Author + information
- Sanaz Samiei,
- Mohammadali Habibi,
- Masamichi Imai,
- Bharath Ambale Venkatesh,
- Colin Wu,
- Anders Opdahl,
- Thomas Helle-Valle,
- Alvaro Alonso,
- Susan Heckbert,
- Jaap Deckers,
- David Bluemke and
- Joao Lima
Strain imaging is a promising technique to quantify left atrial (LA) function. We explored the association between incident atrial fibrillation (AF) and LA strain by MRI using multimodality tissue tracking (MTT).
This nested case-control study was performed in a population free of cardiovascular disease at enrollment in the Multi-Ethnic Study of Atherosclerosis for a 9-year follow-up period. We included MRI studies at baseline from 144 participants who subsequently developed AF and 144 age, gender and ethnicity matched controls by availability of covariates. LA function was quantified by MTT from long-axis 2- and 4-chamber images. Multivariable logistic regression assessed association of maximum LA volume index (LAVI), peak longitudinal strain and LA emptying fraction (LA EmF) with AF independent of traditional risk factors, NT proBNP and LV mass index.
Subjects with AF (age 70±8, 58% male) had lower strain (24.9±11.4 vs 31.9±12.7%, p<0.001), lower LA EmF (39±9.3 vs 44.4±8.9%, p<0.001), but larger LAVI (42.7±14.2 vs 34.8±10.6 mL/m2, p<0.001) compared with controls. All LA parameters were independently associated with AF after adjustment for traditional risk factors, NT proBNP and LV mass index (Table). Addition of strain improved discrimination over and above LAVI.
LAVI, LA EmF and LA strain are associated with AF independent of traditional risk factors. LA strain provides additional discrimination of AF even after addition of NT proBNP, LV mass index and LAVI
|Model 1||Model 2||Model 3|
|LA function parameters||OR (95% CI)||AUC||Diff||P-value||OR (95% CI)||AUC||Diff||P-value||OR (95% CI)||AUC||Diff||P-value|
|Maximum LAVI (mL/m2)||1.05 (1.03–1.08)||0.67||0.10||0.006||1.05 (1.02–1.07)||0.72||0.04||0.07|
|LA EmF (%)||0.93 (0.90–0.96)||0.67||0.10||0.011||0.95 (0.92–0.98)||0.71||0.03||0.18||0.95 (0.92- 0.99)||0.75||0.02||0.10|
|Peak global longitudinal strain (%)||0.95 (0.92–0.97)||0.68||0.11||0.002||0.95 (0.93–0.98)||0.74||0.06||0.02||0.95 (0.93–0.98)||0.76||0.04||0.03|
Model 1: univariate + traditional risk factors of atrial fibrillation (age, gender, race, body mass index, systolic blood pressure, antihypertensive medication, diabetes status, smoking status, cholesterol status). Model 2: model 1 + NT proBNP and LV mass index. Model 3: model 2 + left atrial volume indexed to body surface area (LAVI). Abbreviations: LA, left atrial; OR, odds ratios per unit increase in standard deviation; CI, confidence interval; AUC, area under the receiver operating characteristics (ROC) curve for the multivariable model; Diff, increase in AUC after addition of LA function parameter in the multivariable model; p-value, from difference in area under the ROC curve after the addition of LA function parameter; LA EmF, LA emptying fraction.
Poster Sessions, Expo North
Monday, March 11, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Imaging: MRI VI – Clinical Applications and Advances in CMR
Abstract Category: 19. Imaging: MRI
Presentation Number: 1310-314
- 2013 American College of Cardiology Foundation