Assessment of cardiovascular physiology using dobutamine stress cardiovascular magnetic resonance reveals impaired contractile reserve in patients with cirrhotic cardiomyopathy.

BACKGROUND: Liver cirrhosis has been shown to affect cardiac performance. However cardiac dysfunction may only be revealed under stress conditions. The value of non-invasive stress tests in diagnosing cirrhotic cardiomyopathy is unclear. We sought to investigate the response to pharmacological stimulation with dobutamine in patients with cirrhosis using cardiovascular magnetic resonance. METHODS: Thirty-six patients and eight controls were scanned using a 1.5 T scanner (Siemens Symphony TIM; Siemens, Erlangen, Germany). Conventional volumetric and feature tracking analysis using dedicated software (CMR42; Circle Cardiovascular Imaging Inc, Calgary, Canada and Diogenes MRI; Tomtec; Germany, respectively) were performed at rest and during low to intermediate dose dobutamine stress. RESULTS: Whilst volumetry based parameters were similar between patients and controls at rest, patients had a smaller increase in cardiac output during stress (p = 0.015). Ejection fraction increase was impaired in patients during 10 μg/kg/min dobutamine as compared to controls (6.9 % vs. 16.5 %, p = 0.007), but not with 20 μg/kg/min (12.1 % vs. 17.6 %, p = 0.12). This was paralleled by an impaired improvement in circumferential strain with low dose (median increase of 14.4 % vs. 30.9 %, p = 0.03), but not with intermediate dose dobutamine (median increase of 29.4 % vs. 33.9 %, p = 0.54). There was an impaired longitudinal strain increase in patients as compared to controls during low (median increase of 6.6 % vs 28.6 %, p \u3c 0.001) and intermediate dose dobutamine (median increase of 2.6%vs, 12.6 % p = 0.016). Radial strain response to dobutamine was similar in patients and controls (p \u3e 0.05). CONCLUSION: Cirrhotic cardiomyopathy is characterized by an impaired cardiac pharmacological response that can be detected with magnetic resonance myocardial stress testing. Deformation analysis parameters may be more sensitive in identifying abnormalities in inotropic response to stress than conventional methods

Quantification of left atrial strain and strain rate using Cardiovascular Magnetic Resonance myocardial feature tracking: a feasibility study.

BACKGROUND: Cardiovascular Magnetic Resonance myocardial feature tracking (CMR-FT) is a quantitative technique tracking tissue voxel motion on standard steady-state free precession (SSFP) cine images to assess ventricular myocardial deformation. The importance of left atrial (LA) deformation assessment is increasingly recognized and can be assessed with echocardiographic speckle tracking. However atrial deformation quantification has never previously been demonstrated with CMR. We sought to determine the feasibility and reproducibility of CMR-FT for quantitative derivation of LA strain and strain rate (SR) myocardial mechanics. METHODS: 10 healthy volunteers, 10 patients with hypertrophic cardiomyopathy (HCM) and 10 patients with heart failure and preserved ejection fraction (HFpEF) were studied at 1.5 Tesla. LA longitudinal strain and SR parameters were derived from SSFP cine images using dedicated CMR-FT software (2D CPA MR, TomTec, Germany). LA performance was analyzed using 4- and 2-chamber views including LA reservoir function (total strain [εs], peak positive SR [SRs]), LA conduit function (passive strain [εe], peak early negative SR [SRe]) and LA booster pump function (active strain [εa], late peak negative SR [SRa]). RESULTS: In all subjects LA strain and SR parameters could be derived from SSFP images. There was impaired LA reservoir function in HCM and HFpEF (εs [%]: HCM 22.1 ± 5.5, HFpEF 16.3 ± 5.8, Controls 29.1 ± 5.3, p \u3c 0.01; SRs [s⁻¹]: HCM 0.9 ± 0.2, HFpEF 0.8 ± 0.3, Controls 1.1 ± 0.2, p \u3c 0.05) and impaired LA conduit function as compared to healthy controls (εe [%]: HCM 10.4 ± 3.9, HFpEF 11.9 ± 4.0, Controls 21.3 ± 5.1, p \u3c 0.001; SRe [s]⁻¹: HCM -0.5 ± 0.2, HFpEF -0.6 ± 0.1, Controls -1.0 ± 0.3, p \u3c 0.01). LA booster pump function was increased in HCM while decreased in HFpEF (εa [%]: HCM 11.7 ± 4.0, HFpEF 4.5 ± 2.9, Controls 7.8 ± 2.5, p \u3c 0.01; SRa [s⁻¹]: HCM -1.2 ± 0.4, HFpEF -0.5 ± 0.2, Controls -0.9 ± 0.3, p \u3c 0.01). Observer variability was excellent for all strain and SR parameters on an intra- and inter-observer level as determined by Bland-Altman, coefficient of variation and intraclass correlation coefficient analyses. CONCLUSIONS: CMR-FT based atrial performance analysis reliably quantifies LA longitudinal strain and SR from standard SSFP cine images and discriminates between patients with impaired left ventricular relaxation and healthy controls. CMR-FT derived atrial deformation quantification seems a promising novel approach for the study of atrial performance and physiology in health and disease states

Impaired Exercise Tolerance after Repair of Tetralogy of Fallot—Insights from Real-Time Cardiovascular Magnetic Resonance Imaging

Objectives: Surgical correction of tetralogy of Fallot (cTOF) frequently results in residual pulmonary valve stenosis/regurgitation and impaired right ventricular (RV) function. Reduced capacity in cardiopulmonary exercise testing (CPET) in cTOF patients, however, cannot entirely be explained by these findings. The present study sought to assess biventricular cardiac function during exercise using a comprehensive CPET and real-time cardiovascular magnetic resonance exercise testing (CMR-ET) protocol. Methods: A total of 33 cTOF patients (age 35.6 + 11.3 years) and 33 matched healthy controls (age 34.4 +11.9 years) underwent CPET and CMR-ET. Real-time SSFP and phase contrast sequences were obtained during supine bicycle in scanner CMR-ET at 50, 70, and 90 W. RV and LV volumetry and flow quantification of the pulmonary trunk (Qp) were performed. Correlation between CPET and CMR-ET parameters was investigated using Spearman’s rank test. Results: Exercise capacity on CPET was significantly lower in cTOF than in healthy controls. With incremental exercise levels on CMR-ET, cTOF patients failed to recruit both RV and LV functions and Qp (Table 1). Correlation analysis revealed higher CPET values in those cTOF patients with higher Qp (Qp 90 W vs. VE/VCO2%: r = −0.519, p < 0.05), higher LV EDVi (LV EDVi at 50 W vs. VO2% r = 0.452, p < 0.05) and less change in LV EF (LV-EF at 90 W vs. W % r = −0.463, p < 0.05). No correlation was found with RV EF. Significant RV–LV interaction was observed at 70 W CMR-ET (correlation of RV and LF EF r = 0.52, p < 0.05). Conclusion: Compared with healthy controls, cTOF patients displayed impaired exercise capacity due to a lack in recruitment of both RV function and pulmonary blood flow but also of LV function. RV and LV functions during exercise showed significant interdependence. CMR-ET may be a helpful tool in the assessment of cardiac function in cTOF patients

Quantitative assessment of left ventricular mechanical dyssynchrony using cine cardiovascular magnetic resonance imaging:Inter-study reproducibility

Objectives To determine the inter-study reproducibility of left ventricular (LV) mechanical dyssynchrony measures based on standard cardiovascular magnetic resonance (CMR) cine images. Design Steady-state free precession (SSFP) LV short-axis stacks and three long-axes were acquired on the same day at three time points. Circumferential strain systolic dyssynchrony indexes (SDI), area-SDI as well as circumferential and radial uniformity ratio estimates (CURE and RURE, respectively) were derived from CMR myocardial feature-tracking (CMR-FT) based on the tracking of three SSFP short-axis planes. Furthermore, 4D-LV-analysis based on SSFP short-axis stacks and longitudinal planes was performed to quantify 4D-volume-SDI. Setting A single-centre London teaching hospital. Participants 16 healthy volunteers. Main outcome measures Inter-study reproducibility between the repeated exams. Results CURE and RURE as well as 4D-volume-SDI showed good inter-study reproducibility (coefficient of variation [CoV] 6.4%–12.9%). Circumferential strain and area-SDI showed higher variability between the repeated measurements (CoV 24.9%–37.5%). Uniformity ratio estimates showed the lowest inter-study variability (CoV 6.4%–8.5%). Conclusions Derivation of LV mechanical dyssynchrony measures from standard cine images is feasible using CMR-FT and 4D-LV-analysis tools. Uniformity ratio estimates and 4D-volume-SDI showed good inter-study reproducibility. Their clinical value should next be explored in patients who potentially benefit from cardiac resynchronization therapy

Combination of vertebral bone quality scores from different magnetic resonance imaging sequences improves prognostic value for the estimation of osteoporosis

Background Context Recent findings revealed a correlation between vertebral bone quality based on T1-weighted (VBQT1) magnetic resonance imaging (MRI) and volumetric bone mass density (vBMD) measured using quantitative computerized tomography. The coherence of VBQ for other MRI sequences, such as T2 or short tau inversion recovery (STIR), has not been examined. The combination of different VBQs has not been studied. Purpose The aims of the study were to confirm the correlation between VBQT1 and vBMD and to examine VBQs from other MRI sequences and their combination with vBMD. Study Design/Setting This was a retrospective cross-sectional study. Patient Sample The sample consisted of patients older than 18 years, who received treatment at a level-one university spine center of the German Spine Society for degenerative or traumatic reasons in 2017–2021. Outcome Measures The outcome measures were the correlation of VBQs from different MRI sequences with vBMD and the association of VBQs with osteopenia/osteoporosis. Methods Patients’ VBQ was calculated based on the signal intensities of the vertebral bodies L1–4 in T1-, T2-, and STIR-weighted MRI. The VBQ was standardized according to the signal intensity of the cerebrospinal fluid. The vBMD was determined using data from a calibrated scanner (SOMATOM Definition AS+) and processed with CliniQCT (Mindways Software, Inc., USA). Groups were divided according to vBMD into the following groups: (I) osteoporosis/osteopenia (&lt; 120 mg/m3) and (II) healthy (≥120 mg/m3). An analysis of the correlation between various VBQs and vBMD as well as receiver operating characteristic (ROC) and binary regression analyses were performed for the prediction of osteoporosis/osteopenia. Results We included 136 patients (women: 56.6%) in the study (69.7 ± 15.0 years). According to vBMD, 108 patients (79.4%) had osteoporosis/osteopenia. Women were affected significantly more often than men (p = .045) and had significantly higher VBQT1 and VBQT2 values than men (VBQT1: p = .048; VBQT2: p = .013). VBQT1 and VBQT2 values were significantly higher in patients with osteoporosis/osteopenia than in healthy persons (VBQT1: p&lt;.001; VBQT2: p = .025). VBQT1 and VBQT2 were significantly negatively correlated with vBMD with a moderate effect size (p&lt;.001), while VBQSTIR was not significantly correlated with vBMD, although it showed a positive coherence. The combination of different VBQs in terms of VBQT1 × VBQT2 / VBQSTIR distinctly increased the effect size of the negative correlation with vBMD compared to VBQ alone. A cutoff value for VBQT1 × VBQT2 / VBQSTIR of 2.9179 achieved a sensitivity of 80.0%, a specificity of 75.0%, and an area under the curve (AUC) of 0.775 for the determination of osteoporosis. The mathematical model derived from the binary logistic regression showed an excellent AUC of 0.846. Conclusions This study confirms a significant correlation between VBQT1 and vBMD. The combination of VBQs from different MRI sequences enhances the prognostic value of VBQ for the determination of osteoporosis. While safe clinical application of VBQ for the determination of osteoporosis requires further validation, VBQ might offer opportunistic estimation for further diagnostics