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LA structural remodeling is predicted by arterial stiffening independently of conventional risk factors
https://doi.org/10.1186/1532-429X-18-S1-Q36
© Vieira et al. 2016
- Published: 27 January 2016
Keywords
- Cardiovascular Risk Factor
- Cardiovascular Magnetic Resonance
- Left Atrium
- Late Gadolinium Enhancement
- Arterial Stiffness
Background
Left atrium (LA) size and function are powerful biomarkers of cardiovascular outcomes in many diseases. We sought to determine if the expected age-associated increase in arterial stiffness (AS) and left ventricular (LV)-LA afterload leads to corresponding effects on LA function and this can be measured with cardiovascular magnetic resonance (CMR). Additionally, we investigated the significance of these markers in asymptomatic individuals with cardiovascular risk factors (CRF).
Methods
Female subjects from the Twins UK cohort with no overt cardiac disease were prospectively recruited for a CMR study on a 1.5 Tesla scanner (Philips, Best, Netherlands) with tissue characterization (T1 mapping and late gadolinium enhancement). Patients with atrial fibrillation, valvular disease, regional wall motion abnormalities at rest or areas of myocardial enhancement were excluded from the analysis. LA reservoir, conduit and contractile functions were quantified by both fractional volume changes and CMR feature tracking derived strain and strain rate. Additionally, CMR feature tracking derived myocardial deformation indices and pulse wave velocity (PWV) (foot-to-foot methodology), were calculated.
Results
Baseline characteristics
CHARACTERISTICS | ALL | CRF = 0 | CRF≥1 | p |
|---|---|---|---|---|
Age, years | 69 ± 5.6 [57-77] | 68 ± 5.6 | 69 ± 5.6 | 0.114 |
Women, n (%) | 40 (100%) | 20 | 20 | - |
Cardiovascular risk factors (≥1) | 20 (50%) | 0 | 20 | <0.001 |
Hypertension, n (%) | 9 (21%) | 0 | 9 | 0.0012 |
Diabetes, n (%) | 0 | 0 | 0 | - |
Dyslipidemia | 16 (40%) | 0 | 16 | <0.001 |
Smoker (former), n (%) | 4 (10%) | 0 | 4 | 0.106 |
Pulse wave velocity [PWV (m/s)] | 8.127 ± 2.77 | 6.630 ± 2.77 | 8.127 ± 3.03 | <0.001 |
LV end-diastolic volume indexed [LVEDVi (mL/m2)] | 70 ± 14.5 | 67 ± 8.4 | 71 ± 13.1 | 0.079 |
LV end-systolic volume [LVESVi (mL/m2)] | 41 ± 9.6 | 41 ± 6.4 | 35 ± 9.6 | 0.153 |
LV ejection fraction [LVEF (%)] | 67 ± 7.4 | 61 ± 7.4 | 70 ± 7.4 | 0.975 |
LV mass indexed (mg/m2) | 54 ± 12.5 | 53 ± 12.5 | 55 ± 6.4 | 0.637 |
Global circumferential strain (GCs) | -20.5 ± 8.6 | -24.7 ± 10.4 | -16.4 ± 3.5 | 0.001 |
Global radial strain (GRs) | 29.8 ± 12.0 | 30.7 ± 6.9 | 28.9 ± 15.7 | 0.652 |
Global circumferential strain rate peak systole [GCSr (syst)] | -1.58 ± 0.42 | -1.58 ± 0.41 | -1.57 ± 0.45 | 0.924 |
Global radial strain rate peak systole [GRSr (syst)] | 1.77 ± 0.96 | 2.44 ± 0.50 | 1.09 ± 0.83 | <0.001 |
Global circumferential strain rate early diastole [GCSr (diast)] | 2.17 ± 1.90 | 1.85 ± 0.52 | 2.47 ± 2.6 | 0.293 |
Global radial strain rate early diastole [GRSr (diast)] | -1.7 ± 0.83 | -2.21 ± 0.61 | -1.2 ± 0.71 | <0.001 |
Native T1 (mid septum, ms) | 979 ± 37.6 | 966 ± 30.6 | 993 ± 39.9 | 0.022 |
LA volume indexed [LAVI (mL/m2)] | 42 ± 14.0 | 34 ± 9.6 | 50 ± 13.4 | <0.001 |
LA ejection fraction total [LAEF total (%)] | 61 ± 11.6 | 68 ± 7.8 | 53 ± 9.9 | <0.001 |
LA conduit function (%) | 34 ± 12.0 | 42 ± 10.6 | 26 ± 7.7 | <0.001 |
LA booster pump function (%) | 33.3 ± 9.0 | 30 ± 6.8 | 37 ± 9.7 | 0.012 |
LA total strain (εs) | 28.0 ± 8.0 | 30.7 ± 7.4 | 25.2 ± 7.9 | 0.029 |
LA passive strain (εe) | 18.6 ± 7.2 | 23.3 ± 5.2 | 14.0 ± 5.7 | <0.001 |
LA active strain (εa) | LA active strain (εa) | 7.5 ± 3.6 | 11.2 ± 4.6 | 0.006 |
LA peak positive strain rate (SRs) | 1.2 ± 0.4 | 1.4 ± 0.4 | 1.1 ± 0.3 | 0.016 |
LA peak early negative strain rate (SRe) | -1.2 ± 0.6 | -1.7 ± 0.4 | -0.8 ± 0.3 | <0.001 |
LA peak late negative strain rate (SRa) | -1.0 ± 0.4 | -1.0 ± 0.3 | -0.9 ± 0.4 | 0.341 |
Scatter plots (Panel A) showing the relationships between LA-LV deformation parameters and LA-PWV (abbreviations as shown in table 1). GRs (syst), GRSr (diast), and PWV were identified as independent determinants of LA mechanics in individuals with risk factors on multivariate analysis. Panels B and C. ROC curves comparing the sensitivity and specificity of different diagnostic parameters used in the analysis in the presence of cardiovascular risk factors.
Conclusions
LA mechanics correlates with LV deformation parameters and PWV and differs significantly in elderly subjects with CRF compared to their healthy age-matched peers. LA structural remodeling is predicted by AS (as expressed by PWV/LV parameters) independently of conventional CRF, thus supporting the hypothesis of arterial-ventricular-atrial coupling (AVAC). These novel markers of LA performance can potentially uncover abnormal AVAC in patients with CRF but no overt cardiac disease and give valuable insights into ventricular dysfunction beyond standard volumetrics.
Authors’ Affiliations
Copyright
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
