Association of Left Ventricular Global Longitudinal Strain With Asymptomatic Severe Aortic Stenosis: Natural Course and Prognostic Value.

Importance: The optimal timing to operate in patients with asymptomatic severe aortic stenosis (AS) remains controversial. Left ventricular global longitudinal strain (LV GLS) may help to identify patients who might benefit from undergoing earlier aortic valve replacement. Objective: To investigate the prevalence of impaired LV GLS, the natural course of LV GLS, and its prognostic implications in patients with asymptomatic severe AS with preserved left ventricular ejection fraction (LVEF). Design, Setting, and Participants: This registry-based study included the institutional registries of 3 large tertiary referral centers and 220 patients with asymptomatic severe AS and preserved LVEF (>50%) who were matched for age and sex with 220 controls without structural heart disease. The echocardiograms of patients and controls were performed between 1998 and 2017. Exposures: Both clinical and echocardiographic data were assessed retrospectively. Severe AS was defined by an indexed aortic valve area less than 0.6 cm2/m2. Left ventricular global longitudinal strain was evaluated on transthoracic echocardiography using speckle tracking imaging. Main Outcomes and Measures: The prevalence of impaired LV GLS, the natural course of LV GLS, and the association of impaired LV GLS with symptom onset and the need for aortic valve intervention.
Results: Two hundred twenty patients (mean [SD] age, 68 [13] years; 126 men [57%]) were included. Despite comparable LVEF, LV GLS was significantly impaired in patients with asymptomatic severe AS compared with age- and sex-matched controls without AS (mean [SD] LV GLS, -17.9% [2.5%] vs -19.6% [2.1%]; P < .001). After a median follow-up of 12 (interquartile range, 7-23) months, mean (SD) LV GLS significantly deteriorated (-18.0% [2.6%] to -16.3% [2.8%]; P < .001) while LVEF remained unchanged. Patients with impaired LV GLS at baseline (>-18.2%) showed a higher risk for developing symptoms (P = .02) and needing aortic valve intervention (P = .03) at follow-up compared with patients with more preserved LV GLS (≤-18.2%). Conclusions and Relevance: Subclinical myocardial dysfunction that is characterized by impaired LV GLS is often present in patients with asymptomatic severe AS with preserved LVEF. Left ventricular global longitudinal strain further deteriorates over time and impaired LV GLS at baseline is associated with an increased risk for progression to the symptomatic stage and the need for aortic valve intervention.