Echocardiographic Left Atrial Diameter Research Articles

Abstract 141: Atrial Cardiopathy And Left Ventricular Dysfunction In Patients With ESUS: Findings From The Arcadia Trial

Background: Recent data suggest biomarkers of atrial cardiopathy (ACP) can potentially identify a subset of patients with cryptogenic stroke who may benefit from anticoagulation. However, the specificity of these markers for atrial disease and their independence from measures of more global cardiac dysfunction remain unclear. We hypothesized that biomarkers of ACP collectively reflect left atrial pathology and are not strongly affected by coexisting left ventricular dysfunction. Methods: ARCADIA is an ongoing multicenter trial comparing standard dose apixaban to aspirin therapy in patients with Embolic Stroke of Undetermined Source (ESUS) with ACP, defined as either N-terminal pro-brain natriuretic peptide [NT-proBNP] > 250 pg/mL; P wave terminal force velocity on ECG lead V1 [PTFV1] > 5000 μV*ms; or echocardiographic left atrial diameter index [LADI] ≥ 3 cm/m 2 . Pearson correlation coefficients and descriptive statistics were used to examine the relationship between left ventricular ejection fraction (LVEF) and ACP biomarkers. Results: Among 2,616 ESUS patients screened, 1,046 met ≥ 1 ACP criterion (665 BNP, 531 PTFV1, 14 LADI). Patients with ACP were older (68 ± 11 vs 64 ± 10 years) and 54.5% were women. The great majority (84%) of subjects with ACP had normal LVEF (≥55%). Among them there was no correlation between LVEF and NT-proBNP (r= -0.01, P= 0.5) or PTFV1 (r=0.002, P=0.9). In patients with abnormal LVEF, there was a strong inverse correlation of LVEF with NT-proBNP (r=-0.4, P<0.001), but no correlation with PTFV1 (r=0.11, P=0.16). The LADI criterion was only met in a few patients, precluding further analyses. Among patients with NT-proBNP >250 pg/mL and measured LVEF (n=435), only 19% had abnormal LVEF. Compared to patients with abnormal NT-proBNP alone, those with both abnormal NT-proBNP and abnormal LVEF were younger (66.4 ± 11.0 vs. 71.6 ± 11.0, P<0.001), more often African American (29.6% vs. 11.5%, P<0.001), and more often male (56% vs. 40%, P=0.01). Conclusion: Left ventricular dysfunction (EF ≤ 55%) is uncommon in patients with ACP as defined in ARCADIA. These findings suggest that, among patients with ESUS, atrial cardiopathy may represent a separate entity from LV dysfunction.

Left Atrial Enlargement is Associated with Stroke Severity with Cardioembolic and Cryptogenic Subtypes in a Chinese Population

BackgroundLeft atrial enlargement is associated with increased risk for stroke. However, few studies that evaluated the correlation between left atrial size and ischemic stroke severity. In this study, we aim to evaluate the association between left atrial size and stroke severity, especially with cardioembolic and cryptogenic stroke in the Chinese population. MethodsA total of 1271 patients with acute ischemic stroke were included in this study. Echocardiographic left atrial diameter was measured and indexed to height. Stroke severity was assessed at admission with the National Institutes of Health Stroke Scale (NIHSS). Moderate-to-severe neurologic deficit was defined as NIHSS greater than or equal to 5. Patients were divided into mild, moderate, or severe abnormal left atrial size by tertile distribution. Binary logistic regression analysis was used to identify independent predictors of severe stroke after adjustment. ResultsAmong all enrolled patients, 328 (25.8%) were classified into moderate-to severe stroke severity (NIHSS ≥ 5). In the multivariable model, compared with the lowest tertile of left atrial size, the odds ratio for moderate-to-severe neurologic deficit was 0.902 (95% CI, 0.644-1.264, P = .550) when left atrial size was the highest tertile. Of all patients, 190 patients were further categorized as cardioembolic and cryptogenic subtypes, and 70 (36.8%) were classified into moderate-to-severe stroke severity. After adjusting for confounders, compared with the lowest tertile, the top tertile of left atrial size was significantly associated with moderate-to-severe stroke (3.156, 95% CI, 1.143-8.711, P = .027). ConclusionLeft atrial enlargement was associated with more severe initial neurologic deficits of embolic subtypes (cardioembolic and cryptogenic stroke) in patients with acute ischemic stroke.

Abstract 26: Predictors of Atrial Cardiopathy Among Patients in the Arcadia Trial: An Analysis of the First 924 Patients

Background: Atrial cardiopathy (AC) in absence of atrial fibrillation is a suspected cause of embolic stroke of undetermined source (ESUS). Predictors of AC remain incompletely characterized. We hypothesized that demographics, vascular risk factors, and time from stroke presentation to assessment for AC predict AC among ESUS patients. Methods: ARCADIA is an ongoing, investigator-initiated, NINDS-funded, multicenter, randomized trial of standard dose apixaban versus aspirin 81 mg daily among consented patients with ESUS and biomarker evidence of AC, defined as any of: N-terminal pro-brain natriuretic peptide (NT-proBNP) > 250 pg/ml; P wave terminal force velocity on ECG lead V1>5,000 μV*ms; or echocardiographic left atrial diameter index ≥3 cm/m 2 . Patients may be enrolled up to 120 days after stroke. We used multivariable regression modelling to estimate relative risks and 95% confidence intervals (RR, 95%CI) for association of predictors with AC. Results: Among 924 ESUS patients who met inclusion/exclusion criteria as of July 16, 2019, 251 met > 1 AC criterion (164 NT-proBNP, 114 PTFV1, 4 echo). Compared to those without AC (n=673), those with AC were older (69.0 + 14.5 versus 64.0 + 15.0 years) and more often women (52.2% versus 40.9%). Multivariable predictors of AC were age (RR per decade 1.20, 95%CI 1.09-1.32), race (black versus other RR 1.20, 95%CI 0.95-1.52), sex (RR for women 1.22, 95%CI 0.98-1.52), hemoglobin (per unit RR 0.94, 95%CI 0.88-1.01), and cardiovascular/peripheral arterial disease, RR 1.48, 95%CI 1.16-1.88). Prior history of stroke or TIA, hypertension, diabetes, smoking, cancer, sleep apnea, and time from stroke to consent and blood draw for NT-proBNP were not associated with AC. Conclusions: Older age, female sex, black race, relative anemia, and history of vascular disease associate with AC among ESUS patients. Absence of association with time to assessment, particularly testing for NT-proBNP, provides indirect evidence that AC is not a reaction to stroke, but a stable condition, and supports patients being assessed for ARCADIA participation up to 4 months post stroke. The moderate strength of demographic associations with AC further underscores the importance of enrolling unselected ESUS patients into ARCADIA.

Independent associations of blood pressure and body mass index with interatrial block: a cross-sectional study in general Chinese population

ObjectivesThis current study was performed to characterise the independent associations of obesity and hypertension with interatrial block (IAB) after adjusting for cardiovascular risk factors, echocardiographic left atrial diameter (LAD) and...

Impaired cardiac autonomic regulation and long-term risk of atrial fibrillation in patients with coronary artery disease

The influence of autonomic cardiac regulation on long-term risk of new-onset atrial fibrillation (AF) in coronary artery disease (CAD) is not well established. The purpose of this study was to evaluate the value of heart rate variability, a marker of cardiac autonomic regulation, in predicting new-onset AF in CAD. The Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection study population consisted of 1946 patients with CAD. After exclusions, the present analysis included 1710 patients. Those patients had a 24-hour electrocardiographic recording at baseline. A total of 143 cases (8.4%) of new-onset AF were observed during a follow-up of 5.6 ± 1.5 years. The lower values of the short-term scaling exponent of the detrended fluctuation analysis (DFA1) and the ratio of the low-frequency and high-frequency components of the power spectrum (LF/HF ratio) remained the strongest heart rate variability predictors of the development of AF after relevant adjustments in Cox multivariate regression analysis (P < .001 for both). The accuracy of these parameters in prediction of AF was even better (area under the receiver operating characteristic curve 0.630 and 0.631, respectively) than that of echocardiographic left atrial diameter (area under the curve 0.618). Including DFA1 and LF/HF ratio in the AF risk model increased the C-index from 0.630 (95% confidence interval 0.569-0.692) to 0.666 (95% confidence interval 0.612-0.720). Impaired cardiac autonomic regulation measured by DFA1 and LF/HF ratio predicts the development of new-onset AF as well as or even better than left atrial diameter in patients with CAD.

Left atrial size and risk of recurrent ischemic stroke in a Chinese population.

BackgroundAlthough a number of studies have reported the role of an increased left atrial (LA) size on stroke, limited data are collected about the relationship between LA enlargement and recurrent ischemic stroke in the Chinese population. Our aim was to assess the association of LA size with the risk of stroke recurrence, particularly with recurrent cardioembolic or cryptogenic stroke in ischemic stroke patients.MethodsThe study recruited 313 consecutive patients with acute first‐ever ischemic stroke. Echocardiographic LA diameter was measured and indexed by height and body surface area separately. The endpoint was recurrent ischemic stroke. Cox proportional hazard models were used to examine the association of LA size with total recurrent ischemic stroke and recurrent cardioembolic or cryptogenic stroke while adjusting for baseline demographics characteristics, clinical factors, echocardiographic left ventricular ejection fraction, and medication.ResultsOver a median follow‐up period of 1.63 years, 47 recurrent ischemic strokes (21 were cardioembolic or cryptogenic) occurred. In a multivariate model adjusted for potential confounders, compared with the bottom tertiles of LA diameter indexed to height (LA diameter/H), the top tertile of LA diameter/H was significantly associated with the total recurrent ischemic stroke (adjusted HR 3.610, 95% CI 1.870–6.967, p < .001) and the composite of recurrent cardioembolic or cryptogenic stroke (adjusted HR 5.673, 95% CI 1.780–18.084, p = .003). Results were similar when LA diameter indexed to body surface area (LA diameter/BSA) was involved in the analysis.Conclusion LA size is an independent predictor of total recurrent ischemic stroke and the composite of recurrent cardioembolic or cryptogenic stroke.

Left atrial volumetry from routine diagnostic work up prior to pulmonary vein ablation is a good predictor of freedom from atrial fibrillation

This study aimed to identify whether left atrial (LA) volume assessed by multidetector computed tomography (MDCT) is related to the long-term success of pulmonary vein ablation (PVA). MDCT is used to guide PVA for the treatment of atrial fibrillation (AF). MDCT permits accurate sizing of LA dimensions. We analysed data from 368 ablation procedures of 279 consecutive patients referred for PVA due to drug-refractory symptomatic AF (age 62 ± 10; 58% men; 71% paroxysmal AF). Prior to the procedure, all patients underwent ECG-gated 64-MDCT scan for assessment of LA and PV anatomy, LA thrombus evaluation, LA volume estimation, and electroanatomical mapping integration. Within a mean follow-up of 356 ± 128 days, 64% of the patients maintained sinus rhythm after the initial ablation, and 84% when including repeat PVA. LA diameter (P = 0.004), LA volume (P = 0.002), and type of AF (P = 0.001) were independent predictors of AF recurrence in univariate analysis. There was a relatively low correlation between the echocardiographic LA diameter and LA volume from MDCT (P = 0.01, r = 0.5). In multivariate analysis, paroxysmal AF (P < 0.006) and LA volume below the median value of 106 mL (P = 0.042) were significantly associated with the success of PVA, whereas LA diameter was not (P = 0.245). Analysing receiver-operator characteristics, the area under the curve for LA volume was 0.73 (P = 0.001) compared with 0.60 (P = 0.09) for LA diameter from echocardiography. LA volume assessed by MDCT is a better predictor of AF recurrence after PVA than echocardiograpic LA diameter and can be derived from the pre-procedural imaging data set.

Left atrial diameter and albumin with renal outcomes in chronic kidney disease.

Background and Aim: Echocardiographic left atrial diameter (LAD) has been documented to be an independent predictor of adverse cardiovascular outcomes in various populations. An enlarged left atrium is frequently noted in chronic kidney disease (CKD). We examined the association between albumin and indexed LAD (indexed to height) and assessed whether the combination of indexed LAD and albumin was independently associated with renal outcomes in patients with CKD stages 3-5.Methods: This longitudinal study enrolled 395 patients, who were classified into four groups according to median values of indexed LAD (LAD/height) and albumin. The change in renal function was measured by estimated glomerular filtration rate (eGFR) slope. Rapid renal progression was defined as eGFR slope less than -3 ml/min/1.73 m2/year. The renal end point was defined as commencement of dialysis.Results: Albumin was significantly associated with indexed LAD (β = -0.108, P = 0.024). During follow-up period, seventy-four patients started dialysis. After the multivariate analysis, the group with higher indexed LAD and lower albumin was independently associated with rapid renal progression (odds ratio, 7.979; 95% confidence interval [CI], 3.028 to 21.025) and progression to dialysis (hazard ratio, 2.352; 95% CI, 1.078 to 5.131).Conclusions: Our findings show that albumin is independently associated with indexed LAD and suggest that the combination of increased indexed LAD and hypoalbuminemia is independently associated with rapid renal progression and progression to dialysis in patients with CKD. Assessments of serum albumin and indexed LAD by echocardiography are useful for predicting the risk for adverse renal outcomes.

Association of N‐terminal pro–brain natriuretic peptide with cardiac disease, but not with vascular disease, in systemic lupus erythematosus

Association of N‐terminal pro–brain natriuretic peptide with cardiac disease, but not with vascular disease, in systemic lupus erythematosus

Relation of Electrocardiographic Criteria for Left Atrial Enlargement to Two-Dimensional Echocardiographic Left Atrial Volume Measurements

Left atrial (LA) enlargement by 2-dimensional (2-D) echocardiography predicts adverse cardiovascular outcomes. Electrocardiographic (ECG) criteria for LA enlargement are based on M-mode echocardiographic LA diameter, which is inferior to 2-D-derived LA volumes. This study compared established ECG criteria for LA enlargement with atrial volume obtained by 2-D echocardiography to determine if traditional ECG criteria accurately represent LA chamber enlargement, therefore offering a low-cost screening tool. A total of 261 randomly selected patients who underwent electrocardiography and 2-D echocardiography were enrolled. ECG parameters and electronically derived P-wave medians were analyzed with electronic calipers for maximal accuracy. LA volumes by 2-D echocardiography were measured with Simpson's method of discs, with enlargement defined as 32 ml/m(2). Sensitivity and specificity tables and receiver-operating characteristic curves were constructed for each criterion. Univariate and multivariate analyses were performed for predictors of 2-D echocardiographic LA enlargement. LA enlargement was present in 43% of patients. ECG P-wave duration was the most sensitive for the detection of LA enlargement (69%) but had low specificity (49%). Conversely, a biphasic P wave was the most specific (92%) but had low sensitivity (12%). The maximum area under the receiver-operating characteristic curve for any criterion was 0.64, too low to be of clinical utility. In conclusion, established ECG criteria for LA enlargement do not reliably reflect LA enlargement and lack sufficient predictive value to be useful clinically. These results suggest that P-wave abnormalities should be noted as nonspecific LA abnormalities, with the term "LA enlargement" no longer used.

Electrocardiographic Left Atrial Abnormalities and Risk of Ischemic Stroke

We evaluated the association between electrocardiographic left atrial abnormality (ECG-LAA) and ischemic stroke, especially whether ECG-LAA provides additional prognostic information to that provided by echocardiography. A population-based, case-control study included 146 patients with first ischemic stroke and 195 age-, gender-, and race/ethnicity-matched community control subjects. ECG-LAA was defined as either P-wave duration >120 ms or P-terminal force in precordial lead V1 (PTFV1) >40 ms.mm. PTFV1 >40 ms.mm was associated with ischemic stroke after adjustment for other stroke risk factors (odds ratio [OR], 2.32; 95% CI, 1.29 to 4.18). The association remained significant after adding echocardiographic left atrial diameter to the model (OR, 2.31; 95% CI, 1.28 to 4.17). PTFV1 was independently associated with stroke in patients in the upper half of echocardiographically determined left ventricular mass (adjusted OR, 4.5; 95% CI, 2.20 to 9.15) but not in those in the lower half (OR, 0.58; 95% CI, 0.20 to 1.65; P=0.0008). ECG-LAA can supplement 2D echocardiography in assessing the risk of ischemic stroke, especially in subjects with increased left ventricular mass.

Obesity and the Risk of New-Onset Atrial Fibrillation

ContextObesity is associated with atrial enlargement and ventricular diastolic dysfunction, both known predictors of atrial fibrillation (AF). However, it is unclear whether obesity is a risk factor for AF.ObjectiveTo examine the association between body mass index (BMI) and the risk of developing AF.Design, Setting, and ParticipantsProspective, community-based observational cohort in Framingham, Mass. We studied 5282 participants (mean age, 57 [SD, 13] years; 2898 women [55%]) without baseline AF (electrocardiographic AF or arterial flutter). Body mass index (calculated as weight in kilograms divided by square of height in meters) was evaluated as both a continuous and a categorical variable (normal defined as <25.0; overweight, 25.0 to <30.0; and obese, ≥30.0). In addition to adjusting for clinical confounders by multivariable techniques, we also examined models including echocardiographic left atrial diameter to examine whether the influence of obesity was mediated by changes in left atrial dimensions.Main Outcome MeasureAssociation between BMI or BMI category and risk of developing new-onset AF.ResultsDuring a mean follow-up of 13.7 years, 526 participants (234 women) developed AF. Age-adjusted incidence rates for AF increased across the 3 BMI categories in men (9.7, 10.7, and 14.3 per 1000 person-years) and women (5.1, 8.6, and 9.9 per 1000 person-years). In multivariable models adjusted for cardiovascular risk factors and interim myocardial infarction or heart failure, a 4% increase in AF risk per 1-unit increase in BMI was observed in men (95% confidence interval [CI], 1%-7%; P = .02) and in women (95% CI, 1%-7%; P = .009). Adjusted hazard ratios for AF associated with obesity were 1.52 (95% CI, 1.09-2.13; P = .02) and 1.46 (95% CI, 1.03-2.07; P = .03) for men and women, respectively, compared with individuals with normal BMI. After adjustment for echocardiographic left atrial diameter in addition to clinical risk factors, BMI was no longer associated with AF risk (adjusted hazard ratios per 1-unit increase in BMI, 1.00 [95% CI, 0.97-1.04], P = .84 in men; 0.99 [95% CI, 0.96-1.02], P = .56 in women).ConclusionsObesity is an important, potentially modifiable risk factor for AF. The excess risk of AF associated with obesity appears to be mediated by left atrial dilatation. These prospective data raise the possibility that interventions to promote normal weight may reduce the population burden of AF.

Targeted Modification of Atrial Electrophysiology by Homogeneous Transmural Atrial Gene Transfer

Safe and effective myocardial gene transfer remains elusive. Heterogeneous ventricular gene delivery has been achieved in small mammals but generally with methods not readily transferable to the clinic. Atrium-specific gene transfer has not yet been reported. We hypothesized that homogeneous atrial gene transfer could be achieved by direct application of adenoviral vectors to the epicardial surface, use of poloxamer gel to increase virus contact time, and mild trypsinization to increase virus penetration. We "painted" recombinant adenovirus encoding the reporter gene Escherichia coli beta-galactosidase directly onto porcine atria. Investigational variables included poloxamer use, trypsin concentration, and safety. Using the painting method, we modified the atrial phenotype with an adenovirus expressing HERG-G628S, a long-QT-syndrome mutant. Our results showed that application of virus with poloxamer alone resulted in diffuse epicardial gene transfer with negligible penetration into the myocardium. Dilute trypsin concentrations allowed complete transmural gene transfer. After trypsin exposure, echocardiographic left atrial diameter did not change. Left atrial function decreased on postoperative day 3 but returned to baseline by day 7. Tissue tensile strength was affected only in the 1% trypsin group. HERG-G628S gene transfer prolonged atrial action potential duration and refractory period without affecting ventricular electrophysiology. We show complete transmural atrial gene transfer by this novel painting method. Adaptation of the method could allow application to other tissue targets. Use with functional proteins in the atria could cure or even prevent diseases such as atrial fibrillation or sinus node dysfunction.

Obesity and the Risk of New-Onset Atrial Fibrillation

Obesity is associated with atrial enlargement and ventricular diastolic dysfunction, both known predictors of atrial fibrillation (AF). However, it is unclear whether obesity is a risk factor for AF. To examine the association between body mass index (BMI) and the risk of developing AF. Prospective, community-based observational cohort in Framingham, Mass. We studied 5282 participants (mean age, 57 [SD, 13] years; 2898 women [55%]) without baseline AF (electrocardiographic AF or arterial flutter). Body mass index (calculated as weight in kilograms divided by square of height in meters) was evaluated as both a continuous and a categorical variable (normal defined as <25.0; overweight, 25.0 to <30.0; and obese, > or =30.0). In addition to adjusting for clinical confounders by multivariable techniques, we also examined models including echocardiographic left atrial diameter to examine whether the influence of obesity was mediated by changes in left atrial dimensions. Association between BMI or BMI category and risk of developing new-onset AF. During a mean follow-up of 13.7 years, 526 participants (234 women) developed AF. Age-adjusted incidence rates for AF increased across the 3 BMI categories in men (9.7, 10.7, and 14.3 per 1000 person-years) and women (5.1, 8.6, and 9.9 per 1000 person-years). In multivariable models adjusted for cardiovascular risk factors and interim myocardial infarction or heart failure, a 4% increase in AF risk per 1-unit increase in BMI was observed in men (95% confidence interval [CI], 1%-7%; P = .02) and in women (95% CI, 1%-7%; P = .009). Adjusted hazard ratios for AF associated with obesity were 1.52 (95% CI, 1.09-2.13; P = .02) and 1.46 (95% CI, 1.03-2.07; P = .03) for men and women, respectively, compared with individuals with normal BMI. After adjustment for echocardiographic left atrial diameter in addition to clinical risk factors, BMI was no longer associated with AF risk (adjusted hazard ratios per 1-unit increase in BMI, 1.00 [95% CI, 0.97-1.04], P = .84 in men; 0.99 [95% CI, 0.96-1.02], P = .56 in women). Obesity is an important, potentially modifiable risk factor for AF. The excess risk of AF associated with obesity appears to be mediated by left atrial dilatation. These prospective data raise the possibility that interventions to promote normal weight may reduce the population burden of AF.

Echocardiographic and clinical predictors for outcome of elective cardioversion of atrial fibrillation

Previous studies have suggested that success of elective direct-current cardioversion for atrial fibrillation (AF) can be predicted from clinical features and M-mode echocardiographic left atrial diameter. We evaluated clinical variables as well as M-mode and 2-dimensional echocardiographic measurements of atrial size in 85 patients undergoing electrical cardioversion for AF. Of 65 patients who were initially converted to sinus rhythm, 45 (69%) and 38 (58%) remained in sinus rhythm at 1 and 6 months, respectively. No historical feature predicted initial success, although patients with cardiomyopathy or pulmonary disease underlying their AF had significantly lower success rates compared with those having other etiologies. Furthermore, no M-mode or 2-dimensional echocardiographic measurements of atrial size predicted initial success of cardioversion. Maintenance of sinus rhythm at 1 month was related to short duration of AF before cardioversion (< 3 months vs > 12 months, p < 0.05). Left atrial area and long axis dimension by 2-dimensional echocardiography were significantly larger in patients remaining in sinus rhythm than in those who had reverted to AF at 1 month (28 ± 7 vs 24 ± 5 cm 2 and 65 ± 9 vs 59 ± 8 mm, respectively, both p < 0.05), but overlap was great. No significant difference in atrial dimensions was noted at 6-month follow-up. It appears that, although no clinical or echocardiographic variable predicts initial success for cardioversion of AF, duration of AF does predict maintenance of sinus rhythm 1 month after initial success. Atrial size does not appear to strongly influence outcome of cardioversion and should therefore not be included as an important variable when considering patients for this procedure.