Initial Surgical AVR Improves Long-term Outcomes in Asymptomatic Patients With Severe AS

In asymptomatic patients with severe aortic stenosis (AS), a strategy of initial surgical aortic valve replacement (AVR) reduces the 5-year risk of events including all-cause death and heart failure (HF) hospitalization compared with a conservative strategy of watchful waiting until symptoms emerge, according to data from the CURRENT AS registry reported at TCT 2015 and simultaneously published in the Journal of the American College of Cardiology.

The CURRENT AS registry includes 3,815 consecutive patients with severe AS (defined as peak aortic jet velocity > 4 m/s, mean aortic pressure gradient > 40 mm Hg or aortic valve area < 1 cm²) who were enrolled between January 2003 and December 2008 at 27 centers in Japan. A strategy of initial surgical AVR (n = 291) or conservative management (n = 1,517) was chosen in 1,808 asymptomatic patients. Median follow-up was 3.7 years.

Tomohiko Taniguchi, MD, of Kyoto University Graduate School of Medicine, Kyoto, Japan, reported data from a propensity-score-matched cohort of 582 patients, half of whom treated with each strategy. Baseline characteristics of the two groups were similar, except those managed conservatively were older (77.8 vs. 71.6 years), had a higher STS score (3.5 vs. 2) and had smaller mean aortic valve gradient (54 mm Hg vs. 33 mm Hg).

Long-term outcomes different

During follow-up, 99% of patients in the initial AVR group underwent intervention (including 1 case of TAVR) compared with 41% of patients in the conservative group (median interval 44 days vs. 780 days).

Analyses conducted in the propensity-score matched cohorts and in the overall registry population showed that an initial AVR strategy reduced the primary endpoint of all-cause death and HF hospitalization at 5 years (Figure). The rate of all-cause death was 26.4% in the conservative group vs. 15.4% in the initial AVR group (log-rank P = .009) and HF hospitalization was 19.9% vs. 3.8%, respectively (log-rank P < .001).

Initial AVR also significantly decreased the 5-year risk for secondary endpoints including CV death (9.9% vs. 18.6%; HR 0.59; 95% CI 0.35-0.96), aortic valve-related death (5.3% vs. 13.5%; HR 0.42; 95% CI 0.21-0.79), sudden death (3.6% vs. 5.8%; HR 0.43; 95% CI 0.17-0.99) and emerging symptoms (3.2% vs. 46.3%; HR 0.06; 95% CI 0.03-0.11). However, risk for non-CV death was not significantly different between the groups (6.1% vs. 9.6%; HR 0.74; 95% CI 0.37-1.45).

In the initial AVR group, 63% of patients had a formal indication for undergoing the procedure, which included left ventricular ejection fraction ˂ 50%, very severe AS, other cardiac surgery, rapid hemodynamic progression and active infective endocarditis.

Common symptoms that emerged in the conservative-management group during follow-up included angina, syncope and rising NYHA HF classification.

Results with conservative management ‘dismal’

Current guidelines recommend watchful waiting for patients with asymptomatic AS until symptoms emerge. Only select subgroups — such as those with LV dysfunction or very severe disease — are recommended to receive immediate AVR.

“However, these recommendations are based on a single-center study evaluating symptoms and/or AVR, but not mortality, as outcome measures,” Taniguchi said. “There is no previous large-scale multicenter study comparing the initial AVR strategy with the conservative strategy.”

Although Taniguchi and colleagues designed the CURRENT AS registry to address this question, they pointed out limitations of the study, including its retrospective design and variable patient follow-up, as well as the potential for selection bias and residual confounding.

“Despite these limitations, the long-term outcome of asymptomatic patients with severe AS was dismal when managed conservatively in real clinical practice, which might be substantially improved by the initial AVR strategy,” Taniguchi said.

Disclosures:

• Taniguchi reports no conflicts of interest.