Search

Background: Left atrial (LA) function and strain patterns by magnetic resonance imaging (MRI) have been investigated as markers of several cardiovascular pathologies, including cardiac amyloidosis (CA). However, associations with clinical outcomes have not been investigated., Purpose: To compare LA function and strain by MRI in CA patients to a matched cohort of patients without cardiovascular disease (CVD) and evaluate the association with long-term clinical outcomes in CA patients., Study Type: Retrospective case control., Population: A total of 51 patients with CA and 51 age-, gender-, and race-matched controls without CVD who underwent MRI in sinus rhythm., Field Strength/sequence: ECG-gated balanced steady-state free precession sequence at 1.5 T., Assessment: All measurements were completed by one investigator (M.M.B.). LA function and strain parameters were measured including LA indexed minimum and maximum volumes, LA reservoir (R), contractile (CT), and conduit (CD) strain. We compared groups after adjusting for age, hypertension, New York Heart Association class, modified staging system (troponin-I, BNP, estimated GFR) and left ventricular ejection fraction (LVEF) for an endpoint of all-cause mortality and a composite endpoint of heart failure hospitalization (HFH) or death., Statistical Tests: Differences between groups were evaluated with t tests for continuous variables or χ 2 tests for categorical variables. A multivariable regression model was used to assess the associations of the P values-two-sided tests-<0.05 were considered statistically significant., Results: CA patients with median follow up of 4.9 (8.5) months had significantly lower LA strain and higher LA volumes in comparison to the matched cohort. In the multivariable analysis, only LVEF was significantly associated with death while ƐCT (OR 0.6, CI: 0.41-0.89), indexed minimum LA volume (OR 1.06, CI: 1.02-1.13) and indexed maximum LA volume (OR 1.08, CI: 1.01-1.15) were significantly associated with the composite outcome of death or HFH., Conclusion: In this retrospective study of CA patients, ƐCT and indexed minimum and maximum LA volumes were significantly associated with the composite outcome of death or HFH., Evidence Level: 3 TECHNICAL EFFICACY: Stage 3., (© 2022 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Background: Stroke etiology is undetermined in approximately one-sixth to one-third of patients. The presence of aortic flow reversal and plaques in the descending aorta (DAo) has been identified as a potential retrograde embolic mechanism., Purpose: To assess the relationships between aortic stiffness, wall thickness, and flow reversal in patients with cryptogenic stroke and healthy controls., Study Type: Prospective., Population: Twenty one patients with cryptogenic stroke and proven DAo plaques (69 ± 9 years, 43% female), 18 age-matched controls (age: 65 ± 8 years, 61% female), and 14 younger controls (36 ± 9 years, 57% female)., Field Strength/sequence: 1.5T; 4D flow MRI and 3D dark blood T 1 -weighted turbo spin echo MRI of the aorta., Assessment: Noncontrast aortic 4D flow MRI to measure 3D flow dynamics and 3D dark blood aortic wall MRI to assess wall thickness. 4D flow MRI analysis included automated quantification of aortic stiffness by pulse wave velocity (PWV) and voxelwise mapping of the flow reversal fraction (FRF)., Statistical Tests: Analysis of variance (ANOVA) or Kruskal-Wallis tests, Student's unpaired t-tests or Wilcoxon rank-sum tests, regression analysis., Results: Aortic PWV and FRF were statistically higher in patients (8.9 ± 1.7 m/s, 18.4 ± 7.7%) than younger controls (5.3 ± 0.8 m/s, P < 0.0167; 8.5 ± 2.9%, P < 0.0167), but not age-matched controls (8.2 ± 1.6 m/s, P = 0.22; 15.6 ± 5.8%, P = 0.22). Maximum aortic wall thickness was higher in patients (3.1 ± 0.7 mm) than younger controls (2.2 ± 0.2 mm, P < 0.0167) and age-matched controls (2.7 ± 0.5 mm) (P < 0.0167). For all subjects, positive relationships were found between PWV and age (R 2 = 0.71, P < 0.05), aortic wall thickness (R 2 = 0.20, P < 0.05), and FRF (R 2 = 0.47, P < 0.05). Patients demonstrated relationships between PWV and FRF in the ascending aorta (R 2 = 0.32, P < 0.05) and arch (R 2 = 0.24, P < 0.05)., Data Conclusion: This study showed the utility of 4D flow MRI for evaluating aortic PWV and voxelwise flow reversal. Positive relationships between aortic PWV, wall thickness, and flow reversal support the hypothesis that aortic stiffness is involved in this retrograde embolic mechanism., Level of Evidence: 2 TECHNICAL EFFICACY STAGE: 1., (© 2020 International Society for Magnetic Resonance in Medicine.)

Background: Blood flow reversal is a possible mechanism for retrograde embolism in the setting of high-risk atherosclerotic plaques in the descending aorta (DAo). Evidence suggests that pulse wave velocity (PWV) is a determinant of blood flow reversal and can be reduced by the destiffening effect of renin-angiotensin system inhibitors (RASI)., Purpose: To evaluate the impact of antihypertensive therapy on in vivo changes in PWV and flow reversal in patients with cryptogenic stroke., Study Type: Prospective., Population: Sixteen patients (69 ± 9 years; 10 males) included after cryptogenic stroke., Field Strength/sequence: 3T. 4D flow sequence (temporal resolution = 19.6 msec) ASSESSMENT: Patients underwent aortic MRI at baseline and at 6-month follow-up. Patients received standard-of-care antihypertensive therapy that were classified as RASI vs. non-RASI medications (ie, destiffening vs. nondestiffening).We compared aortic PWV, flow reversal fraction (FRF), aortic measurements, cardiac function, and other aortic and cardiac measurements in the antihypertensive therapy groups., Statistical Tests: Two-tailed paired or unpaired Student's t-tests (normal distributions) or Wilcoxon tests (nonnormal distribution). Univariate correlations using Pearson correlation coefficients., Results: There was a significant decrease in PWV in the RASI (n = 10) group (9.4 ± 1.6 m/s vs. 8.3 ± 1.9 m/s; P < 0.05), as well as FRF (18.6% ± 4.1% vs. 16.3% ± 4.0%; P < 0.05) between baseline and the 6-month MRI studies. There were no changes in PWV or FRF in the non-RASI (n = 6) group (P = 0.146 and P = 0.32). A decrease in FRF was significantly correlated with a decrease in PWV (r = 0.53; P < 0.05)., Data Conclusion: The findings of our study suggest that RASI therapy after cryptogenic stroke resulted in a decrease of blood flow reversal and aortic stiffness., Evidence Level: 1 TECHNICAL EFFICACY STAGE: 4., (© 2020 International Society for Magnetic Resonance in Medicine.)