Left ventricular dysfunction in atrial fibrillation and heart failure risk

Abstract

Aims: This study aimed to investigate the functional correlate, clinical relevance, and prognostic implications of novel left ventricular (LV) deformations in patients with atrial fibrillation (AF).

Methods and results: LV deformational indices, including peak global longitudinal strain (GLS), systolic strain rates (SRs), and early diastolic strain rates (SRe) were measured in a large-scale AF population. We related such measures to key clinical heart failure (HF) markers, conventional echocardiographic ventricular parameters, and clinical outcomes. Among 1483 subjects with newly diagnosed AF (mean age, 71.6 ± 12.4 years; 55.5% male), worsened GLS (mean, - 12.6 ± 3.9%) and strain rates (SRs and SRe: mean, - 0.86 ± 0.27 and 1.25 ± 0.41 1/s, respectively) by our three-beat measures were independently correlated with higher C-reactive protein, N-terminal pro-B-type natriuretic peptide, higher E/e', more impaired LV ejection fraction (LVEF < 50%), lower estimated glomerular filtration rate, permanent AF, and prevalent HF (all P < 0.05). LV deformations by three-beat analysis well correlated with the respective results of traditional methods. Abnormal GLS (>- 14.7%) was common in our cohort (67.8%) despite an averaged preserved LVEF (58.4 ± 14.2%), with worse GLS and SRe being associated with higher composite HF re-admissions/death during the 2.9 year follow-up (inter-quartile range, 1.6-4.1 years) in multivariate models incorporating key LV indices (LVEF, LV mass index, and E/e') (all P < 0.001). Sensitivity analysis by excluding those with regional wall motion abnormality showed broadly similar findings. An improved risk reclassification was observed when GLS and SRe were separately added to the LVEF. Comparison of the AF cohort with a fully matched independent non-AF cohort at the same baseline LVEF level showed a substantially lower GLS [- 13.2 ± 3.8% (AF) vs. 18.1 ± 3.2% (non-AF)] and higher clinical events rate (hazard ratio, 1.41 [95% confidence interval, 1.14-1.75]; log-rank P = 0.002) in the AF cohort.

Conclusions: Impaired LV function defined by myocardial deformation was common in patients with AF and provides independent prognostic values over conventional measures with improved risk prediction. Our data highlight the need for implementing cardiac deformations in daily practice for patients with AF.

Keywords: Atrial fibrillation; Global longitudinal strain; Heart failure; Left ventricular deformation; Mortality; Strain rate.

FIGURE 1

(A) Study flowchart. (B) Illustration of the speckle‐tracking measurement of the left ventricular global longitudinal strain (right upper panel) and strain rate curves (right lower panel) in the apical four‐chamber view.

FIGURE 2

Burden and distribution of abnormal GLS (defined as GLS > −14.7%) using community‐derived cut‐off for high risk of AF incidence in the current study population, by the presence of either prevalent HF or preserved/impaired LVEF categories (refer to Lang et al. ¹⁶ for GLS cut‐off). AF, atrial fibrillation; GLS, global longitudinal strain; LVEF, left ventricular ejection fraction.

FIGURE 3

CRP, BNP, eGFR levels, E/e′, LVEF < 50%, and HF were associated with reduced LV GLS and strain rates (A, B). The global LV strain and strain rate were adjusted for age, sex, BMI, HR, HTN, HF, DM, dyslipidaemia, vascular disease, eGFR, ACEI/ARB, diuretics, and beta‐blockers. LV deformation measurements and cardiac outcomes according to the three clinical categories: LVEF ≥ 50% without HF, LVEF ≥ 50% with HF, and LVEF < 50% (C, D). ACEI, angiotensin‐converting enzyme inhibitor; ARB, angiotensin II‐receptor; BNP, N‐terminal pro‐B‐type natriuretic; CAD, coronary artery disease; CRP, C‐reactive protein; DM, diabetes mellitus; eGFR, estimate glomerular filtration rate; GLS, global longitudinal strain; HF, heart failure; HTN, hypertension; LV, left ventricular; LVEF, left ventricular ejection fraction; PAD, peripheral arterial disease.

FIGURE 4

Kaplan–Meier survival estimates according to LV GLS tertiles and LVEF categories (LVEF ≥ 50% without HF, LVEF ≥ 50% with HF, and LVEF < 50%). GLS, global longitudinal strain; HF, heart failure; LV, left ventricular; LVEF, left ventricular ejection fraction.

FIGURE 5

GLS distribution, associations of GLS with LVEF, and comparisons of the composite outcome of HF/all‐cause death between AF and non‐AF cohorts. AF, atrial fibrillation; GLS, global longitudinal strain; LVEF, left ventricular ejection fraction.