Clinical Predictors of Left Atrial Thrombus and Spontaneous Echocardiographic Contrast in Patients with Atrial Fibrillation

External validation and comparison of CHA2DS2-VASc-RAF and CHA2DS2-VASc-LAF scores for predicting left atrial thrombus and spontaneous echo contrast in patients with non-valvular atrial fibrillation

PURPOSE

CHA₂DS₂-VASc-RAF (R is renal dysfunction, and AF is atrial fibrillation type) and CHA₂DS₂-VASc-LAF (L is left atrial diameter, and AF is atrial fibrillation type) scores have been developed to estimate the risk of left atrial thrombus (LAT) and spontaneous echo contrast (SEC) in patients with non-valvular atrial fibrillation (NVAF). However, few external validations have been conducted to assess their accuracy. Thus, this study aimed to validate and compare the two modified scores for predicting LAT/SEC in patients with NVAF.

METHODS

This study included 399 patients with NVAF who underwent transesophageal echocardiography. Risk factors related to LAT/SEC were identified through logistic regression analysis, and predictive value and diagnostic efficiency were evaluated using receiver operating characteristic (ROC) curve.

RESULTS

Approximately 9.8% (39/399) of the patients with NVAF had LAT/SEC. Multivariate logistic regression analysis showed that history of stroke/transient ischemic attack, congestive heart failure, non-paroxysmal atrial fibrillation, lack of anticoagulation therapy, enlarged left atrial diameter, enlarged left ventricular end diastolic diameter, decreased left ventricular ejection fraction, decreased left atrial appendage emptying velocity, and decreased estimated glomerular filtration rate were independent risk factors for LAT/SEC. The CHA₂DS₂-VASc-LAF (area under the ROC curve [AUC] = 0.839) and CHA₂DS₂-VASc-RAF (AUC = 0.829) scores showed larger predictive values than the CHA₂DS₂-VASc (AUC = 0.737) and CHADS₂ (AUC = 0.736) scores. The AUC of the CHA₂DS₂-VASc-RAF score was similar to that of the CHA₂DS₂-VASc-LAF score (Z = 0.432; P = 0.666).

CONCLUSION

This study validated that the CHA₂DS₂-VASc-RAF and CHA₂DS₂-VASc-LAF scores are useful prognostic scoring systems for predicting LAT/SEC in patients with NVAF.

Relationship of warfarin versus DOACs with thrombogenic milieu in the left atrium among patients with nonvalvular atrial fibrillation

BACKGROUND

Thrombogenic milieu (TM) within the left atrium plays a pivotal role in the pathogenesis of thromboembolic events, for which anticoagulation treatment is indicated typically on the mandatory basis. Little is known, however, about which regimen of anticoagulation, warfarin or direct oral anticoagulants (DOACs), is more likely associated with TM. We evaluated relative relationship of the two treatment options with concurrently-observed TM in patients with nonvalvular atrial fibrillation (AF) who underwent transesophageal echocardiography.

METHODS

TM was defined as the presence of either left atrial spontaneous echo contrast (SEC) or thrombus, or both. To determine which regimen was more likely related to TM, we firstly compared the prevalence of TM in 208 patients taking warfarin (Warfarin group) versus 486 patients taking DOACs (DOAC group); and secondly, did the same analysis after propensity score matching.

RESULTS

Warfarin group was more likely associated with TM compared with DOAC group (46% vs 29%, p < 0.001). Similar findings were observed for dense SEC (18% vs 7%, p < 0.001) and thrombus (4% vs 1%, p = 0.057). The propensity score matching (198 patients for each group), where several baseline parameters were matched including age, gender, chronicity of AF, estimated glomerular filtration rate and B-type natriuretic peptide as well as the left ventricular ejection fraction, resulted in similar findings to the original groups (TM, 47% vs 32%, p = 0.002; dense SEC, 18% vs 7%, p = 0.001; thrombus, 4% vs 1%, p = 0.047).

CONCLUSIONS

This study may strengthen the data on randomized trials that DOACs are superior to warfarin in preventing thromboembolic events in nonvalvular AF patients. Further studies are required to elucidate the details behind this difference.

Atherosclerotic Burden and Vascular Risk in Stroke Patients With Atrial Fibrillation

[Figure: see text].

Clinical characteristics and outcomes in patients with echocardiographic left ventricular spontaneous echo contrast

BACKGROUND

Spontaneous echo contrast (SEC) is a known precursor to thrombus formation and thromboembolic events. This study aims to demonstrate the clinical characteristics and outcomes of patients with left ventricular spontaneous echo contrast (LV-SEC).

METHODS

Patients with consecutive echocardiogram performed from October 2009 to September 2019 were enrolled in this retrospective, single-center study. Those with LV-SEC were included, while patients complicated by left ventricular thrombus, with history of infective endocarditis, prosthetic valves, or lost to follow-up were excluded. The clinical endpoint was 1-year thromboembolic events (i.e. stroke and peripheral embolism).

RESULTS

Among 417 patients (mean age 63.5 ± 14.7 years; 86.8% men) with LV-SEC, the incidence of 1-year embolism was 12.9%. In multivariate Cox proportional hazard model, significant risk factors for thromboembolic event were age [hazard ratio (HR) = 1.022, 95% confidence interval (CI): 1.000-1.045], atrial fibrillation (AF) (HR = 2.292, 95% CI: 1.237-4.244), hemoglobin (HR = 1.032, 95% CI: 1.017-1.047), left ventricular ejection fraction (LVEF) (HR = 1.021, 95% CI: 1.002-1.041), and anticoagulant therapy (HR = 0.310, 95% CI: 0.168-0.572). For patients with repeated measurements for echocardiography, D-dimer (HR = 1.137, 95% CI: 1.051-1.231), and _△LVEF (HR = 0.961, 95% CI: 0.928-0.996) were independently associated with the persistent LV-SEC.

CONCLUSION

The present study reported a high incidence of 1-year thromboembolic event in patients with LV-SEC. Age, AF, hemoglobin, LVEF were independent risk factors for 1-year embolism and a reduced risk of embolism was observed among patients with anticoagulation therapy. Additionally, D-dimer and _△LVEF are independently associated with the persistent LV-SEC.

Predictors of left atrial thrombus in acute ischemic stroke patients without atrial fibrillation: A single-center cross-sectional study

INTRODUCTION

The present study aimed to determine independent predictors of left atrial thrombus (LAT) in acute ischemic stroke (AIS) patients without atrial fibrillation (AF) using transesophageal echocardiography (TEE).

METHODS

In this single-center, retrospective study, we enrolled 149 consecutive AIS patients. All of the patients underwent a TEE examination to detect LAT within 10 days following admission. Multivariate logistic regression analysis was performed to assess independent predictors of LAT.

RESULTS

Among all cases, 14 patients (9.3%) had a diagnosis of LAT based on the TEE examination. In a multivariate analysis, elevated mean platelet volume (MPV), low left-ventricle ejection fraction (EF), creatinine, and reduced left-atrium appendix (LAA) peak emptying velocity were independent predictors of LAT. The area under the receiver operating characteristic curve analysis for MPV was 0.70 (95%CI: 0.57-0.83; p = 0.011). With the optimal cut-off value of 9.45, MPV had a sensitivity of 71.4% and a specificity of 63% to predict LAT.

CONCLUSION

AIS patients with low ventricle EF and elevated MPV should undergo further TEE examination to verify the possibility of a cardio-embolic source. In addition, this research may provide novel information with respect to the applicability of MPV to predict LAT in such patients without AF.

Left atrial spontaneous echo contrast occurring in patients with low CHADS2 or CHA2DS2-VASc scores

Background

Left atrial spontaneous echo contrast (LASEC) is common in patients with atrial fibrillation (AF), although scarce information exists on LASEC occurring in nonvalvular AF patients who have low thromboembolic risk scores. We therefore examined prevalence and determinants of LASEC under low CHADS₂ or CHA₂DS₂-VASc scores in these patients.

Methods

Among 713 patients who underwent transesophageal echocardiography, 349 with a CHADS₂ score < 2 (CHADS₂ group) (93 women, mean age 65 years) and 221 with a CHA₂DS₂-VASc score < 2 (CHA₂DS₂-VASc group) (39 women, mean age 62 years) were separately examined for clinical and echocardiographic findings.

Results

LASEC was found in 77 patients of CHADS₂ group (22%) and in 41 of CHA₂DS₂-VASc group (19%). Multivariate logistic regression analysis, adjusted for several parameters including non-paroxysmal AF, LA enlargement (LA diameter ≥ 50 mm), left ventricular (LV) hypertrophy, and an elevated B-type natriuretic peptide (BNP) (BNP ≥200 pg/mL) revealed that for CHADS₂ group, non-paroxysmal AF (Odds ratio 5.65, 95%CI 3.08–10.5, P < 0.001), BNP elevation (Odds ratio 3.42, 95%CI 1.29–9.06, P = 0.013), and LV hypertrophy (Odds ratio 2.26, 95%CI 1.19–4.28, P = 0.013) were significant independent determinants of LASEC, and that for CHA₂DS₂-VASc group, non-paroxysmal AF (Odds ratio 3.38, 95%CI 1.51–7.54, P = 0.003) and LV hypertrophy (Odds ratio 2.53, 95%CI 1.13–5.70, P = 0.025) were significant independent determinants of LASEC.

Conclusions

LASEC was present in a considerable proportion of patients with nonvalvular AF under low thromboembolic risk scores. Information on AF chronicity, BNP, and LV hypertrophy might help identify patients at risk for thromboembolism, although large-scale studies are necessary to confirm our observations.

Real-Time Pathophysiologic Correlates of Left Atrial Appendage Thrombus in Patients Who Underwent Transesophageal-Guided Electrical Cardioversion for Atrial Fibrillation

Although current guidelines advocate using the CHA₂DS₂-VASc score to assess the risk of stroke in patients with atrial fibrillation (AF), compared with transesophageal echocardiography (TEE), its ability to predict left atrial appendage thrombus (LAAT) is limited. We studied 3,324 consecutive patients with sustained AF from our prospective registry of patients who underwent first-time TEE-guided electrical cardioversion (ECV) from May 2000 through March 2012. The association of CHA₂DS₂-VASc score or TEE risk factors with the occurrence of LAAT was analyzed. The mean (SD) age was 69 (12.5) years and 67% were men. LAAT was identified in 49 (1.5%) during pre-ECV TEE. Compared with patients without LAAT, those with LAAT had lower peak left atrial appendage emptying velocity (LAAEV) (17.2 ± 8.5 vs 36.6 ± 20.8; p <0.001) and left ventricular ejection fraction (LVEF) (39.9 ± 17.6 vs 51.4 ± 13.7; p <0.001); their CHA₂DS₂-VASc score also was higher, but the difference was not statistically significant (3.6 ± 1.4 vs 3.2 ± 1.6; p = 0.06). Multivariate logistic regression analysis identified an LVEF ≤40% (adjusted odds ratio 2.48, 95% confidence interval 1.38 to 4.46), LAAEV 20.3 to 33.9 cm/s (odds ratio 12.19, 95% confidence interval 1.53 to 96.86), and LAAEV ≤20.2 cm/s as independent predictors of LAAT. An LAAEV cut-point of 20 cm/s and an LVEF ≤40% were optimal for detecting LAAT (sensitivity 75% and 62%; specificity 77% and 75%; area under the curve 0.822 and 0.776, respectively). On follow-up, LAAT was an independent risk factor of subsequent ischemic stroke but did not influence survival. In conclusion, reduced LVEF and reduced LAAEV are important pathophysiologic correlates of left atrial appendage thrombogenesis and subsequent ischemic stroke in patients who underwent TEE-guided ECV for AF.

Ischaemic cardiovascular mortality in patients with non-valvular atrial fibrillation according to CHADS2 score

The CHADS2 score predicts the risk of ischaemic stroke in patients with non-valvular atrial fibrillation (NVAF). Most components of the CHADS2 score are also risk factors of atherosclerosis, and clustering of these risk factors is associated with increased risk of cardiovascular disease, including ischaemic heart disease. The aim of this study was to investigate whether the CHADS2 score and CHA2DS2-VASc score are predictive of fatal ischaemic heart disease as well as fatal ischaemic stroke. Among 5,268 stroke patients admitted between August 1994 and December 2008, 770 stroke patients with NVAF were enroled in this study. The relationship between CHADS2 score or CHA2DS2-VASc score and the fatal ischaemic events was examined using a Cox regression model. During the follow-up period of 1156.0 ± 1205.0 days (median 729.5, in-terquartile range 179.0 – 1751.0), 321 patients died (41.7%). The CHADS2 score or CHA2DS2-VASc score was positively correlated with fatal ischaemic heart disease as well as with fatal ischaemic stroke. After adjustment for all potential confounders, the occurrence of fatal ischaemic heart disease was independently associated with CHADS2 score or CHA2DS2-VASc score, and previous history of ischaemic heart disease. The CHADS2 and CHA2DS2-VASc scores provide valuable information for identifying high-risk individuals for fatal ischaemic heart and brain diseases among stroke patients with NVAF.

Pre-stroke glycemic control is associated with early neurologic deterioration in acute atrial fibrillation-related ischemic stroke

Background

It has been suggested that AF-related ischemic stroke (IS) that is accompanied by atherosclerotic burden have poorer outcomes. The aim of this study was to investigate the importance of pre-stroke glycemic control (PSGC) on the early neurologic deterioration (END) of patients with acute AF-related IS.

Methods

We retrospectively recruited 121 patients with AF-related IS who also had Diabetes mellitus (DM). The HbA1C level was measured in all subjects. END was defined as an increase in the National Institute of Health Stroke Scale (NIHSS) score of 4 NIHSS points within 7 days of symptom onset compared to the initial NIHSS score.

Results

In this study, 20.7% (25 patients) were classified as having a poor PSGC status with a HbA1C level above 8.0%. In the univariate analysis, a poor PSGC status (p < 0.01), smoking (p = 0.01), severe neurologic deficits at admission (p = 0.01), and a larger size of ischemic lesions on DWI (p < 0.01) were associated with the occurrence of END. In the multivariate model, a poor PSGC status (p = 0.02) and larger size of ischemic lesions on MRI (p < 0.01) were independent predictors of END in acute AF-related IS.

Conclusion

The HbA1c level upon admission was independently associated with significant prediction of END in acute AF-related IS.

Left atrial thrombi and spontaneous echo contrast in patients with atrial fibrillation : Systematic analysis of a single-center experience

BACKGROUND

Atrial fibrillation is associated with a high risk for thromboembolic events. Thrombi in the left atrial appendage and spontaneous echo contrast (SEC) correlate positively with this embolic risk. We studied the laboratory, echocardiographic, and epidemiologic parameters that could predict left atrial thrombi and the intensity of the SEC.

PATIENTS AND METHODS

Between September 2013 and June 2015 we included 372 patients with atrial fibrillation before planned electrical cardioversion (transesophageal-guided strategy) in this study. After assessing the risk of stroke and bleeding (CHA₂DS₂-VASc and HAS-BLED scores), we measured the concentration of the D-dimer and B-type natriuretic peptide at the time of the transesophageal echocardiography as well as the left atrial volume and the ejection fraction during transthoracic echocardiography.

RESULTS

The ejection fraction and the CHA₂DS₂-VASc score were identified as independent predictors of both left atrial thrombi and SEC, whereas the left atrial volume could only predict the intensity of SEC. In contrast to the results of other studies, the biomarkers in this study failed to predict the outcome.

CONCLUSION

Only the echocardiographic and epidemiologic parameters were predictors of left atrial thrombi and SEC intensity, while the studied biomarkers had no predictive power. Using clinical data and transthoracic echocardiography, we can change the therapeutic strategy in high-risk patients.

Prevalence of left atrial thrombus in patients with non-valvular atrial fibrillation. A systematic review and meta-analysis of the literature

We performed a meta-analysis about the prevalence of left atrial thrombus (LAT) in patients with atrial fibrillation (AF) undergoing trans-esophageal echocardiography (TEE). Studies reporting on LAT presence in AF patients were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases and the pooled LAT prevalence was evaluated as weighted mean prevalence (WMP). Seventy-two studies (20,516 AF patients) showed a LAT WMP of 9.8 % (95 %CI: 7.6 %-12.5 %). LAT presence was associated with a higher age (mean difference: 2.56, 95 %CI: 1.49-3.62), and higher prevalence of female gender (OR: 1.35, 95 %CI: 1.04-1.75), hypertension (OR: 1.78, 95 %CI: 1.38-2.30), diabetes mellitus (OR: 1.86, 95 %CI: 1.33-2.59) and chronic heart failure (OR: 3.67, 95 %CI: 2.40-5.60). Overall, LAT patients exhibited a higher CHADS2-score (mean difference 0.88, 95 %CI: 0.68-1.07) and a higher risk of stroke/systemic embolism (OR: 3.53, 95 %CI: 2.24-5.56) compared with those without LAT. A meta-regression showed an inverse association between LAT prevalence and the presence of anticoagulation (Z-value: -7.3, p< 0.001). Indeed, studies in which 100 % of patients received oral anticoagulation reported a 3.4 % WMP of LAT (95 %CI: 1.3 %-8.7 %), whereas studies in which 0 % of patients received anticoagulation showed a LAT WMP of 7.4 % (95 %CI: 2.3 %-21.5 %). Our data suggest that LAT is present in ≍10 % of AF patients, and is associated with a 3.5-fold increased risk of stroke/systemic embolism. Interestingly, LAT is also reported in some of patients receiving anticoagulation. The implementation of the screening of LAT in AF patients before cardioversion/ablation could be useful for the prevention of vascular events.

Prevalence and Clinical Determinants of Left Atrial Appendage Thrombus in Patients With Atrial Fibrillation Before Pulmonary Vein Isolation

The CHADS2 score is considered a reliable predictor of stroke/thromboembolism risk in patients with atrial fibrillation (AF). However, thromboembolism can occasionally occur even in patients with AF with low CHADS2 score (CHADS2 score = 0 or 1). To investigate the incidence and predictors of left atrial appendage (LAA) thrombus (LAAT) formation in patients with AF, we studied consecutive 543 Japanese patients with AF who underwent transesophageal echocardiography before pulmonary vein isolation from 2008 to 2012. All patients were treated with anticoagulation therapy with warfarin, and their clinical and echocardiographic characteristics were evaluated. LAATs were observed in 35 (6.4%) of 543 patients, and the prevalence was clearly correlated with the patient's CHADS2 scores. Of 338 patients with low CHADS2 score, LAATs were observed in 7 patients (2.1%). By multivariate analysis, increased left atrial volume (≥50 ml), decreased ejection fraction (<56%), and increased brain natriuretic peptide level (>75 pg/ml) were significantly associated with increased prevalence of LAATs, even in patients with low CHADS2 score. Accordingly, we proposed a new scoring system to predict LAAT (left atrial volume ≥50 ml: score 2; ejection fraction <56%: score 1; brain natriuretic peptide >75 pg/ml: score 1). Patients with a score ≥2 have a greater risk of LAAT, whereas all patients with score ≤1 have no LAATs. Our scoring system is useful for evaluation of the risk of LAAT in patients with AF even with low CHADS2 score.

Relationship between CHADS2 score and complex aortic plaques by transesophageal echocardiography in patients with nonvalvular atrial fibrillation

The CHADS2 score is widely used for risk stratification of thromboembolism in patients with non-valvular atrial fibrillation (NVAF). Although the correlation of CHADS2 score with left atrial (LA) abnormality as detected by transesophageal echocardiography (TEE) has been reported in previous studies, the relationship between CHADS2 score and complex aortic plaque, which is also a significant risk factor for thromboembolism, has not been fully investigated. We assessed aortic plaques by TEE in 150 patients age ≥ 55 y with NVAF. The prevalence of complex aortic plaques increased along with increases in CHADS2 score (p = 0.001). In a multivariate analysis that included atherosclerotic risk factors and LA abnormality, a CHADS2 score ≥2 was independently associated with the presence of complex aortic plaques (odds ratio [OR] 3.39; 95% confidence interval [CI], 1.29-8.90). A high CHADS2 score is closely associated with the presence of complex aortic plaques, which explains, in part, the increased risk of thromboembolism in NVAF patients with high CHADS2 score.

Adenosine diphosphate-induced platelet aggregation might contribute to poor outcomes in atrial fibrillation-related ischemic stroke

Systemic atherosclerosis is involved in ischemic damages and cardioembolism after atrial fibrillation (AF)-related ischemic stroke (IS). Platelet activation is a critical factor in systemic atherosclerosis; however, there is little information regarding the role of platelet activation on the outcome of AF-related IS. We investigated the relationship between adenosine diphosphate (ADP)-induced platelet aggregation and the long-term outcomes of AF-related IS. We studied 249 patients who were exclusively treated with anticoagulation therapy after they had experienced AF-related IS. We evaluated their platelet function 5 days after admission to the hospital by using an optic platelet aggregometer test. We also assessed the prognoses of patients 90 days after the AF-related IS. Our results showed that ADP-induced platelet aggregation was positively correlated with CHA2DS2-VASc scores (r = .285, P < .01). Totally, 107 (43.0%) patients had a poor outcome at 90 days after IS. Univariate analysis showed that the following factors significantly contribute to a poor outcome: older age (odds ratio [OR] = 1.07, confidence interval [CI] 1.04-1.10, P < .01), a history of stroke (OR = 3.24, CI 1.61-6.53, P < .01), high scores on the National Institutes of Health Stroke Scale (NIHSS; OR = 1.25, CI 1.18-1.32, P < .01), increased white blood cell counts (OR = 1.12, CI 1.02-1.24, P < .01), high CHA2DS2-VASc scores (≥5, OR = 7.31, CI 3.36-15.93, P = .025), and the highest tertile of ADP-induced platelet aggregation (≥72%, OR = 3.17, CI 1.67-5.99, P < .01). Of these factors, high NIHSS scores (OR = 1.27, CI 1.20-1.36, P < .01), high CHA2DS2-VASc scores (OR = 4.69, CI 1.21-18.14, P = .03), and the highest tertile of ADP-induced platelet aggregation (OR = 2.49, CI 1.17-5.27, P = .02) were independently associated with a poor outcome at 90 days after IS. Therefore, our results suggest that platelet activation might affect the outcome of AF-related IS.

Efficacy of the CHADS₂ scoring system to assess left atrial thrombogenic milieu risk before cardioversion of non-valvular atrial fibrillation

The CHADS₂ scoring system was found to be a good predictor for risk stratification of stroke in patients with atrial fibrillation. The effectiveness of this scoring system in assessing thrombogenic milieu before direct-current cardioversion has not yet fully been established on a large scale. In this study, data from 2,369 consecutive patients in whom transesophageal echocardiography was performed for screening before direct-current cardioversion from 1999 to 2008 were analyzed. Left atrial (LA) or LA appendage (LAA) thrombogenic milieu (spontaneous echo contrast, sludge, and thrombus) was investigated. The results were correlated with CHADS₂ score findings. The mean age was 66 ± 13 years, and the ratio of men to women was 2.2:1. CHADS₂ scores of 0, 1, 2, 3, 4, 5 and 6 were present in 11%, 25%, 30%, 22%, 8%, 3%, and 1% of the studies, respectively. The prevalence of LA or LAA sludge or thrombus increased with increasing CHADS₂ scores (2.3%, 7%, 8.5%, 9.9%, 12.3%, and 14.1% for scores of 0, 1, 2, 3, 4, and 5 or 6, respectively, p = 0.01). In a multivariate model, an ejection fraction ≤20% was the best predictor of LA or LAA sludge or thrombus (odds ratio 2.99, p <0.001). In conclusion, transesophageal echocardiographic markers of thrombogenic milieu were highly correlated with increasing CHADS₂ scores in patients who underwent transesophageal echocardiography-guided cardioversion. Giving more value to echocardiographic findings, such as the left ventricular ejection fraction, and its different levels (especially an ejection fraction ≤20%) might improve the precision of the CHADS₂ scoring scheme to predict thrombogenic milieu in the left atrium or LAA as a surrogate to cardioembolic risk in patients with atrial fibrillation.

Prevalence of left chamber cardiac thrombi in patients with dilated left ventricle at sinus rhythm: the role of transesophageal echocardiography

BACKGROUND

Left atrial appendage (LAA) may be a source of thrombi in patients with dilated cardiomyopathy at sinus rhythm. The objectives of our study were to assess the prevalence of intracardiac left chamber thrombus and/or spontaneous echo contrast and to identify clinical and echocardiographic predictors for left ventricle (LV), left atrium (LA), and/or LAA thrombus formation, particularly as regard to LV, LA, and LAA size, in heart failure patients at sinus rhythm.

METHODS

We included 45 patients with dilated cardiomyopathy of ischemic or idiopathic origin with mild to moderate systolic dysfunction, who were at sinus rhythm and without anticoagulation therapy.

RESULTS

Mean left ventricular end diastolic diameter was 64.9 ± 6.1 mm, and mean LV ejection fraction was 39.9 ± 7.3%. LV thrombus was found in 13.3% of patients and LAA thrombus in 68. 9%. Left ventricular end diastolic diameter was correlated with LA volume (r = 0.59, p < 0.0001) and LV thrombus (r = 0.38, p = 0.005). LA volume was correlated with LAA maximal area (r = 0.34, p = 0.01), which was an independent predictor for LAA thrombus formation (p = 0.003).

CONCLUSIONS

Dilation of left cardiac chambers offers a suitable terrain for thrombus formation. The high probability of LAA thrombosis should be kept in mind when designing the treatment strategy for patients with dilated cardiomyopathy at sinus rhythm.

Correlation of CHADS2 and CHA2DS2-VASc scores with transesophageal echocardiography risk factors for thromboembolism in a multiethnic United States population with nonvalvular atrial fibrillation

BACKGROUND

The aims of this study were to evaluate the relationship of the CHA(2)DS(2)-VASc score and risk categories with transesophageal echocardiographic (TEE) risk factors for thromboembolism and to compare the CHA(2)DS(2)-VASc and CHADS(2) risk stratification schemes with respect to their ability to predict these risk factors in a multiethnic US population with nonvalvular atrial fibrillation.

METHODS

Transesophageal echocardiograms of 167 patients (mean age, 66.3 ± 11.6 years; 146 men [87%]; 100 whites [60%]; 40 Hispanics [24%]; 27 blacks [16%]) with nonvalvular atrial fibrillation were retrospectively reviewed for smoke, sludge, thrombus, and left atrial appendage (LAA) emptying velocity ≤20 cm/sec. The patients' CHA(2)DS(2)-VASc and CHADS(2) risk scores and categories were also calculated.

RESULTS

Any LAA abnormality, smoke, sludge, thrombus, and abnormal LAA emptying velocity were present in 45%, 38%, 13%, 3%, and 22% of patients, respectively. Heart failure (P < .001), age (P < .001 for age ≥75 vs ≤64 years, P = .013 for age 65-74 vs ≤64 years), and diabetes (P = .019) were independent predictors of LAA abnormalities, while ethnicity was not. The prevalence of TEE risk factors for thromboembolism increased with increasing CHA(2)DS(2)-VASc score and risk category. The CHADS(2) risk categories of 35 patients (21%) were upgraded by the CHA(2)DS(2)-VASc scheme. Using the latter scheme, fewer patients were classified as at intermediate risk compared with the CHADS(2) system (21 [13%] vs 46 [28%]). Patients classified as at low risk by either scheme had almost no TEE risk factors. Of 30 intermediate-risk patients by CHADS(2) score upgraded to high risk using CHA(2)DS(2)-VASc score, eight (27%) had at least one TEE risk factor for thromboembolism. C-statistics, sensitivity, and specificity for predicting any LAA abnormality were 0.607 (95% confidence interval, 0.549-0.665), 92.0%, and 28.9% for CHA(2)DS(2)-VASc score and 0.685 (95% confidence interval, 0.615-0.755), 81.3%, and 54.2% for CHADS(2) score.

CONCLUSIONS

CHA(2)DS(2)-VASc score is associated with TEE risk factors for thromboembolism in a multiethnic US population. Compared with CHADS(2) score, it has increased sensitivity, decreased specificity, and lower ability for predicting TEE risk factors in this population.

Left ventricular mass predicts left atrial appendage thrombus in persistent atrial fibrillation

AIMS

Atrial fibrillation (AF) can result in the development of left atrial appendage (LAA) thrombi. We sought to examine demographic and echocardiographic predictors of LAA thrombus in patients with persistent AF.

METHODS AND RESULTS

One hundred and sixty-five patients in persistent AF (36 with LAA thrombus and 129 without thrombus) were studied. Demographic and cardiovascular risk factors were retrospectively examined. Transthoracic (TTE) and transoesophageal echocardiography (TOE) were performed to assess the size and function of the left ventricle (LV), left atrium (LA), LAA, and spontaneous echo contrast (SEC) in the LA and right atrium (RA). Univariate demographic predictors of LA thrombus included systolic blood pressure, ischaemic heart disease and congestive heart failure. Indexed LV mass and septal E' velocity on TTE and mean LAA emptying velocity and the presence of SEC in both the LA and RA on TOE were predictors of thrombus. In a multiple logistic regression analysis the only independent predictor of thrombus was indexed LV mass (P < 0.001). Receiver operator characteristic curve analysis also demonstrated that indexed LV mass had the highest area under the curve (AUC: 0.98).

CONCLUSION

In the present study, increased LV mass was the strongest predictor of LAA thrombus in persistent AF. LA SEC and RA SEC were univariate predictors of LAA thrombus but did not add predictive value to a multivariate model including LV mass. This study highlights the importance of diagnosing and treating LV hypertrophy associated with persistent AF, which may reduce the risk of LAA thrombus and thrombo-embolic stroke.

The role of repeat transesophageal echocardiography in patients without atrial thrombus prior to cardioversion or ablation

BACKGROUND

Cardioversion (CV) and radiofrequency catheter ablation (RFA) are often used to restore sinus rhythm in patients with atrial fibrillation (AF). These procedures are associated with a risk for stroke. The use of transesophageal echocardiography (TEE) to guide the management of AF is a validated strategy for patients in whom CV is planned, as well patients before RFA. For patients in whom the initial procedure fails, repeat TEE is often performed before repeat CV or RFA. The aim of this study was to test the hypothesis that patients with initial negative results on TEE would be unlikely to have thrombi detected on subsequent TEE and thus may avoid repeat procedures.

METHODS

A total of 2,999 patients with AF were identified via retrospective review who had undergone TEE before CV or RFA, and 418 of these individuals underwent repeat TEE. After excluding patients who underwent repeat TEE >365 days from the initial study (n = 135) and those with thrombi on initial TEE (n = 20), 263 patients who had underwent two or more examinations were identified and analyzed.

RESULTS

Of 263 eligible patients, two (0.8%; 95% confidence interval, 0.21-2.7%) had thrombi on subsequent TEE.

CONCLUSIONS

Fewer than 1% of patients with AF with negative results on baseline TEE had thrombi detected on repeat TEE before subsequent CV or RFA. Thus, it may be possible to selectively screen patients to identify those at low risk for developing thrombi subsequent to negative results on initial TEE, especially if patients are in sinus rhythm. These results suggest the need for a prospective trial to definitively answer the question regarding repeat TEE in low-risk patients.

Early detection of left atrial strain abnormalities by speckle-tracking in hypertensive and diabetic patients with normal left atrial size

BACKGROUND

Systemic hypertension and type 2 diabetes mellitus are associated with impaired left atrial (LA) function, but whether LA functional abnormalities also occur in patients with hypertension and diabetes who have normal LA sizes is unknown. The aim of this study was to explore LA strain using speckle-tracking echocardiography in patients with hypertension or diabetes and normal LA size.

METHODS

LA strain was studied by speckle-tracking echocardiography in 155 patients with hypertension or diabetes with LA volume indexes < 28 mL/m(2) (83 with hypertension, 34 with diabetes, and 38 with both diabetes and hypertension) and 36 age-matched controls. The following indexes were measured: peak atrial longitudinal strain, time to peak atrial longitudinal strain, atrial longitudinal strain during early diastole and late diastole, and peak LA strain rate during ventricular systole, early diastole, and late diastole.

RESULTS

Peak atrial longitudinal strain was lower in patients with hypertension (29.0 ± 6.5%) and those with diabetes (24.7 ± 6.4%) than in controls (39.6 ± 7.8%) and further reduced in patients with diabetes and hypertension (18.3 ± 5.0%) (P < .0001). Similar results were found for atrial longitudinal strain during early diastole, atrial longitudinal strain during late diastole, and peak LA strain rate during ventricular systole and early diastole (P < .0001 for all). An inverse trend was found for time to peak atrial longitudinal strain, whereas no differences in peak LA strain rate during late diastole were observed. Two-way analysis of variance showed no interactions between hypertension and diabetes. In multivariate analyses, hypertension and diabetes were both independently associated with decreases in all LA strain and strain rate indexes, with the exception of peak LA strain rate during late diastole.

CONCLUSIONS

LA deformation mechanics are impaired in patients with hypertension or diabetes with normal LA size. The coexistence of both conditions further impairs LA performance in an additive fashion. Speckle-tracking echocardiography may be considered a promising tool for the early detection of LA strain abnormalities in these patients.

Impact of routine transoesophageal echocardiography on safety, outcomes, and cost of pulmonary vein ablation: inferences drawn from a decision analysis model

AIMS

The practice of routine vs. selective transoesophageal echocardiography (TEE) surveillance for left atrial appendage or intracavitary thrombus prior to pulmonary vein isolation (PVI) varies widely as evidence to guide this decision in terms of important clinical outcomes is lacking.

METHODS AND RESULTS

We constructed a decision analysis model to compare the cost-effectiveness of routine TEE for detection of left atrial thrombus vs. no TEE. The model incorporated health outcomes and costs. Markov methodology was used to follow patients as they transition through varying health states. We examined a hypothetical cohort of patients with symptomatic atrial fibrillation suitable for PVI, and expected outcomes were modelled over a period of 2 years. Simulated patients (SPs) undergoing a strategy of a routine TEE experienced significantly fewer transient ischemic attacks (TIAs) [OR 0.28 (0.22-0.37)], and debilitating strokes [OR 0.23 (0.15-0.33)]. Routine TEE led to an absolute risk reduction for stroke of 1.2% [number needed to treat (NNT) 84 (79-100)] and 1.9% for TIA [NNT 53 (48-59)]. The incremental cost-effectiveness ratio (ICER) for TEE was $226,608 per quality-adjusted life year (QALY). The ICER for TEE among high-risk SPs, with pre-existing clot in the left atrium, was $2232 per QALY.

CONCLUSION

Decision analysis and microsimulation suggest that routine use of TEE in an unselected population prior to PVI lowers the incidence of cerebral thrombo-embolic events but with considerable cost per QALY.

Usefulness of CHADS2 score to predict C-reactive protein, left atrial blood stasis, and prognosis in patients with nonrheumatic atrial fibrillation

The CHADS2 score (congestive heart failure, hypertension, age >75 years, diabetes, and previous stroke/transient ischemic attack) is used for embolic risk stratification in patients with atrial fibrillation (AF). Although systemic inflammation is a known predictor of left atrial thrombus formation in patients with nonrheumatic AF, the relation between the CHADS2 score and systemic inflammation is unknown. A total of 165 patients with nonrheumatic AF were enrolled and analyzed. According to the CHADS2 score, the study patients were grouped into low- (score 0 to 1), intermediate- (score 2 to 3), or high- (score 4 to 6) risk categories. The plasma C-reactive protein levels, transesophageal echocardiographic findings, and cardiovascular events (death, stroke, and heart failure) were compared. Patients in the high-risk group had significantly greater C-reactive protein levels than those in the intermediate- and low-risk groups (0.80 mg/dl, range 0.21 to 1.50, vs 0.16 mg/dl, range 0.06 to 0.50, vs 0.08 mg/dl, range 0.04 to 0.21, p <0.01). Using transesophageal echocardiography, the incidence of left atrial spontaneous echo contrast and left atrial thrombus increased with an increasing CHADS2 score. During the follow-up period, the cardiovascular event-free survival was significantly lower in the high-risk group than in the intermediate- or low-risk groups. In conclusion, in patients with nonrheumatic AF, CHADS2 score is related to systemic inflammation, left atrial thrombus formation, and prognosis.

Body mass index and risk of left atrial thrombus in patients with atrial fibrillation

This study sought to assess the impact of body mass index (BMI) on the risk of left atrial (LA)/left atrial appendage (LAA) thrombus in patients with atrial fibrillation (AF) before catheter ablation. From January 2007 to March 2008, 433 consecutive patients with nonvalvular AF were enrolled. Patients with valvular heart disease, deep vein thrombosis, or pulmonary embolism were excluded. All patients underwent transesophageal echocardiography. Twenty-six of 433 patients (6.0%) had LA/LAA thrombus and the patients with thrombus had a significantly higher BMI (27.9 +/- 3.1 vs 26.0 +/- 3.3 kg/m(2), p = 0.005). The area under the receiver operating characteristic curve of BMI predicting thrombus was 0.662. With a cut-off point of 27.0 kg/m(2), the sensitivity and specificity of BMI for the diagnosis of thrombus were 69.2% and 83.1%, respectively. The incidence of LA/LAA thrombus was 10.6% in patients with BMI > or =27.0 kg/m(2) versus only 3.0% for patients with BMI <27.0 kg/m(2) (p = 0.001). In multivariable analysis, BMI > or =27.0 kg/m(2) (odds ratio 4.02, 95% confidence interval 1.19 to 13.55, p = 0.025), Cardiac Failure, Hypertension, Age, Diabetes, Stroke Doubled score > or =2, and nonparoxysmal AF were independent risk factors of LA/LAA thrombus. In conclusion, BMI > or =27.0 kg/m(2) is an independent risk factor of LA/LAA thrombus in patients with AF.

Role of the CHADS2 score in the evaluation of thromboembolic risk in patients with atrial fibrillation undergoing transesophageal echocardiography before pulmonary vein isolation

OBJECTIVES

The goals of this study were to determine: 1) if low-risk patients assessed by a CHADS(2) score, a clinical scoring system quantifying a risk of stroke in patients with atrial fibrillation (AF), require a routine screening transesophageal echocardiogram (TEE) before pulmonary vein isolation (PVI); and 2) the relationship of a CHADS(2) score with left atrial (LA)/left atrial appendage (LAA) spontaneous echo contrast, sludge, and thrombus.

BACKGROUND

There is no clear consensus of whether a screening TEE before catheter ablation of AF should be performed in every patient.

METHODS

Initial TEEs for pre-PVI of 1,058 AF patients (age 57 +/- 11 years, 80% men) were reviewed and compared with a CHADS(2) score.

RESULTS

CHADS(2) scores of 0, 1, 2, 3, 4, 5, and 6 were present in 47%, 33%, 14%, 5%, 1%, 0.3%, and 0% of patients, respectively. The prevalence of LA/LAA thrombus, sludge, and spontaneous echo contrast were present in 0.6%, 1.5%, and 35%. The prevalence of LA/LAA thrombus/sludge increased with ascending CHADS(2) score (scores 0 [0%], 1 [2%], 2 [5%], 3 [9%], and 4 to 6 [11%], p < 0.01). No patient with a CHADS(2) score of 0 had LA/LAA sludge/thrombus. In a multivariate model, history of congestive heart failure and left ventricular ejection fraction <35% were significantly associated with sludge/thrombus.

CONCLUSIONS

The prevalence of LA/LAA sludge/thrombus in patients with AF undergoing a pre-PVI screening TEE is very low (<2%) and increases significantly with higher CHADS(2) scores. This suggests that a screening TEE before PVI should be performed in patients with a CHADS(2) score of >or=1, and in patients with a CHADS(2) score of 0 when the AF is persistent and therapeutic anticoagulation has not been maintained for 4 weeks before the procedure.

Alternative presentation of tako-tsubo syndrome with spontaneous echo-contrast and "onion" shaped apical ballooning

We report the case of a 79-year-old woman with transient left ventricular systolic dysfunction with apical ballooning (tako-tsubo like syndrome, TTS) showing an alternative newly reported "onion" shape. The patient was also characterized by atrial fibrillation and marked spontaneous echo-contrast: possible precipitating role for these conditions in TTS are discussed.

Incidence and predictors of left atrial thrombus prior to catheter ablation of atrial fibrillation

BACKGROUND

Transesophageal echocardiography (TEE) is commonly used prior to catheter ablation of atrial fibrillation (AF) in order to exclude left atrial (LA) thrombus. However, the incidence and predictors of LA thrombus detected with TEE have not been systematically examined in this setting.

METHODS

This study included 732 cases (mean age 57 +/- 11 years; 23% female; 353 persistent AF) in 585 consecutive patients referred for catheter ablation of AF. Patients were anticoagulated for at least 4 weeks prior to the procedure and then bridged with enoxaparin. TEE was performed in all cases within 24 hours prior to ablation.

RESULTS

Preprocedural TEE revealed LA thrombus in 12 of 732 cases (1.6%), all located in the LA appendage. Among these 12 patients, 9 had persistent AF and 3 had paroxysmal AF. All patients with thrombus had an LA size >or= 4.5 cm. LA thrombus was present in 0.3%, 1.4%, and 5.3% of patients with CHADS(2) scores of 0, 1, and >or= 2, respectively. In multivariate analysis, a CHADS(2) score >or= 2 and larger LA diameter remained significant predictors of LA thrombus.

CONCLUSIONS

Despite oral anticoagulation treatment, there is a small but significant incidence of LA thrombus by TEE prior to AF ablation. A CHADS(2) score >or= 2 and larger LA diameter are independent predictors of LA thrombus in this patient population, while type of AF or rhythm at the time of TEE is not. The risk of LA thrombus is low in patients with a CHADS(2) score of 0 and in patients with an LA diameter < 4.5 cm.