Association of Echocardiographic Left Ventricular End-Systolic Volume and Volume-Derived Ejection Fraction With Outcome in Asymptomatic Chronic Aortic Regurgitation

Abstract

IMPORTANCE Volumetric measurements by transthoracic echocardiogram may better reflect left ventricular (LV) remodeling than conventional linear LV dimensions. However, the association of LV volumes with mortality in patients with chronic hemodynamically significant aortic regurgitation (AR) is unknown.OBJECTIVE To assess whether LV volumes and volume-derived LV ejection fraction (Vol-LVEF) are determinants of mortality in AR. DESIGN, SETTING, AND PARTICIPANTSThis cohort study included consecutive asymptomatic patients with chronic moderately severe to severe AR from a tertiary referral center (January 2004 through April 2019.EXPOSURES Clinical and echocardiographic data were analyzed retrospectively. Aortic regurgitation severity was graded by comprehensive integrated approach. De novo disk-summation method was used to derive LV volumes and Vol-LVEF. MAIN OUTCOME AND MEASURESAssociations between all-cause mortality under medical surveillance and the following LV indexes: linear LV end-systolic dimension index (LVESDi), linear LVEF, LV end-systolic volume index (LVESVi), and Vol-LVEF. RESULTSOf 492 asymptomatic patients (mean [SD] age, 60 [17] years; 425 men [86%]), ischemic heart disease prevalence was low (41 [9%]), and 453 (92.1%) had preserved linear LVEF (Ն50%) with mean (SD) LVESVi of 41 (15) mL/m 2 . At a median (interquartile range) of 5.4 (2.5-10.1) years, 66 patients (13.4%) died under medical surveillance; overall survival was not different than the age-and sex-matched general population (P = .55). Separate multivariate models, adjusted for age, sex, Charlson Comorbidity Index, and AR severity, demonstrated that in addition to linear LVEF and LVESDi, LVESVi and Vol-LVEF were independently associated with mortality under surveillance (all P < .046) with similar C statistics (range, 0.83-0.84). Spline curves showed that continuous risks of death started to rise for both linear LVEF and Vol-LVEF less than 60%, LVESVi more than 40 to 45 mL/m 2 , and LVESDi above 21 to 22 mm/m 2 . As dichotomized variables, patients with LVESVi more than 45 mL/m 2 exhibited increased relative death risk (hazard ratio, 1.93; 95% CI, 1.10-3.38; P = .02) while LVESDi more than 20 mm/m 2 did not (P = .32). LVESVi more than 45 mL/m 2 showed a decreased survival trend compared with expected population survival. CONCLUSIONS AND RELEVANCEIn this large asymptomatic cohort of patients with hemodynamically significant AR, LVESVi and Vol-LVEF worked equally as well as LVESDi and linear LVEF in risk discriminating patients with excess mortality. A LVESVi threshold of 45 mL/m 2 or greater was significantly associated with an increased mortality risk.

Why are left ventricular linear internal diameters still so important for clinical decision-making to undergo surgery in asymptomatic patients with chronic severe aortic or primary mitral regurgitation?

“…The rate of change in LV end-diastolic diameter (mm/year) was 0.5 ± 2.4, whereas the rate of change in LV end-systolic diameter (mm/year) was 0.4 ± 2.8 during a follow-up of 7.1 ± 5.1years, range 1.1–19.5 years 9 . Further support for the prognostic importance of linear LV internal diameters has been recently reported for aortic regurgitation, with similar discriminative power as compared with the volumetric assessment 10,11 . In fact, an increment of LV end-systolic diameter indexed of 5 mm/m 2 did show a hazard ratio of 1.38 for all-cause death and 1.49 for aortic valve surgery at a median follow-up time of 5.4 (2.5–10.1) years 10 .…”

Multi-modality imaging assessment of native valvular regurgitation: an EACVI and ESC council of valvular heart disease position paper

“…RF is an independent predictor of outcome in patients with AR, 42 and a RF >33% has been shown to predict the likelihood of requiring surgery within 9 years. 43 RF limits that optimize concordance of CMR and echo severity grades are: mild < _15%, moderate 16-25%, moderate-severe 26-48%, and severe >48%. 1,12 Key point: The CW Doppler density of the AR jet does not provide useful information about the severity of AR.…”

“…Three-dimensional echocardiography allows more accurate measurement of LV volumes and EF than 2D echocardiography. LV volumetric data derived by echocardiography (LV endsystolic volume index > _45 mL/m 2 ) 43 or CMR (LV end-diastolic volume >246 mL with RF >33%) 42 may be instrumental in the identification of patients at increased risk of clinical progression. Strain imaging (GLS < -19%) may be helpful in identifying subclinical LV dysfunction in the setting of serial echocardiograms and may help for risk stratification.…”

Automated Global Longitudinal Strain Exhibits a Robust Association with Death in Asymptomatic Chronic Aortic Regurgitation

“…Recent clinical research has focused on identifying lower thresholds (i.e., LVEF < 60% and LVESDi > 20 mm/m 2 ) 2,20,21 as well as new markers of early LV contractility deterioration that may inform clinical decision-making in these patients. 9,18,[22][23][24][25][26] Herein, we report the usefulness of LVGLS as a death risk marker above all other LV indexes, including LVEF, for asymptomatic AR. Interestingly, and emphasizing the differences between LVGLS and other LV indexes, the correlation between LVGLS with LVEF was only modest, and the correlations with LVESDi and LVESVi were negligible (Supplemental Figure 2).…”

“…When our recently proposed 18 LVESVi threshold of 45 ml/m 2 was added to risk-stratify patients, the combination of LVGLS < 15% and LVESVi $ 45 mL/m 2 adjusted for the core model showed an even higher 3.95-fold increased risk (95% CI, 1.94-8.03; P = .0001) for death under medical surveillance. Also, the combination of LVGLS < 15% and LVESDi > 20 mm/m 2 exhibited a risk of 3.1-fold (95% CI, 1.67-5.65; P = .0003).…”