Purpose: To investigate the association between left atrial (LA) function and left ventricular myocardial fibrosis using cardiac magnetic resonance (MR) imaging in a multi-ethnic population.
Materials and Methods: For this HIPAA-compliant study, the institutional review board at each participating center approved the study protocol, and all participants provided informed consent. Of 2839 participants who had undergone cardiac MR in 2010-2012, 143 participants with myocardial scar determined with late gadolinium enhancement and 286 age- , sex-, and ethnicity-matched control participants were identified. LA volume, strain, and strain rate were analyzed by using multimodality tissue tracking from cine MR imaging. T1 mapping was applied to assess diffuse myocardial fibrosis. The association between LA parameters and myocardial fibrosis was evaluated with the Student t test and multivariable regression analysis.
Results: The scar group had significantly higher minimum LA volume than the control group (mean, 22.0 ± 10.5 [standard deviation] vs 19.0 ± 7.8, P = .002) and lower LA ejection fraction (45.9 ± 10.7 vs 51.3 ± 8.7, P < .001), maximal LA strain (Smax) (25.4 ± 10.7 vs 30.6 ± 10.6, P < .001) and maximum LA strain rate (SRmax) (1.08 ± 0.45 vs 1.29 ± 0.51, P < .001), and lower absolute LA strain rate at early diastolic peak (SRE) (-0.77 ± 0.42 vs -1.01 ± 0.48, P < .001) and LA strain rate at atrial contraction peak (SRA) (-1.50 ± 0.62 vs -1.78 ± 0.69, P < .001) than the control group. T1 time 12 minutes after contrast material injection was significantly associated with Smax (b coefficient = 0.043, P = .013), SRmax (β coefficient = 0.0025, P = .001), SRE (β coefficient = 20.0016, P = .027), and SRA (β coefficient 20.0028, P = .01) in the regression model. T1 time 25 minutes after contrast material injection was significantly associated with SRmax (β coefficient = 0.0019, P = .016) and SRA (β coefficient = 20.0022, P = .034).
Conclusion: Reduced LA regional and global function are related to both replacement and diffuse myocardial fibrosis processes.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging