Left atrial expansion index measured with cardiovascular magnetic resonance estimates pulmonary capillary wedge pressure in dilated cardiomyopathy.

BACKGROUND: Pulmonary capillary wedge pressure (PCWP) assessment is fundamental for managing dilated cardiomyopathy (DCM) patients. Although cardiovascular magnetic resonance (CMR) has become the gold-standard imaging technique for evaluating cardiac chamber volume and function, PCWP is not routinely assessed with CMR. Therefore, this study aimed to validate the left atrial expansion index (LAEI), a LA reservoir function parameter able to estimate filling pressure with echocardiography, as a novel CMR-measured parameter for non-invasive PCWP estimation in DCM patients. METHODS: We performed a retrospective, single-center, cross-sectional study. We included electively admitted DCM patients referred to our tertiary center for further diagnostic evaluation that underwent a clinically indicated right heart catheterization (RHC) and CMR within 24 h. PCWP invasively measured during RHC was used as the reference. LAEI was calculated from CMR-measured LA maximal and minimal volumes as LAEI = ( (LAVmax-LAVmin)/LAVmin) × 100. RESULTS: We enrolled 126 patients (47 ± 14 years; 68% male; PCWP = 17 ± 9.3 mmHg) randomly divided into derivation (n = 92) and validation (n = 34) cohorts with comparable characteristics. In the derivation cohort, the log-transformed (ln) LAEI showed a strong linear correlation with PCWP (r = 0.81, p < 0.001) and remained a strong independent PCWP determinant over clinical and conventional CMR parameters. Moreover, lnLAEI accurately identified PCWP ≥ 15 mmHg (AUC = 0.939, p < 0.001), and the optimal cut-off identified (lnLAEI ≤ 3.85) in the derivation cohort discriminated PCWP ≥ 15 mmHg with 82.4% sensitivity, 88.2% specificity, and 85.3% accuracy in the validation cohort. Finally, the equation PCWP = 52.33- (9.17xlnLAEI) obtained from the derivation cohort predicted PCWP (-0.1 ± 5.7 mmHg) in the validation cohort. CONCLUSIONS: In this cohort of DCM patients, CMR-measured LAEI resulted in a novel and useful parameter for non-invasive PCWP evaluation.

Venous flow patterns after percutaneous atrial septal defect closure: Does the mechanical device decrease right atrial compliance?

INTRODUCTION: Systemic venous flow patterns become abnormal and restrictive after surgical closure of ostium secundum atrial septal defect (ASD) but rarely studied after percutaneous device closure. METHODS: From January 2017 to January 2018, systemic venous Doppler flow patterns were documented prospectively in 50 subjects who underwent percutaneous closure of ASD, prior to, after procedure, and at 6-month follow-up and correlated with defect size and device size. RESULTS: In hepatic veins and superior venacava post device-closure closure, the velocity time integral (VTI) of forward flow in both systole (S) and diastole (D) increased. Overall S was higher than D, and D/S ratio was <1. The D/S ratio increased after device closure significantly reflecting that the improvement in atrial filling increase in diastolic flow more than the increase in systolic flow. Increase in flow velocities was more prominent at 6 months with further increase in D/S VTI ratios. When correlated with the defect size, in those with defect size less than 15 mm/sq.m (mean device size 13.05 ± 3.21 mm), the changes in S- or D-wave, D/S ratio were less prominent and statistically not significant, while in subjects with defect size ≥ 15 mm/sq.m (mean device size 23.02 (±4.77 mm), these changes were greater and statistical significant. CONCLUSION: Residual filling defects with restriction of systolic venous flow were observed in subjects after device closure, correlating with larger device sizes, implying the compliance abnormality conferred by them which progresses at 6 months. Subjects with persistent abnormalities would need careful follow up for incomplete remodeling and increase in atrial size related arrhythmias.

Impact of left atrial compliance improvement on functional status after percutaneous mitral valvuloplasty.

BACKGROUND: Conventional hemodynamic parameters may not accurately predict symptomatic improvement after percutaneous mitral valvuloplasty (PMV). Changes in left heart chamber compliance following adequate relief o0066 mitral stenosis (MS) may be useful in determining functional capacity after PMV. This study aims to determine the acute effects of PMV on compliance of the left heart and whether its changes relate to the patient's functional capacity. METHODS: One-hundred thirty-seven patients with severe MS undergoing PMV were enrolled. Left atrial (Ca ) and left ventricular (Cv ) compliance were invasively estimated and net atrioventricular compliance (Cav ) was calculated before and immediately after the procedure. B-type natriuretic peptide (BNP) levels were obtained before and 24 hr after the procedure. The primary endpoint was functional status at 6-month follow-up, and the secondary endpoint was a composite of death, mitral valve (MV) replacement, repeat PMV, new onset of atrial fibrillation, or stroke in patients in whom PMV was successful. RESULTS: The mean age was 43 ± 12 years, and 119 patients were female (87%). After PMV, Ca and Cav improved significantly from 5.3 [IQR 3.2-8.2] mL/mmHg to 8.7 [5.3-19.2] mL/mmHg (P < 0.001) and 2.2 [1.6-3.4] to 2.8 [2.1-4.1] mL/mmHg (P < 0.001), respectively, whereas Cv did not change (4.6 [3.2-6.8] to 4.4 [3.1-5.6]; P = 0.637). Plasma BNP levels significantly decreased after PMV, with no correlation between its variation and changes in left chamber compliance. At 6-month follow-up, NYHA functional class remained unchanged in 32 patients (23%). By multivariable analyses, changes in Ca immediately after PMV (adjusted OR 1.42; 95% CI 95% 1.02 to 1.97; P = 0.037) and younger age (adjusted OR 0.95; CI 95% 0.92-0.98; P = 0.004), predicted improvement in functional capacity at 6-month follow-up, independent of postprocedural data. The secondary endpoint were predicted by post-PMV mean gradient (adjusted HR 1.363; 95% CI 95% 1.027-1.809; P = 0.032), and lack of functional improvement at 6-month follow-up (adjusted HR 4.959; 95% 1.708-14.403; P = 0.003). CONCLUSIONS: Ca and Cav increase significantly after PMV with no change in Cv . The improvement of Ca is an important predictor of functional status at 6-month follow up, independently of other hemodynamic data. Postprocedural mean gradient and lack of short-term symptomatic improvement were predictors of adverse outcome.

Left atrial compliance index predicts exercise capacity in patients with heart failure and preserved ejection fraction irrespective of right ventricular dysfunction.

BACKGROUND AND AIM: Predictors of exercise capacity in heart failure (HF) with preserved ejection fraction (HFpEF) remain of difficult determination. The aim of this study was to identify predictors of exercise capacity in a group of patients with HFpEF and right ventricle (RV) dysfunction METHODS: In 143 consecutive patients with HFpEF (age 62 ± 9 years, LV EF ≥45) and 41 controls, a complete echocardiographic study was performed. In addition to conventional measurements, LA compliance was calculated using the formula: [LAV max - LAV min/LAV min × 100]. Exercise capacity was assessed using the six-minute walking test (6-MWT). Tricuspid annular plane systolic excursion (TAPSE) < 1.7 cm was utilized to categorize patients with RV dysfunction (n = 40) from those with maintained RV function (n = 103). RESULTS: Patients with RV dysfunction were older (P = 0.002), had higher NYHA class (P = 0.001), higher LV mass index (P = 0.01), reduced septal and lateral MAPSE (all P < 0.001), enlarged LA (P = 0.001) impaired LA compliance index (P < 0.001) and exhibited a more compromised 6-MWT (P = 0.001). LA compliance index correlated more closely with 6-MWT (r = 0.51, P < 0.001) compared with the other LA indices (AP diameter, transverse diameter and volume indexed; r = -0.30, r = -0.35 and r = -0.38, respectively). In multivariate analysis, LA compliance index <60% was 88% sensitive and 61% specific (AUC 0.80, CI = 0.67-0.92 P = 0.001) in predicting exercise capacity. CONCLUSION: An impairment in LA compliance was profound in patients with HFpEF and RV dysfunction and seems to be most powerful independent predictor of limited exercise capacity.

Correlation between circulating fibrosis biomarkers with left atrial function and left atrial volume index in rheumatic mitral stenosis.

Mitral stenosis is the most common rheumatic heart disease (RHD) disorder worldwide, including in Indonesia. This pathological condition causes left atrial pressure, leading to left atrial fibrosis that affects the structure and function of the left atrial as well as the clinical condition. The aim of this study was to assess the correlation between circulating fibrosis biomarkers with net atrioventricular compliance (Cn) as a parameter of left atrial function, and left atrial volume index (LAVI) as a parameter left atrium structure of changes. A cross-sectional study was conducted at Panti Rahayu Hospital and Permata Bunda Hospital, Purwodadi, Central Java, with a total of 40 RHD patients with severe mitral stenosis. The ELISA was used to measure the levels of carboxy-terminal propeptide of type I procollagen (PICP), matrix metalloproteinase I (MMP-1), tissue inhibitor matrix metalloproteinase 1 (TIMP-1), and transforming growth factor-ß1 (TGF-ß1). The left atrial function was assessed by measuring Cn, and the LAVI parameters were measured to assess left atrium structure/size. The mean levels of circulating fibrosis biomarkers were as follows: PICP 153.96±89.12 ng/mL; MMP-1 1.44±2.12 ng/mL; MMP-1/TIMP-1 ratio 0.38±0.54 and TGF-ß1 2.66±1.96 pg/mL. From the echocardiographic evaluation, the mean Cn was 5.24±1.93 mL/mmHg and the mean LAVI was 152.55±79.36 mL/m2. There were significant correlation between MMP-1 and MMP-1/TIMP-1 ratio with Cn (r=0.345 and r=0.333, respectively; both had p<0.05). PICP and TGF-ß1 biomarkers did not significantly correlate with Cn (p>0.05). Meanwhile, none of the biomarkers had a significant correlation with LAVI (p>0.05). This study highlights that MMP-1 and MMP-1/TIMP-1 ratio are potentially to be used as markers to determine the Cn in RHD patients with severe mitral stenosis. However, further studies with a higher sample size are needed to confirm this finding.

Identification of Subclinical Heart Failure With Preserved Ejection Fraction in Patients With Symptomatic Atrial Fibrillation.

BACKGROUND: Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) commonly coexist. We hypothesize that patients with symptomatic AF but without overt clinical HF commonly exhibit subclinical HFpEF according to established hemodynamic criteria. OBJECTIVES: The authors sought to use invasive hemodynamics to investigate the prevalence and implications of subclinical HFpEF in AF ablation patients. METHODS: Consecutive symptomatic AF ablation patients were prospectively recruited. Diagnosis of subclinical HFpEF was undertaken by invasive assessment of left atrial pressure (LAP). Participants had HFpEF if the baseline mean LAP was >15 mm Hg and early HFpEF if the mean LAP was >15 mm Hg after a 500-mL fluid challenge. LA compliance was assessed invasively by monitoring the LAP and LA diameter during direct LA infusion of 15 mL/kg normal saline. LA compliance was calculated as Δ LA diameter/ΔLAP. LA cardiomyopathy was further studied with exercise echocardiography and electrophysiology study. Functional impact was evaluated using cardiopulmonary exercise testing and the AF Symptom Severity questionnaire. RESULTS: Of 120 participants, 57 (47.5%) had HFpEF, 31 (25.8%) had early HFpEF, and 32 (26.7%) had no HFpEF. Both HFpEF and early HFpEF were associated with lower LA compliance compared with those without HFpEF (P < 0.001). Participants with HFpEF and early HFpEF also displayed decreased LA emptying fraction (P = 0.004), decreased LA voltage (P = 0.001), decreased VO2peak (P < 0.001), and increased AF symptom burden (P = 0.002) compared with those without HFpEF. CONCLUSIONS: Subclinical HFpEF is common in AF ablation patients and is characterized by a LA cardiomyopathy, decreased cardiopulmonary reserve and increased symptom burden. The diagnosis of HFpEF may identify patients with AF with the potential to benefit from novel HFpEF therapies. (Characterising Left Atrial Function and Compliance in Atrial Fibrillation; ACTRN12620000639921).

Non-invasive evaluation of pulmonary capillary wedge pressure using the left atrial expansion index in mitral valve stenosis, prosthesis and repair.

Pulmonary capillary wedge pressure (PCWP) non-invasive evaluation is limited in patients with mitral valve (MV) stenosis, prosthesis, and surgical repair. This study aimed to assess the left atrial expansion index (LAEI) measured through transthoracic echocardiography (TTE) as a novel parameter for estimating PCWP in these challenging cardiac conditions. We performed a retrospective, cross-sectional study, including chronic cardiac patients receiving within 24 h a clinically indicated right heart catheterization (RHC) and transthoracic echocardiographic (TTE) exam. PCWP measured during RHC was used as the reference. TTE measurements were performed offline, blinded to RHC results. LAEI was calculated as LAEI = [(LAmaxVolume-LAminVolume)/LAminVolume] × 100. We included 167 patients (age = 73 ± 11.5 years; PCWP = 18 ± 7.7 mmHg) with rheumatic mitral valve (MV) stenosis (16.2%), degenerative MV stenosis (51.2%), MV prosthesis (18.0%), and MV surgical repair (13.8%). LAEI correlated logarithmically with PCWP, and the log-transformed LAEI (lnLAEI) showed a good linear association with PCWP (r = - 0.616; p < 0.001). lnLAEI was an independent PCWP determinant, providing added predictive value over conventional clinical (age, atrial fibrillation, heart rate, MV subgroups) and echocardiographic variables (LVEF, MV effective orifice area, MV mean gradient, net atrioventricular compliance, and pulmonary arterial systolic pressure). lnLAEI identified PCWP > 12 mmHg with AUC = 0.870, p < 0.001; and PCWP > 15 mmHg with AUC = 0.797, p < 0.001, with an optimal cut-off of lnLAEI < 3.69. The derived equation PCWP = 36.8-5.5xlnLAEI estimated the invasively measured PCWP ± 6.1 mmHg. In this cohort of patients with MV stenosis, prosthesis, and surgical repair, lnLAEI resulted in a helpful echocardiographic parameter for PCWP estimation.

Lessons from a case with stiff left atrial syndrome complicated by iatrogenic inter-atrial shunts: a case report.

Background: In patients with stiff left atrial (LA) syndrome, reservoir function is significantly impaired due to extensive LA fibrosis; consequently, the increase in LA pressure during haemodynamic stress is prominent, easily leading to pulmonary venous hypertension and subsequent pulmonary congestion, and eventually results in intractable heart failure. Case summary: A 79-year-old female with mitral stenosis and atrial fibrillation underwent valve replacement, Cox-Maze IV procedure, LA plication, and appendage ligation 4 years prior to presentation. Thereafter, she underwent a total of two catheter ablation procedures for recurrent atrial tachycardia. Transthoracic echocardiography revealed two continuous colour jets across the interatrial septum, with a peak pressure gradient of 23 mmHg, which was consistent with the residual puncture hole at the catheter ablation procedures. Although transoesophageal echocardiography showed no evidence of prosthetic valve dysfunction, the pulmonary venous flow signal showed a significantly blunted systolic forward flow, extremely small retrograde reversal flow during atrial contraction, and prominent diastolic flow velocities, all of which indicated significantly impaired LA function. Cardiac catheter examination revealed a characteristic pulmonary capillary wedge pressure waveform, which consisted of a steep ascending limb of v wave with a large peak, consistent with stiff LA syndrome. Discussion: Treatment of patients with stiff LA syndrome is quite challenging and restricted to the use of diuretics only, which has limited efficacy and eventually results in intractable heart failure. In this case, owing to the inter-atrial pressure-relieving gateway, the patient was only mildly symptomatic despite the existence of a non-compliant LA.

Determinants of Left Atrial Compliance in the Metabolic Syndrome: Insights from the "Linosa Study".

The association between left atrial (LA) impairment and cardiovascular diseases (CVD) and between dyslipidaemia and CVD are well known. The present study aims to investigate the relationships between metabolic factors and LA dimensions and compliance, as well as test the hypothesis that metabolic factors influence LA function independent from hemodynamic mechanisms. Arterial blood pressure (BP), waist and hip circumference, metabolic indices, and a complete echocardiographic assessment were obtained from 148 selected inhabitants (M/F 89/59; age 20−86 years) of Linosa Island, who had no history of CVD. At enrollment, 27.7% of the subjects met the criteria for metabolic syndrome (MetS) and 15.5% for arterial hypertension (HTN). LA compliance was reduced in subjects with MetS compared to those without (53 ± 27% vs. 71 ± 29%, p = 0.04) and was even lower (32 ± 17%, p = 0.01) in those with MetS and HTN. At multiple regression analysis, the presence of MetS independently determined LA maximal area (r = 0.56, p < 0.001), whereas systolic BP and the total cholesterol/HDL cholesterol ratio determined LA compliance (r = 0.41, p < 0.001). In an apparently healthy population with a high prevalence of MetS, dyslipidaemia seems to independently influence LA compliance. At a 5-year follow-up, LA compliance was reduced in both all-cause and CVD mortality groups, and markedly impaired in those who died of CVD. These findings may contribute to understanding the prognostic role of LA function in CVD and strengthen the need for early and accurate lipid control strategies.

Impaired Relaxation and Reduced Lusitropic Reserve in Atrial Myocardium in the Obese Patients.

Background: Obesity can influence the structure and function of the atrium, but most studies focused on the relationship of body mass index (BMI) and overt left atrium (LA) dysfunction as assessed by clinical imaging. We combined the assessment of right atrium (RA) function in vivo and in vitro in obese and non-obese patients scheduled for elective cardiac surgery. Methods: Atrial structure and function were quantified pre-operatively by echocardiography. RA tissue removed for the establishment of extracorporeal support was collected and RA trabeculae function was quantified in vitro at baseline and with adrenergic stimulation (isoproterenol). Fatty acid-binding protein 3 (FABP3) was quantified in RA tissue. Results were stratified according to the BMI of the patients. Results: About 76 patients were included pre-operatively for the echocardiographic analysis. RA trabeculae function at baseline was finally quantified from 46 patients and RA function in 28 patients was also assessed with isoproterenol. There was no significant correlation between BMI and the parameters of atrial function measured by the clinical echocardiography. However, in vitro measurements revealed a significant correlation between BMI and a prolonged relaxation of the atrial myocardium at baseline, which persisted after controlling for the atrial fibrillation and diabetes by the partial correlation analysis. Acceleration of relaxation with isoproterenol was significantly lower in the obese group (BMI ≥ 30 kg/m2). As a result, relaxation with adrenergic stimulation in the obese group remained significantly higher compared to the overweight group (25 kg/m2 ≤ BMI < 30 kg/m2, p = 0.027) and normal group (18.5 kg/m2 ≤ BMI < 25 kg/m2, p = 0.036). There were no differences on impacts of the isoproterenol on (systolic) developed force between groups. The expression of FABP3 in the obese group was significantly higher compared to the normal group (p = 0.049) and the correlation analysis showed the significant correlations between the level of FABP3 in the RA trabeculae function. Conclusion: A higher BMI is associated with the early subclinical changes of RA myocardial function with the slowed relaxation and reduced adrenergic lusitropy.

Left atrial compliance: an overlooked predictor of clinical outcome in patients with mitral stenosis or atrial fibrillation undergoing invasive management.

In the assessment of cardiovascular disease, the clinical significance of left atrial (LA) pressure-volume relations has largely been overlooked in contrast to left ventricular (LV) compliance. However, LA compliance has recently gained more attention. Net atrioventricular compliance (Cn), a joint measure of LA and LV compliance, can be calculated non-invasively by a previously validated method using parameters from standard echocardiography. Compliance measurement may be of relevance in selected clinical settings. First, subjects with low Cn are more likely to have their mitral valve area overestimated by the traditional mitral pressure half-time method. Consequently, low Cn in mitral stenosis, usually resulting from reduced LA compliance, can be mistaken for mild mitral stenosis. Second, low Cn independently predicted pulmonary hypertension and disease progression in medically treated mitral stenosis, and late cardiovascular complications after successful percutaneous mitral valvuloplasty. Decreased LA compliance also accounts for stiff LA syndrome, a rare complication of radiofrequency catheter ablation for atrial fibrillation, manifesting as otherwise unexplained heart failure with elevated LA pressure and pulmonary hypertension. Finally, depressed pre-ablation LA stiffness index, i.e. the ratio of the change in LA pressure to the corresponding change in LA volume during passive LA filling, was an independent predictor of arrhythmia recurrence. Thus, LA stiffening translates into adverse clinical outcomes in patients with mitral stenosis or atrial fibrillation undergoing interventional procedures. Whether reduced LA compliance after LA appendage occlusion can result in the LA stiff syndrome, has not been reported so far.

Effects of diabetes mellitus on left atrial volume and functions in normotensive patients without symptomatic cardiovascular disease.

PURPOSE: Left atrial (LA) size has been shown to be a predictor of adverse cardiovascular outcomes. The aim of the study was to evaluate the direct effect of diabetes mellitus (DM) on left atrial volume and phasic functions by using real-time three-dimensional echocardiography (RT3DE) in a population of patients free of symptomatic cardiovascular disease and hypertension. METHODS: Comprehensive transthoracic echocardiographic examination was performed on 40 consecutive patients with DM (20 male, age: 50.5±7.3 years) and 40 healthy controls (20 male, age: 48.4±6.7 years). In addition to conventional 2D echocardiographic measurements RT3DE was performed to assess LA volumes and phasic functions. RESULTS: There were no significant difference between groups regarding parameters reflecting LV systolic function as LV diameters and ejection fraction. However, regarding parameters reflecting LV diastolic function; transmitral deceleration time and E/E' ratio values were significantly higher and majority of early diastolic tissue Doppler velocity values were significantly lower in diabetic patients compared with controls. RT3DE demonstrated significantly higher LA maximum and minimum volumes for diabetic patients compared with controls (40.9±11.9 vs 34.6±9.3 mL, p: 0.009 and 15.6±5.9 vs 11.9±4.6 mL, p: 0.002, consecutively). LA total emptying fraction (TEF), expansion index (EI) and active emptying fraction (AEF) were found to be significantly lower in diabetics reflecting depressed LA reservoir and pump functions. There was no significant difference between groups regarding passive emptying fraction (PEF) which is assumed to be a marker of left atrial conduit function. CONCLUSION: Patients with type 2 diabetes mellitus were found to have increased LA volume and impaired atrial compliance and contractility. Evaluation of asymptomatic diabetic patients by using RT3DE atrial volume analysis may facilitate recognition of subtle myocardial alterations related with type 2 diabetes.