Key result
In patients with low-flow, low-gradient aortic stenosis and low LVEF, rest right ventricular longitudinal strain < |13|% was associated with increased all-cause mortality (HR 2.70; 95% CI 1.19-6.11).
Why the study?
Does reduced right ventricular longitudinal strain predict all-cause mortality in patients with low-flow, low-gradient aortic stenosis and low ejection fraction?
Cohort (n=128)
Does reduced right ventricular longitudinal strain predict all-cause mortality in patients with low-flow, low-gradient aortic stenosis and low ejection fraction?
Hazard Ratio: 2.7 (95% CI 1.19–6.11)
Absolute Event Rate: 53% vs 69%
p-value: p=0.018
In patients with low-flow, low-gradient aortic stenosis and low ejection fraction, reduced right ventricular longitudinal strain at rest and during dobutamine stress echocardiography is a strong independent predictor of all-cause mortality.
RV strain <13% may refine mortality risk stratification in low-flow low-gradient AS with low LVEF; leaves open need for prospective validation.
BACKGROUND: Left ventricular global longitudinal strain (LVLS) is a powerful predictor of outcome in patients with low-flow, low-gradient aortic stenosis (LF-LG AS) and low LV ejection fraction (LVEF). However, the impact of right ventricular (RV) function on the outcome of these patients remains unknown. OBJECTIVES: The aim of this study was to examine the impact of RV function as evaluated by RV free wall longitudinal strain (RVLS) on mortality in patients with LF-LG AS and low LVEF. METHODS: 211 patients with LF-LG AS (mean gradient < 40 mm Hg and indexed aortic valve area (AVA) ≤ 0.6 cm²/m²) and low LVEF (≤ 40%)) were prospectively recruited in the True or Pseudo-severe Aortic Stenosis study. AS severity was assessed using the projected AVA (AVAproj) at normal flow rate. Among the 211 patients, 128 had RVLS measurement available at rest and were included in this analysis. RVLS measurement at dobutamine stress echocardiography (DSE) was available in 58 of the 128 patients. RESULTS: Two-year survival was lower in patients with RVLS < |13|% (53% ± 9%) compared with those with RVLS > |13|% (69% ± 5%) (p = 0.04). In multivariable Cox analysis stratified for the type of treatment (aortic valve replacement vs conservative) and adjusted for age, AS severity, previous myocardial infarction and LVLS, rest RVLS < |13|% (HR = 2.70; 95% CI 1.19 to 6.11; p = 0.018) was independently associated with all-cause mortality. RVLS had incremental prognostic value over baseline risk factors and LVLS (χ² = 20.13 vs 13.56; p = 0.01). Reduced stress RVLS was also associated with increased risk of mortality (stress RVLS <| 14|%: HR = 2.98; 95% CI 1.30 to 6.52; p = 0.01). In multivariable Cox analysis, stress RVLS < |14|% remained independently associated with mortality (HR = 2.94; 95% CI 1.23 to 7.02; p = 0.015). After further adjustment for rest RVLS, stress RVLS < |14|% remained independently associated with mortality (HR = 3.29; 95% CI 1.17 to 9.25; p = 0.024), whereas rest RVLS was not (p > 0.05). CONCLUSIONS: In this series of patients with LF-LG AS and low LVEF, reduced RVLS was independently associated with increased risk of mortality. Furthermore, stress RVLS provided incremental prognostic value beyond that obtained from rest RVLS. Thus, RVLS measurement at rest and at DSE may be helpful to enhance risk stratification in this high-risk population. TRIAL REGISTRATION NUMBER: NCT01835028; Results.
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Dahou et al. (2016) conducted a cohort in Low-flow, low-gradient aortic stenosis with low LVEF (n=128). Rest right ventricular longitudinal strain (RVLS) < |13|% vs. Rest RVLS > |13|% was evaluated on All-cause mortality (reported alongside 2-year survival) (HR 2.70, 95% CI 1.19-6.11, p=0.018). In patients with low-flow, low-gradient aortic stenosis and low LVEF, rest right ventricular longitudinal strain < |13|% was associated with increased all-cause mortality (HR 2.70; 95% CI 1.19-6.11).