Prognostic superiority of global longitudinal strain beyond four-tiered ventricular hypertrophy in asymptomatic individuals

Abstract

This study aims to explore the clinical correlates of myocardial deformations using speckle-tracking algorithm and to determine the prognostic utility of such measures in asymptomatic ethnic Chinese population. Global longitudinal (GLS), circumferential strain (GCS), and torsion were analyzed using featured tissue-tracking algorithm among 4049 symptom-free ethnic Chinese population. Hypertrophy (LVH) was classified into 4 tiers: indeterminate, dilated, thick and thick/dilated, by gender-stratified partition of end-diastolic volume index (EDVi) and LV mass/EDV0.67. LVH (7.3%) showed substantially lower GLS (-20.3±1.82% vs. -18.9±2.08%) yet higher torsion (2.20±0.90 vs. 2.39±1.01, p<0.001) than non-LVH participants. Those with thick LVH (n=123) were more obese, had higher blood pressure and increased high-sensitivity C-reactive protein (hs-CRP); with dilated/thick LVH (n=26) group demonstrating highest pro-brain natriuretic peptide (NT-proBNP) and worse GLS compared to indeterminate-/non-LVH groups. There were independent associations among larger EDVi, higher NT-proBNP and decreased torsion, and among greater LV mass/EDV0.67, worse GLS, greater GCS/torsion and hs-CRP. Over a median of 2.3 years (IQR: 1.2-4.8), the dilated, thick, and dilated/thick LVH categorizations were associated with higher risk of composite all-cause death and heart failure (HF) compared to non-LVH (adjusted hazard ratio [HR]: 3.65, 3.72, 6.01, respectively, all p<0.05). Per 1% GLS reduction was independently associated with higher risk (adjusted HR: 1.31, p<0.001) and improved risk prediction (p≤0.001 by integrated discrimination improvement [IDI]: 3.5%, 95% CI: 1.5%-5.6%, and continuous net reclassification improvement [NRI]: 42.3%, 95% CI: 24.0%-60.6%) over LVH. GLS improved risk stratification of four-tiered classification of LVH in asymptomatic ethnic Chinese.