Mediating effect of the NLR on the relationship between HbA1c and left atrial stiffness in overweight patients with hypertension

BACKGROUND

We aimed to investigate the association between hemoglobin A1c (HbA1c) and left atrial (LA) stiffness in patients with hypertension and to explore the mediating effect of the neutrophil/lymphocyte ratio (NLR) on this association.

METHODS

Essential hypertensive patients (n=292) aged 18 to 83 years were enrolled and divided into two groups based on the LA stiffness index (LASI): Group I (LASI≤0.32, n=146) and Group II (LASI>0.32, n=146). The LASI was defined as the ratio of early diastolic transmitral flow velocity/lateral mitral annulus myocardial velocity (E/e') to LA reservoir strain. Multivariate linear regression analysis was performed to determine the independent predictors of the LASI.

RESULTS

Age, BMI, SBP, HbA1c, CRP and the NLR were significantly greater in Group II than in Group I (P<0.05). Additionally, Group II had a greater LA volume index (LAVI), left ventricular mass index (LVMI), and E/e' and lower LA reservoir, conduit and booster pump strains than Group I (P<0.001). Univariate and multivariate linear regression models revealed that age, SBP, HbA1c, and the NLR were independently associated with the LASI. Further mediation analysis was performed to determine the mediating effect of the NLR on the association between HbA1c and the LASI and revealed that the NLR had a mediating role only in overweight hypertensive patients, and the proportion of the mediating effect was 21.9%.

CONCLUSIONS

The NLR was independently correlated with the LASI and played a mediating role in the relationship between HbA1c and the LASI in overweight hypertensive patients.

Postoperative evaluation of left atrial stiffness in patients with congenital heart diseases

Left atrial (LA) stiffness is one of the most important factors involved in LA remodeling. LA stiffness has rarely been studied postoperatively in patients with congenital heart diseases (CHDs). This study aimed to evaluate LA stiffness in CHD patients postoperatively. Seventy-five patients (CHDs, 67; controls, 8; age range, 10-41 years) who underwent cardiac catheterization at our institution were included in this study. From the pulmonary artery wedge pressure waveform obtained during cardiac catheterization, the pressure range between the v wave and x trough was determined, and this value was divided by the LA reservoir strain obtained by echocardiography to calculate LA stiffness, as previously reported. LA stiffness was significantly higher in postoperative CHD patients than in controls (0.28 ± 0.17 vs. 0.13 ± 0.03, p = 0.001). Nineteen of 52 (37%) patients in their teens, 8 of 11 (73%) patients in their 20 s, and 1 of 4 (25%) patients aged > 30 years had elevated LA stiffness values. In particular, all patients with an LA reservoir strain < 20% had elevated LA stiffness. In postoperative CHD patients, LA stiffness was frequently elevated from a young age. CHD patients with elevated LA stiffness should be cautious of possible LA dysfunction in the future.

Associations of brachial-ankle pulse wave velocity with left atrial stiffness and left atrial phasic function in inpatients with hypertension

Hypertension induces left atrial (LA) and left ventricular (LV) dysfunction, and an increase in arterial stiffness. This study aimed to investigate the associations of brachial-ankle pulse wave velocity (baPWV) with LA stiffness and LA phasic function in hypertension. A total of 305 hypertensive inpatients enrolled and were divided into two groups based on baPWV [Group I, baPWV ≤ 1515 (cm/s), n = 153; Group II, baPWV > 1515 (cm/s), n = 152]. Two-dimensional speckle tracking echocardiography (2D-STE) based LA phasic strains (LAS-S, LAS-E, LAS-A) and LV global longitudinal strain (LVGLS) were evaluated. LA stiffness index (LASI) was defined as the ratio of E/e' to LAS-S. Multivariate linear regression modeling was used to analyze the associations of baPWV with LASI and LA phasic function in all patients as well as age-specific and sex-specific subgroups. LASI was significantly higher in Group II [0.35(0.26, 0.52)] compared with Group I [0.26(0.20, 0.36)] (P < 0.001). After adjusting cardiovascular risk factors, medication, and LV structural and functional parameters (LVEF, LVMI, E/A ratio, and LVGLS), baPWV remained significantly correlated with LASI (P < 0.05). We also evaluated the predictive value of baPWV for LASI, the area under the curve (AUC) was 0.663 (95% CI: 0.607-0.716, P < 0.001). In conclusion, BaPWV was independently associated with LA stiffness in hypertensive inpatients. BaPWV also exhibited a certain predictive value for LA stiffness in these inpatients. Measuring arterial stiffness can provide clinicians clues for early cardiac target organ damage (TOD) in addition to vascular TOD.

Usefulness of the pulmonary venous flow waveform for assessing left atrial stiffness

PURPOSE

This study investigated the novel non-invasive left atrial (LA) stiffness parameter using pulmonary venous (PV) flow measurements and the clinical usefulness of the novel LA stiffness parameter.

METHODS

We retrospectively analyzed 237 patients who underwent right heart catheterization and echocardiography less than one week apart. From the pulmonary artery wedge pressure waveform, the difference between x-descent and v-wave (ΔP) was measured. Using the echocardiographic biplane method of disks, the difference between LA maximum volume and that just before atrial contraction (ΔV_MOD) was calculated, and the ΔP/ΔV_MOD was calculated as a standard LA stiffness index. From the PV flow waveform, the peak systolic velocity (S), peak diastolic velocity (D), and minimum velocity between them (R) were measured, and S/D, S/R, and D/R were calculated. From the speckle tracking echocardiography-derived time-LA volume curve, the difference between LA maximum volume and that just before atrial contraction (ΔV_STE) was measured. Each patient's prognosis was investigated until three years after echocardiography.

RESULTS

Among the PV flow parameters, D/R was significantly correlated with ΔP (r = 0.62), and the correlation coefficient exceeded that between S/D and ΔP (r =  - 0.39) or S/R and ΔP (r = 0.14). The [D/R]/ΔV_STE was significantly correlated with ΔP/ΔV_MOD (r = 0.61). During the follow-up, 37 (17%) composite endpoints occurred. Kaplan-Meier analysis showed that patients with [D/R]/ΔV_STE greater than 0.13 /mL were at higher risk of cardiac events.

CONCLUSION

The [D/R]/ΔV_STE was useful for assessing LA stiffness non-invasively and might be valuable in the prognostic evaluation of patients with cardiac diseases.

Left atrial stiffness predicts cardiac events in patients with heart failure and reduced ejection fraction: The impact of diabetes

BACKGROUND

The aim of this study was to investigate the relationship between diabetes mellitus (DM) and left atrial (LA) remodelling in a group of patients with heart failure and reduced ejection fraction (HFrEF), and their combined impact on cardiac events (CE).

METHODS

This study included 136 consecutive HFrEF patients (65 ± 11 years), 36 had DM, and 86 had increased LA stiffness (LASt). All patients underwent complete conventional and tissue Doppler echocardiographic measurements were made including LA volumes and function. LASt was calculated using the formula: LASt = E/e' ratio / PALS.

RESULTS

At 55 ± 37 months follow-up, free survival from CE was 69% in patients without DM and 44.4% in those with DM (p < .0001). The CE free survival was lower in patients with increased LASt compared to normal LASt, (50 versus. 80%, p < .001), irrespective of the presence of DM (27 versus. 71%, p < .001).The best cut-off value of LASt for predicting CE in the group as a whole was ≥ 0.82% [81% sensitivity, 72% specificity and AUC 0.82 (p < .001)]. LASt ≥ 0.82% also predicted CE in no DM patients [78% sensitivity, 71% specificity and AUC 0.80 (p < .001)] and was a stronger predictor in DM patients [85% sensitivity, 71% specificity and AUC = 0.847 (p < .001)].

CONCLUSION

High LA stiffness is associated with poor clinical outcome in patients with HFrEF. Diabetes has an additional incremental value in determining clinical outcome in those patients.

Left atrial stiffness is superior to volume and strain parameters in predicting elevated NT-proBNP levels in systemic sclerosis patients

Heart failure with preserved ejection fraction (HFpEF) is common in systemic sclerosis (SSc) and implies a worse prognosis therefore non-invasive assessment of left ventricular (LV) filling pressure is pivotal. Besides E/eʹ the use of maximal left atrial volume (LA Vmax index) is recommended. LA reservoir strain was also reported to be useful. The utility of LA stiffness, however, was never investigated in SSc. Thus we aimed to compare the diagnostic power of LA Vmax index, reservoir strain and stiffness in predicting elevated LV filling pressure in SSc patients. 72 SSc patients (age: 57 ± 11 years) were investigated. LA stiffness was calculated as ratio of E/eʹ to LA reservoir strain. Elevated LV filling pressure was defined as NT-proBNP > 220 pg/ml. Receiver-operating characteristic (ROC) curves were used to estimate the diagnostic performance of the investigated parameters. Average NT-proBNP level was 181 ± 154 pg/ml. NT-proBNP > 220 pg/ml was found in 21 SSc patients. LA stiffness showed the highest diagnostic performance in predicting NT-pro-BNP > 220 pg/ml, with a cut off value of 0.314 (Area under the curve: 0.719, specificity: 89.4%, sensitivity: 42.1%). AUC values for LA reservoir strain and Vmax index were 0.595 and 0.521, respectively. LA stiffness was superior to Vmax index and reservoir strain in predicting elevated NT-proBNP levels in SSc patients. Although invasive validation studies on larger samples are required, our data suggest, that the use of LA stiffness may significantly contribute to diagnostic precision in populations with a high suspicion of HFpEF.

The association between left atrial stiffness and low-voltage areas of left atrium in patients with atrial fibrillation

The low-voltage areas of left atrium (LA-LVA) have recently been of significant focus. However, very few studies have focused on the association between LA function and LA-LVA, and the mechanism of appearance of LA-LVA remains unclear. We investigated the marker for the existence of LA-LVA using automated 3-D mapping system. We studied 92 patients (75 males, 68 ± 9 years, 47 non-paroxysmal AF) who received CA for AF and 40 control patients without AF. Echocardiography was performed before the CA, and high-density voltage mapping during sinus rhythm after pulmonary isolation was performed in AF patients. LA-LVA was defined as < 0.5 mV, and LA stiffness index (LASI) was defined as the ratio of E/e' to LA peak strain. LA-LVA (LVA burden > 10%) was detected in 19/92 AF patients (21%). Patients with LA-LVA were associated with higher LASI (1.64 ± 1.70 vs. 0.61 ± 0.46, p < 0.0001), larger LA volume, non-paroxysmal AF, higher brain natriuretic peptide, structural heart disease, and older age. On multivariate analysis, LASI, LA volume, and age were independently associated with the existence of LA-LVA. Of these markers, the highest area under curve was obtained with LASI. The rate of high LASI (≥ 0.552) was highest in AF patients with LA-LVA. Moreover, the existence of LVA in anterior LA wall was associated with higher LASI. High LA stiffness index was associated with the presence of LA-LVA. The LA-LVA might be attributed to LA functional remodeling rather than LA anatomical remodeling.

Left atrial mechanical function and stiffness in patients with paroxysmal atrial fibrillation

Background

Abnormalities in the left atrial (LA) structure and function may develop in patients with paroxysmal atrial fibrillation (AF). We sought to determine the contribution of LA mechanical function, including LA stiffness, to AF by comparing patients with paroxysmal AF with normal control subjects, and to evaluate whether LA mechanical function and stiffness are related with the structural changes of LA.

Methods

Sixty-four paroxysmal AF patients (57 ± 13 years, 59% male) were studied, using a speckle tracking echocardiography, and were compared with 34 age-, gender-, and left ventricular (LV) mass-matched controls (53 ± 14 years, 61% male). LA volume indices, expansion index for reservoir function, active emptying fraction for contractile function, mitral annular velocities, and global longitudinal LA strain were measured. The ratio of E/e' to LA strain was used as an index of LA stiffness.

Results

Patients with paroxysmal AF had similar LV volume indices, ejection fraction, and diastolic function, when compared with that of the normal controls. However, paroxysmal AF patients showed increased LA volume indices and decreased LA reservoir function, but similar contractile function. LA stiffness was increased in patients with paroxysmal AF than in the control subjects (0.40 ± 0.25 vs. 0.29 ± 0.10, p = 0.002), and was related with LA volume indices and reservoir function.

Conclusion

Patients with paroxysmal AF have decreased LA reservoir function and increased stiffness, in comparison with that of the control subjects. LA stiffness was significantly related with LA volume indices and reservoir function. LA stiffness can be used for the assessment of LA function in patients with paroxysmal AF.