The Role of Magnetic Resonance Imaging and Cardiac Computed Tomography in the Assessment of Left Atrial Anatomy, Size, and Function

Impact of SGLT2 inhibition on markers of reverse cardiac remodelling in heart failure: Systematic review and meta-analysis

INTRODUCTION

Several landmark randomized-controlled trials (RCTs) have demonstrated the efficacy of sodium-glucose co-transport 2 (SGLT2) inhibitors in reducing all-cause mortality, cardiovascular (CV) mortality and heart failure (HF) hospitalizations. Much interest surrounds their mechanism of action and whether they have direct effects on reverse cardiac remodelling. Therefore, we conducted a meta-analysis of placebo controlled RCTs evaluating the impact of SGLT2 inhibition on imaging derived markers of reverse cardiac remodelling in patients with HF.

METHODS

We performed a systematic review and meta-analysis in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Statement and Cochrane Collaboration. Data interrogation of each major database including PubMed, EMBASE, MEDLINE and Cochrane Library was performed. RCTs evaluating HF patients >18 years comparing SGLT2 inhibitor versus placebo-control were included. Outcome measures included left ventricular end-diastolic volume and volume index (LVEDV/LVEDVi), left ventricular end-systolic volume and volume index (LVSDV/LVSDVi), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMi), left atrial volume index (LAVi) and left ventricular global longitudinal strain (LV GLS). Studies with an HF with preserved ejection fraction population were excluded from analysis of parameters, which would be significantly affected by baseline LVEF, such as volumes and LVEF. The mean difference and standard error were extracted from each study and a random effects model used pool the mean difference and standard error across studies. A pre-specified sub-group analysis was performed to stratify results according to imaging modality used (cardiac magnetic resonance imaging and echocardiography). This study is registered on PROSPERO: CRD42023482722.

RESULTS

Seven randomized, placebo-controlled trials in patients with HF comprising a total population of 657 patients were included. Overall LVEF of included studies ranged from 29 ± 8.0% to 55.5 ± 4.2%. In studies included in analysis of HFrEF parameters, baseline LVEF ranged from 29 ± 8% to 45.5 ± 12%. Pooled data demonstrated SGLT2 inhibition, compared with placebo control, resulted in significant improvements in mean difference of LVEDV [-11.62 ml (95% confidence interval, CI -17.90 to -5.25; z = 3.67, P = 0.0004)], LVEDVi [-6.08 ml (95% CI -9.96 to -2.20; z = 3.07; P = 0.002)], LVESV [-12.47 ml (95% CI -19.12 to -5.82; z = 3.68; P = 0.0002)], LVESVi [-6.02 ml (95% CI -10.34 to -1.70; z = 2.73; P = 0.006)], LVM [-9.77 g (95% CI -17.65 to -1.89; z = 2.43; P = 0.02)], LVMi (-3.52 g [95% CI -7.04 to 0.01; z = 1.96; P = 0.05)] and LVEF [+2.54 mL (95% CI 1.10 to 3.98; z = 3.62; P = 0.0005)]. No significant difference in GLS (n = 327) [+0.42% (95%CI -0.19 to 1.02; P = 0.18)] or LAVi [-3.25 ml (95% CI -8.20 to 1.69; z = 1.29; P = 0.20)] was noted.

CONCLUSION

This meta-analysis provides additional data and insight into the effects of SGLT2 inhibition on reverse cardiac remodelling in patients with HF. Compared with placebo control, we found that treatment with a SGLT2 inhibitor produced significant improvements in several markers of reverse cardiac remodelling.

Evaluating left atrial function changes by speckle tracking echocardiography in type 2 diabetes patients in Central Vietnam: a cross-sectional comparative study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disorder that detrimentally affects multiple systems in the body, with a particular emphasis on the vascular and nervous systems. Despite its significant impact, limited studies have explored the influence of this condition on the left atrial (LA) function. To address this gap, our study utilized speckle tracking echocardiography (STE) to assess LA function in patients with T2DM in Central Vietnam.

RESULTS

The cross-sectional comparative study enrolled 134 subjects involving 66 patients with T2DM and 68 healthy individuals meeting the selection and exclusion criteria of the study. In our study, healthy individuals demonstrated higher values for LA reservoir strain (LASr), LA conduit strain (LAScd), and LA contractile strain (LASct), measuring 38.75% ± 5.43%, 19.58% ± 5.91%, and 19.16% ± 4.98%, respectively. In contrast, the T2DM group exhibited lower values for LASr, LAScd, and LASct, which measured 31.2% ± 4.56%, 14.77% ± 6.3%, and 16.36% ± 4.82%, respectively (p < 0.05). T2DM patients with normal LA volume index (LAVI) and normal left ventricular mass index (LVMI), LASr, LAScd, and LASct results were 32.07% ± 5.28%, 16.28% ± 6.95%, and 15.64% ± 5.32%. respectively.

CONCLUSIONS

STE of the LA reveals a noteworthy reduction in reservoir, conduit, and contractile functions within the T2DM group when compared to the control group (p < 0.05). Furthermore, these impaired functions persist in T2DM patients even in the absence of increased LAVI and LVMI.

Atrial Cardiomyopathy in Valvular Heart Disease: From Molecular Biology to Clinical Perspectives

This review discusses the evolving topic of atrial cardiomyopathy concerning valvular heart disease. The pathogenesis of atrial cardiomyopathy involves multiple factors, such as valvular disease leading to atrial structural and functional remodeling due to pressure and volume overload. Atrial enlargement and dysfunction can trigger atrial tachyarrhythmia. The complex interaction between valvular disease and atrial cardiomyopathy creates a vicious cycle of aggravating atrial enlargement, dysfunction, and valvular disease severity. Furthermore, atrial remodeling and arrhythmia can predispose to atrial thrombus formation and stroke. The underlying pathomechanism of atrial myopathy involves molecular, cellular, and subcellular alterations resulting in chronic inflammation, atrial fibrosis, and electrophysiological changes. Atrial dysfunction has emerged as an essential determinant of outcomes in valvular disease and heart failure. Despite its predictive value, the detection of atrial fibrosis and dysfunction is challenging and is not included in the clinical routine. Transthoracic echocardiography and cardiac magnetic resonance imaging are the main diagnostic tools for atrial cardiomyopathy. Recently published data have revealed that both left atrial volumes and functional parameters are independent predictors of cardiovascular events in valvular disease. The integration of atrial function assessment in clinical practice might help in early cardiovascular risk estimation, promoting early therapeutic intervention in valvular disease.

Total Anomalous Pulmonary Venous Return in the Time of SARS-CoV-2-Case Report

The management of children with complex and life-threatening heart malformations became a clinical conundrum during the SARS-CoV-2 pandemic. The pathophysiological features of the new coronavirus infection have raised major dilemmas regarding the postoperative evolution of an infected patient, and the epidemiological limitations have tightened the criteria for selecting cases. We present the case of a newborn diagnosed with total anomalous pulmonary venous return (TAPVR) who underwent surgical repair of the defect with favorable outcome, despite a prior diagnosis of SARS-CoV-2 infection. We discuss the medical and surgical management of TAPVR, highlighting possible management difficulties brought by the SARS-CoV-2 pandemic.

Multivalvular involvement associated with Libman-Sacks endocarditis detected by multimodality imaging: A case report

Libman-Sacks endocarditis accounts for 6-11 percent of systemic lupus erythematosus patients and is associated with varying degrees of valvular dysfunction, increased risk for stroke and transient ischemic attacks, and increased mortality. In previous studies, left-sided valvular Libman-Sacks vegetations were more frequently detected than right sided vegetations; reported cases of bilateral involvement is very rare. A comprehensive clinical assessment and the multimodality imaging is of utmost importance in the management of systemic lupus erythematosus. In this case report, we describe a 31-year-old female patient with uncontrolled systemic lupus erythematosus initially presented with gastrointestinal symptoms but eventually had a vegetation-like structure on the posterior leaflet of the mitral valve which was revealed during routine echocardiography. Two-dimensional/three-dimensional transthoracic and transesophageal echocardiography, cardiac magnetic resonance, and cardiac computed tomography further characterized the mitral valve vegetation and revealed an additional vegetation of the pulmonary valve. Echocardiography remains the cornerstone for the detection of Libman-Sacks vegetations. Cardiac MRI and cardiac CT are useful in characterizing lesion size and effects and may prove particularly helpful in the assessment of right-sided or multivalvular endocarditis. The presence of focal brain lesions on brain MRI prompted antithrombotic therapy.

Left atrial strain correlates with severity of cardiac involvement in Anderson-Fabry disease

OBJECTIVES

Cardiac involvement in Anderson-Fabry disease (AFD) results in myocardial lipid depositions. An early diagnosis can maximize therapeutic benefit. Thus, this study aims to investigate the potential of cardiac MRI (CMR) based parameters of left atrial (LA) function and strain to detect early stages of AFD.

METHODS

Patients (n = 58, age 40 (29-51) years, 31 female) with genetically proven AFD had undergone CMR including left ventricular (LV) volumetry, mass index (LVMi), T1, and late gadolinium enhancement, complemented by LA and LV strain measurements and atrial emptying fractions. Patients were stratified into three disease phases and compared to age and sex-matched healthy controls (HC, n = 58, age 41 [26-56] years, 31 female).

RESULTS

A total of 19 early-, 20 intermediate-, and 19 advanced-phase patients were included. LV and LA reservoir strain was significantly impaired in all AFD phases, including early disease (both p < 0.001). In contrast, LA volumetry, T1, and LVMi showed no significant differences between the early phase and HC (p > 0.05). In the intermediate phase, LVMi and T1 demonstrated significant differences. In advanced phase, all parameters except active emptying fractions differed significantly from HC. ROC curve analyses of early disease phases revealed superior diagnostic confidence for the LA reservoir strain (AUC 0.88, sensitivity 89%, specificity 75%) over the LV strain (AUC 0.82).

CONCLUSIONS

LA reservoir strain showed impairment in early AFD and significantly correlated with disease severity. The novel approach performed better in identifying early disease than the established approach using LVMi and T1. Further studies are needed to evaluate whether these results justify earlier initiation of therapy and help minimize cardiac complications.

KEY POINTS

• Parameters of left atrial function and deformation showed impairments in the early stages of Anderson-Fabry disease and correlated significantly with the severity of Anderson-Fabry disease. • Left atrial reservoir strain performed superior to ventricular strain in detecting early myocardial involvement in Anderson-Fabry disease and improved diagnostic accuracies of approaches already using ventricular strain. • Further studies are needed to evaluate whether earlier initiation of enzyme replacement therapy based on these results can help minimize cardiac complications from Anderson-Fabry disease.

The Atrium in Atrial Fibrillation - A Clinical Review on How to Manage Atrial Fibrotic Substrates

Atrial fibrillation (AF) is the most common sustained arrhythmia in the population and is associated with a significant clinical and economic burden. Rigorous assessment of the presence and degree of an atrial arrhythmic substrate is essential for determining treatment options, predicting long-term success after catheter ablation, and as a substrate critical in the pathophysiology of atrial thrombogenesis. Catheter ablation of AF has developed into an essential rhythm-control strategy. Nowadays is one of the most common cardiac ablation procedures performed worldwide, with its success inversely related to the extent of atrial structural disease. Although atrial substrate evaluation remains complex, several diagnostic resources allow for a more comprehensive assessment and quantification of the extent of left atrial structural remodeling and the presence of atrial fibrosis. In this review, we summarize the current knowledge on the pathophysiology, etiology, and electrophysiological aspects of atrial substrates promoting the development of AF. We also describe the risk factors for its development and how to diagnose its presence using imaging, electrocardiograms, and electroanatomic voltage mapping. Finally, we discuss recent data regarding fibrosis biomarkers that could help diagnose atrial fibrotic substrates.

Medical image analysis on left atrial LGE MRI for atrial fibrillation studies: A review

Late gadolinium enhancement magnetic resonance imaging (LGE MRI) is commonly used to visualize and quantify left atrial (LA) scars. The position and extent of LA scars provide important information on the pathophysiology and progression of atrial fibrillation (AF). Hence, LA LGE MRI computing and analysis are essential for computer-assisted diagnosis and treatment stratification of AF patients. Since manual delineations can be time-consuming and subject to intra- and inter-expert variability, automating this computing is highly desired, which nevertheless is still challenging and under-researched. This paper aims to provide a systematic review on computing methods for LA cavity, wall, scar, and ablation gap segmentation and quantification from LGE MRI, and the related literature for AF studies. Specifically, we first summarize AF-related imaging techniques, particularly LGE MRI. Then, we review the methodologies of the four computing tasks in detail and summarize the validation strategies applied in each task as well as state-of-the-art results on public datasets. Finally, the possible future developments are outlined, with a brief survey on the potential clinical applications of the aforementioned methods. The review indicates that the research into this topic is still in the early stages. Although several methods have been proposed, especially for the LA cavity segmentation, there is still a large scope for further algorithmic developments due to performance issues related to the high variability of enhancement appearance and differences in image acquisition.

Anatomical-MRI Correlations in Adults and Children with Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy (HCM) is the most frequent hereditary cardiovascular disease and the leading cause of sudden cardiac death in young individuals. Advancements in CMR imaging have allowed for earlier identification and more accurate prognosis of HCM. Interventions aimed at slowing or stopping the disease’s natural course may be developed in the future. CMR has been validated as a technique with high sensitivity and specificity, very few contraindications, a low risk of side effects, and is overall a good tool to be employed in the management of HCM patients. The goal of this review is to evaluate the magnetic resonance features of HCM, starting with distinct phenotypic variants of the disease and progressing to differential diagnoses of athlete’s heart, hypertension, and infiltrative cardiomyopathies. HCM in children has its own section in this review, with possible risk factors that are distinct from those in adults; delayed enhancement in children may play a role in risk stratification in HCM. Finally, a number of teaching points for general cardiologists who recommend CMR for patients with HCM will be presented.

Trans-esophageal Echocardiographic Assessment of Left Atrial and Left Atrial Appendage Function in Atrial Fibrillation and Rheumatic Heart Disease

Introduction: Rheumatic heart disease (RHD) is one of the most typical causes of atrial fibrillation in developing countries like India. The left atrial and left atrial appendage structure and function are deranged in atrial fibrillation and are a major source of thromboembolism. The goal of this study was to assess the left atrial and left atrial appendage function by transesophageal echocardiography in patients with atrial fibrillation and their comparison in patients with or without RHD.

Methods: A total of 172 consecutive patients with atrial fibrillation with or without RHD were subjected to trans-esophageal echocardiography to assess and compare left atrial (LA) and left atrial appendage (LAA) function.

Results: Out of 172 patients with atrial fibrillation, 100 were female (58.1%) and 72 were male (48.9%). The mean age was 54.11±12.3 years, and rheumatic heart disease (RHD) was the commonest cause of atrial fibrillation found in 121 (70.3%) patients. The mean left atrium diameter was significantly higher in RHD patients than in Non-RHD patients (52.08±10.13 vs. 46.67±6.78 mm, p=0.001). Mean left atrial ejection fraction was significantly lower in RHD patients as compared to Non-RHD patients (33.53±5.06 vs. 35.49±5.40%, p=0.024). The mean LAA orifice area of RHD patients was significantly higher than the Non-RHD patients (7.52±1.22 vs 6.94±1.17 mm², p=0.005). Mean LAA emptying velocity was significantly lower in RHD patients than Non-RHD (20.49±3.95 vs. 22.8±5.96 ml/s, p=0.002).

Conclusion: Rheumatic heart disease is still a common cause of atrial fibrillation in developing countries. LA and LAA function is impaired in atrial fibrillation, more in patients with rheumatic heart disease.

Left Atrial Geometry and Phasic Function Determined by Cardiac Magnetic Resonance Are Independent Predictors for Outcome in Non-Ischaemic Dilated Cardiomyopathy

Left atrial (LA) geometry and phasic functions are frequently impaired in non-ischaemic dilated cardiomyopathy (NIDCM). Cardiac magnetic resonance (CMR) can accurately measure LA function and geometry parameters. We sought to investigate their prognostic role in patients with NIDCM. We prospectively examined 212 patients with NIDCM (49 ± 14.2-year-old; 73.5% males) and 106 healthy controls. LA volumes, phasic functions, geometry, and fibrosis were determined using CMR. A composite outcome (cardiac death, ventricular tachyarrhythmias, heart failure hospitalization) was ascertained over a median of 26 months. LA phasic functions, sphericity index (LASI) and late gadolinium enhancement (LA-LGE) were considerably impaired in the diseased group (p < 0.001) and significantly correlated with impaired LV function parameters (p < 0.0001). After multivariate analysis, LA volumes, LASI, LA total strain (LA-ε_t) and LA-LGE were associated with increased risk of composite outcome (p < 0.001). Kaplan-Meier analysis showed significantly higher risk of composite endpoint for LA volumes (all p < 0.01), LASI > 0.725 (p < 0.003), and LA-ε_t < 30% (p < 0.0001). Stepwise Cox proportional-hazards models demonstrated a considerable incremental predictive value which resulted by adding LASI to LA-ε_t (Chi-square = 10.2, p < 0.001), and afterwards LA-LGE (Chi-Square = 15.8; p < 0.0001). NIDCM patients with defective LA volumes, LASI, LA-LGE and LA-ε_t had a higher risk for an outcome. LA-ε_t, LASI and LA-LGE provided independent incremental predictive value for outcome.

Compressed sensing acceleration of cardiac cine imaging allows reliable and reproducible assessment of volumetric and functional parameters of the left and right atrium

Objectives

To compare volumetric and functional parameters of the atria derived from highly accelerated compressed sensing (CS)–based cine sequences in comparison to conventional (Conv) cine imaging.

Methods

CS and Conv cine sequences were acquired in 101 subjects (82 healthy volunteers (HV) and 19 patients with heart failure with reduced ejection fraction (HFrEF)) using a 3T MR scanner in this single-center study. Time-volume analysis of the left (LA) and right atria (RA) were performed in both sequences to evaluate atrial volumes and function (total, passive, and active emptying fraction). Inter-sequence and inter- and intra-reader agreement were analyzed using correlation, intraclass correlation (ICC), and Bland-Altman analysis.

Results

CS-based cine imaging led to a 69% reduction of acquisition time. There was significant difference in atrial parameters between CS and Conv cine, e.g., LA minimal volume (LAVmin) (Conv 24.0 ml (16.7–32.7), CS 25.7 ml (19.2–35.2), p < 0.0001) or passive emptying fraction (PEF) (Conv 53.9% (46.7–58.4), CS 49.0% (42.0–54.1), p < 0.0001). However, there was high correlation between the techniques, yielding good to excellent ICC (0.76–0.99) and small mean of differences in Bland-Altman analysis (e.g. LAVmin − 2.0 ml, PEF 3.3%). Measurements showed high inter- (ICC > 0.958) and intra-rater (ICC > 0.934) agreement for both techniques. CS-based parameters (PEF AUC = 0.965, LAVmin AUC = 0.864) showed equivalent diagnostic ability compared to Conv cine imaging (PEF AUC = 0.989, LAVmin AUC = 0.859) to differentiate between HV and HFrEF.

Conclusion

Atrial volumetric and functional evaluation using CS cine imaging is feasible with relevant reduction of acquisition time, therefore strengthening the role of CS in clinical CMR for atrial imaging.

Key Points

• Reliable assessment of atrial volumes and function based on compressed sensing cine imaging is feasible.

• Compressed sensing reduces scan time and has the potential to overcome obstacles of conventional cine imaging.

• No significant differences for subjective image quality, inter- and intra-rater agreement, and ability to differentiate healthy volunteers and heart failure patients were detected between conventional and compressed sensing cine imaging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07830-z.

Cardiac CT angiography: normal and pathological anatomical features-a narrative review

The normal and pathological anatomy of the heart and coronary arteries are nowadays widely developed topics and constitute a fundamental part of the cultural background of the radiologist. The introduction of cardiac ECG-gated synchronized CT scanners with an ever-increasing number of detectors and with increasingly high structural characteristics (increase in temporal resolution, increase in contrast resolution with dual-source, dual energy scanners) allows the virtual measurement of anatomical in vivo structures complying with heart rate with submillimetric precision permitting to clearly depict the normal anatomy and follow the pathologic temporal evolution. Accordingly to these considerations, cardiac computed tomography angiography (CCTA) asserts itself as a gold standard method for the anatomical evaluation of the heart and permits to evaluate, verify, measure and characterize structural pathological alterations of both congenital and acquired degenerative diseases. Accordingly, CCTA is increasingly used as a prognostic model capable of modifying the outcome of diseased patients in planning interventions and in the post-surgical/interventional follow-up. The profound knowledge of cardiac anatomy and function through highly detailed CCTA analysis is required to perform an efficient and optimal use in real-world clinical practice.

Computed Tomography of the Left Atrium and Left Atrial Appendage: A Pictorial Essay on the Anatomy, Normal Variants, and Pathology

전산화단층촬영(이하 CT) 영상 기술의 발전으로 박동하는 심장에 대한 섬세한 영상의학적 평가가 가능해졌다. 심초음파 및 MRI에 비해 심장 CT의 강점은 대부분의 의료기관에 보급되어 있고 고품질 이미지의 빠른 생산이 가능하며 해부학적 묘사가 뛰어나다는 것이다. 좌심방과 좌심방이에서 생기는 대부분의 변이 혹은 병리적 상태들은 CT 상의 소견만으로도 추정진단을 내릴 수 있다. 또한 CT 영상은 성공적인 카테터 기반 시술 또는 수술에 중요한 해부학적 정보들을 제공한다. 특히 좌심방과 좌심방이는 심방세동 환자들의 치료 및 관리에 중요한데, 이는 다양한 카테터 기반 시술들이 두 구조물의 기계적 혹은 전기적 차단을 목표로 하기 때문이다. 따라서 임상적으로 의미 있는 판독을 위해서는 병리적 상태의 CT 소견 기술과 함께 좌심방 및 좌심방이의 모양, 크기 및 주변 구조물과의 상대적 위치 관계 등에 대한 포괄적인 검토를 해야 한다.

Significant incidental cardiac disease on thoracic CT: what the general radiologist needs to know

Objective

Incidental cardiac findings are often found on chest CT studies, some of which may be clinically significant. The objective of this pictorial review is to illustrate and describe the appearances and management of the most frequently encountered significant cardiac findings on non-electrocardiographically gated thoracic CT. Most radiologists will interpret multidetector chest CT and should be aware of the imaging appearances, significance, and the appropriate next management steps, when incidental significant cardiac disease is encountered on thoracic CT.

Conclusion

This article reviews significant incidental cardiac findings which may be encountered on chest CT studies. After completing this review, the reader should not only be familiar with recognizing clinically significant cardiac findings seen on thoracic CT examinations but also have the confidence to direct their further management.

Quantification of the left atrium applying cardiovascular magnetic resonance in clinical routine

OBJECTIVES

In recent years the impact of the left atrium (LA) has become more evident in different cardiovascular pathologies. We aim to provide LA parameters in healthy volunteers for cardiovascular magnetic resonance (CMR) using a fast approach.

DESIGN

We analyzed 203 healthy volunteers (mean age 44.6 years (y), range 19y-76y) at 1.5 and 3.0 Tesla (T) using steady-state free precession (SSFP) cine in routine long axis view. Left atrial enddiastolic volume (LA-EDV), endsystolic volume (LA-ESV), stroke volume (LA-SV) and ejection fraction (LA-EF) were quantified and indexed to body-surface-area (BSA). Dependency on age and sex was analyzed.

RESULTS

21 subjects had to be excluded. In the remaining, there was no significant difference between 1.5 T and 3.0 T. Absolut LA-EDV and LA-ESV were larger in men than in women (LA-EDV: male 70 ± 19 ml vs. female 61 ± 16 ml (p = .001); LA-ESV: male 24 ± 9 ml vs. female 21 ± 8 ml (p = .01)). These differences disappeared after indexing to BSA (LA-EDV/BSA: male 34 ± 10 ml/m² vs. female 33 ± 9 ml/m² (p = .65) and LA-ESV/BSA: male 12 ± 4 ml/m² vs. female 11 ± 4 ml/m² (p = .71)). LA-EDV/BSA decreased with older age.

CONCLUSIONS

Reference values for LA size and function based on a fast approach are provided. LA size decreases with older age. Normalization to body size overcomes sex-dependency. Reports should be related to body size.

High sensitivity troponin T and I reflect left atrial function being assessed by cardiac magnetic resonance imaging

Background

Left atrial function (LAF) plays an interactive role between pulmonary and systemic circulation. Cardiac biomarkers, such as amino-terminal pro-brain natriuretic peptide (NT-proBNP) and troponins, might reflect cardiac function. This study aims to evaluate the association between high sensitivity troponins (hsTn) and left atrial function in patients undergoing cardiac magnetic resonance imaging (cMRI).

Methods

Patients undergoing cardiac magnetic resonance imaging (cMRI) were enrolled prospectively. Patients with right ventricular dysfunction (<50%) were excluded. Blood samples for measurements of hsTn and NT-proBNP were collected at the time of cMRI.

Results

Eighty-four patients were included. Median LVEF was 59% (IQR 51–64%). HsTn correlated inversely with LAF within multivariable linear regression models (hsTnI: Beta −0.46; T −4.44; P = 0.0001; hsTnT: Beta −0.29; T −3.06; P = 0.003). High sensitivity troponins increased significantly according to decreasing stages of impaired LAF ( P = 0.0001). High sensitivity troponins discriminated patients with impaired LAF < 55% (hsTnT: AUC = 0.80; P = 0.0001; hsTnI: AUC = 0.74; P = 0.0001) and <45% (hsTnT: AUC = 0.75; P = 0.0001; hsTnI: AUC = 0.73; P = 0.001) and were still significantly associated in multivariable logistic regression models (LAF < 55%: hsTnT: OR = 21.78; P = 0.0001; hsTnI: OR = 5.96; P = 0.009; LAF < 45%: hsTnT: OR = 10.27; P = 0.0001; hsTnI: OR = 12.56; P = 0.001).

Conclusions

This study demonstrates that hsTn are able to reflect LAF being assessed by cardiac magnetic resonance imaging.

Left atrial size and risk of stroke in patients in sinus rhythm

Little is known about the risk of stroke associated with left atrial enlargement in patients in sinus rhythm, and whether such patients may have an unmet need for thromboprophylaxis. In this systematic review we summarise the existing evidence concerning left atrial size and risk of stroke in patients in sinus rhythm. Nine cohort studies were identified, analysing a total of 67,875 participants and 3,093 stroke outcomes. Rates of stroke per 100 person-years in patients with left atrial enlargement and in sinus rhythm ranged from 0.59 in a population-based cohort to 2.06 in patients referred for echocardiography. All studies reported a higher risk of stroke with larger/enlarged left atrium compared to smaller/normal sized left atrium. Two studies found indications of modification by sex, with only positive associations observed in women. Left atrial enlargement may represent an important predictor of stroke across a variety of patient populations in sinus rhythm. The underlying aetiology explaining this observed higher risk is likely to be multifactorial and not confined to a potential direct effect of left atrial enlargement on thromboembolic risk. Formal stroke risk stratification among patients with left atrial enlargement may further help identify patients who stand to gain from preventive antithrombotic therapy.

Supplementary Material to this article is available online at www.thrombosis-online.com.