PHILADELPHIA – Early aortic valve replacement surgery for patients with asymptomatic, severe aortic stenosis has been a controversial strategy, but the first randomized trial comparing early surgery with conservative management found that early-surgery patients had a 17-fold improved survival at 8 years, according to trial results reported at the American Heart Association scientific sessions.
Albeit small – 145 patients randomized to early surgery or conservative therapy – thetrial results provide important evidence to support early preemptive aortic valve replacement for patients with asymptomatic but severe aortic stenosis, said , of the division of cardiology, Asan Medical Center in Seoul, South Korea.
The trial randomized 73 patients to early surgical aortic valve replacement (SAVR) and 72 to conventional treatment. Baseline characteristics were similar between the two groups, with a mean EuroSCORE II of 0.9, peak aortic-valve jet velocity (Vmax) of 5.1 m/sec, and mean aortic-valve area of 0.63 cm2. Fifty-three conventional treatment patients went on to have SAVR when symptoms developed during follow-up. There were no operation-related deaths in either group, although one early surgery patient had a stroke and one conventional treatment patients had an MI during the operative period.
At a median follow-up of 6.2 years, 1 early-surgery patient (1.4%) and 11 conventional-therapy patients (15.3%) died from operative or cardiovascular death, Dr. Kang said (P = 0.003). “The number needed to treat to prevent one cardiovascular death within 4 years was 20 patients,” Dr. Kang said. At 4 and 8 years, the cumulative incidences of operative CV or death were 1.4% for both in the early-surgery group and 5.7% and 25.5% in the conventional-treatment group, Dr. Kang said (P = 0.003).
Rates of all-cause mortality were 6.8% and 20.8% (P = 0.030) in the respective groups. “The number needed to treat to save one life in 4 years was 16 patients,” Dr. Kang said. At 4 and 8 years, the cumulative incidence of any-cause death was 4.1% and 10.2% in the early-surgery patients and 9.7% and 31.8% in the conventional group (P = 0.018).
Among the trial limitations Dr. Kang acknowledged were that the population had severe AS with aortic velocity of 4.5 m/sec or greater. “The benefit of early surgery may be relatively smaller in asymptomatic patients with less severe aortic stenosis,” he said.
Not all patients had an exercise test to confirm their asymptomatic status, but as discussant, of Northwestern University in Chicago pointed out, “this is what we’re dealing with clinically.” Also the mean age of the patient population – 64.9 years – is relatively young, and they had a high incidence of bicuspid aortic valve, few comorbidities, and low operative risk, Dr. Kang said. “Thus, our study population is quite different from the populations enrolled in the TAVR [transcatheter AVR] trials, and the results of our study cannot be directly applied to early TAVR for asymptomatic severe aortic stenosis,” he said.
The mean age in both the PARTNER 3 () and EVOLUT ( ) trials comparing TAVR and SAVR in low-risk patients was 73.6 years, and they had higher rates of comorbidities than did the RECOVERY patients.
Dr. Bonow said the RECOVERY findings add to the PARTNER 3 and EVOLUT findings and raise the question about rethinking guideline indications for AVR in asymptomatic severe AS patients. “Should we be talking about moving our Vmax threshold down to 4.5 m/sec, or maybe increasing the Class IIa indications to Class I?” he said. “I think we need to wait to see more data to support these excellent results.”
However, most of these asymptomatic patients do eventually have surgery “in a very short period of time,” Dr. Bonow said. “So from a clinical management point of view, I think we already have the data suggesting that we could move the ball forward, and now we have these excellent outcome data from Korea as well.”
Results were published simultaneously in the New England Journal of Medicine (2019 Nov 16.).
Dr. Kang and Dr. Bonow had no financial relationships to disclose.