.
The 78 patients in the early-surgery group “were expected” to have the procedure within 8 weeks of randomization, the published report states; the median time was 55 days. Six of them ultimately did not have the surgery. There was only one periprocedural death, for an operative mortality of 1.4%.
The 79 patients assigned to conservative care were later referred for surgery if they developed symptoms, their LVEF dropped below 50%, or they showed a 0.3-m/sec jump in peak aortic jet velocity at follow-up echocardiography. That occurred with 25 patients a median of 400 days after randomization.
The rate of the primary endpoint – death from any cause, acute myocardial infarction, stroke, or unplanned HF hospitalization – was 16.6% in the early-surgery group and 32.9% for those managed conservatively over a median of 32 months. The hazard ratio by intention-to-treat analysis was 0.46 (95% confidence interval, 0.23-0.90; P = .02). The HR for death from any cause or HF hospitalization was 0.40 (95% CI, 0.19-0.84; P = .013). Any differences in the individual endpoints of death, first HF hospitalizations, thromboembolic complications, or major bleeding were not significant.
If early aortic valve replacement is better for patients like those in AVATAR, some sort of screening for previously unknown severe aortic stenosis may seem attractive for selected populations. “Echocardiography would be the screening test for aortic stenosis, but it’s fairly expensive and therefore has never been advocated as a test to screen everyone,” Dr. Pellikka observed.
“But things are changing,” given innovations such as point-of-care ultrasonography and machine learning, she noted. “Artificial intelligence is progressing in its application to echocardiography, and it’s conceivable that in the future, there might be some abbreviated or screening type of test. But I don’t think we’re quite there yet.”
Dr. Banovic had no conflicts; disclosures for the other authors are in the report. Dr. Delgado disclosed speaker fees from Edwards Lifesciences, Abbott Vascular, Medtronic, Merck, Novartis, and GE Healthcare and unrestricted research grants to her institution from Abbott Vascular, Bayer, Biotronik, Bioventrix, Boston Scientific, Edwards Lifesciences, GE Healthcare, Ionis, and Medtronic. Dr. Pellikka disclosed receiving a research grant from Ultromics and having unspecified modest relationships with GE Healthcare, Lantheus, and OxThera.
A version of this article first appeared on Medscape.com.