Temporal changes in left ventricular longitudinal strain in general population: Clinical correlates and impact on cardiac remodeling

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Subclinical left atrial dysfunction profiles for prediction of cardiac outcome in the general population

OBJECTIVE

Echocardiographic definitions of subclinical left atrial dysfunction based on epidemiological data remain scarce. In this population study, we derived outcome-driven thresholds for echocardiographic left atrial function parameters discriminating between normal and abnormal values.

METHODS

In 1306 individuals (mean age, 50.7 years; 51.6% women), we echocardiographically assessed left atrial function and LV global longitudinal strain. We derived cut-off values for left atrial emptying fraction (LAEF), left atrial function index (LAFI) and left atrial reservoir strain (LARS) to define left atrial dysfunction using receiver-operating curve threshold analysis. Main outcome was the incidence of cardiac events and atrial fibrillation (AFib) on average 8.5 years later.

RESULTS

For prediction of new-onset AFib, left atrial cut-offs yielding the best balance between sensitivity and specificity (highest Youden index) were: LAEF less than 55%, LAFI less than 40.5 and LARS less than 23%. Applying these cut-offs, abnormal LAEF, LAFI and LARS were, respectively, present in 27, 37.1 and 18.1% of the cohort. Abnormal LARS (<23%) was independently associated with higher risk for cardiac events and new-onset AFib (P ≤ 0.012). Participants with both abnormal LAEF and LARS presented a significantly higher risk to develop cardiac events (hazard ratio: 2.10; P = 0.014) and AFib (hazard ratio: 6.45; P = 0.0036) than normal counterparts. The concomitant presence of an impaired LARS and LV global longitudinal strain improved prognostic accuracy beyond a clinical risk model for cardiac events and the CHARGE-AF Risk Score for AFib.

CONCLUSION

Left atrial dysfunction based on outcome-driven thresholds predicted cardiac events and AFib independent of conventional risk factors. Screening for subclinical left atrial and LV systolic dysfunction may enhance cardiac disease prediction in the community.

Myocardial strain in hypertension: a meta-analysis of two-dimensional speckle tracking echocardiographic studies

AIM

Available evidence on systolic dysfunction in systemic hypertension, as assessed by left ventricular (LV) mechanics, is still based on single studies. Thus, we performed a systematic meta-analysis of two-dimensional speckle-tracking studies in order to provide an updated comprehensive information on this issue.

METHODS

The PubMed, OVID-MEDLINE, and Cochrane library databases were analyzed to search English language articles published from the inception up to 31 December 2020. Studies were identified by using MeSH terms and crossing the following search items: 'myocardial strain', 'left ventricular mechanics', 'speckle tracking echocardiography', 'systolic dysfunction', 'hypertensive heart disease', 'systemic hypertension', 'essential hypertension'.

RESULTS

Data from 4276 individuals (2089 normotensive controls and 2187 mostly uncomplicated hypertensive patients) were included. Left ventricular (LV) mass index, relative wall thickness, left atrial volume index and E/e' ratio were significantly higher in hypertensive patients than in normotensive controls. LV ejection fraction did not differ in the two pooled groups (SMD -0.048 ± 0.054, 95% CI -0.20 to 0.10, P = 0.30), whereas LV global longitudinal strain (GLS) was significantly impaired in the hypertensive group (SMD: 1.07 ± 0. 15, 95% CI 0.77-1.36, P < 0.0001). Similar findings were obtained in a sub-analysis restricted to 15 studies in which mean age was similar in cases and controls (SMD 1.21 ± 0.23, 95% CI 0.76-1.67, P = 0.002).

CONCLUSION

The present meta-analysis suggests that GLS assessment unmasks systolic dysfunction undetected by conventional ejection fraction in the uncomplicated hypertension setting and that this parameter should be incorporated into routine work-up aimed to identify hypertension-mediated cardiac damage.

Contractile Fronts In The Interventricular Septum: A Case For High Frame Rate Echocardiographic Imaging

The real time high frame rate (HFR) 2-dimensional ultrasound system, T5, at Duke University is capable of imaging at up to 1000 images per second for adult cardiac imaging. A method for detecting and visualizing the mechanical contraction fronts using HFR echocardioagraphy-derived Strain Rate Image (SRI) was described in 26 patients. The Tissue Shortening Onset front durations for echocardiographic normal patients were significantly shorter than conduction disorder patients with left bundle branch block (LBBB) with intrinsic conduction and conduction disorder patients without LBBB (non-LBBB) with simulated LBBB (sLBBB). Echocardiographic normal patients had significantly higher correlation coefficients between their SRIs and spatially inverted versions of themselves compared to non-LBBB patients with intrinsic conduction and sLBBB. In conclusion, SRIs could spatially resolve contractile event fronts in patients.

[The changes of left ventricular longitudinal systolic function depending on hypertension and its control: analysis in a population]

Aim To evaluate changes in left ventricular (LV) systolic function by LV myocardial global longitudinal strain (GLS) and global strain rate (GSR) in patients with arterial hypertension (AH) and based on the effectiveness of blood pressure (BP) control in a Russian population sample of individuals older than 55 years.Materials and methods This cross-sectional study was a population-based cohort study (HAPIEE, Novosibirsk). LV myocardial GLS and GSR were studied by echocardiography in a random sample (n=1004, 55-84 years). Statistical analysis was performed with multivariate models of logistic regression.Results AH prevalence in the study sample was 78.4 %. Mean GLS was 19.1 % (SD, 4.07), which was less for men than for women (p=0.001). Mean GSR was 0.86 s-1 (SD, 0.19) and was not different between men and women. In individuals with AH, the GLS absolute value was lower than in normotensive people (18.8 %; SD, 4.04 vs. 20.2 %; SD, 4.03, p˂0.001); these differences remained irrespective of the age, gender, body weight index (BWI) (p=0.027), and LV mass index (p=0.05). When people with AH were divided into groups, the lowest GLS absolute values were observed among "ineffectively treated" or not receiving any therapy individuals (p&lt;0.001 vs. normotensive group). AH 1.6 times increased the risk of LV GLS decrease. In individuals with AH, the GSR absolute value was lower than in normotensive people (- 0.85 s-1 (SD, 0.19) vs.- 0.92 s-1 (SD, 0.18), p&lt;0.001); this difference remained in multivariate models. The lowest GSR absolute values were observed in the "ineffectively treated" group irrespective of the gender, age, and BWI (p=0.036 vs. normotensive group). AH doubled the risk of LV GSR decrease, which could be partially explained by the contribution of BWI and myocardial mass index.Conclusion In this population sample, LV GLS and GSR were independently associated with AH. The lowest GLS and GSR values were observed for ineffectively treated" individuals with AH, which may reflect an early decline of LV systolic function with inadequate control of AH.

Associations of Left Ventricular Structure and Function With Blood Pressure in Heart Failure With Preserved Ejection Fraction: Analysis of the TOPCAT Trial

Background

Data on the association of systolic and diastolic blood pressure with the structure and function of failing hearts with preserved ejection fraction (EF) are sparse.

Methods and Results

This analysis included 935 patients with heart failure (49.4% women; mean age, 69.9 years) with preserved EF (≥45%) enrolled in the TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist) Trial before initiation of randomized therapy. Left ventricular (LV) structure (dimensions, wall thickness, and mass index), diastolic function (left atrial volume index, transmitral blood flow, and mitral annular velocities), and systolic function (EF and longitudinal strain) were assessed echocardiographically. In multivariable‐adjusted analyses, association sizes expressed per 1‐SD (14.8–mm Hg) increment in systolic blood pressure were 0.020 cm (P=0.003) and 0.018 cm (P=0.004) for LV septal and posterior wall thickness, respectively, and 2.42 mg/m² (P=0.018) for LV mass index. The corresponding associations with diastolic blood pressure were nonsignificant (P≥0.067). In similarly adjusted analyses, the association sizes expressed per 1‐SD (10.7–mm Hg) increment in diastolic blood pressure were −0.15 for E/A (P<0.001), −0.76 for E/e′ (P=0.006), and −0.62% for EF (P=0.024). These findings were consistent, if models including systolic blood pressure were additionally adjusted for diastolic blood pressure and vice versa, albeit that the relation of EF with diastolic blood pressure weakened (−0.54%; P=0.10).

Conclusions

In diastolic heart failure, LV wall thickness and LV mass index increased with higher systolic blood pressure, but not with higher diastolic blood pressure, whereas functional measures reflecting diastolic LV function decreased with higher diastolic blood pressure, independent of systolic blood pressure. These observations highlight the importance of controlling both systolic and diastolic blood pressure as modifiable risk factors to reduce the risk of LV remodeling and diastolic LV dysfunction.

The influence of sex on left ventricular remodeling in arterial hypertension

Hypertension represents one of the most important and most frequent cardiovascular risk factors responsible for heart failure (HF) development. Both sexes are equally affected by arterial hypertension. The difference is lying in the fact that prevalence of hypertension as well as hypertension-induced target organ damage varies during lifetime due to substantial variation of sex hormones in women. Left ventricular (LV) structural, functional, and mechanical changes induced by hypertension are well-known complications that occur in both sexes and they are responsible for HF development. However, their prevalence is significantly different between women and men, which could potentially explain the variation in HF occurrence and prognosis between the sexes. Studies have shown that the prevalence of left ventricular hypertrophy is higher in men. The data are not consistent regarding LV diastolic dysfunction and a similar report has been given for LV mechanical changes. Most investigations agree that LV longitudinal strain is lower among hypertensive men. However, even in the healthy population, men have lower LV longitudinal strain and the cutoff values are still missing. Therefore, it would be difficult to draw the conclusion that LV mechanical dysfunction is more prevalent among men. The main mechanisms responsible for sex-related LV remodeling are sex hormones and their influence on biohumoral systems. This review provides an updated overview of the available data about sex-related LV remodeling, as well as potential mechanisms for these changes, in the patients with arterial hypertension.

Impact of age, sex and heart rate variability on the acute cardiovascular response to isometric handgrip exercise

Isometric handgrip exercise (IHG) triggers acute increases in cardiac output to meet the metabolic demands of the active skeletal muscle. An abnormal cardiovascular response to IHG might reflect early stages of cardiovascular disease. In a large community-based cohort, we comprehensively assessed the clinical correlates of acute cardiovascular changes during IHG. In total, 333 randomly recruited subjects (mean age, 53 ± 13 years, 45% women) underwent simultaneous echocardiography and finger applanation tonometry at rest and during 3 min of IHG at 40% maximal handgrip force. We calculated time-domain measures of short-term heart rate variability (HRV) from finger pulse intervals. We assessed the adjusted associations of changes in blood pressure (BP) and echocardiographic indexes with clinical characteristics and HRV measures. During IHG, men presented a stronger absolute increase in heart rate, diastolic BP, left ventricular (LV) volumes and cardiac output than women, even after adjustment for covariables. In adjusted continuous and categorical analyses, age correlated positively with the increase in systolic BP and pulse pressure, but negatively with the increase in LV stroke volume and cardiac output during exercise. After full adjustment, a greater increase in systolic and diastolic BP during exercise was associated with lower absolute real variability (P ≤ 0.026) and root mean square of successive differences (P ≤ 0.032) in pulse intervals at rest. In a general population sample, women presented a weaker cardiovascular response to IHG than men. Older age was associated with greater rise in BP pulsatility and diminished cardiac reserve. Low HRV at rest predicted a higher BP increase during isometric exercise.

Polar Coordinate Description of Blood Pressure Measurements and Implications for Sex-Specific and Personalized Analysis

Vascular properties and their associated impact on cardiovascular risk factors are often evaluated by metrics such as pulse pressure (PP) and the augmentation index (AIx). All derived metrics are essentially based on the combination of blood pressure recordings. These clinically used metrics typically concern a difference (as in PP) or a ratio (as in AIx). A polar coordinate description reveals the companion (C) of the traditional metric. The aim of this study is to evaluate the impact of PPC and AIxC by analyzing both patient data and a detailed data set on healthy children derived from the literature.Companions are calculated using the Pythagorean theorem, and show that PPC is related to mean arterial pressure, thus complementing the biomarker PP. Also, inflection pressure is tied to systolic pressure, implying a possible simplification of obtaining the numerical value of AIx. Outcomes for adults and children are comparable. We conclude that derived metrics such as PP and AIx are incomplete. The associated companion metrics PPC and AIxC can easily be calculated. They add clinically relevant information without the need to perform additional measurements. Combination of traditional and the newly described companion metrics permits more precise characterization of individual patients.

Global myocardial longitudinal strain in a general population-associations with blood pressure and subclinical heart failure: The Tromsø Study

The early detection of subclinical myocardial dysfunction can contribute to the treatment and prevention of heart failure (HF). The aim of the study was to (i) describe myocardial global longitudinal strain (GLS) patterns in a large general population sample from Norway and their relation to established cardiovascular disease (CVD) risk factors; (ii) to determine its normal thresholds in healthy individuals and (iii) ascertain the relation of myocardial GLS to stage A subclinical heart failure (SAHF). Participants (n = 1855) of the 7th survey of the population-based Tromsø Study of Norway (2015-2016) with GLS measurements were studied. Linear and logistic regression models were used for assessment of the associations between CVD risk factors and GLS. Mean GLS (SD) in healthy participants was - 15.9 (2.7) % in men and - 17.8 (3.1) % in women. Among healthy subjects, defined as those without known cardiovascular diseases and comorbidities, GLS declined with age. An increase of systolic blood pressure (SBP) of 10 mm Hg was associated with a 0.2% GLS reduction. Myocardial GLS in individuals with SAHF was 1.2% lower than in participants without SAHF (p < 0.001). Mean myocardial GLS declines with age in both sexes, both in a general population and in the healthy subsample. SBP increase associated with GLS decline in women. Our findings indicate high sensitivity of GLS for early subclinical stages of HF.