Quantification of left atrial volume and phasic function using cardiovascular magnetic resonance imaging-comparison of biplane area-length method and Simpson's method

Association Between Family History in Patients with Primary Gout and Left Ventricular Diastolic Function: A Cross-Sectional Study

Objective

This study aimed to employ echocardiography for measuring the markers of left ventricular (LV) diastolic function to investigate the effects of family history of gout on the LV diastolic function in patients with primary gout.

Methods

Two hundred and eighty-four patients with primary gout who visited the Department of Rheumatology and Immunology of the First Affiliated Hospital of Chengdu Medical College from September 2020 to July 2022 were selected and their family history of gout, general information, and laboratory markers were recorded. Parameters of LV diastolic function were measured via echocardiography. The correlation between family history and LV diastolic function markers was analyzed using univariate and multivariate regression and the receiver operating characteristic (ROC) curve analyses.

Results

LV diastolic function parameters, peak early mitral diastolic velocity (E)/peak late mitral diastolic velocity (A), and early septal mitral annulus diastolic motion velocity (Sepe'), early lateral mitral annulus diastolic motion velocity (Late') and their mean (e'), were significantly lower in patients with familial primary gout, while left atrial volume index (LAVI) and E/e' were markedly elevated in patients with sporadic primary gout. In patients with family history, the proportion of grade ≥2 LV diastolic insufficiency was distinctly higher than that in patients without family history (41.6% vs 12.3%). Even after adjusting for confounding variables, LAVI, E/A, Sepe', Late', e', E/e' were obviously associated with family history of gout. The area under ROC of family history combined with SUA level for identifying grade ≥2 LV diastolic insufficiency in patients with primary gout was 0.872 (P<0.05).

Conclusion

Family history of gout was closely related to echocardiographic LV diastolic function parameters in patients with gout, what is more, family history of gout combined with SUA level was found to be a valuable indicator for discriminating grade ≥2 LV diastolic insufficiency in patients with primary gout.

Comparison of Biplane Area-Length Method and 3D Volume Quantification by Using Cardiac MRI for Assessment of Left Atrial Volume in Atrial Fibrillation

Purpose

To compare maximum left atrial (LA) volume (LAV) from the routinely used biplane area-length (BAL) method with three-dimensional (3D)-based volumetry from late gadolinium-enhanced MRI (3D LGE MRI) and contrast-enhanced MR angiography (3D CE-MRA) in patients with atrial fibrillation (AF).

Materials and Methods

Sixty-four patients with AF (mean age, 63 years ± 9 [SD]; 40 male patients) were retrospectively included from a prospective cohort acquired between October 2018 and February 2021. All patients underwent a research MRI examination that included standard two- and four-chamber cine acquisitions, 3D CE-MRA, and 3D LGE MRI performed prior to the atrial kick. Contour delineation on cine imaging and LA 3D segmentations were performed by a radiologist. Maximum LAV (BALmax) was extracted from the BAL volume-time curve and compared with LAV from 3D CE-MRA and 3D LGE MRI. The Kruskal-Wallis test was performed, followed by the Dunn post hoc test and Bland-Altman analyses. Interobserver variability was assessed in 10 patients.

Results

BALmax underestimated LAV compared with 3D CE-MRA (bias: -23.5 mL ± 46.2, P < .001) and 3D LGE MRI (bias: -31.3 mL ± 58.3, P < .001), whereas 3D LGE MRI volumes showed no evidence of a difference from 3D CE-MRA (bias: 7.8 mL ± 45.7, P = .38). Interobserver variability yielded excellent agreement for each method (intraclass correlation coefficient, 0.96-0.98).

Conclusion

BALmax underestimated LAV in patients with AF compared with 3D LGE MRI and 3D CE-MRA, suggesting that the geometric assumption of an ellipsoidal LA shape in BAL does not reflect LA geometry in patients with AF.Keywords: Left Atrial Volume, Biplane Area-Length, Late Gadolinium-enhanced 3D MRI, Contrast-enhanced 3D MR Angiography, Atrial Fibrillation Supplemental material is available for this article. © RSNA, 2023.

Quantification of left atrial function by the area-length method overestimates left atrial emptying fraction

PURPOSE

The biplane area-length method is commonly used in cardiac magnetic resonance (CMR) to assess left atrial (LA) volume (LAV) and function. Associations between left atrial emptying fraction (LAEF) and clinical outcomes have been reported. However, only limited data are available on the calculation of LAEF using the biplane method compared to 3D assessment. This study aimed to compare volumetric and functional LA parameters obtained from the biplane method with 3D assessment in a large, multiethnic cohort.

METHOD

158 participants of MESA (Multi-Ethnic Study of Atherosclerosis) underwent CMR that included standard two- and four-chamber steady-state free precession (SSFP) cine imaging for the biplane method. For 3D-based assessment, short-axis SSFP cine series covering the entire LA were obtained, followed by manual delineation of LA contours to create a time-resolved 3D LAV dataset. Paired t-tests and Bland-Altman plots were used to analyze the data.

RESULTS

Standard volumetric assessment showed that LAVmin (bias: -8.35 mL, p < 0.001), LAVmax (bias: -9.38 mL, p < 0.001) and LAVpreA (bias: -10.27 mL, p < 0.001) were significantly smaller using the biplane method compared to 3D assessment. Additionally, the biplane method reported significantly higher LAEFtotal (bias: 7.22 %, p < 0.001), LAEFactive (bias: 6.08 %, p < 0.001), and LAEFpassive (bias: 4.51 %, p < 0.001) with wide limits of agreement.

CONCLUSIONS

LA volumes were underestimated using the biplane method compared to 3D assessment, while LAEF parameters were overestimated. These findings demonstrate a lack of precision using the biplane method for LAEF assessment. Our results support the usage of 3D assessment in specific settings when LA volumetric and functional parameters are in focus.

The use of dedicated long-axis views focused on the left atrium improves the accuracy of left atrial volumes and emptying fraction measured by cardiovascular magnetic resonance

BACKGROUND

The use of apical views focused on the left atrium (LA) has improved the accuracy of LA volume evaluation by two-dimensional (2D) echocardiography. However, routine cardiovascular magnetic resonance (CMR) evaluation of LA volumes still uses standard 2- and 4-chamber cine images focused on the left ventricle (LV). To investigate the potential of LA-focused CMR cine images, we compared LA maximuml (LAVmax) and minimum (LAVmin) volumes, and emptying fraction (LAEF), calculated on both standard and LA-focused long-axis cine images, with LA volumes and LAEF obtained by short-axis cine stacks covering the LA. LA strain was also calculated and compared between standard and LA-focused images.

METHODS

LA volumes and LAEF were obtained from 108 consecutive patients by applying the biplane area-length algorithm to both standard and LA-focused 2- and 4-chamber cine images. Manual segmentation of a short-axis cine stack covering the LA was used as the reference method. In addition, LA strain reservoir (εs), conduit (εe) and booster pump (εa) were calculated using CMR feature-tracking.

RESULTS

Compared to the reference method, the standard approach significantly underestimated LA volumes (LAVmax: bias - 13 ml; LOA =  + 11, - 37 ml; LAVmax i: bias - 7 ml/m2; LOA =  + 7, - 21 ml/m2; LAVmin; bias - 10 ml, LOA: + 9, - 28 ml; LAVmin i: bias - 5 ml/m2, LOA: + 5, - 16 ml/m2), and overestimated LA-EF (bias 5%, LOA: + 23, - 14%). Conversely, LA volumes (LAVmax: bias 0 ml; LOA: + 10, - 10 ml; LAVmax i: bias 0 ml/m2; LOA: + 5, - 6 ml/m2; LAVmin: bias - 2 ml; LOA: + 7, - 10 ml; LAVmin i: bias - 1 ml/m2; LOA: + 3, - 5 ml/m2) and LAEF (bias 2%, LOA: + 11, - 7%) by LA-focused cine images were similar to those measured using the reference method. LA volumes by LA-focused images were obtained faster than using the reference method (1.2 vs 4.5 min, p < 0.001). LA strain (εs: bias 7%, LOA = 25, - 11%; εe: bias 4%, LOA = 15, - 8%; εa: bias 3%, LOA = 14, - 8%) was significantly higher in standard vs. LA-focused images (p < 0.001).

CONCLUSION

LA volumes and LAEF measured using dedicated LA-focused long-axis cine images are more accurate than using standard LV-focused cine images. Moreover, LA strain is significantly lower in LA-focused vs. standard images.

Early cardiac involvement detected by cardiac magnetic resonance feature tracking in idiopathic inflammatory myopathy with preserved ejection fraction

Cardiac involvement is common in idiopathic inflammatory myopathy (IIM) but often subclinical. Cardiac magnetic resonance (CMR) is a promising tool in detecting cardiac involvement in patients with IIM. The aim of this study was to assess cardiac involvement in IIM patients by CMR feature tracking (CMR-FT). Thirty-seven IIM patients and 25 controls were enrolled in this retrospective study. The left ventricular (LV) functional parameters such as volume and ejection fraction were measured. Global and regional LV peak strain (PS) in radial, circumferential and longitudinal directions were derived from cine images. Left atrial (LA) volume, longitudinal strain and strain rate (SR) parameters and LA reservoir function, conduit function and booster pump function were assessed, respectively. IIM patients with preserved LVEF showed significantly reduced global and regional LV PS in longitudinal direction (all p < 0.05). Compared with controls, LA reservoir and conduit function were significantly impaired in IIM patients (all p < 0.05). The global LV longitudinal PS, LAVpre-ac and SRe were independent predictors of IIM. By Pearson's correlation analysis, the LV global radial, circumferential and longitudinal PS were all correlated to LVEF in IIM patients (r = 0.526, p < 0.001 vs. r = - 0.514, p < 0.001 vs. r = - 0.288, p = 0.023). CMR-FT based LV and LA deformation performance could early detect cardiac involvement in IIM patients with preserved LVEF.

Associations between fully-automated, 3D-based functional analysis of the left atrium and classification schemes in atrial fibrillation

Background

Atrial fibrillation (AF) has been linked to left atrial (LA) enlargement. Whereas most studies focused on 2D-based estimation of static LA volume (LAV), we used a fully-automatic convolutional neural network (CNN) for time-resolved (CINE) volumetry of the whole LA on cardiac MRI (cMRI). Aim was to investigate associations between functional parameters from fully-automated, 3D-based analysis of the LA and current classification schemes in AF.

Methods

We retrospectively analyzed consecutive AF patients who underwent cMRI on 1.5T systems including a stack of oblique-axial CINE series covering the whole LA. The LA was automatically segmented by a validated CNN. In the resulting volume-time curves, maximum, minimum and LAV before atrial contraction were automatically identified. Active, passive and total LA emptying fractions (LAEF) were calculated and compared to clinical classifications (AF Burden score (AFBS), increased stroke risk (CHA₂DS₂VASc≥2), AF type (paroxysmal/persistent), EHRA score, and AF risk factors). Moreover, multivariable linear regression models (mLRM) were used to identify associations with AF risk factors.

Results

Overall, 102 patients (age 61±9 years, 17% female) were analyzed. Active LAEF (LAEF_active) decreased significantly with an increase of AFBS (minimal: 44.0%, mild: 36.2%, moderate: 31.7%, severe: 20.8%, p<0.003) which was primarily caused by an increase of minimum LAV. Likewise, LAEF_active was lower in patients with increased stroke risk (30.7% vs. 38.9%, p = 0.002). AF type and EHRA score did not show significant differences between groups. In mLRM, a decrease of LAEF_active was associated with higher age (per year: -0.3%, p = 0.02), higher AFBS (per category: -4.2%, p<0.03) and heart failure (-12.1%, p<0.04).

Conclusions

Fully-automatic morphometry of the whole LA derived from cMRI showed significant relationships between LAEF_active with increased stroke risk and severity of AFBS. Furthermore, higher age, higher AFBS and presence of heart failure were independent predictors of reduced LAEF_active, indicating its potential usefulness as an imaging biomarker.

Impact of different degrees of left ventricular strain on left atrial mechanics in heart failure with preserved ejection fraction

Background

Impairment of left atrial (LA) function is linked to left ventricle (LV) mechanics in patients with heart failure with preserved ejection fraction (HFpEF). In this study, we set forth to determine the difference in LA mechanics compared between HFpEF patients with different degrees of LV strains using the cardiac magnetic resonance feature tracking technique.

Methods

This retrospective study enrolled 79 patients with prior heart failure event and LV ejection fraction (LVEF) ≥ 50% (HFpEF group) together with 2:1 matched controls. LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS); LA emptying fraction (LAEF); and, LA strains consisting of reservoir phase strain (LAS_r), conduit phase strain (LAS_cd), and contraction phase strain (LAS_ct) were derived from cine images. All LA parameters were compared between HFpEF subgroups (lower and higher LV strain stratified by the median of each LV strain value) and controls.

Results

A total of 237 subjects were included. HFpEF had a lower LAEF and LA strain values compared with controls. The mean GLS value was significantly different between HFpEF and controls (− 13.3 ± 3.4% vs. − 15.4 ± 2.2%, p < 0.001). HFpEF with lower GLS (value ≥  − 13.1%) had significantly impaired LA mechanical parameters compared with both HFpEF with higher GLS and controls independent of potential confounders, as follows: LAEF (38.8 ± 16.6% vs. 48.6 ± 15.7% and 54.2 ± 12.2%), LAS_r (14.6 ± 7.1% vs. 24.3 ± 9.6% and 26.7 ± 8.8%), and LAS_cd (− 6.6 ± 3.9% vs. − 12.9 ± 6.0% and − 14.7 ± 7.4%) (post hoc analysis of variance p < 0.05 for all comparisons). Similarly, HFpEF with lower GCS (value ≥  − 16.6%) or lower GRS (value < 27.9%) also had significant impairment of LAS_r and LAS_cd compared with the higher strain group and controls. Abnormal LAEF (< 50%) and abnormal LAS_r (< 23%) are independently associated with NYHA class ≥ II (Odds ratio [OR] 3.894 [95% CI 2.202–6.885] p < 0.001, adjusted OR 3.382 [1.791–6.389] p < 0.001 for abnormal LAEF; and OR 2.613 [1.497–4.562] p = 0.001, adjusted OR 2.064 [1.118–2.110] p = 0.021 for abnormal LAS_r).

Conclusions

Patients with HFpEF were found to have impaired LV and LA mechanics. Abnormal LA mechanics was highly prevalent in HFpEF patients with lower LV strain and significantly associated with the symptomatic status of the patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02608-7.

Systems analysis of the mechanisms governing the cardiovascular response to changes in posture and in peripheral demand during exercise

Blood flows and pressures throughout the human cardiovascular system are regulated in response to various dynamic perturbations, such as changes to peripheral demands in exercise, rapid changes in posture, or loss of blood from hemorrhage, via the coordinated action of the heart, the vasculature, and autonomic reflexes. To assess how the systemic and pulmonary arterial and venous circulation, the heart, and the baroreflex work together to effect the whole-body responses to these perturbations, we integrated an anatomically-based large-vessel arterial tree model with the TriSeg heart model, models capturing nonlinear characteristics of the large and small veins, and baroreflex-mediated regulation of vascular tone and cardiac chronotropy and inotropy. The model was identified by matching data from the Valsalva maneuver (VM), exercise, and head-up tilt (HUT). Thirty-one parameters were optimized using a custom parameter-fitting tool chain, resulting in an unique, high-fidelity whole-body human cardiovascular systems model. Because the model captures the effects of exercise and posture changes, it can be used to simulate numerous clinical assessments, such as HUT, the VM, and cardiopulmonary exercise stress testing. The model can also be applied as a framework for representing and simulating individual patients and pathologies. Moreover, it can serve as a framework for integrating multi-scale organ-level models, such as for the heart or the kidneys, into a whole-body model. Here, the model is used to analyze the relative importance of chronotropic, inotropic, and peripheral vascular contributions to the whole-body cardiovascular response to exercise. It is predicted that in normal physiological conditions chronotropy and inotropy make roughly equal contributions to increasing cardiac output and cardiac power output during exercise. Under upright exercise conditions, the nonlinear pressure-volume relationship of the large veins and sympathetic-mediated venous vasoconstriction are both required to maintain preload to achieve physiological exercise levels. The developed modeling framework is built using the open Modelica modeling language and is freely distributed.

Pulmonary blood volume measured by cardiovascular magnetic resonance: influence of pulmonary transit time methods and left atrial volume

BACKGROUND

Increased pulmonary blood volume (PBV) is a measure of congestion and is associated with an increased risk of cardiovascular events. PBV can be quantified using cardiovascular magnetic resonance (CMR) imaging as the product of cardiac output and pulmonary transit time (PTT), the latter measured from the contrast time-intensity curves in the right and left side of the heart from first-pass perfusion (FPP). Several methods of estimating PTT exist, including pulmonary transit beats (PTB), peak-to-peak, and center of gravity (CoG). The aim of this study was to determine the accuracy and precision for these methods of quantifying the PBV, taking the left atrium volume (LAV) into consideration.

METHODS

Fifty-eight participants (64 ± 11 years, 24 women) underwent 1.5 T CMR. PTT was quantified from (1) a basal left ventricular short-axis image (FPP), and (2) the reference method with a separate contrast administration using an image intersecting the pulmonary artery (PA) and the LA (CoG(PA-LA)).

RESULTS

Compared to the reference, PBV for (a) PTB(FPP) was 14 ± 17% larger, (b) peak-peak(FPP) was 17 ± 16% larger, and (c) CoG(FPP) was 18 ± 10% larger. Subtraction of the LAV (available for n = 50) decreased overall differences to - 1 ± 19%, 2 ± 18%, and 3 ± 12% for PTB(FPP), peak-peak(FPP), and CoG(FPP), respectively. Lowest interobserver variability was seen for CoG(FPP) (- 2 ± 7%).

CONCLUSIONS

CoG(PA-LA) and FPP methods measured the same PBV only when adjusting for the LAV, since FPP inherently quantifies a volume consisting of PBV + LAV. CoG(FPP) had the best precision and lowest interobserver variability among the FPP methods of measuring PBV.

Impact of corrected sinus node recovery time in predicting recurrence in patients with paroxysmal atrial fibrillation

Objective

Atrial fibrillation (AF) and sinus node dysfunction (SND) have common underlying pathophysiological mechanisms. As an index of SND, corrected sinus node recovery time (CSNRT) may also reflect atrial function. The aim of the present study was to determine whether CSNRT predicts AF recurrence in patients undergoing AF ablation.

Methods

Consecutive patients with paroxysmal atrial fibrillation (PAF) who underwent radiofrequency catheter ablation between January 2017 and December 2018 were enrolled. Clinical data, CSNRT, and other electrophysiology indices were collected and analysed between patients with or without AF recurrence.

Results

A total of 159 patients with PAF who underwent the same radiofrequency catheter ablation procedure were enrolled, including 25 patients with SND. During the one-year follow-up period, 22 patients experienced AF recurrence. Patients with recurrence had a significantly longer CSNRT and a larger left atrial volume index (LAVI) than patients without AF recurrence. SND (CSNRT > 550 ms) and a larger LAVI were independently associated with AF recurrence after ablation. A statistically significant CSNRT cut-off value of 550 ms predicted AF recurrence with 73% sensitivity and 85% specificity.

Conclusion

CSNRT and LAVI are independent predictors of PAF recurrence following ablation.

Clinical significance of left atrial geometry in dilated cardiomyopathy patients: A cardiovascular magnetic resonance study

Background

Clinical significance of left atrial (LA) function and geometry in patients with dilated cardiomyopathy (DCM) remains uncertain.

Hypothesis

LA geometric parameters assessed by cardiac magnetic resonance (CMR) predict the prognosis in patients with DCM.

Methods

The present study included patients with DCM and sinus rhythm who underwent CMR between December 2007 and April 2018. LA volume was measured using CMR. LA sphericity index was computed as the ratio of the measured maximum LA volume by the volume of a sphere with maximum LA length diameter.

Results

We included 255 patients in this study. During the mean follow‐up of 3.92 years, hospitalization for HF occurred in 37 patients. The LA sphericity index was significantly higher in patients with hospitalization for HF than in those without (0.78 ± 0.35 vs. 0.58 ± 0.18, p < .001). Multivariable Cox regression analysis identified a higher LA sphericity index as an independent predictor of hospitalization for HF. Patients were categorized based on the median of LA sphericity index. The Kaplan–Meier curve showed that patients with a high LA sphericity index (≥0.57) had a significantly higher risk of hospitalization for HF than those with a low LA sphericity index (<0.57).

Conclusion

LA sphericity index was an independent predictor of hospitalization for HF. Assessment of LA geometric parameters might be useful for risk stratification in patients with DCM.

Multislice left ventricular ejection fraction prediction from cardiac MRIs without segmentation using shared SptDenNet

We propose a spatiotemporal model for cardiac magnetic resonance images (MRI) named SptDenNet. The proposed model is based on DenseNet and extracts spatial and temporal features simultaneously to exploit three-dimensional information on the heart over the cardiac loop cycle. To balance the model performance and efficiency, we construct a shared end-to-end framework, in which all frames of each selected short-axis (SAX) view slices are input to SptDenNet individually to extract spatiotemporal features. Then, the extracted features of all selected SAX view slices of a patient are concatenated and input to the subsequent fully connected layer and then a softmax layer to predict the left ventricular ejection fraction directly. To address the problem of class imbalance, we use FocalLoss function by reshaping the standard cross-entropy loss such that it down-weights the loss assigned to well-classified samples. We validate our proposed framework on the Second Annual Data Science Bowl dataset. Our prediction for the left ventricular ejection fraction obtains results comparable with state-of-the-art end-to-end approaches but without segmentation. The average mean absolute error of the ejection fraction is 6.84. To further verify the effectiveness of the proposed framework, we use 4-chamber view images from the same dataset to predict the cardiac function; we obtain an accuracy of 86.07%. Our approach constructs an end-to-end model to predict the ejection fraction automatically without using image segmentation, which helps reduce manual work. Moreover, the proposed approach is computationally efficient.

Assessment of diastolic dysfunction: comparison of different cardiovascular magnetic resonance techniques

Aims

Heart failure with preserved ejection fraction is still a diagnostic and therapeutic challenge, and accurate non‐invasive diagnosis of left ventricular (LV) diastolic dysfunction (DD) remains difficult. The current study aimed at identifying the most informative cardiovascular magnetic resonance (CMR) parameters for the assessment of LVDD.

Methods and results

We prospectively included 50 patients and classified them into three groups: with DD (DD+, n = 15), without (DD−, n = 26), and uncertain (DD±, n = 9). Diagnosis of DD was based on echocardiographic E/E′, invasive LV end‐diastolic pressure, and N‐terminal pro‐brain natriuretic peptide. CMR was performed at 1.5 T to assess LV and left atrial (LA) morphology, LV diastolic strain rate (SR) by tissue tracking and tagging, myocardial peak velocities by tissue phase mapping, and transmitral inflow profile using phase contrast techniques. Statistics were performed only on definitive DD+ and DD− (total number 41). DD+ showed enlarged LA with LA end‐diastolic volume/height performing best to identify DD+ with a cut‐off value of ≥0.52 mL/cm (sensitivity = 0.71, specificity = 0.84, and area under the receiver operating characteristic curve = 0.75). DD+ showed significantly reduced radial (inferolateral E peak: DD−: −14.5 ± 6.5%/s vs. DD+: −10.9 ± 5.9%/s, P = 0.04; anterolateral A peak: DD−: −4.2 ± 1.6%/s vs. DD+: −3.1 ± 1.4%/s, P = 0.04) and circumferential (inferolateral A peak: DD−: 3.8 ± 1.2%/s vs. DD+: 2.8 ± 0.8%/s, P = 0.007; anterolateral A peak: DD−: 3.5 ± 1.2%/s vs. DD+: 2.5 ± 0.8%/s, P = 0.048) SR in the basal lateral wall assessed by tissue tracking. In the same segments, DD+ showed lower peak myocardial velocity by tissue phase mapping (inferolateral radial peak: DD−: −3.6 ± 0.7 ms vs. DD+: −2.8 ± 1.0 ms, P = 0.017; anterolateral longitudinal peak: DD−: −5.0 ± 1.8 ms vs. DD+: −3.4 ± 1.4 ms, P = 0.006). Tagging revealed reduced global longitudinal SR in DD+ (DD−: 45.8 ± 12.0%/s vs. DD+: 34.8 ± 9.2%/s, P = 0.022). Global circumferential and radial SR by tissue tracking and tagging, LV morphology, and transmitral flow did not differ between DD+ and DD−.

Conclusions

Left atrial size and regional quantitative myocardial deformation applying CMR identified best patients with DD.

Left atrial volume and function assessed by cardiac magnetic resonance imaging are markers of subclinical atrial fibrillation as detected by continuous monitoring

Aims

We aimed to investigate whether left atrial (LA) markers from cardiovascular magnetic resonance (CMR) were able to predict atrial fibrillation (AF) in elderly patients with risk factors for stroke.

Methods and results

At baseline, 203 participants with stroke risk factors but without history of AF underwent advanced CMR and received an implantable loop recorder. During a median of 40 (37–42) months of continuous monitoring, incident AF was detected in 79 patients (39%). With regards to CMR markers, a steep increase in incidence rate of AF was seen with LA maximum volume (LAmax) above 55 mL/m2, LA minimum volume (LAmin) above 30 mL/m2, LA total emptying fraction (LA TEF) below 45%, LA active emptying fraction (LA AEF) below 37%, LA strain S below 25%, LA strain A below 17%, and LA strain rate A above −1.7 s−1. After multivariate adjustment, the above-mentioned CMR markers remained associated with AF incidence: hazard ratio (95% confidence interval) 1.25 (1.06–1.48) and 1.51 (1.22–1.87) per 10 mL/m2 increase of LAmax and LAmin, respectively, 1.49 (1.26–1.76) and 1.46 CI (1.25–1.71) per 5% decrease in LA TEF and LA AEF, respectively, 1.23 (1.05–1.44) and 1.56 (1.18–2.06) per 5% decrease in LA strain S and A, respectively, and 2.06 (1.31–3.23) per s−1 increase in LA strain rate A. In prediction analyses, LA functional indices increased area under the receiver operating characteristic curve significantly.

Conclusion

The risk of AF, including asymptomatic AF, increases significantly with increasing LA volumes and worsening LA function.

Atrial mechanics and their prognostic impact in Takotsubo syndrome: a cardiovascular magnetic resonance imaging study

Aims

The exact pathophysiology of Takotsubo syndrome (TTS) remains not fully understood with most studies focussing on ventricular pathology. Since atrial involvement may have a significant role, we assessed the diagnostic and prognostic potential of atrial cardiovascular magnetic resonance feature tracking (CMR-FT) in TTS.

Methods and results

This multicentre study recruited 152 TTS patients who underwent CMR on average within 3 days after hospitalization. Reservoir [total strain εs and peak positive strain rate (SR) SRs], conduit (passive strain εe and peak early negative SRe), and booster pump function (active strain εa and peak late negative SRa) were assessed in a core laboratory. Results were compared with 21 control patients with normal biventricular function. A total of 20 patients underwent follow-up CMR (median 3.5 months, interquartile range 3–5). All patients were approached for general follow-up. Left atrial (LA) but not right atrial (RA) reservoir and conduit function were impaired during the acute phase (εs: P = 0.043, εe: P < 0.001, SRe: P = 0.047 vs. controls) and recovered until follow-up (εs: P < 0.001, SRs: P = 0.04, εe: P = 0.001, SRe: P = 0.04). LA and RA booster pump function were increased in the acute setting (LA-εa: P = 0.045, SRa: P = 0.002 and RA-εa: P = 0.004, SRa: P = 0.002 vs. controls). LA-εs predicted mortality [hazard ratio 1.10, 95% confidence interval (CI) 1.01–1.20; P = 0.037] irrespectively of established cardiovascular risk factors (P = 0.019, multivariate analysis) including left ventricular ejection fraction (LVEF) (area under the curve 0.71, 95% CI 0.55–0.86, P = 0.048).

Conclusion

TTS pathophysiology comprises transient impairments in LA reservoir and conduit functions and enhanced bi-atrial active booster pump functions. Atrial CMR-FT may evolve as a superior marker of adverse events over and above established parameters such as LVEF and atrial volume.

The Role of Cardiac Magnetic Resonance Imaging to Detect Cardiac Toxicity From Cancer Therapeutics

PURPOSE OF REVIEW

The emerging complexity of cardiac toxicity caused by cancer therapies has created demand for more advanced non-invasive methods to better evaluate cardiac structure, function, and myocardial tissue characteristics. Cardiac magnetic resonance imaging meets these needs without exposure to ionizing radiation, and with superior spatial resolution.

RECENT FINDINGS

Special applications of cardiac magnetic resonance (CMR) to assess for cancer therapy-induced cardiac toxicity include the detection of subclinical LV dysfunction through novel methods of measuring myocardial strain, detection of microcirculatory dysfunction, identification of LV and LA fibrosis, and more sensitive detection of inflammation caused by immune checkpoint inhibitors. CMR plays a significant role in the non-invasive workup of cardiac toxicity from cancer therapies, with recent advancements in the field that have opened avenues for further research and development.