Valve Surgery Bests 'Watchful Waiting' in Asymptomatic Patients with Severe Aortic Stenosis

October 20, 2015

SAN FRANCISCO, CA — Registry data from Japan showed that an aggressive strategy of aortic-valve replacement (AVR) in patients with severe aortic stenosis but without symptoms results in better clinical outcomes than a more conservative "watch-and-wait" approach[1].

Presented last week at TCT 2015 by lead investigator Dr Tomohiko Taniguchi (Kyoto University Graduate School of Medicine, Japan), and published simultaneously in JACC: Cardiovascular Interventions, the data showed the 5-year rate of all-cause mortality was 15.4% among patients who underwent surgery and 26.4% among those treated conservatively (P=0.009).

Dr Tomohiko Taniguchi

In addition to the reduction in all-cause mortality, the researchers also showed that AVR was associated with a significant reduction in hospitalizations for heart failure. At 5 years, the rates were 3.8% in the AVR-treated patients compared with 19.9% among those who were treated with a strategy of watchful waiting (P<0.001).

"Despite clinical indications, the long-term outcomes of asymptomatic patients with severe aortic stenosis was dismal when managed conservatively in real-world clinical practice," Taniguchi told the media during a press conference announcing the results. Outcomes, he believes, could be substantially improved with an initial AVR strategy.

The data are taken from the Japanese Contemporary Outcomes after Surgery and Medical Treatment in Patients with Severe Aortic Stenosis (CURRENT-AS) registry. In the analysis, the researchers studied 1808 patients with severe stenosis who were asymptomatic, of whom 291 underwent AVR and 1517 were managed conservatively. To account for differences in baseline characteristics—the AVR patients were younger, had fewer comorbidities, and had a lower Society of Thoracic Surgeons (STS) risk score, among other variables—the 291 AVR-treated patients were propensity-matched with 291 patients in the conservative arm.

At 5 years, there were significant reductions in cardiovascular mortality (9.9% vs 18.6%; P=0.01) in the AVR-treated patients and significant reductions in deaths related to the aortic valve (5.3% vs 13.5%; P=0.003). Like the propensity-matched results, the reductions in mortality and heart-failure hospitalization were also observed in the entire cohort.

Taniguchi said that of the 1517 patients who were managed conservatively, 492 patients became symptomatic during follow-up.

The American Heart Association/American College of Cardiology (AHA/ACC) clinical guidelines for the management of patients with valvular heart disease currently recommend monitoring asymptomatic patients with aortic stenosis. The potential benefits of AVR are not believed to outweigh the operative risks of the procedure.

Commenting on the results, Dr Jeffrey Popma (Beth Israel Deaconess Medical Center, Boston, MA) said that while the AHA/ACC guidelines recommend watchful waiting in asymptomatic patients, AVR is a reasonable option in certain patients, such as those with a reduced ejection fraction or a high transvalvular pressure gradient, for example.

"Does the patient care that they have symptoms or does the ventricle care that they have symptoms?" Popma said to heartwire from Medscape. "Even in asymptomatic individuals, things might be looking bad for the heart," he said. "The patient might not be feeling anything, but heart might not be doing very well."

Dr Ajay Kirtane (Columbia University Medical Center, New York) noted that AVR is avoided in asymptomatic patients because of the up-front risks of surgery, but the emergence of transcatheter aortic-valve replacement (TAVR) might mean the bar doesn't need to be set as high for valve replacement. However, as Popma told heartwire , even with the up-front risk with AVR, mortality in the CURRENT-AS registry was significantly lower with surgery than in patients treated conservatively.

Dr Roxana Mehran (Icahn School of Medicine at Mount Sinai, New York), along with Popma, noted that registries are inherently flawed, pointing out that it is not known how many patients underwent exercise stress testing. As a result, it is not known if all included patients were truly asymptomatic.

"When you see a large number of patients developing symptoms over time, you have to question if they got the right patients into conservative management," she said. "We need to strengthen our way of evaluating patients with aortic stenosis, that's what this registry is teaching us. Maybe our evaluation of aortic stenosis—with or without symptoms, but particularly in asymptomatic patients—needs to be reevaluated."

As Dr Samir Kapadia (Cleveland Clinic, OH) pointed out, once a patient develops symptoms, if untreated, long-term prognosis is extremely poor without valve replacement. "Once they develop symptoms, you have to treat them, because you waited for the symptoms to develop," said Kapadia. In PARTNER II, for example, only six of the 179 patients who were ineligible for surgery and treated with best medical care were alive at 5 years.

Taniguchi reports no relevant financial relationships. Popma has served as advisor/consultant for Abbott Laboratories and Boston Scientific and as a speaker/member of a speaker's bureau for Abbott Laboratories, Boston Scientific, Covidien, Cook Medical, Direct Flow Medical, and Medtronic. Kirtane receives research grants from Medtronic, Boston Scientific, and Abbott, which are paid directly to his institution. Mehran reports advising/consulting for Abbott Laboratories, AstraZeneca Pharmaceuticals, Bayer, Boston Scientific, Covidien, CSL Behring, Janssen Pharmaceuticals, Sanofi Merck, Osprey Medical, and Watermark Research Partners and receiving research grants from AstraZeneca Pharmaceuticals, DSI/Eli Lilly, Bristol-Myers Squibb/Sanofi, and the Medicines Company. Kapadia reports no relevant financial relationships.

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