Risk Of Left Atrial Appendage Thrombus Research Articles

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 24h 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 0.40m/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.

Left Atrial Appendage Thrombus Formation Despite Continuous Non-Vitamin K Antagonist Oral Anticoagulant Therapy in Atrial Fibrillation Patients Undergoing Electrical Cardioversion or Catheter Ablation: A Comparison of Dabigatran and Rivaroxaban.

Left atrial appendage thrombus (LAAT) may be detected by transesophageal echocardiography (TOE) in patients with atrial fibrillation (AF) despite continuous anticoagulation therapy. We examined the factors predisposing to LAAT in patients treated with the anticoagulants dabigatran and rivaroxaban. We retrospectively evaluated 1,256 AF patients from three centres who underwent TOE before electrical cardioversion (n = 611, 51.4%) or catheter ablation (n = 645, 48.6%) from January 2013 to December 2019 and had been on at least three weeks of continuous dabigatran (n = 603, 48%) or rivaroxaban (n = 653, 52%) therapy. Preprocedural TOE diagnosed LAAT in 51 patients (4.1%), including 30 patients (5%) treated with dabigatran and 21 patients (3.2%) treated with rivaroxaban (p=0.1145). In multivariate logistic regression, predictors of LAAT in patients treated with dabigatran were non-paroxysmal AF (vs. paroxysmal AF) (OR = 6.2, p=0.015), heart failure (OR = 3.22, p=0.003), and a eGFR <60 ml/min/1.73 m2 (OR = 2.65, p=0.012); the predictors in patients treated with rivaroxaban were non-paroxysmal AF (vs. paroxysmal AF) (OR = 5.73, p=0.0221) and heart failure (OR = 3.19, p=0.116). In ROC analysis of the dabigatran group, the area under the curve (AUC) for the CHA2DS2-VASc-RAF score was significantly higher (0.78) than those for the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores (0.67, 0.70, and 0.72, respectively). In the rivaroxaban group, the CHA2DS2-VASc-RAF score also performed significantly better (AUC of 0.77) than the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores (AUC of 0.66, 0.64, and 0.67, respectively). The risk of LAAT was the same for patients in both treatment groups. In all patients, non-paroxysmal AF or heart failure, and in patients treated with dabigatran an eGFR <60 ml/min/1.73 m2, were independent predictors of LAAT. The new CHA2DS2-VASc-RAF scale had the highest predictive value for LAAT in the entire study population.

Predictors of left atrial appendage thrombus despite NOAC use in nonvalvular atrial fibrillation and flutter

ObjectiveA small but significant proportion of patients with atrial fibrillation or atrial flutter (AF) develop left atrial appendage thrombus (LAAT) despite non-vitamin K antagonist oral anticoagulant (NOAC) prescription. This study examines clinical and echocardiographic risk factors associated with LAAT by transesophageal echocardiogram (TEE) despite NOAC use in patients with non-valvular AF, to inform the decision whether a TEE should be performed prior to cardioversion. MethodsWe compared clinical and echocardiographic characteristics of patients with LAAT despite NOAC prescription for >3 weeks (n = 38) with a consecutive sample of patients on NOAC without LAAT (n = 101). ResultsThe prevalence of LAAT despite NOAC prescription was 2.6%. Left atrial dilation (adjusted odds ratio [aOR] 3.310, 95% CI 1.144–9.580, p = 0.02) and greater CHA2DS2-VASC score (per-point increase, aOR 1.293, 1.027–1.628, p = 0.03) increased the odds for LAAT. Higher LVEF (per 5%, aOR 0.834, 0.704–0.987, p = 0.03) and presence of severe mitral regurgitation (aOR 0.147, 0.048–0.446, p = 0.002) were protective against LAAT. LAA emptying velocities were also independently associated with presence of LAAT (aOR per 10 cm/s, 0.46, 0.27–0.77). ConclusionLeft atrial dilation, greater CHA2DS2-VASC score, absence of severe mitral regurgitation and lower left ventricular ejection fraction are associated with LAAT despite NOAC therapy. In addition to suspected NOAC noncompliance, presence of such high-risk features may warrant pre-cardioversion TEE. Similarly, in patients with LVEF > 50% and CHA2DS2-VASC < 2, risk of LAAT was exceedingly low and thus TEE before cardioversion is low-yield.

Inhibition of renin-angiotensin axis reduces the risk of thrombus formation in the left atrial appendage in patients with hypertension complicated by atrial fibrillation.

Aims:We examined whether the use of a renin-angiotensin-aldosterone system (RAS) inhibitor plays a role in protecting against left atrial appendage thrombus (LAAT) in patients with hypertension complicated by atrial fibrillation (AF).Methods:Two observational studies were conducted on patients with diagnoses of hypertension and AF, who were categorized into RAS inhibitor user or nonuser groups. Demographic characteristics, clinical characteristics, echocardiographic parameters and hemostatic markers were examined and the occurrence of LAAT during follow-up were recorded.Results:In the first study (n = 131), LA peak systolic strain and LAA emptying flow velocity (LAA eV) were significantly increased in patients on RAS inhibitors compared with the nonuser group (p < 0.05). Lower D-dimer and fibrinogen levels were observed in patients on RAS inhibitors (p < 0.05). In the second study (n = 99), 25.9% (n = 11) of patients on RAS inhibitors developed LAAT, compared with 46.7% (n = 21) in the nonuser group (p < 0.05). After controlling for risk factors related to LAAT, use of RAS inhibitors remained associated with a significantly lower risk of developing LAAT (HR, 0.406; 95% CI, 0.191–0.862; p = 0.019).Conclusions:RAS inhibitors use was associated with a significant reduction in the risk of LAAT in patients with hypertension and AF.

Asymmetric dimethylarginine predicts left atrial appendage thrombus in patients with non-valvular atrial fibrillation

IntroductionAtrial fibrillation (AF) is associated with increased thrombo-embolic events, with thrombi most frequently located in the left atrial appendage (LAA). Asymmetric dimethylarginine (ADMA), a potent endogenous inhibitor of nitric oxide synthase, is elevated in subjects with AF. We investigated the relationship between ADMA and risk of LAA thrombus in patients with non-valvular AF. Methods and resultsA total of 223 consecutive patients with non-valvular AF were enrolled (63±10years, 65% male). LAA thrombus was detected in 27 subjects by transesophageal echocardiography. Serum ADMA was significantly increased (2.5±0.6μmol/L vs 1.8±0.4μmol/L, p<0.001), while serum nitrite/nitrate was significantly reduced in patients with LAA thrombus (30.3±7.1μmol/L vs 48.4±9.3μmol/L, p<0.001). ADMA was positively correlated with age and left atrium diameter, and was negatively correlated with nitrite/nitrate and LAA peak flow velocity. The area under the receiver operating characteristic curve of ADMA predicting thrombus was 0.84. In multivariate logistic regression analysis, ADMA (OR 4.0, 95% CI 1.2–13.0; p=0.003) was one of independent risk factors for LAA thrombus. ConclusionsOur study suggested that high ADMA was independently associated with the presence of LAA thrombus in patients with non-valvular AF.

The value of diastolic function parameters in the prediction of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

BackgroundLeft ventricular diastolic impairment and consequently elevated filling pressure may contribute to stasis leading to left atrial appendage thrombus (LAAT) in nonvalvular atrial fibrillation (AF). We investigated whether transthoracic echocardiographic parameters can predict LAAT independent of traditional clinical predictors.MethodsWe conducted a retrospective cohort study of 297 consecutive nonvalvular AF patients who underwent transthoracic echocardiogram followed by a transesophageal echocardiogram within one year. Multivariate logistic regression analysis models were used to determine factors independently associated with LAAT.ResultsNineteen subjects (6.4%) were demonstrated to have LAAT by transesophageal echocardiography. These patients had higher mean CHADS2 scores [2.6 ± 1.2 vs. 1.9 ± 1.3, P = 0.009], higher E:e’ ratios [16.6 ± 6.1 vs. 12.0 ± 5.4, P = 0.001], and lower mean e’ velocities [6.5 ± 2.1 cm/sec vs. 9.1 ± 3.2 cm/sec, P = 0.001]. Both E:e’ and e’ velocity were associated with LAAT formation independent of the CHADS2 score, warfarin therapy, left ventricular ejection fraction (LVEF), and left atrial volume index (LAVI) [E:e’ odds-ratio = 1.14 (95% confidence interval = 1.03 – 1.3), P = 0.009; e’ velocity odds-ratio = 0.68 (95% confidence interval = 0.5 – 0.9), P = 0.007]. Similarly, diastolic function parameters were independently associated with spontaneous echo contrast.ConclusionThe diastolic function indices E:e’ and e’ velocity are independently associated with LAAT in nonvalvular AF patients and may help identify patients at risk for LAAT.

PREDICTING VALUE OF LEFT ATRIAL APPENDAGE THROMBUS IN NONVALVULAR ATRIAL FIBRILLATION PATIENTS BY CHADS2 AND CHADS2-VAS’SCORE AND BY TRANSTHORACIC ECHOCARDIOGRAPHIC PARAMETERS

Objectives: To evaluate size and function of left atrium and left atrial appendage (LAA) by using transthoracic and transesophageal echocardiography in nonvalvular atrial fibrillation (NVAF) patients. Method: 127 NVAF patients (mean age 65,8 ± 10,0 years) were assessed by using CHADS2 and CHADS2-VAS score, transthoracic and transesophageal echocardiographic parameters. Results: CHADS2 ≥3, CHADS2-VAS ≥ 4 and LAVI ≥ 38ml/m2, diagnosis of LAA thrombus has been expected in turn with Se=67% and Sp=70%, Se=67% and Sp=71% and Se=80% and Sp=60%; With LEVF/LAVI ≤1,5, risk of LAA thrombus was OR=13,3; 95% CI (1,8 – 98,5) with p=0,001. Conclusion: CHADS2, CHADS2-VAS, LAVI and ratio LVEF/LAVI are predictors of LAA thrombus in NVAF patients. Key words: CHADS 2, CHADS 2 -VAS, left atrial appendage thrombus, thromboembolism, nonvalvular atrial fibrillation

Left Atrial Blood Stasis and Von Willebrand Factor–ADAMTS13 Homeostasis in Atrial Fibrillation

Left atrial blood stasis is associated with increased risk for left atrial appendage thrombus (LAAT) and stroke in atrial fibrillation (AF). Von Willebrand factor (VWF) is associated with thromboembolism in AF. VWF thrombogenic activity is proportional to multimer size, which is regulated by VWF-cleaving protease (ADAMTS13). To assess the association between left atrial blood stasis and VWF-ADAMTS13 system, plasma VWF antigen (VWF:Ag), VWF activity (VWF:Act), and ADAMTS13 activity were measured in 414 consecutive patients with nonvalvular AF (age 63±13 years; 25% women) and in 100 patients (age 64±14 years; 39% women) with normal sinus rhythm. Spontaneous echocardiographic contrast (SEC), left atrial appendage emptying velocity, and LAAT were assessed by transesophageal echocardiography. Presence and intensity of SEC varied directly with VWF:Ag and VWF:Act but not with ADAMTS13 activity. AF patients with LAAT had higher VWF:Ag (200±61 versus 155±52, P=0.0006) and VWF:Act (179±57 versus 141±51 P=0.0026) compared with those without LAAT. VWF:Ag and VWF:Act were independent predictors of LAAT after adjustment for CHADS2 score (P=0.0179 and P=0.0497, respectively). The association between VWF and SEC may explain the thrombotic propensity in AF. Elevated VWF:Ag may help identify AF patients at risk for LAAT.

LEFT ATRIAL STASIS AND VWF-ADAMTS 13 SYSTEM IN AATRIAL FIBRILLATION

Abstract Category: PCI - Valvular; Atrial Fibrillation TherapiesPresentation Number: 2505-439Authors: Waldemar E. Wysokinski, Ewa Konik, Robert D. McBane, II, Susan J. Eifert Rain, Dong Chen, Edyta Sutkowska, Thomas G. McLeod, Paul A. Friedman, Naser M. Ammash, Mayo Clinic, Rochester, MNBackground: Stasis within the left atrial appendage (LAA) is associated with increased risk of left atrial appendage thrombus (LAAT) and stroke in atrial ibrillation (AF). The thrombogenic propensity of von Willebrand factor (VWF) is directly proportional to multimer size regulated by VWF-cleaving protease (ADAMTS-13).Methods: To assess the association between LAA blood stasis and VWF-ADAMTS 13, we measured VWF antigen (VWF Ag) by ELISA, VWF activity (VWF Act) by immunoturbidimetry and ADAMTS 13 activity by ACTIFLUOR assay in 425 consecutive patients with non-valvular AF (age 6314 years; 25% women). All AF patients underwent TEE to assess left atrial appendage emptying velocity (LAAEV), spontaneous echo contrast (SEC), and LAAT. Data were compared to 100 patients (age 6414 years; 39% women) with normal sinus rhythm (NSR).Results: A direct relationship was noted between VWF (Ag and Act) and intensity of SEC (Figure). No relationship was observed between measures of blood stasis and ADAMTS 13. VWF Ag was one of the strongest determinants of LAAT (c-stat=0.711, p=0.0015) together with LAAEV (c-stat=0.959, p=0004) and heart failure (c-stat=0.715, p<0.0001). CONCLUSSION. A direct correlation exists between VWF and the severity of LAA blood stasis in AF patients. Elevated VWF:Ag may identify AF patients at risk for LAAT.