Heart, Lung and Circulation

Global Longitudinal Strain is a Strong Independent Predictor of All-Cause Mortality in Patients with Aortic Stenosis

      Background: Global longitudinal strain (GLS), measured with speckle tracking echocardiography, is a sensitive marker of LV systolic function, however its prognostic capacity in patients with aortic stenosis (AS) is uncertain. We hypothesised that in patients with AS, GLS would predict: (1) All-cause mortality and (2) Major adverse cardiac events (MACE: death or hospitalisation due to cardiac causes).
      Methods: Subjects with AS (n = 146) and controls (n = 10) underwent baseline echocardiography to assess AS severity and GLS. Global longitudinal strain was graded as: normal function (GLS < −20%), mild dysfunction (GLS: −15 to −19.9%), moderate dysfunction (GLS: −10 to −14.9%) and severe dysfunction (GLS > −10%). Baseline demographics, symptom severity class (composite of angina/dyspnoea/syncope) and comorbidities were recorded. Outcomes were identified via hospital record review.
      Results: The age (mean ± SD) of subjects was 75 ± 11, 62% were male. Baseline aortic valve area (AVA) was 1.0 ± 0.4 cm2 and LVEF was 59 ± 11%. Subjects with AS had lower GLS (−15 ± 4%) than controls (−21 ± 2%) (p < 0.001) and GLS was associated with symptom severity (p < 0.001). During a mean follow-up of 1.4 ± 0.4 years, there were 14 deaths and 90 MACE. Unadjusted hazard ratios for GLS were: all-cause mortality (HR 6.4 (per grade) (2.8–14.3), p < 0.001) and MACE (HR 1.5 (per grade) (1.2–2.0), p = 0.002). With multivariate analysis, GLS (HR 6.2 (2.1–17.9), p = 0.001) was a stronger predictor of all-cause mortality than AVA (per cm2) (HR 0.19, p = 0.053), symptom class (HR 1.69, p = 0.07) and LVEF (1.01, p = 0.84).
      Conclusion: Global longitudinal strain independently predicts all-cause mortality in AS and its incorporation into risk stratification models may enable better identification of the optimal timing for aortic valve replacement.