Role of strain echocardiography in patients with hypertension

Myosin Light Chain Phosphatase Plays an Important Role in Cardiac Fibrosis in a Model of Mineralocorticoid Receptor-Associated Hypertension

BACKGROUND

Myosin phosphatase targeting subunit 2 (MYPT2) is an important subunit of cardiac MLC (myosin light chain) phosphatase, which plays a crucial role in regulating the phosphorylation of MLC to phospho-MLC (p-MLC). A recent study demonstrated mineralocorticoid receptor-related hypertension is associated with RhoA/Rho-associated kinase/MYPT1 signaling upregulation in smooth muscle cells. Our purpose is to investigate the effect of MYPT2 on cardiac function and fibrosis in mineralocorticoid receptor-related hypertension.

METHODS AND RESULTS

HL-1 murine cardiomyocytes were incubated with different concentrations or durations of aldosterone. After 24-hour stimulation, aldosterone increased CTGF (connective tissue growth factor) and MYPT2 and decreased p-MLC in a dose-dependent manner. MYPT2 knockdown decreased CTGF. Cardiac-specific MYPT2-knockout (c-MYPT2-/-) mice exhibited decreased type 1 phosphatase catalytic subunit β and increased p-MLC. A disease model of mouse was induced by subcutaneous aldosterone and 8% NaCl food for 4 weeks after uninephrectomy. Blood pressure elevation and left ventricular hypertrophy were observed in both c-MYPT2-/- and MYPT2+/+ mice, with no difference in heart weights or nuclear localization of mineralocorticoid receptor in cardiomyocytes. However, c-MYPT2-/- mice had higher ejection fraction and fractional shortening on echocardiography after aldosterone treatment. Histopathology revealed less fibrosis, reduced CTGF, and increased p-MLC in c-MYPT2-/- mice. Basal global radial strain and global longitudinal strain were higher in c-MYPT2-/- than in MYPT2+/+ mice. After aldosterone treatment, both global radial strain and global longitudinal strain remained higher in c-MYPT2-/- mice compared with MYPT2+/+ mice.

CONCLUSIONS

Cardiac-specific MYPT2 knockout leads to decreased myosin light chain phosphatase and increased p-MLC. MYPT2 deletion prevented cardiac fibrosis and dysfunction in a model of mineralocorticoid receptor-associated hypertension.

Exercise-induced desaturation during a six-minute walk test is associated with poor clinical outcomes in patients with pulmonary arterial hypertension

BACKGROUND

The six-minute walk test (6MWT) is an established exercise test for patients with pulmonary arterial hypertension (PAH), affording insight into both exercise intolerance and overall prognosis. Despite the widespread application of the 6MWT, the prognostic implications of exercise-induced desaturation (EID) during this test has been inadequately studied in PAH patients. Thus, we evaluated the occurrence of EID and its prognostic significance in PAH patients.

METHODS

We analyzed PAH patients in a single-center cohort from April 2016 to March 2021. EID was defined as a reduction in oxygen saturation exceeding 4% from the baseline or to below 90% at any point during the test.

RESULTS

We analyzed 20 PAH patients in this cohort, primarily consisting of 16 females with an average age of 48.4 ± 13.3 years. Among them, ten exhibited EID. Baseline characteristics, echocardiographic data and right heart catheterization data were similar between the two groups. However, total distance (354.3 ± 124.4 m vs. 485.4 ± 41.4 m, P = 0.019) and peak oxygen uptake (12.9 ± 3.2 mL/kg⋅min vs. 16.4 ± 3.6 mL/kg⋅min, P = 0.019) were significantly lower in the EID group. During the total follow-up duration of 51.9 ± 25.7 months, 17 patients had at least one adverse clinical event (2 deaths, 1 lung transplantation, and 13 hospital admissions). The presence of EID was associated with poor clinical outcome (hazard ratio = 6.099, 95% confidence interval = 1.783-20.869, P = 0.004).

CONCLUSIONS

During the 6MWT, EID was observed in a half of PAH patients and emerged as a significant prognostic marker for adverse clinical events.

Advanced echocardiography techniques (AETs) to assess left atrial structure and function in individuals with resistant hypertension

AIMS

Resistant hypertension (RH) is a challenging phenotype within the hypertension (HTN) spectrum, requiring careful assessment and follow-up. Evaluation of left atrial function may be clinically informative, but is usually neglected. Advanced Echocardiography Techniques (AETs), such as Strain Analysis and three-dimensional echocardiography (3D ECHO) may be useful complementary tools to assess atrial function in patients with RH.

METHODS AND RESULTS

Ninety-six eligible adult patients were categorized into three groups: resistant hypertensive (RH), controlled hypertensive (CH), and normotensive (N), and underwent AETs to identify morphofunctional changes in the left atrium (LA) across different HTN phenotypes. The LA reservoir strain was significantly lower among RH than in N and CH patients (p < .001). Accordingly, LA conduit strain showed a gradient through the groups: higher among N, followed by CH and RH patients (p = .015). LA contraction strain was higher among CH than in N and RH patients (p = .02). Maximum indexed, pre-A, and minimum atrial volumes obtained by 3D ECHO showed differences between N and the others (p < .001), but not between CH and RH. N patients showed a higher fraction of passive emptying of the LA than the others (p = .02), with no difference between CH and RH. Total emptying of the LA only differed between N and RH patients, while active emptying of the LA showed no difference between the groups (p = .82).

CONCLUSION

The left atrium may present early functional changes in response to HTN, which are detectable by AETs. AETs, especially S-LA, allowed to identify markers of atrial myocardial damage in both RH and CH patients.

Blood pressure control and left ventricular echocardiographic progression in hypertensive patients: an 18-month follow-up study

Objectives

The impact of blood pressure (BP) control and its timing on left ventricular (LV) structure and function remains unclear. The present study was to evaluate whether BP control correlated with conventional LV geometry and function indexes or global longitudinal strain (GLS) progression, and when echocardiographic changes would occur in essential hypertension.

Methods and results

A total of 62 participants (mean age 55.2 ± 11.5, male 71.0%) with uncontrolled hypertension were enrolled in the longitudinal study. Patients were followed up at the 6-month and 18-month, when echocardiographic measurements were performed and BP control was evaluated during the follow up period. At the 6- and 18-month examination, we divided the hypertensive patients into two groups as BP controlled and uncontrolled group. Patients with BP uncontrolled (n = 33) had higher LV mass index (P = 0.02), higher left atrial volume index (P = 0.01), worse GLS (P = 0.005) and GLS changes (P = 0.003) compared with controlled BP (n = 29) at the 6-month follow-up examination. Patients with uncontrolled BP (n = 25) had higher LV mass index (P = 0.001), higher LV mass index changes (P = 0.01), higher relative wall thickness (P = 0.01), higher E/e' (P = 0.046), worse GLS (P = 0.02) and GLS changes (P = 0.02) compared to BP controlled group (n = 24) at the 18-month follow-up examination. GLS changes were associated with BP control (β = 0.370, P = 0.004 at the 6-month examination and β = 0.324, P = 0.02 at the 18-month examination, respectively) in stepwise multivariate regression analysis. LV mass index changes was corelated with systolic BP (β = 0.426, P = 0.003) at the 18-month follow-up examination in stepwise multivariate regression analysis. Neither was GLS changes nor LV mass index changes were related to antihypertensive medication class, including combination therapy in 6- or 18-month follow up examination.

Conclusions

Our findings offer new clinical evidence on the association of BP control with echocardiographic changes in hypertensive patients, and, in particular, support the view that GLS progression was earlier and subtler than conventional LV geometry and function parameters. GLS changes were significant between BP controlled and uncontrolled patients even in 6-month follow-up period.

Assessment of subclinical cardiac dysfunction by speckle-tracking echocardiography among people living with human immunodeficiency virus

Background

People living with HIV (PLWH) have an increased risk of developing cardiovascular diseases (CVD). As speckle-tracking echocardiography (STE) has been used to detect subclinical myocardial abnormalities, this study aims to detect early cardiac impairment among Asian PLWH using STE and to investigate the associated risk factors.

Methods

We consecutively recruited asymptomatic PLWH without previous CVD from a medical center of Taiwan, and their cardiac function was evaluated by conventional echocardiogram and STE. Enrolled PLWH were classified as antiretroviral therapy (ART)-experienced and ART-naive, and multivariable regressions were used to assess the association between myocardial strain and risk factors including traditional CVD and HIV-associated factors.

Results

A total of 181 PLWH (mean age: 36.4 ± 11.4 years, 173 males) were recruited and conventional echocardiogram parameters were within normal ranges. Decreased myocardial strain across the myocardium was found, with a mean left ventricular (LV) global longitudinal strain of -18.7 ± 2.9%. The LV strain in the ART-experienced group (-19.0 ± 2.9%) was significantly better than the ART-naive group (-17.9 ± 2.8%), despite a younger age and lesser CVD risk factors in the ART-naive group. Hypertension [B = 1.92, 95% confidence interval (95% CI) 0.19-3.62, p = 0.029] and ART-naive with both low and high viral loads (VL) (B = 1.09, 95% CI 0.03-2.16, p = 0.047; and B = 2.00, 95% CI, 0.22-3.79, p = 0.029) were significantly associated with reduced myocardial strain.

Conclusion

This is the first and largest cohort using STE to investigate myocardial strain in Asian PLWH. Our results suggest that hypertension and detectable VL are associated with impaired myocardial strain. Thus, timely ART administration with VL suppression and hypertension control are crucial in preventing CVD when making the management parallel with the improved life expectancy of PLWH on ART.

Speckle tracking echocardiography in early disease stages: a therapy modifier?

Echocardiography has been included as a first-line tool in several international guidelines for the management of patients with various cardiac diseases. Beyond diagnosis, echocardiographic examination helps in characterizing the severity of the condition since the very first stages. In particular, the application of second-level techniques, speckle tracking echocardiography in particular, can also reveal a subclinical dysfunction, while the standard parameters are in the normality range. The present review describes the potentialities of advanced echocardiography in different settings, including arterial hypertension, atrial fibrillation, diastolic dysfunction, and oncological patients, thus opening up potential starting points for its application as a clinical routine changer.

Detection of myocardial dysfunction using global longitudinal strain with speckle-tracking echocardiography in patients with vs without rheumatoid arthritis: a systematic review and meta-analysis

OBJECTIVES

Rheumatoid arthritis (RA) is a systemic autoimmune disorder primarily involving the peripheral joints. Systemic involvement can occur, including myocardial dysfunction. Speckle tracking echocardiography (STE) is a novel diagnostic study which is recently being used to detect subclinical cardiac dysfunction. Global longitudinal strain (GLS) by STE is more sensitive than standard echocardiographic parameters to detect occult cardiac dysfunction.

METHODS

A systematic search of PUBMED, EMBASE, Cochrane, and Google Scholar databases was performed to identify studies comparing the STE parameters between RA and non-RA patients.

RESULTS

Left ventricular (LV) GLS was significantly lower in patients with RA compared to non-RA patients with a standard mean difference (SMD) of -1.09 (-1.48--0.70, P < 0.001). LV Global Circumferential Strain (GCS) was reported in five studies, and it was found to be lower in RA patients with an SMD of -1.25 (-2.59--0.10; P < 0.0010). Meta regression analysis studies failed to show any significant impact of disease duration, activity, age, sex and BMI on LV GLS and RV GLS.

CONCLUSIONS

RA patients have lower LV GLS and LV GCS compared to controls suggesting impaired myocardial dysfunction. Further studies need to be done to delineate the importance of lower GLS in asymptomatic rheumatoid patients to guide disease management and risk factor modification in this selected population.