Role of transthoracic left atrial appendage wall motion velocity in patients with persistent atrial fibrillation and a low CHADS2 score

Echocardiographic Evaluation of Atrial Remodelling for the Prognosis of Maintaining Sinus Rhythm after Electrical Cardioversion in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is the most common atrial tachyarrhythmia. One of the methods of AF treatment is direct current cardioversion (DCCV), but in the long-term follow-up we observe quite a high percentage of AF recurrences after this procedure. In order to assess the prognosis of DCCV effectiveness, we use clinical, biochemical and echocardiographic parameters. The objective of this review is to systematise the current knowledge on echocardiographic measurements in patients with persistent AF used to assess the progress of remodelling of the atrial wall, which affects the likelihood of maintaining sinus rhythm after DCCV. In this article, echocardiographic parameters for the evaluation of remodelling of the atrial wall are divided into groups referring to structural, mechanical, and electrical remodelling, as well as parameters for the evaluation of left ventricular filling pressure. The article aims to draw attention to the clinical value of echocardiographic measurements, which is the selection of patients who will maintain sinus rhythm after DCCV in the long-term follow-up, which will allow to avoid unnecessary risks associated with the procedure and enable the selection of the appropriate treatment strategy.

Assessment of left atrial appendage function by echocardiography

The left atrial appendage (LAA) is considered not only to be the most frequent site of thrombus formation, but also to play a pivotal role in maintaining normal cardiac function. Transesophageal echocardiography (TEE) is widely used to assess LAA function. The LAA flow velocity has been used as a surrogate for LAA function, and it varies with multiple interrelated factors including age, hemodynamics, type of arrhythmia, and antiarrhythmic interventions. Relatively great importance of LAA function is involved with intraatrial thrombus formation and subsequent thromboembolism, and thus, understanding of characteristics and behaviors of the LAA under various clinical conditions may help determine strategies against atrial thrombosis. Also, techniques other than TEE-derived Doppler to assess LAA function, such as tissue Doppler imaging, have been proposed. In this review, we introduce clinical and echocardiographic correlates of LAA function, the LAA flow velocity in particular, its significance, and how to interpret functional patterns of the LAA each relevant to specific clinical settings.

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.

Difference in left atrial appendage remodeling between diabetic and nondiabetic patients with atrial fibrillation

Background

Diabetes mellitus (DM) is a common and increasingly prevalent condition in patients with atrial fibrillation (AFib). The left atrium appendage (LAA), a small outpouch from the LA, is the most common location for thrombus formation in patients with AFib.

Hypothesis

In this study, we examined LAA remodeling differences between diabetic and nondiabetic patients with AFib.

Methods

This retrospective study analyzed data from 242 subjects subdivided into two subgroups of 122 with DM (diabetic group) and 120 without DM (nondiabetic group). The study group underwent real‐time 3‐dimensional transesophageal echocardiography (RT3DTEE) for AFib ablation, cardioversion, or LAA device closure. The LAA dimensions were measured using the “Yosefy rotational 3DTEE method.”

Results

The RT3DTEE analysis revealed that diabetic patients display larger LAA diameters, D1‐lengh (2.09 ± 0.50 vs 1.88 ± 0.54 cm, P = .003), D2‐width (1.70 ± 0.48 vs 1.55 ± 0.55 cm, P = .024), D3‐depth (2.21 ± 0.75 vs 1.99 ± 0.65 cm, P = .017), larger orifice areas (2.8 ± 1.35 and 2.3 ± 1.49 cm², P = .004), and diminished orifice flow velocity (37.3 ± 17.6 and 43.7 ± 19.5 cm/sec, P = .008).

Conclusions

Adverse LAA remodeling in DM patients with AFib is characterized by significantly LAA orifice enlargement and reduced orifice flow velocity. Analysis of LAA geometry and hemodynamics may have clinical implications in thrombotic risk assessment and treatment of DM patients with AFib.

In Paroxysmal Atrial Fibrillation Patients, the Neutrophil-to-lymphocyte Ratio Is Related to Thrombogenesis and More Closely Associated with Left Atrial Appendage Contraction than with the Left Atrial Body Function

Objective The neutrophil-to-lymphocyte ratio (NLR) is an inflammation marker that can be used to detect atrial inflammatory changes, which may contribute to a reduced left atrial (LA) function and thrombosis. Our study aimed to determine whether or not the association of NLR with the LA appendage (LAA) function in relation to thrombogenesis differs from the association with the LA body function in paroxysmal atrial fibrillation (PAF) patients. Methods A total of 183 PAF patients were studied. The LA volume index, mitral flow velocity (A), and mitral annular motion velocity (A') were examined using transthoracic echocardiography. The LAA area, LAA wall motion velocity, and presence of spontaneous echo contrast (SEC) were examined using transesophageal echocardiography. Results The NLR of patients with cerebral embolism was significantly greater than in patients without the disorder. A cut-off point of 2.5 for the NLR had a sensitivity of 71% and a specificity of 74% in predicting cerebral embolism. The patients with an NLR ≥2.5 had a higher CHADS2 score and greater LA volume index or LAA area than those with an NLR <2.5. The NLR was an independent risk factor for SEC and was significantly correlated with the LAA wall motion velocity (r=-0.409) in 153 patients without SEC and with the LAA wall motion velocity and LAA area (r=-0.583, r=0.654, respectively) in 30 patients with SEC, but not with the LA volume index, A, or A' in either group. Conclusion In PAF patients, a high NLR indicates thrombogenesis with a high degree of certainty and is associated with reduced LAA contraction rather than with the LA body function.

Relevance of transthoracic left atrial appendage wall velocity measurement in addition to left atrial volume for noninvasive and quantitative assessment of left atrial thrombogenesis in patients with atrial fibrillation and normal D-dimer levels

PURPOSE

This study examined the role of left atrial (LA) appendage wall velocity (LAAWV) measurement in addition to LA size for the noninvasive assessment of thrombogenesis in patients with atrial fibrillation (AF) and normal plasma D-dimer levels.

METHODS

In 58 non-valvular AF patients, LAAWV and the LA volume index (LAVI) were determined by transthoracic echocardiography. LA appendage flow velocity and severity of spontaneous echo contrast (SEC) were determined by transesophageal echocardiography.

RESULTS

LAAWV was strongly correlated with LA appendage flow velocity (r = 0.82), and LAVI was weakly correlated with LA appendage flow velocity (r = -0.37). As SEC severity increased, LAAWV decreased (p < 0.001) and LAVI increased (p < 0.001). Among 52 patients with normal D-dimer levels, LAAWV < 10 cm/s had 71 % sensitivity and 94 % specificity for diagnosing severe SEC. Severe SEC was not found in 18/32 large LAVI patients (>34 mL/m(2)), but 17 of the 18 patients (94 %) had LAAWV < 10 cm/s. Severe SEC was found in 3/20 patients with normal LAVI, but all of them showed LAAWV < 10 cm/s.

CONCLUSION

The noninvasive measurement of transthoracic LAAWV in addition to LA volume is clinically relevant for quantitatively assessing thrombogenesis in AF patients with normal D-dimer levels.

High plasma human atrial natriuretic peptide and reduced transthoracic left atrial appendage wall-motion velocity are noninvasive surrogate markers for assessing thrombogenesis in patients with paroxysmal atrial fibrillation

BACKGROUND

The clinical relevance of examining human atrial natriuretic peptide (HANP) or left atrial appendage (LAA) wall-motion velocity during sinus rhythm in paroxysmal atrial fibrillation (AF) patients has not been clearly elucidated.

METHODS

The subjects were 38 patients with paroxysmal AF who underwent transesophageal and transthoracic echocardiography during sinus rhythm. The presence of spontaneous echocontrast (SEC) was examined with transesophageal echocardiography and LAA wall-motion velocity (LAAWV) was measured with transthoracic tissue Doppler echocardiography. Plasma HANP was measured within 3 hours after echocardiography.

RESULTS

Human atrial natriuretic peptide ranged from 12 to 106 pg/mL with an average of 43 ± 24 pg/mL and had a significant correlation with LAAWV (r = -0.57) or LAA flow velocity (r = -0.41). HANP was significantly higher in patients with SEC than in patients without SEC (64 ± 29 vs. 34 ± 15 pg/mL, P = 0.008) and LAAWV was significantly lower in patients with SEC than in patients without SEC (13 ± 5 vs. 20 ± 5 cm/sec, P = 0.002). HANP >44 pg/mL had a sensitivity of 73% and specificity of 89% for diagnosing SEC. SEC was more frequently observed (73%) in patients with HANP >44 pg/mL and/or LAAWV <10 cm/sec as compared with patients (11%) with normal HANP and LAA wall-motion velocity (P < 0.0001).

CONCLUSION

Higher plasma HANP and lower LAA wall-motion velocity may be noninvasive surrogate markers for assessing left atrial thrombogenesis during sinus rhythm in paroxysmal AF patients.