Aortic Stenosis: Watchful Waiting Works Only for So Long

Watchful waiting only worked for about a year before patients with severe but asymptomatic aortic stenosis were put at a survival disadvantage, researchers at one center found.

In a retrospective analysis involving 265 asymptomatic patients, a mortality difference became apparent as time went on from the 39% who were recommended aortic valve replacement (AVR) and the rest advised to wait:

• 1 year: 4.7% with AVR recommended vs 5.2% waiting (not significant)
• 2 years: 7.5% vs 16.1% (P=0.044)
• 3 years: 9.0% vs 21.1% (P=0.011)

"The current data indicate that the prognosis for patients initially recommended WW [watchful waiting] for asymptomatic, severe AS [aortic stenosis] is poor," according to S. Chris Malaisrie, MD, of Northwestern Memorial Hospital in Chicago, and colleagues, in their report online in The Annals of Thoracic Surgery.

"Previous studies have shown that expectant management for asymptomatic AS can be a safe management strategy. Our study similarly suggests a 'safe' period for WW, but only within the first year of expectant management. The divergence of survival between the WW and AVR groups by 2 years is consistent with other studies suggesting a benefit to early AVR."

After 5 years, 97 of the 104 people advised to get AVR ultimately got the surgery (one transcatheter aortic valve replacement [TAVR] among those procedures), as did 76 out of 161 in the watchful-waiting group (with four TAVRs).

AVR was an independent predictor of survival both for those advised to get it (HR 0.17, P=0.038) and others advised to wait (HR 0.39, P=0.044), relative to those who never received it.

"Our data suggest that those patients who ultimately did undergo AVR derived a similar survival benefit regardless of recommendation group (as long as they had AVR). This finding highlights that the failure of expectant management in the WW group may be entirely a result of the failure to recognize symptom onset and treat with timely AVR," the authors said.

"Often, patients don't report typical symptoms (shortness of breath, chest pain, syncope and pre-syncope, etc.) but have rather adjusted their lifestyle to increasing fatigue and tiredness which they frequently attribute to aging," commented Mario Goessl, MD, PhD, of the Minneapolis Heart Institute, who was not involved with the study.

"With the excellent results of both low-risk TAVR trials presented at ACC 2019 last weekend (including asymptomatic patients in both), I personally think that aortic valve replacement and especially TAVR has become safe enough that treating patients earlier trumps the watchful-waiting alternative," Goessl told MedPage Today.

Age issues aside, asymptomatic patients who are "reasonably low risk" may generally be candidates for early surgical AVR, otherwise early TAVR, said Michael Reardon, MD, of Houston Methodist.

The study could not determine the optimal age for intervention, Malaisrie's group acknowledged. Another limitation was the imbalance between groups: the cohort recommended to get AVR was younger, had smaller aortic valve areas, and higher gradients from the start.

Trials including EARLY TAVR are underway to determining more definitively how AVR performs in asymptomatic aortic stenosis.

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