Clinical Investigation
Valvular Heart Disease
Natural History of Moderate Aortic Stenosis with Preserved and Low Ejection Fraction

https://doi.org/10.1016/j.echo.2021.02.014Get rights and content

Highlights

  • Patients with moderate AS have increased mortality compared with matched controls.

  • Detrimental effect of moderate AS applies to patients with reduced and preserved EFs.

  • Patients with moderate AS and low gradients also suffer increased mortality.

  • Future studies are needed to examine the use of aortic valve replacement in this population.

Background

There is a shortage of data concerning the natural history of patients with moderate aortic stenosis (AS). The aim of this study was to assess the effect of moderate AS on mortality in the general population and in the subgroups of patients with moderate AS and reduced ejection fractions (EF) and patients with moderate AS and low aortic valve gradients. The study was not designed to address the applicability of treatment in this population.

Methods

Outcomes were compared between patients with moderate AS and a propensity-matched cohort (1:3 ratio) without AS. The primary outcome was survival until end of follow-up.

Results

Among approximately 40,000 patients who underwent echocardiographic evaluations between 2011 and 2016, 952 had moderate AS. Median follow-up duration was 181 weeks (interquartile range, 179–182 weeks) for the entire cohort and 174 weeks (interquartile range, 169–179 weeks) for the propensity-matched groups. Propensity matching successfully balanced most preexisting clinical differences. Increased mortality was observed in the group of patients with moderate AS before propensity matching and persisted following propensity matching (median survival 4.1 vs 5.2 years, P = .008). Survival rates and corresponding standard errors at 1, 2, 3, and 5 years were 80 ± 1% versus 82 ± 0.7%, 70 ± 1.5% versus 74 ± 0.8%, 62 ± 1.7% versus 66 ± 0.9%, and 47 ± 2.4% versus 52 ± 1.3%, respectively. A survival difference was similarly observed for the subgroup analyses of moderate AS and reduced ejection fraction (P = .028) and moderate AS and low aortic valve gradients (P = .039).

Conclusions

Moderate AS is associated with increased mortality. The increased mortality was also observed in the subgroups of patients with either reduced ejection fraction or low aortic valve gradients.

Section snippets

Database

Our database includes all patients who underwent echocardiographic examinations (for any indication) at the Tel Aviv Sourasky Medical Center between 2011 and 2016.

In addition to detailed echocardiographic measurements regarding systolic, diastolic, valvular, and right-sided functions and sizes, we also documented extensive clinical details of the patients, including demographics, hospitalization details, background illnesses, and follow-up data regarding invasive interventions and mortality.

Results

In total, our data set comprised 37,037 examinees with data suitable for analysis. Nine hundred fifty-two patients had moderate AS. The average AVA-I and mean pressure gradient for the moderate AS group were 0.71 ± 0.08 cm2/m2 and 20.5 ± 9.3 mm Hg, respectively, and median follow-up time was 181 weeks (IQR, 179–182 weeks).

For the outcome variables of survival under medical management (from diagnosis to surgery or TAVR or death), there were no missing data in the original data set. As for the

Discussion

Our study demonstrates that patients with moderate AS have increased mortality rates compared with control subjects in an unadjusted analysis. These results are similar to those recently presented by researchers in Australia.21 We show that following propensity matching with patients without AS, survival analysis continues to demonstrate a difference in survival. Although several statistically significant differences remain in the propensity-matched groups, the differences are minor and

Conclusion

Patients with moderate AS have increased mortality rates in comparison with matched control subjects. This increased mortality is observed in patients with low or preserved EFs and even in patients with low transaortic gradients.

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Conflicts of interest: None.

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