Impact of Diastolic Function Parameters on the Risk for Left Atrial Appendage Thrombus in Patients with Nonvalvular Atrial Fibrillation: A Prospective Study

Spontaneous echo contrast in the left atrial appendage is linked to a higher risk of thromboembolic events and mortality in patients with atrial fibrillation

Background

Cardioversion, a rhythm control treatment for atrial fibrillation (AF), requires ruling out cardiac embolic sources, often originating from the left atrial appendage (LAA). Transesophageal echocardiography (TEE) is used for LAA evaluation, but it is invasive and not widely available. This study aimed to identify cardiovascular risk factors linked to LAA abnormalities and predictors of thromboembolic events and all-cause mortality.

Methods

A single-center retrospective analysis included AF patients admitted to the University Hospital Würzburg between 2009 and 2018 undergoing TEE.

Results

Among 2400 AF patients (median age 72; 36 % women), 469 (20 %) had LAA abnormalities: 282 (60 %) had spontaneous echo contrast (SEC), 72 (15 %) had thrombus formation (THR), and 115 (25 %) had both. Predictors of LAA abnormalities included age (OR 1.04; p = 0.002), congestive heart failure (OR 1.70; p = 0.009), diabetes (OR 1.74; p = 0.007), stroke history (OR 3.36; p = 0.001), vascular disease (OR 1.57; p = 0.026), elevated alkaline phosphatase (OR 1.15; p = 0.003), prior VKA intake (OR 1.53; p = 0.002), and DOAC intake (OR 0.57; p = 0.038). SEC with or without THR independently predicted thromboembolic events (HR 1.74, p = 0.031 and HR 1.53, p = 0.006) and all-cause mortality (HR 1.77, p = 0.011 and HR 1.57, p = 0.002), adjusted for cardiovascular risk factors, anticoagulation, and laboratory data.

Conclusions

In AF patients undergoing TEE, SEC, often overlooked in cardioversion decisions, independently predicted thromboembolic events and mortality.

Clinical significance of echocardiographic left ventricular hypertrophy for predicting left atrial appendage thrombotic milieu in patients with atrial fibrillation and CHA2DS2-VASc scores of 0-2

BACKGROUND

The clinical significance of echocardiographic left ventricular hypertrophy (LVH) in risk stratification of left atrial appendage (LAA) thrombogenic milieu, as a surrogate for cardioembolic risk, in patients with atrial fibrillation (AF) and HA2DS2-VASc scores of 0-2 is unknown.

METHODS AND RESULTS

We enrolled 707 consecutive patients with AF and CHA2DS2-VASc scores of 0-2 who underwent transesophageal echocardiography. LAA thrombogenic milieu was defined as the presence of a thrombus, severe spontaneous echo contrast, sludge in the LAA, or LAA flow velocity ≤ 20 cm/s. Alongside conventional parameters, longitudinal strain values for the left ventricle (LV) and left atrium were obtained using transthoracic echocardiography. Among the 707 patients, 77 (10.9 %) exhibited LVH. The LVH group exhibited a significantly higher prevalence of LAA thrombogenic milieu than the non-LVH group (32.5 % vs. 2.5 %, p < 0.001). LVH independently associated with LAA thrombogenic milieu after adjusting for clinical factors (including CHA2DS2-VASc score, AF type, and serum brain natriuretic peptide levels) and conventional echocardiographic parameters (including LV ejection fraction, LV end-diastolic volume index, and left atrium volume index) (odds ratio [OR]: 7.54, 95 % confidence interval [CI]: 3.49-16.29, p < 0.001 and OR: 7.16, 95 % CI: 3.26-15.73, p < 0.001, respectively). Moreover, LVH provided incremental value for predicting LAA thrombogenic milieu, even when added to the longitudinal strain of the LV and left atrium reservoir strains (p < 0.001).

CONCLUSION

Echocardiographic LVH significantly improves the prediction of LAA thrombogenic milieu, offering potential utility in further cardioembolic risk stratification for patients with AF and CHA2DS2-VASc scores of 0-2.

Impact of left ventricular diastolic function and direct oral anticoagulant use for predicting embolic events in patients with heart failure and atrial fibrillation

Background

Patients with atrial fibrillation (AF) and heart failure (HF) have high stroke risk owing to left atrial dysfunction. However, anticoagulation is a concern in patients with high bleeding risk. We aimed to identify independent predictors of stroke in HF patients with AF.

Methods

We retrospectively examined 320 patients (mean age 79 ± 12 years, 163 women) hospitalized with acute HF complicated by AF between January 2014 and December 2018. Patients were followed from admission until ischemic stroke or systemic embolism (SSE) onset or death or were censored at the last contact date or September 2023.

Results

SSE occurred in 40 patients (median follow-up of 528 days). Multivariate Cox regression analysis identified age (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.00-1.07, p = .034), direct oral anticoagulant (DOAC) use (HR 0.26, 95% CI 0.11-0.60, p = .002), and early diastolic peak flow velocity to early diastolic peak annular velocity (E/e'; HR 1.05, 95% CI 1.02-1.08, p < .001) to be independent predictors of SSE, whereas left atrial reservoir strain was not. After determining an appropriate E/e' cutoff by receiver-operating characteristic curve analysis and adjusting the multivariate Cox model, E/e' ≥17.5 (HR 3.30, 95% CI 1.56-6.83, p = .001) independently predicted SSE. The results were consistent with no interaction in the subanalysis except for gender.

Conclusion

Elderly patients not on DOACs with elevated E/e' may be at higher risk of stroke, suggesting that DOACs should be the first choice for patients with elevated E/e' and aggressive additional prophylaxis and careful follow-up are needed.

A nomogram for predicting left atrial thrombus or spontaneous echo contrast in non-valvular atrial fibrillation patients using hemodynamic parameters from transthoracic echocardiography

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with a high risk of stroke. This study was designed to investigate the relationship between hemodynamic parameters and left atrial thrombus/spontaneous echo contrast (LAT/SEC) in non-valvular atrial fibrillation (NVAF) patients and establish a predictive nomogram that integrates hemodynamic parameters with clinical predictors to predict the risk of LAT/SEC.

Methods

From January 2019 to September 2022, a total of 354 consecutive patients with NVAF were enrolled in this cross-sectional study at the First Affiliated Hospital of Guangxi Medical University. To identify the optimal predictive features, we employed least absolute shrinkage and selection operator (LASSO) regression. A multivariate logistic regression model was subsequently constructed, and the results were visualized with a nomogram. We evaluated the model's performance using discrimination, calibration, and the concordance index (C-index).

Results

We observed a 38.7% incidence of SEC/TH in NVAF patients. Independent influencing factors of LAT/SEC were identified through LASSO and multivariate logistic regression. Finally, four indicators were included, namely, previous stroke/transient ischaemic attack (OR = 4.25, 95% CI = 1.57-12.23, P = 0.006), left atrial volume index (LAVI) (OR = 1.04, 95% CI = 1.01-1.06, P = 0.001), S/D ratio (OR = 0.27, 95% CI = 0.11-0.59, P = 0.002), and left atrial acceleration factor (OR = 4.95, 95% CI = 2.05-12.79, P = 0.001). The nomogram, which incorporated these four influencing factors, demonstrated excellent predictive ability. The training set had a C-index of 0.878, while the validation set had a C-index of 0.872. Additionally, the calibration curve demonstrated great consistency between the predicted probabilities and the observed outcomes, and the decision curve analysis confirmed the important clinical advantage of the model for patients with NVAF.

Conclusion

Our findings indicate that an enlarged left atrium and abnormal hemodynamic parameters in the left atrial and pulmonary veins are linked to a greater risk of LAT/SEC. Previous stroke/transient ischaemic attack, LAVI, the S/D ratio, and left atrial acceleration factor were independently associated with LAT/SEC in NVAF patients. With the incorporation of these four variables, the developed nomogram effectively predicts the risk of LAT/SEC and outperforms the CHA2DS2-VASc score.

Medical record data-enabled machine learning can enhance prediction of left atrial appendage thrombosis in nonvalvular atrial fibrillation

BACKGROUND

As a major complication of non-valvular atrial fibrillation (NVAF), left atrial appendage (LAA) thrombosis is associated with cerebral ischemic strokes, as well as high morbidity. Due to insufficient incorporation of risk factors, most current scoring methods are limited to the analysis of relationships between clinical characteristics and LAA thrombosis rather than detecting potential risk. Therefore, this study proposes a clinical data-driven machine learning method to predict LAA thrombosis of NVAF.

METHODS

Patients with NVAF from January 2014 to June 2022 were enrolled from Southwest Hospital. We selected 40 variables for analysis, including demographic data, medical history records, laboratory results, and the structure of LAA. Three machine learning algorithms were adopted to construct classifiers for the prediction of LAA thrombosis risk. The most important variables related to LAA thrombosis and their influences were recognized by SHapley Addictive exPlanations method. In addition, we compared our model with CHADS2 and CHADS2-VASc scoring methods.

RESULTS

A total of 713 participants were recruited, including 127 patients with LAA thrombosis and 586 patients with no obvious thrombosis. The consensus models based on Random Forest and eXtreme Gradient Boosting LAA thrombosis prediction (RXTP) achieved the best accuracy of 0.865, significantly outperforming CHADS2 score and CHA2DS2-VASc score (0.757 and 0.754, respectively). The SHAP results showed that B-type natriuretic peptide, left atrial appendage width, C-reactive protein, Fibrinogen and estimated glomerular filtration rate are closely related to the risk of LAA thrombosis in nonvalvular atrial fibrillation.

CONCLUSIONS

The RXTP-NVAF model is the most effective model with the greatest ROC value and recall rate. The summarized risk factors obtained from SHAP enable the optimization of the treatment strategy, thereby preventing thromboembolism events and the occurrence of cardiogenic ischemic stroke.

Left atrial appendage thrombus formation, potential of resolution and association with prognosis in a large real-world cohort

Comprehensive data on factors influencing left atrial appendage (LAA) thrombus formation, resolution and impact on survival are limited. In this single-center, retrospective study 7759 (2010-2015) patients with symptomatic ongoing atrial fibrillation (AF) on admission were screened for LAA thrombi. 450 patients had LAA thrombi. 481 patients without LAA thrombi were randomly selected as controls. We assessed clinical, echocardiographic, laboratory parameters and long-term survival of both groups. Patients with LAA thrombi compared to controls were older, had more strokes, higher CHA₂DS₂ -VASc scores, worse renal function, less controlled diabetes, advanced heart failure, lower LAA emptying velocities, higher levels of cardiac and inflammatory markers (all p < 0.001). 56.3% of followed-up patients (304) dissolved their LAA thrombi. Chances of thrombus resolution increased with rising LAA flow velocities (OR 1.061, p = 0.022), whereas advanced age (OR 0.950, p < 0.001) and presence of permanent AF (OR 0.354, p < 0.001) decreased chances of thrombus resolution. Presence of LAA thrombi was associated with a markedly reduced 10-year survival probability (31% versus 69%). LAA thrombus formation is promoted by advanced structural heart disease, inflammation, diabetes and impaired renal function. Younger age, non-permanent AF and higher LAA flow velocities were predictors of thrombus resolution. Thrombus formation was associated with poor prognosis.

Relationship between left ventricular diastolic function and the risk of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

In patients with nonvalvular atrial fibrillation (NVAF), the impact of left ventricular diastolic function on the risk of left atrial appendage (LAA) thrombus has rarely been studied. This prospective study aimed to investigate the relationship between diastolic function and the risk of LAA thrombus in patients with NVAF. Seventy-six patients with NVAF admitted to receive radiofrequency catheter ablation were prospectively enrolled. All the patients underwent transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in 24 h before ablation. Diastolic function was estimated by TTE including left atrial volume index (LAVI) and E/e', as well as invasive left atrial pressure (LAP) measured during the ablation procedure. LAA peak emptying velocity (LAA-PEV) and the intensity of spontaneous echo contrast (SEC) were determined by TEE. Average E/e', LAVI and mean LAP had a significant positive correlation with the intensity of SEC, the coefficient of correlation were 0.344 (p = 0.002), 0.416 (p < 0.001) and 0.402 (p < 0.001), respectively. After adjustment for CHA₂DS₂-VASc score and type of AF, multivariate regression analysis revealed that increased LAP (OR 1.144, 95% CI 1.012-1.293, p = 0.031) independently correlated with the risk of LAA thrombus (SEC ≥ Grade 2). LAA-PEV showed a significantly inverse relationship with mean LAP in patients with AF (r =  - 0.525, p < 0.001), and in the assessment of elevated LAP with TEE, the LAA-PEV cut-off of 0.40 m/s had a sensitivity of 80%, specificity of 81%. Left ventricular diastolic dysfunction may constitute a potential risk for LAA thrombus and stroke. Furthermore, evaluation of LAA emptying with use of TEE is helpful for assessing the LAP status of patients with AF.

The Effect of Renal Denervation on Cardiac Diastolic Function in Patients with Hypertension and Paroxysmal Atrial Fibrillation

Objective

Renal artery denervation (RDN) can treat hypertension and paroxysmal atrial fibrillation (PAF). Hypertension and PAF can affect cardiac diastolic function. The study aimed to evaluate the effect of RDN on cardiac diastolic function in patients with refractory hypertension and PAF.

Methods

190 consecutive patients with hypertension and PAF were recruited. The levels of NT-proBNP and metrics of echocardiography were measured before and after RDN in patients with refractory hypertension and PAF. The 190 patients were divided into the decreasing HR and nondecreasing HR group, the decreasing MAP and nondecreasing MAP group, the HFPEF group, and the normal diastolic function group, respectively.

Results

Before RDN, the indices about cardiac diastolic function were out of the normal range. After RDN, the diastolic function improved in the indices of NT-proBNP, E/e′, e′. The diastolic function about the indices of NT-proBNP, E/e′, e′ was improved in the decreasing HR group, the decreasing mean arterial pressure (MAP) group, and the HFPEF group, correspondingly compared to the nondecreasing HR group, the non-decreasing MAP group, and the preoperative normal diastolic function group. In the multivariate analysis, the MAP and HR were the only two indicators significantly associated with the improvement of diastolic function.

Conclusion

RDN could improve the diastolic function in patients with refractory hypertension and PAF. Patients with HFPEF could receive benefits through RDN. It was speculated that RDN improved the diastolic function mainly through decreasing HR and MAP.

Left Atrial Thrombus in Patients With Non-valvular Atrial Fibrillation: A Cross-Sectional Study in China

Background

Stroke is predominately attributed to left atrial thrombus (LAT) in patients with non-valvular atrial fibrillation (NVAF), however, its detection rate in real clinical practice has been few reported in China.

Objective

This study aimed to investigate the prevalence and associated factors of LAT in patients with NVAF in China.

Methods

All adult NVAF patients undergoing transesophageal echocardiography (TEE) in the China Atrial Fibrillation Center database from January 2017 to January 2022 were enrolled in this study. The prevalence of LAT was calculated, and associated factors were identified.

Results

A total of 36,007 NVAF inpatients from 602 hospitals in 30 provinces/autonomous regions/municipalities were included in the final analysis, with a median age of 66 years and 39.4% were female. LAT was present in 1,467 (4.1%) patients overall, 2.7, 5.7, and 6.8% in patients with paroxysmal, persistent, and long-standing persistent AF, respectively. In subgroup analysis, including age ≥ 65 years, CHA2DS2-VASC score ≥ 2, left atrial diameter (LAD) ≥ 50 mm, left ventricular ejection fraction (LVEF) < 50%, and anticoagulation, patients with paroxysmal AF always had the lowest LAT prevalence, followed by patients with persistent and long-standing persistent AF. Patients treated with anticoagulants had less prevalent LAT than those without anticoagulation (2.1 vs. 5.0%, p < 0.001). In multivariate analysis, AF pattern (both persistent AF and long-standing persistent AF), hypertension, chronic heart failure, coronary heart disease, transient ischemic attack/stroke, diabetes mellitus, and LAD (per 5 mm) were associated with an increased prevalence of LAT. However, LVEF (per 5%) and anticoagulation were associated with a reduced prevalence of LAT.

Conclusion

LAT was found in 4.1% of Chinese adult NVAF inpatients underwent TEE in real-world experience. The prevalence of LAT mainly associated with non-paroxysmal AF, cardiovascular diseases, diabetes mellitus, enlarged left atrium, lower LVEF, and lack of anticoagulation therapy.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

Value of left atrial diameter with CHA2DS2-VASc score in predicting left atrial/left atrial appendage thrombosis in non-valvular atrial fibrillation

Fundamentos

A fibrilação atrial é a arritmia persistente mais comum e é o principal fator que leva ao tromboembolismo.

Objetivo

Investigar o valor do diâmetro do átrio esquerdo combinado com o escore CHA2DS2-VASc na predição da trombose atrial esquerda/trombose de apêndice atrial esquerdo na fibrilação atrial não valvar.

Métodos

Trata-se de estudo retrospectivo. 238 pacientes com fibrilação atrial não valvar foram selecionados e divididos em dois grupos: trombose e não trombose. Determinou-se o escore CHA2DS2-VASc. Valores de p<0,05 foram considerados estatisticamente significativos.

Resultados

A análise de regressão logística multivariada revelou que histórico de acidente vascular cerebral/ataque isquêmico transitório, doença vascular, escore CHA2DS2-VASc, DAE, DDFVE e FEVE foram fatores de risco independentes para trombose atrial esquerda/trombose de apêndice atrial esquerdo (p<0,05). A análise da curva ROC ( Receiver Operating Characteristic ) revelou que a área sob a curva para o escore CHA2DS2-VASc na predição de trombose atrial esquerda/trombose de apêndice atrial esquerdo foi de 0,593 quando o escore CHA2DS2-VASc foi ≥3 pontos, e a sensibilidade e especificidade foram 86,5% e 32,6%, respectivamente, enquanto a área sob a curva para o DAE na predição de trombose atrial esquerda/trombose de apêndice atrial esquerdo foi 0,786 quando o DAE foi ≥44,17 mm, e a sensibilidade e especificidade foram 89,6% e 60,9%, respectivamente. Entre os diferentes grupos CHA2DS2-VASc, a taxa de incidência de trombose atrial esquerda/trombose de apêndice atrial esquerdo em pacientes com DAE ≥44,17 mm foi maior do que em pacientes com DAE <44,17 mm (p <0,05).

Conclusão

O escore CHA2DS2-VASc e o DAE estão correlacionados com a trombose atrial esquerda/trombose de apêndice atrial esquerdo na fibrilação atrial não valvar. Para pacientes com escore CHA2DS2-VASc de 0 ou 1, quando o DAE é ≥44,17 mm, o risco de trombose atrial esquerda/trombose de apêndice atrial esquerdo permaneceu alto. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

The Effect of Echocardiography Based on Lipid Nano Contrast Agent on Cardiology Patients with Heart Failure and Atrial Fibrillation

This paper discusses the effect and evaluation of echocardiography based on lipid nano contrast agent on patients with heart failure and atrial fibrillation in cardiology department, providing reference for clinical diagnosis and treatment. Fifty two patients with diastolic heart failure diagnosed by echocardiography were selected for routine echocardiographic examination after optimizing the drug treatment scheme, and then the patients underwent treadmill exercise test and stress echocardiography evaluation. The results of conventional echocardiography and stress echocardiography after treatment were compared with those before treatment, and the clinical parameters and biochemical indexes before and after treatment were compared. Results after treatment, the clinical symptoms of the patients improved, the level of NT proBNP in the N-terminal forebrain decreased significantly, and the exercise tolerance increased significantly. Compared with the conventional echocardiography before and after treatment, the left ratio and e' value of stress echocardiography after treatment increased significantly, while E/e' decreased significantly. There was no significant difference in the indexes of general echocardiography before and after treatment. After treatment, positively correlated with the ratio of peak a to peak E. The results show that the sensitivity of stress echocardiography to evaluate ischemic diastolic heart failure has been improved, and some indexes have clinical significance. Compared with conventional echocardiography, it can effectively evaluate the therapeutic effect of drugs.

A Study of Cardiogenic Stroke Risk in Non-valvular Atrial Fibrillation Patients

Objectives: We attempted to develop more precisely quantified risk models for predicting cardiogenic stroke risk in non-valvular atrial fibrillation (NVAF) patients. Methods: We conducted a case-control study, using data from hospitalized patients with AF who underwent transesophageal echocardiography at Shanghai Chest Hospital. A total of 233 high cardiogenic stroke risk patients with left atrial appendage thrombus (LAT) or left atrial spontaneous echo contrast (LA-SEC) and 233 controls matched for age, sex, AF type. Results: AF history, LA diameter enlargement, larger left ventricular end diastolic diameter, lower ejection fraction, greater serum uric acid (SUA), and brain natriuretic peptide (BNP) levels showed association with high stroke risk. The multivariate logistic regression analysis revealed that AF duration, left atrial diameter (LAd), left ventricular ejection fraction (LVEF), SUA, and BNP were independent risk factors of the LAT/LA-SEC. We used LAd, LVEF, SUA, and BNP to construct a combined predictive model for high stroke risk in NVAF patients (the area under ROC curve: 0.784; sensitivity 66.1%; specificity 76.8%; 95% CI 0.744-0.825, P < 0.001). Conclusion: Comprehensive evaluation of LAd, LVEF, SUA, and BNP may help stratify the cardiogenic stroke risk among non-valvular AF patients, guiding anticoagulation therapy.

A new risk model of assessing left atrial appendage thrombus in patients with atrial fibrillation - Using multiple clinical and transesophageal echocardiography parameters

BACKGROUNDS

Predicting left atrial appendage thrombus (LAAT) in non-valvular atrial fibrillation (NVAF) patients need more precisely quantified risk models. In this study, we attempted to review the risk markers for LAAT and develop a simple and reliable model for LAAT prediction.

METHODS

The study included 307 patients with NVAF who were scheduled for transesophageal echocardiography (TEE) to exclude LAA thrombus before synchronized electrical cardioversion or radiofrequency ablation for atrial fibrillation (AF). We analyzed the relationship between echo, clinical parameters and the presence or absence of LAAT.

RESULTS

A total of 33 patients were found having LAAT (10.7%, 33/307). The age, left atrial appendage emptying velocity (LAAEV), left atrial or left atrial appendage spontaneous echocardiographic contrast (SEC), less than moderate to severe mitral regurgitation (≤mild MR), and left atrial enlargement showed association with LAAT. The multivariate logistic regression analysis revealed that LAAEV, SEC and ≤mild MR were independent risk factors of the LAAT. We used LAAEV ≤ 21.5 cm/s, SEC and ≤mild MR to construct a combined predictive model for LAAT in NVAF patients (the area under receiver operator characteristic curve: 0.88; 95% confidence interval: 0.82-0.95, P < 0.0001).

CONCLUSION

Comprehensive evaluation of LAAEV, SEC, and MR with associated LAAT may help risk stratifying the NVAF patients, especially if the LAA imaging quality was suboptimal for identifying thrombus. These parameters may facilitate the decision-making process at the time of TEE.

Diastolic function in young patients with cryptogenic stroke: A case-control pilot study

BACKGROUND

Ischaemic stroke in young individuals often remains cryptogenic. In this pilot study, we investigated, whether advanced echocardiography methods could find differences in the diastolic function between young cryptogenic stroke patients and stroke-free controls.

METHODS

We recruited 30 cryptogenic ischaemic stroke patients aged 18-49 and 30 age- and sex-matched stroke-free controls among participants of the Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome (SECRETO) study (NCT01934725). We measured diastolic function parameters derived from speckle tracking strain rate, Doppler techniques and 4D volumetry. We also performed statistical analyses comparing only the highest and lowest tertile of cases and controls for each parameter.

RESULTS

None of our patients or controls had diastolic dysfunction according to ASE/EACVI criteria. However, compared to stroke-free controls, the stroke patient group had lower E/A ratio of mitral inflow, lower lateral and mean e', lower A/a' ratio, lower strain rate in early diastole and lower speckle tracking-derived e/a ratio. When comparing the lowest tertiles, patients also had a lower peak filling rate by 4D volumetry, a lower peak early filling fraction (fraction of left ventricular filling during early diastole), and lower velocities in a series of the tissue Doppler-derived diastolic parameters and blood flow/tissue velocity ratios.

CONCLUSION

Our study displayed subtle differences in diastolic function between patients and stroke-free controls, which may play a role in early-onset cryptogenic stroke. The differences were clearer when the lowest tertiles were compared, suggesting that there is a subgroup of young cryptogenic stroke patients with subclinical heart disease.

A novel risk score for predicting left atrial and left atrial appendage thrombogenic milieu in patients with non-valvular atrial fibrillation

BACKGROUND

Although the CHADS2 and CHA2DS2-VASc scoring systems are commonly used as measures of thromboembolic risk in patients with nonvalvular atrial fibrillation (NVAF), data are inconsistent as to their value in predicting the presence of left atrial (LA) and/or left atrial appendage (LAA) thrombogenic milieu (TM). The present study aimed to establish a novel risk score to assess the risk of LA and/or LAATM in NVAF patients.

METHODS

This is a retrospective case-control study that included 125 consecutive patients with NVAF plus TM, as evidenced by transesophageal echocardiography (TEE) during a period from1 January 2010 to 1 February 2017. The controls were 1098 NVAF patients without TM during the same period. Risk factors for LA and/or LAATM were identified using univariable analysis and multivariable logistic regression. The risk score model was developed based on 10-fold validation and multiple regression. Risk model performance was evaluated using receiver operating characteristic (ROC) curves. Net reclassification improvement (NRI) was used for the comparison of C-statistics. The AUCs were compared using the Z test.

RESULTS

Among all 1223 NVAF patients, 125 (10.22%) patients had LA and/or LAATM. A score system (0-12) was developed based on the following 6 independent variables identified by 10-fold validation with sequential methods. Different points were assigned for each variable, according to multivariable regression using relative coefficients (coefficient of the index risk factor divided by the lowest coefficient among the 6 risk factors; rounded to closest integer): 1 for blood type A and N-terminal B-type natriuretic peptide (NT-proBNP) ≥864.85 pg/mL; 2 for LAD ≥43.5 mm and age ≥ 73.5 years old; 3 for previous heart failure and previous stroke or TIA. The present risk score system had a sensitivity of 58.3%, specificity of 91.4 and accuracy of 81.6%. The area under the ROC curve (AUC) was 0.832, (95% CI: 0.784-0.881; P < 0.001). The negative predictive value (NPV) was 92% when we set the cut-off point at 4; when the cut-off point was set at 8, the positive predictive value (PPV) was 85.7%. Compared with CHADS2 and CHA2DS2-VASc score, the present novel risk score has better predictive power [net reclassification improvement (NRI) +96.3% and +66.2%, respectively; all P < 0.001].

CONCLUSION

This study developed a novel risk score to help predicting LA and/or LAATM in NVAF patients, which had higher accuracy than CHADS2 and CHA2DS2-VASc score system.

Disappearance of an anticoagulation-resistant left atrial appendage thrombus after administration of low-dose pimobendan

Anticoagulation therapy is essential for preventing thrombus formation in the left atrial appendage (LAA) and subsequent ischemic strokes in patients with atrial fibrillation (AF). The complete disappearance of any existing LAA thrombi is crucial before AF ablation. Currently, warfarin and direct oral anticoagulants are widely used for this purpose. However, treatment strategies for anticoagulation-resistant LAA thrombi are not well established. Here, we present a case of an 85-year-old male who was scheduled to undergo AF ablation. He developed an LAA thrombus that was resistant to 300 mg/day of dabigatran. Low-dose pimobendan was prescribed in addition to dabigatran; three months later, the thrombus was dissolved successfully. This case demonstrates the potential efficacy of a low-dose oral inotrope for treating an anticoagulation-resistant LAA thrombus. <Learning objective: Treatment strategies for anticoagulation-resistant left atrial appendage thrombi are not well established. This case demonstrates that a low-dose oral inotrope, such as pimobendan, is capable of dissolving such thrombi and is a potentially useful treatment modality.>.

Value of Index Beat in Evaluating Left Ventricular Systolic and Diastolic Function in Patients with Atrial Fibrillation: A Dual Pulsed-Wave Doppler Study

Atrial fibrillation (AF) poses challenges in use of the echocardiogram to assess left ventricular (LV) function. The index beat method has been found to agree well with the average method. We aimed to assess the value of the index beat method in evaluation of LV function using the dual pulsed wave Doppler technique. Peak early diastolic mitral inflow velocity (E) and diastolic (e') and systolic (s') mitral annulus velocity were simultaneously obtained and measured beat-to-beat in patients with AF. The index beat s' exhibited the best correlation (r = 0.96 and 0.92, respectively, for septal and lateral wall, both p values = 0.000) with the mean, while E/e' at the pre-index beat, rather than at the index beat-initiated cycle, had the best correlation with the mean (r = 0.88 for septal and 0.97 for lateral wall, both p values = 0.000).

Incident Heart Failure and Long-Term Risk for Venous Thromboembolism

BACKGROUND

Heart failure (HF) hospitalization places patients at increased short-term risk for venous thromboembolism (VTE). Long-term risk for VTE associated with incident HF, HF subtypes, or structural heart disease is unknown.

OBJECTIVES

In the ARIC (Atherosclerosis Risk In Communities) cohort, VTE risk associated with incident HF, HF subtypes, and abnormal echocardiographic measures in the absence of clinical HF was assessed.

METHODS

During follow-up, ARIC identified incident HF and subcategorized HF with preserved ejection fraction or reduced ejection fraction. At the fifth clinical examination, echocardiography was performed. Physicians adjudicated incident VTE using hospital records. Adjusted Cox proportional hazards models were used to evaluate the association between HF or echocardiographic exposures and VTE.

RESULTS

Over a mean of 22 years in 13,728 subjects, of whom 2,696 (20%) developed incident HF, 729 subsequent VTE events were identified. HF was associated with increased long-term risk for VTE (adjusted hazard ratio: 3.13; 95% confidence interval: 2.58 to 3.80). In 7,588 subjects followed for a mean of 10 years, the risk for VTE was similar for HF with preserved ejection fraction (adjusted hazard ratio: 4.71; 95% CI: 2.94 to 7.52) and HF with reduced ejection fraction (adjusted hazard ratio: 5.53; 95% confidence interval: 3.42 to 8.94). In 5,438 subjects without HF followed for a mean of 3.5 years, left ventricular relative wall thickness and mean left ventricular wall thickness were independent predictors of VTE.

CONCLUSIONS

In this prospective population-based study, incident hospitalized HF (including both heart failure with preserved ejection fraction and reduced ejection fraction), as well as echocardiographic indicators of left ventricular remodeling, were associated with greatly increased risk for VTE, which persisted through long-term follow-up. Evidence-based strategies to prevent long-term VTE in patients with HF, beyond time of hospitalization, are needed.

Inverse Correlation Between Left Atrial Appendage Function and CHA2DS2-VASc Score in Patients with Atrial Flutter

Impaired left atrial appendage ejection fraction (LAA-EF) and peak LAA flow velocity (LAA-FV) are associated with high thromboembolic risks in patients with atrial fibrillation (AF). Herein, we examined LAA function among patients with atrial flutter (AFL) stratified by the CHA₂DS₂-VASc score using transesophageal echocardiography (TEE). Of 231 consecutive patients with typical AFL, 84 who fulfilled the inclusion criteria were enrolled. Among them, 57 had ongoing AFL and were divided into the isolated AFL (n = 38) and AFL with paroxysmal AF (PAF) (n = 19) groups, depending on whether they had sporadic AF before TEE. The remaining 27 patients with spontaneous sinus rhythm during TEE were designated as controls. Both the LAA-FV (31.9 cm/s vs. 51.5 cm/s, P = 0.004) and LAA-EF (28.4% vs. 36.5%, P = 0.024) measured during AFL were significantly lower in the AFL + PAF group than in the isolated AFL group. Significant inverse correlations between the CHA₂DS₂-VASc score and LAA-EF were identified in the AFL (P = 0.008) and AFL + PAF (P = 0.032) groups. We observed progressive LAA dysfunction in patients with AFL + PAF compared with that in patients with isolated AFL, and the LAA-EF was inversely correlated with the CHA₂DS₂-VASc score in these patients. Our findings may have implications on the application of thromboprophylactic therapy in patients with AFL.

Average e' velocity on transthoracic echocardiogram is a novel predictor of left atrial appendage sludge or thrombus in patients with atrial fibrillation

BACKGROUND

Studies have demonstrated the value of transthoracic echocardiogram (TTE) diastolic parameters in predicting left atrial appendage (LAA) thrombus; however, these studies have been small. We aim to clarify the relationship between TTE diastolic parameters, in particular average e', and LAA thrombus or sludge.

METHODS

A case-control review was conducted of subjects with non-valvular atrial fibrillation (n = 2263) who had undergone TEE (transesophageal echocardiogram) and had a TTE within 1 year of TEE. Cases of LAA sludge or thrombus were matched to controls by age, sex, left ventricular ejection fraction (LVEF), and anticoagulation status.

RESULTS

Forty-three subjects (mean age 73 ± 12, 65% male, LVEF 47%, 44% on anticoagulation) with LAA sludge or thrombus were identified. Compared to matched controls, average TTE e' (7.3 ± 2.1 cm/s vs 8.7 ± 2.1 cm/s, P < 0.001) and the E:e' ratio (15 ± 7 cm/s vs 12 ± 5 cm/s; P = 0.005) were significant predictors of LAA sludge or thrombus. Average TTE e' value of >11 cm/s had 100% sensitivity for ruling out LAA sludge or thrombus.

CONCLUSION

In individuals with atrial fibrillation, average e' >11 cm/s on TTE is a promising independent predictor of the absence of LAA sludge or thrombus on TEE.

Clinical Relevance of the Spectral Tissue Doppler E/e' Ratio in the Management of Patients with Atrial Fibrillation: a Comprehensive Review of the Literature

Atrial fibrillation is the most common cardiac rhythm disorder observed in clinical practice. It carries high morbidity and mortality rates, primarily related to heart failure, stroke and death. Validation of noninvasive markers in the diagnosis of heart failure with preserved ejection fraction and risk stratification is relevant in this clinical setting. The spectral tissue Dopplerderived E/e' ratio is a simple and reproducible index, which has been validated in noninvasive assessment of left ventricular diastolic pressures, regardless of rhythm. Septal E/e' >11 is a good predictor of invasively determined left ventricular diastolic pressure >15 mmHg in patients with atrial fibrillation. Several studies have validated the clinical relevance of abnormal values for E/e' at rest and during exercise in the diagnosis and risk stratification of heart failure with preserved ejection fraction in patients with atrial fibrillation. Increased E/e' value is associated with adverse outcome (death, left atrial appendage thrombus, stroke and heart failure) in patients with atrial fibrillation and predicts arrhythmia recurrence after cardioversion and catheter ablation. In conclusion, E/e' by spectral tissue Doppler is clinically relevant in the clinical management of any patients with atrial fibrillation referred for transthoracic Doppler echocardiography.

Predictive value of left atrial appendage lobes on left atrial thrombus or spontaneous echo contrast in patients with non-valvular atrial fibrillation

Background

Left atrial appendage morphology has been proved to be an important predictor of left atrial thrombus (LAT) and left atrial spontaneous echo contrast (LASEC) and stroke in patients with non-valvular atrial fibrillation (NVAF). However, the relation between left atrial appendage (LAA) lobes and LAT or LASEC is still unknown. The aim of this study is to investigate the correlation between the number of left atrial appendage lobes and LAT/LASEC in patients with NVAF.

Methods

This monocentric cross-sectional study enrolled 472 consecutive patients with non-valvular atrial fibrillation, who had transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) prior to cardioversion or left atrial appendage closure (LAAC) from July 2009 to August 2015 in department of cardiology of Shanghai Tenth People’s Hospital. Patients who had significant mitral or aortic valve disease, previous cardiac valvular surgery and other complicated cardiac diseases were excluded. Individuals were divided into two groups:the LAT/LASEC group (16.95%), which comprised patients with LAT or LASEC, as confirmed by TEE; and a negative control group (83.05%).Baseline overall group characterization with demographic, clinical, laboratory data and echocardiographic parameters, alongside with information on medication was obtained for all patients. Subgroup analysis with line chart was applied for exploring the association between LAA lobes and LAT/LAESC. Receptor-operating curves (ROC) were used to test the value of LA anteroposterior diameter detected by different echocardiography methods predicting LAT or LASEC. Multivariable logistic regression analysis was used to investigate independent predictors of LAT/LASEC.

Results

Among 472 patients, 23 (4.87%) had LA/LAA thrombus and 57 (12.1%) had LA spontaneous echo contrast. Compared to the negative group, patients in LAT/LASEC group had higher CHA₂DS₂-VASc score (3.79 ± 1.75 vs 2.65 ± 1.76, p < 0.001), larger LAD (measured by TTE, 48.1 ± 7.7 vs 44.6 ± 6.5, P < 0.001; measured by TEE, 52.2 ± 6.2 vs 46.7 ± 7.1, P < 0.001), lower left upper pulmonary venous flow velocity (LUPVFV) (0.54 ± 0.17 m/s vs 0.67 ± 0.26 m/s, CI 95% 0.05–0.22, P = 0.003), more left atrial appendage lobes (1.67 ± 0.77 vs 1.25 ± 0.50, p < 0.001). There was a good discriminative capacity for LAD detected by TTE (area under the curve (AUC), 0.67, CI 95% 0.61–0.73, p < 0.001) and LAD detected by TEE (AUC, 0.73, CI 95% 0.67–0.79, p < 0.001). The subgroup analysis based on gender and different LAA lobes yielded similar results (male group: p < 0.001;female group: p = 0.004) that the number of LAA lobes were significantly associated with LA thrombus or SEC. In multivariable logistic regression analysis, both the number of LAA lobes (odds ratio: 2.37; CI 95% 1.37–4.09; p = 0.002) and the persistent AF (odds ratio: 3.57; CI 95% 1.68–7.57; p = 0.001) provided independent and incremental predictive value beyond CHA₂DS₂-VASc score.

Conclusion

The number of LAA lobes is an independent risk factor and has a moderate predictive value for LAT/LASEC among NVAF patients in China.

Incremental value of left atrial mechanical dispersion over CHA2 DS2 -VASc score in predicting risk of thrombus formation

PURPOSE

To assess the potential ability of two-dimensional speckle tracking analysis (STE) during atrial fibrillation (AF) to identify patients with LA appendage thrombi (LAAT).

METHODS

This study involved 93 patients with AF (39% female, 67.1 ± 9.5 years) who were referred for a clinical indication for transesophageal echocardiography (TEE). TEE revealed LAAT in 39 (42%) patients. We analyzed standard parameters of the left ventricle (LV) and LA in transthoracic echocardiography. Using STE, we assessed LV global longitudinal strain (LVGLS), peak atrial longitudinal strain (PALS), and intra-atrial asynchrony. The PALS was calculated using the global strain curve (GPALS) and as the mean of peaks derived from segmental strain curves (MPALS).

RESULTS

Patients were comparable with regard to the clinical data. A subgroup with LAAT had lower LV ejection fraction (LVEF) and a lower absolute value of the LVGLS, as well as greater impairment in the LA standard parameters, PALS, and asynchrony. Receiver operating characteristic curve analysis revealed that the LVEF of 30% (P < .001), the LVGLS of -7% (P < .0001), the GPALS of 11% (P < .005), and the LA asynchrony of 22% (P < .01) were the optimal cutoff values for distinguishing both subgroups. LA asynchrony, LVEF, and LVGLS were independently associated with the presence of LAAT in multivariate analyses, and PALS had additional significance over the CHA₂ DS₂ -VASc score.

CONCLUSIONS

Left ventricular systolic dysfunction characterized by both LVEF and LVGLS is an independent factor for LAAT. LA asynchrony provides additional diagnostic value for discriminating between patients with and without LAAT.

Evaluation of sex differences in the relationship between diastolic dysfunction and thromboembolism using propensity score analysis

BACKGROUND

Female sex is a risk factor for thromboembolism (TE) in atrial fibrillation (AF); however, the underlying mechanisms are unclear. We postulated that left ventricular (LV) diastolic dysfunction (LVDD) could be associated with increased thromboembolic risk in women.

METHODS

From a retrospective cohort, 158 patients (female : male = 79:79) with nonvalvular AF were propensity score-matched for age, presence of diabetes, hypertension, coronary artery disease, congestive heart failure, embolic history, AF type, and AF duration. Cardiac size and function and central aortic stiffness parameters were evaluated. Diastolic function was classified as normal, indeterminate, and LVDD according to recent guidelines. Surrogate markers for thromboembolism (dense spontaneous echo contrast and thrombus) were evaluated using transesophageal echocardiography.

RESULTS

Surrogate markers for TE showed a trend to be more frequent in women than in men (21.5% vs 11.4%, P = .086). LVDD was more prevalent in women than in men (22.8% vs 2.5%, P < .001); however, the prevalence of indeterminate diastolic function was not different between sexes (26.6% vs 20.3%, P = .453). Surrogate markers for TE were detected mostly in women with LVDD. LV diastolic parameters showed a restrictive pattern, and aortic stiffness parameters were worse in women than in men. Women with LVDD had increased aortic stiffness compared to women with indeterminate and normal function, whereas aortic stiffness did not differ among men in all groups. Significant relations between LV diastolic function and aortic stiffness parameters were observed only in women.

CONCLUSION

LVDD due to increased aortic stiffness could be related to a higher thromboembolic risk in women with AF.