Sex-Related Differences of Left Atrial Strain in Patients With Hypertension Using Cardiac Magnetic Resonance Feature Tracking

PURPOSE

Previous studies demonstrated the impact of sex on left ventricular (LV) strain in patients with essential hypertension. However, little is known about the effect of sex on left atrial (LA) strain in patients with hypertension. This study aimed to explore the sex-related differences of LA strain by using cardiac magnetic resonance feature tracking in patients with hypertension and preserved LV ejection fraction.

MATERIALS AND METHODS

One hundred and fifty hypertensive patients (100 men and 50 women) and 105 age-matched and sex-matched normotensive controls (70 men and 35 women) were retrospectively enrolled and underwent cardiac magnetic resonance examination. LA strain parameters included LA reservoir strain (εs), conduit strain (εe), pump strain (εa), and their corresponding strain rate (SRs, SRe, and SRa).

RESULTS

Men had significantly higher LV mass index, lower εs and εe than women in both patients and controls (all P <0.05). LA strain and strain rate were significantly reduced in hypertensive patients compared with controls, both in men and women (all P <0.05). In men, hypertension and its interaction were associated with increased LV mass index and decreased εs and εe. In multivariable analysis, men, LV ejection fraction, and LA minimum volume index remained independent determinants of εs and εe in all hypertensive patients (all P <0.05).

CONCLUSION

LA strain was significantly impaired in hypertensive patients, and men had more impaired LA strain than women. These findings further emphasize the sex-related differences in the response of LA strain to hypertension in the early stage.

Incremental Effect of Mitral Regurgitation on Left Atrial Dysfunction and Atrioventricular Interaction in Hypertensive Patients by MRI

BACKGROUND

Mitral regurgitation may occur when hypertension causes left ventricular (LV) and left atrial (LA) remodeling. However, its role in LA function in hypertensive patients remains unclear.

PURPOSE

To explore how mitral regurgitation affects LA function in hypertension and to investigate atrioventricular interaction in hypertensive patients with mitral regurgitation.

STUDY TYPE

Retrospective.

POPULATION

A total of 193 hypertensive cases and 64 controls.

FIELD STRENGTH/SEQUENCE

A 3.0 T/balanced steady-state free precession.

ASSESSMENT

LA volume (LAV), LA strain (reservoir, conduit, and active), LA ejection fraction, and LV strain (global peak longitudinal [GLS], circumferential [GCS], and radial strain [GRS]) were evaluated and compared among groups. Regurgitant fraction (RF) was evaluated in regurgitation patients and used to subdivide patients into mild (RF: 0%-30%), moderate (RF: 30%-50%), and severe (RF: >50%) regurgitation categories.

STATISTICAL TESTS

One-way analysis of variance, Spearman and Pearson's correlation coefficients (r), and multivariable linear regression analysis. A P value <0.05 was considered statistically significant.

RESULTS

Hypertensive patients without mitral regurgitation showed significantly impaired LA reservoir and conduit functions and significantly decreased LV GLS but preserved pump function and LAV compared to controls (P = 0.193-1.0). Hypertensive cases with mild regurgitation (N = 22) had significantly enlarged LAV and further reduced LA reservoir function, while the group with moderate regurgitation (N = 20) showed significantly reduced LA pump function, further impaired conduit function, and significantly reduced LV strain. The severe regurgitation (N = 13) group demonstrated significantly more severely impaired LA and LV functions and LAV enlargement. Multivariable linear regression showed that regurgitation degree, GRS, GCS, and GLS were independently correlated with the LA reservoir, conduit, and active strain in hypertensive patients with mitral regurgitation.

DATA CONCLUSION

Mitral regurgitation may exacerbate LA and LV impairment in hypertension. Regurgitation degree, LV GRS, GCS, and GLS were independent determinants of the LA strain in hypertensive patients with mitral regurgitation, which demonstrated atrioventricular interaction.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 3.

Atrial Function Impairments after Pediatric Cardiac Surgery Evaluated by STE Analysis

Background: Applications of atrial speckle tracking echocardiography (STE) strain (ε) analysis in pediatric cardiac surgery have been limited. This study aims to evaluate the feasibility of atrial STE ε analysis and the progression of atrial ε values as a function of post-operative time in children after pediatric cardiac surgery. Methods: 131 children (mean 1.69 ± 2.98; range 0.01−15.16 years) undergoing cardiac surgery were prospectively enrolled. Echocardiographic examinations were performed pre-operatively and at 3 different post-operative intervals: Time 1 (24−36 h), Time 2 (3−5 days), Time 3 (>5 days, before discharging). The right and left atrium longitudinal systolic contractile (Ct), Conduit (Cd), and Reservoir (R) ε were evaluated with a novel atrial specific software with both P- and R-Gating methods. One hundred and thirty-one age-matched normal subjects (mean 1.7 ± 3.2 years) were included as controls. Results: In all, 309 examinations were performed over the post-operative times. For each post-operative interval, all STE atrial ε parameters assessed were significantly lower compared to controls (all p < 0.0001). The lowest atrial ε values were found at Time 1, with only partial recovery thereafter (p from 0.02 to 0.04). All atrial ε values at discharge were decreased compared to the controls (all p < 0.0001). Significant correlations of the atrial ε values with cardio-pulmonary-bypass time, left and right ventricular ε values (p < 0.05), and ejection fraction (p < 0.05) were demonstrated. Conclusions: Atrial ε is highly reduced after surgery with only partial post-operative recovery in the near term. Our study additionally demonstrates that post-surgical atrial and ventricular ε responses correlated with each other.

Cardiac Imaging for the Assessment of Left Atrial Mechanics Across Heart Failure Stages

The left atrium (LA) is emerging as a key element in the pathophysiology of several cardiac diseases due to having an active role in contrasting heart failure (HF) progression. Its morphological and functional remodeling occurs progressively according to pressure or volume overload generated by the underlying disease, and its ability of adaptation contributes to avoid pulmonary circulation congestion and to postpone HF symptoms. Moreover, early signs of LA dysfunction can anticipate and predict the clinical course of HF diseases before the symptom onset which, particularly, also applies to patients with increased risk of HF with still normal cardiac structure (stage A HF). The study of LA mechanics (chamber morphology and function) is moving from a research interest to a clinical application thanks to a great clinical, prognostic, and pathophysiological significance. This process is promoted by the technological progress of cardiac imaging which increases the availability of easy-to-use tools for clinicians and HF specialists. Two-dimensional (2D) speckle tracking echocardiography and feature tracking cardiac magnetic resonance are becoming essential for daily practice. In this context, a deep understanding of LA mechanics, its prognostic significance, and the available approaches are essential to improve clinical practice. The present review will focus on LA mechanics, discussing atrial physiology and pathophysiology of main cardiac diseases across the HF stages with specific attention to the prognostic significance. Imaging techniques for LA mechanics assessment will be discussed with an overlook on the dynamic (under stress) evaluation of the chamber.

Progress in the Study of the Left Atrial Function Index in Cardiovascular Disease: A Literature Review

Some studies have shown that left ventricular structure and function play an important role in the risk stratification and prognosis of cardiovascular disease. The clinical application of left atrial function in cardiovascular disease has gradually attracted attention in the cardiovascular field. There are many traditional methods to evaluate left atrial function. Left atrial function related indexes measured by echocardiography has been identified as a powerful predictor of cardiovascular disease in recent years, but they have some limitations. The left atrial function index has been found to evaluate left atrial function more effectively than traditional parameters. Furthermore, it is a valuable predictor of the risk stratification and prognosis in patients with clinical cardiovascular disease such as heart failure, atrial fibrillation, hypertension, and coronary heart disease.

Left atrial myocardial dysfunction in patients with primary aldosteronism as assessed by speckle-tracking echocardiography

BACKGROUND

We investigated the left atrial myocardial deformation in patients with primary aldosteronism using the speckle-tracking echocardiographic (STE) strain imaging technique.

METHODS

Our study included 107 primary aldosteronism patients [52 aldosterone-producing adenoma (APA) and 55 idiopathic hyperaldosteronism (IHA)] and 50 primary hypertensive patients. We performed conventional echocardiography to measure left atrial volume and ejection fraction, and STE to estimate left atrial myocardial deformation including peak velocity, strain and strain rate and calculate the ratio of E/e' to left atrial strain during left ventricular systole as the left atrial stiffness index.

RESULTS

Patients with APA, compared with those with IHA and primary hypertension had a significantly (P < 0.001) lower serum potassium concentration and higher 24-h urinary aldosterone excretion and plasma aldosterone-to-renin ratio. Patients with APA had a significantly (P < 0.01) larger maximal, precontraction, and minimal left atrial volumes and lower total, active and passive left atrial emptying fractions than those with IHA and primary hypertension. Among the three groups, patients with APA showed lowest left atrial velocity, strain, and strain rate during ventricular systole, early diastole and late diastole (P < 0.05) and highest left atrial stiffness index (P < 0.001). In unadjusted analysis, the left atrial strain, strain rate and stiffness index were significantly (P < 0.05) associated with plasma aldosterone concentration and urinary aldosterone excretion. After adjustment for various confounding factors, these associations remained statistically significant for urinary aldosterone excretion (P < 0.05) but not plasma aldosterone concentration (P ≥ 0.05).

CONCLUSION

Patients with primary aldosteronism, especially APA, had impaired left atrial deformation mechanics and increased left atrial stiffness, providing a promising insight into early detection of subclinical left atrial dysfunction by strain echocardiography.

Evaluation of Left Atrial Functions by 2-dimensional Speckle-Tracking Echocardiography During Healthy Pregnancy

OBJECTIVES

We aimed to determine the effects of normal pregnancy on left atrial (LA) mechanics using 2-dimensional speckle-tracking echocardiography.

METHODS

A total of 47 healthy women with singleton pregnancies were prospectively enrolled in this study. A total of 4 visits, including each trimester and postpartum at 6 months, were planned. Echocardiographic studies were performed with a Vivid 7 device equipped with a 2.5-MHz transducer (GE Vingmed Ultrasound AS, Horten, Norway).

RESULTS

Although the LA reservoir phase strain showed a gradual decrease from the first trimester to the third trimester during pregnancy, the measurements in the postpartum period were found to return to initial levels (mean ± SD: first trimester, 40.3% ± 11.7%; second trimester, 37.5% ± 12.9%; third trimester, 33.5% ± 9.0%; postpartum, 42.1% ± 11.1%; P < .001). The LA pump function strain was also parallel to the LA reservoir strain and gradually decreased from the first trimester to the third trimester during pregnancy, and it was observed that rose to the initial level in the postpartum period (first trimester, 16.7% ± 7.4%; second trimester, 14.8% ± 5.5%; third trimester, 12.7% ± 4.3%; postpartum, 15.8% ± 5.5%; P < .001).

CONCLUSIONS

We prospectively determined normal reference values for LA deformation parameters using speckle-tracking echocardiography in each trimester and the postpartum period in healthy pregnancy. These reference values may help identify subclinical LA dysfunction in several cardiovascular or systemic conditions. According to this study, these parameters decreased toward the third trimester during pregnancy and recovered in the postpartum period.

Early detection of left atrial dysfunction assessed by CMR feature tracking in hypertensive patients

OBJECTIVES

To evaluate whether early left atrial (LA) dysfunction in hypertension (HTN), with or without left ventricular hypertrophy (LVH), can be detected by cardiovascular magnetic resonance feature tracking (CMR-FT).

METHODS

Seventy-three HTN patients and 29 healthy controls were retrospectively recruited. HTN patients were divided into the LVH (n = 29) and non-LVH group (n = 44). LA performance was analysed using CMR-FT in 2- and 4-chamber cine images, including LA reservoir function (total ejection fraction [EF], total strain [εs], peak positive strain rate [SRs]), conduit function (passive EF, passive strain [εe], peak early negative strain rate [SRe]) and booster pump function (booster EF, active strain [εa], late peak negative strain rate [SRa]). One-way analysis of variance with post hoc LSD tests, Spearman analysis, receiver operating characteristic curve and intra-class correlation coefficient analysis were applied for statistical analyses.

RESULTS

Compared with healthy controls, LA reservoir (LA total EF, εs, SRs) and conduit function (LA passive EF, εe, SRe) were significantly impaired in HTN patients with or without LVH, and these parameters significantly correlated with mitral E/A < 1 (all p < 0.05). However, LA booster pump function was relatively preserved in non-LVH patients, representing an intermediate stage between the LVH group and controls. Among LA deformation parameters, εe showed the highest diagnostic value for differentiation of HTN patients with healthy controls (AUC, 0.82; sensitivity, 80.82%; specificity, 72.41%). Observer reproducibility was good-excellent (ICC, 0.83-0.97) for all CMR-FT derived parameters.

CONCLUSIONS

CMR-FT is a promising tool for quantification of LA function. LA reservoir and conduit dysfunction might be detected early by CMR-FT in HTN patients before the presence of LVH.

KEY POINTS

• CMR-FT is a promising tool in quantifying LA function, including deformation and volumetric parameters. • LA reservoir and conduit dysfunction might be detected early by CMR-FT in HTN patients with or without LVH. • The LA booster pump function was relatively preserved in non-LVH patients.

Association of the plasma aldosterone concentration, left atrial deformation and ambulatory blood pressure in never-treated early hypertensive patients

Left atrial (LA) strain is known to exhibit an early progressive reduction in hypertensive patients with diastolic dysfunction. However, an association of the renin-angiotensin-*aldosterone system (RAAS) with LA deformation has not been found in these patients. We aimed to investigate the association of plasma aldosterone concentration (PAC) and 24-hour ambulatory blood pressure monitoring (ABPM) with LA and left ventricle (LV) deformation in never-treated early hypertensive patients. This cross-sectional study included 101 never-treated subjects who were registered in a working group at The Catholic University of Korea. The patients were divided into a hypertension group (n = 71), which was defined as having a systolic blood pressure (BP) ≥130 mm Hg and/or a diastolic BP ≥80 mm Hg based on ABPM, and a control group (n = 30). Enrolled patients underwent conventional and speckle tracking echocardiography, ABPM, and measurement of pulse wave velocity, PAC, and plasma renin activity. Compared with the control group, the hypertension group had significantly increased PAC, global longitudinal strain (GLS), atrial reservoir strain, atrial pump strain, and atrial systolic strain rate. LA pump strain was independently associated with nighttime systolic BP. PAC was correlated with GLS but not LA deformation in hypertensive patients without clinically apparent target organ damage. The raised LV pressure secondary to the nocturnal systemic pressure overload might be more strongly associated with LA deformation than with the RAAS.