Beyond standard echocardiography: Strain imaging as the AI-powered key to comprehensive cardiac function evaluation.

Application of left ventricular and left atrial strain to distinguish cardiac from non-cardiac dyspnea.

Echocardiography 2020: Toward deciphering the "Rosetta stone" of left ventricular diastolic function.

In the year 1997, nearly a quarter-century ago, Nishimura and Tajik (J Am Coll Cardiol. 1997;30:8) suggested that Doppler echocardiography was the "Rosetta stone" (a metaphor for decrypting secrets of diastole) of left ventricular diastole, based solely on transmitral E/A ratio and its progression from grade I through IV, supported by cardiac catheterization, as the filling pressure started to increase to over 15 mm Hg. Ten years later, in 2007, the same Mayo group (Nagueh et al, J Am Coll Cardiology. 2008;51:679) was searching to decipher the secrets of diastole using multiple measures such as left atrial (LA) volume, E/E' ratio, pulmonary venous flow, and mitral inflow propagation velocity. This substantial leap from E/A ratio led to the more formal recommendation proposed by the American Society of Echocardiography in 2009 (Nagueh et al, J Am Soc Echocardiogr. 2009;22:107) and, as an update, in the year 2016 (Nagueh et al, J Am Soc Echocardiogr. 2016;29:277): the later version gained popularity for the simplified approach to identify diastolic dysfunction in healthy subjects as well as in those with poorly contracting left ventricle. Despite 30 years of continuous search, we are not sure if we have been able to decipher the hidden secrets of diastolic function. With this background, the Echocardiography Journal under the leadership of Dr Navin Nanda as the Editor-in-Chief has taken this initiative to publish a theme issue on left ventricular diastolic function and when this becomes dysfunctional to diminish life.

Irbesartan in Marfan syndrome (AIMS): a double-blind, placebo-controlled randomised trial.

BACKGROUND: Irbesartan, a long acting selective angiotensin-1 receptor inhibitor, in Marfan syndrome might reduce aortic dilatation, which is associated with dissection and rupture. We aimed to determine the effects of irbesartan on the rate of aortic dilatation in children and adults with Marfan syndrome. METHODS: We did a placebo-controlled, double-blind randomised trial at 22 centres in the UK. Individuals aged 6-40 years with clinically confirmed Marfan syndrome were eligible for inclusion. Study participants were all given 75 mg open label irbesartan once daily, then randomly assigned to 150 mg of irbesartan (increased to 300 mg as tolerated) or matching placebo. Aortic diameter was measured by echocardiography at baseline and then annually. All images were analysed by a core laboratory blinded to treatment allocation. The primary endpoint was the rate of aortic root dilatation. This trial is registered with ISRCTN, number ISRCTN90011794. FINDINGS: Between March 14, 2012, and May 1, 2015, 192 participants were recruited and randomly assigned to irbesartan (n=104) or placebo (n=88), and all were followed for up to 5 years. Median age at recruitment was 18 years (IQR 12-28), 99 (52%) were female, mean blood pressure was 110/65 mm Hg (SDs 16 and 12), and 108 (56%) were taking ß blockers. Mean baseline aortic root diameter was 34·4 mm in the irbesartan group (SD 5·8) and placebo group (5·5). The mean rate of aortic root dilatation was 0·53 mm per year (95% CI 0·39 to 0·67) in the irbesartan group compared with 0·74 mm per year (0·60 to 0·89) in the placebo group, with a difference in means of -0·22 mm per year (-0·41 to -0·02, p=0·030). The rate of change in aortic Z score was also reduced by irbesartan (difference in means -0·10 per year, 95% CI -0·19 to -0·01, p=0·035). Irbesartan was well tolerated with no observed differences in rates of serious adverse events. INTERPRETATION: Irbesartan is associated with a reduction in the rate of aortic dilatation in children and young adults with Marfan syndrome and could reduce the incidence of aortic complications. FUNDING: British Heart Foundation, the UK Marfan Trust, the UK Marfan Association.

Biatrial and right ventricular deformation imaging: Implications of the recent EACVI consensus document in the clinics and beyond.

In this review, right ventricular (RV), right atrial (RA), and left atrial (LA) strain in some selected clinical situations has been discussed in light of the current literature. To exemplify the significance of the use of multichamber strain, we have provided some illustrations of common cardiac problems. The recently published European Association of Cardiovascular Imaging (EACVI) consensus document for standardization of RV, RA, and LA strain, using the currently available software, has fulfilled the aspirations of investigators world over who have been studying atrial strain using a bailed-out algorithm designed principally to quantify left ventricular deformation. The purpose of this review was to reiterate the value of the application of RV and biatrial strain imaging in research and day-to-day clinical practice, using the 2-dimensional speckle tracking echocardiography (2D-STE). Also, we present a short report on how RA strain may remain coupled to pulmonary hemodynamics. Besides, we have highlighted the technical challenges of atrial strain quantification. We have not used the nomenclature of chamber deformation proposed by the EACVI document as the publications cited in this review have used different sets of nomenclature.

Deformation imaging of the atria using 2D strain: A noninvasive modality to characterize operating compliance?

This viewpoint with two illustrated case summaries of biventricular and biatrial mechanical function/dysfunction emphasizes the importance of continued research in deformation imaging beyond the left ventricle, as there are no Cinderellas in the heart and we just cannot afford to be nonchalant toward the atria, particularly the right atrium.

Incremental prognostic value of multichamber deformation imaging and renal function status to predict adverse outcome in heart failure with reduced ejection fraction.

AIMS: Deformation imaging, particularly of left-sided heart, is fast becoming an essential tool in clinical cardiology. However, data are scant regarding the value of biventricular and bi-atrial deformation in association with comorbidities in heart failure with reduced left ventricular ejection fraction (HFREF). METHODS AND RESULTS: Forty-nine subjects (72 ± 13 years; 28 male) with HFREF and 14 age-matched controls underwent deformation imaging including LV global longitudinal strain (LVGLS%), right ventricular strain (RVS%), and left atrial reservoir strain (LARS%). Standard echo parameters included LVEF%, E/E' ratio, and pulmonary artery systolic pressure (PASP). Mean ± SD of LVEF, LVGLS%, and RVS% were 31% ± 8%, 7% ± 3%, and 17% ± 7%, respectively, and were significantly lower compared with controls (all P < .0001). Over a follow-up period of 4.2 years, 24% of patients died and 48% had a composite outcome of death and heart failure hospitalization. In the logistic regression model, taking the composite of death and heart failure hospitalization as a dichotomous variable, RVS%, E/E' ratio, and PASP were the only significant univariate predictors of adverse outcome (R2  = .68, all P < .05). In the multivariate model, however, only PASP predicted adverse outcome. PASP also had the largest AUC (0.8) in the ROC analysis. A creatinine level of >88 µmol/L (SCREAT) and a cutoff value of LA reservoir strain (LARS %) at <16.7% provided the best sensitivity (86%) and specificity (40%) with an odds ratio of 3.8. In the Kaplan-Meier survival estimate, LARS%-SCREAT predicted all-cause mortality and HF hospitalization. CONCLUSION: Multichamber deformation imaging along with renal function and PASP could best predict adverse outcome in HFREF.

Right atrial myocardial deformation by two-dimensional speckle tracking echocardiography predicts recurrence in paroxysmal atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is a bi-atrial disease yet little attention has been given to right heart function in AF. We propose that the assessment of right atrial (RA) and right ventricular function (RV) using two-dimensional speckle tracking echocardiography (2D-STE) could be valuable in predicting AF recurrence in patients with paroxysmal AF (PAF). METHODS: Thirty patients with PAF were prospectively recruited from a dedicated AF clinic. Right atrial size, volume, and area and RV dimensions were analyzed along with RA and RV strain derived from 2D-STE at baseline and at 3 and 12 months. RESULTS: Higher RA booster strain independently predicted sinus rhythm (SR) maintenance for up to 1 year (P = 0.001). RV strain was impaired in patients with recurrent AF compared to those in SR (P < 0.05) but did not predict AF recurrence. Two-dimensional STE for RA and RV function was simple to perform with excellent reproducibility (adjusted R 2 0.92-0.99). CONCLUSIONS: Two-dimensional STE is useful and highly reproducible in assessing right heart function in AF patients. RA booster strain function was predictive of sinus rhythm maintenance for up to 1 year.

The role of advanced echocardiography and cardiovascular magnetic resonance in the assessment of myocardial function in Marfan syndrome-An update.

Cardiovascular assessment of patients with Marfan syndrome has normally focused on the aortic root and vascular manifestations of the disease due to the high risk of aortic dissection. Although primary myocardial impairment has long been suspected in these patients, the evidence has been controversial. Advanced echocardiography and cardiovascular magnetic resonance imaging have proven to be effective, accurate, and more sensitive in the detection of subtle cardiac dysfunction. The application of these techniques to Marfan syndrome over the last 10 years has made significant progress in demonstrating the presence of primary myocardial impairment in these patients, but further work is still required to obtain confirmatory molecular, pathophysiological, and prognostic clinical data. Phenotypic expression of the disease has prognostic value, also suggesting potential effective medical therapy.

Prognostic value of left atrial expansion index and exercise-induced change in atrial natriuretic peptide as long-term predictors of atrial fibrillation recurrence.

AIMS: We propose to assess the value of exercise-induced change in N-terminal-pro atrial natriuretic peptide (NT-proANP) and left atrial expansion index (LAEI) in predicting AFR after cardioversion and their effect on AF-free survival. METHODS AND RESULTS: Fifty-five patients with persistent AF of <18 months duration needing cardioversion were recruited for the study. Fifty-four patients were successfully cardioverted. At 3 months 28/54 (51%) were in SR and at 12 months 21/53 (39%). On multivariate analysis, only exercise-induced change in NT-proANP and LAEI were found to be predictive of AFR up to 12 months post-cardioversion and had an effect on AF-free survival. N-terminal-pro brain natriuretic peptide was elevated in all persistent AF patients but did not predict recurrent AF. CONCLUSIONS: Left atrial expansion index and exercise-induced atrial natriuretic peptide change show promise as predictors of AFR after cardioversion. These predictors may identify patients at an early stage in their disease with intact neurohumoral feedback systems and less advanced atrial remodelling. Further studies are required to confirm these findings.

Value of two-dimensional speckle tracking and real time three-dimensional echocardiography for the identification of subclinical left ventricular dysfunction in patients referred for routine echocardiography.

BACKGROUND: While speckle tracking echocardiography (2DSTE) can be used to study longitudinal, circumferential, and radial function, real time 3D echocardiography (3DE) generates dynamic time-volume curves, offering a wide array of new parameters for characterizing mechanical and volumetric properties of the left ventricle (LV). Our aim was to investigate the merit of these new techniques to separate normal from abnormal echocardiograms as well as to identify subclinical disease in reportedly normal subjects. METHODS: Eighty-one patients (mean age 61 ± 16 years) underwent standard 2D echocardiography (2DE) enhanced by 2DSTE and 3DE. The data included LV volumes and ejection fraction (EF), velocities, strain/strain rate, and peak ejection/filling rates. The patients were divided into Group 1: normal (n = 42) and Group 2: abnormal (n = 39) on the basis of an expert interpretation of the resting 2DE. RESULTS: Global longitudinal strain (%) was 17 ± 4 in Group1 and 14 ± 4 in Group2 (P < 0.002). Strain rates (SR, 1/sec) at peak systole (1.1 ± 0.2 vs 0.9 ± 0.3, P < 0.001) and early diastole (1.3 ± 0.3 vs 0.9 ± 0.3, P < 0.001) were also higher in Group1. Three-dimensional peak ejection and filling rates (EDV/sec) were significantly higher in Group1 (-2.5 ± 0.4 vs -2.1 ± 0.7, and 1.8 ± 0.2 vs 1.5 ± 0.5, P < 0.002, P < 0.001, respectively). The best discriminatory power for predicting a normal 2DE was systolic SR with a sensitivity of 82% and a specificity of 54% using a cutoff value of 1.09. Interestingly, 19/41 (46%) of Group1 patients had systolic SR < 1.09, suggesting subclinical disease. CONCLUSIONS: 2DSTE and 3DE can discriminate between normal and abnormal echocardiograms and have the potential to detect subclinical LV dysfunction.

Role of N-terminal pro-brain natriuretic peptide in ST-segment elevation myocardial infarction: experience from a tertiary centre in India.

BACKGROUND: Role of biomarkers in ST-segment elevation myocardial infarction (STEMI) is paramount, as they aid in diagnosis and gauge prognosis of the disease. In this project, we sought to study the short-term outcome and clinical associates of N-terminal pro-brain natriuretic peptide (NT-proBNP) in the setting of STEMI at a tertiary center in India. METHODS: In all, 173 STEMI patients (mean age: 57 ± 12 years, 38 women) had their NT-proBNP assayed in addition to troponins and high-sensitive C-reactive protein. Subjects were divided according to NT-proBNP levels into 2 groups: group 1 (NT-proBNP ≤100 pg/mL) and group 2 (NT-proBNP >100 pg/mL). RESULTS: NT-proBNP values (pg/mL) were elevated in group 2 (group 1: 61.7 ± 6.2; group 2: 1006.5 ± 990.6, P < 0.0001). Significantly greater number of females had elevated NT-proBNP (P < 0.05) that could be predicted by the duration of chest pain related to STEMI (area under the curve: 0.72), and age at presentation (area under the curve: 0.66). Multiple regression analysis showed a strong inverse association between NT-proBNP and left ventricular ejection fraction and a strong positive association between the peptide and high-sensitive C-reactive protein. A significant positive association was also noted between NT-proBNP and troponin I (all P < 0.05, Global R = 0.47). Diabetes mellitus and/or hypertension, and infarction localization showed no effect on NT-proBNP levels along with death, primary coronary intervention-related bleeding, and arrhythmias, (χ, P = ns). CONCLUSIONS: The data suggest that women are more likely to have increased NT-proBNP while presenting with STEMI. Duration of chest pain and age at presentation are the best predictors of elevated NT-proBNP, though without much bearing on short-term morbidity and mortality.

Validation of echocardiographic left atrial parameters in atrial fibrillation using the index beat of preceding cardiac cycles of equal duration.

BACKGROUND: The clinical assessment of left atrial function during atrial fibrillation is challenging and often inaccurate because of the beat-to-beat variability in the cycle length. The aim of this study was to validate the use of an index beat, the beat following two preceding cardiac cycles of equal duration, for the measurement of left atrial functional indices, including area, volume, and expansion index. The index beat was compared with the conventional but time-consuming method of averaging multiple consecutive cardiac cycles. METHODS: Thirty patients with persistent or permanent atrial fibrillation were studied using two-dimensional echocardiography, and left atrial indices were measured from the average of 17 consecutive cardiac cycles compared with that of an index beat taken from outside of these 17 cycles. RESULTS: The index beat showed good correlation with the averaging technique, and comparison of the two methods showed them to be interchangeable. Clinically, the differences in left atrial functional indices between the two methods were minor. CONCLUSIONS: Use of the index beat to measure dynamic left atrial function in atrial fibrillation can easily be performed and is as accurate as and less time consuming than the onerous method of averaging of multiple cardiac cycles.

Impaired biventricular deformation in Marfan syndrome: a strain and strain rate study in adult unoperated patients.

OBJECTIVE: To investigate the presence of any regional myocardial deformation abnormalities in Marfan syndrome (MFS) and determine the benefits of using advanced echocardiography compared to conventional techniques. BACKGROUND: Myocardial dysfunction in MFS may be caused by extracellular matrix remodeling thus, resulting in uniform reduced functionality. However, increased aortic stiffness may cause segmental ventricular abnormalities. Strain rate imaging (SRI) constitutes a validated technique to assess regional deformation in various clinical conditions. With this in mind, we aimed to investigate biventricular function in MFS using SRI. METHODS: Forty-four MFS patients (mean age 30 ± 12 years, 26 men) and 49 controls without valvular disease were examined using SRI. Ejection fraction (EF) was calculated by the Simpson's biplane method. Biventricular deformation was assessed by measuring strain/strain rate. Strain values were divided by left ventricular (LV) end-diastolic volume to adjust LV deformation for geometry changes providing a strain index (SI). Aortic stiffness was evaluated using the ß-stiffness index. RESULTS: EF (%) was reduced in MFS patients (59 ± 5 vs 72 ± 4, P < 0.001), whereas ß-stiffness was increased (P < 0.001). LV radial and LV and right ventricular (RV) long-axis strain values (%) were reduced in the patient group (70 ± 17 vs 93 ± 10; 19 ± 2 vs 25 ± 2; 30 ± 9 vs 36 ± 8, respectively, P < 0.001). Strain rate measurements were also reduced (P < 0.001). In a multiple regression analysis, MFS diagnosis was negatively associated with LV SI (-0.262 [-0.306, -0.219], P < 0.001). ß-Stiffness was negatively associated with SI obtained from the septum, inferior and anterior walls. ROC analyses demonstrated that SRI, when compared with conventional echocardiography, had higher sensitivity and specificity in predicting biventricular dysfunction in MFS. CONCLUSIONS: Our study showed a uniform reduction in biventricular deformation in MFS. These findings suggest that assessment of myocardial function using advanced echocardiographic techniques could be more accurate in MFS patient evaluation than conventional echocardiography alone.

Global left atrial strain correlates with CHADS2 risk score in patients with atrial fibrillation.

BACKGROUND: The aim of this cross-sectional study was to explore the association between echocardiographic parameters and CHADS2 score in patients with nonvalvular atrial fibrillation (AF). METHODS: Seventy-seven subjects (36 patients with AF, 41 control subjects) underwent standard two-dimensional, Doppler, and speckle-tracking echocardiography to compute regional and global left atrial (LA) strain. RESULTS: Global longitudinal LA strain was reduced in patients with AF compared with controls (P < .001) and was a predictor of high risk for thromboembolism (CHADS2 score ≥ 2; odds ratio, 0.86; P = .02). LA strain indexes showed good interobserver and intraobserver variability. In sequential Cox models, the prediction of hospitalization and/or death was improved by addition of global LA strain and indexed LA volume to CHADS2 score (P = .003). CONCLUSIONS: LA strain is a reproducible marker of dynamic LA function and a predictor of stroke risk and cardiovascular outcomes in patients with AF.