Synergistic Utility of Brain Natriuretic Peptide and Left Ventricular Global Longitudinal Strain in Asymptomatic Patients With Significant Primary Mitral Regurgitation and Preserved Systolic Function Undergoing Mitral Valve Surgery

Relationship between NT-proBNP, echocardiographic abnormalities and functional status in patients with subclinical siabetic cardiomyopathy

INTRODUCTION

Persons with diabetes are at risk for developing a cardiomyopathy through several pathophysiological mechanisms independent of traditional risk factors for heart failure. Among those with diabetic cardiomyopathy (DbCM), the relationship between natriuretic peptides, cardiac structural abnormalities and functional capacity is largely unknown.

METHODS

In this prespecified subgroup analysis of the Aldose Reductase Inhibition for Stabilization of Exercise Capacity in Heart Failure (ARISE-HF) trial, 685 participants with asymptomatic DbCM underwent baseline echocardiography data, laboratory investigations, and functional assessments. Participants were stratified by N-terminal pro-B type natriuretic peptide (NT-proBNP) quartiles, and correlation with echocardiographic and functional parameters were assessed using Spearman correlation test.

RESULTS

The median NT-proBNP was 71 (Q1, Q3: 33, 135) ng/L. No association was observed between NT-proBNP concentrations and echocardiographic parameters of either diastolic or systolic dysfunction including global longitudinal strain, left ventricular ejection fraction, left ventricular mass index, left atrial volume index, E/E', or right ventricular systolic pressure. In contrast, NT-proBNP was significantly correlated with overall Kansas City Cardiomyopathy Questionnaire score (rho = - 0.10; p = 0.007), the Physical Activity Scale in the Elderly (rho = - 0.12; p = 0.004), duration of cardiopulmonary exercise testing (rho = - 0.28; p < 0.001), peak VO2 (rho = - 0.26; p < 0.001), and ratio of minute ventilation/carbon dioxide production (rho = 0.12; p = 0.002). After adjustment for known confounders, the correlation with Physical Activity Scale in the Elderly and overall Kansas City Cardiomyopathy Questionnaire score was no longer significant.

CONCLUSION

Among patients with subclinical DbCM, elevated NT-proBNP concentrations are associated with worse health status, lower activity levels, and reduced functional capacity, but not with cardiac structural abnormalities. These findings suggest that regardless of cardiac structural abnormalities, biomarker concentrations reflect important deterioration in functional capacity in affected individuals.

TRIAL REGISTRATION

ARISE-HF, NCT04083339 Date Registered August 23, 2019.

Moving from left ventricular ejection fraction to deformation imaging in mitral valve regurgitation

The increasing prevalence of valvular heart diseases, specifically mitral regurgitation (MR), underscores the need for a careful and timely approach to intervention. Severe MR, whether primary or secondary, when left untreated leads to adverse outcomes, emphasizing the critical role of a timely surgical or transcatheter intervention. While left ventricular ejection fraction (LVEF) remains the guideline-recommended measure for assessing left ventricle damage, emerging evidence raises concerns regarding its reliability in MR due to its volume-dependent nature. This review summarizes the existing literature on the role of LVEF and deformation imaging techniques, emphasizing the latter's potential in providing a more accurate evaluation of intrinsic myocardial function. Moreover, it advocates the need for an integrated approach that combines traditional with emerging measures, aiming to optimize the management of patients with MR. It attempts to highlight the need for future research to validate the clinical application of deformation imaging techniques through large-scale studies.

The Role of Natriuretic Peptides in Predicting Adverse Outcomes After Cardiac Surgery: An Updated Systematic Review

The increasing global burden of cardiovascular disease, particularly, in the aging population, has led to an increase in high-risk cardiac surgical procedures. The current preoperative risk stratification scores, such as the European System for Cardiac Operative Risk Evaluation and the Society for Thoracic Surgeons score, have limitations in their predictive accuracy and tend to underestimate the mortality risk in higher-risk populations. This systematic review aimed to evaluate the utility of natriuretic peptides, brain natriuretic peptide (BNP) and its precursor prohormone (N-terminal prohormone BNP), as predictive biomarkers for adverse outcomes after cardiac surgery. A comprehensive search strategy was performed, and 63 studies involving 40,667 patients who underwent major cardiac operations were included for data extraction. Preoperative levels of BNP and N-terminal prohormone BNP seemed to be associated with an increased risk of short- and long-term mortality, postoperative heart failure, kidney injury, and length of intensive care unit stay. However, their predictive value for postoperative arrhythmias and myocardial infarction was less established. Our findings suggest that natriuretic peptides may play an important role in risk prediction in patients who underwent cardiac surgery. The addition of these biomarkers to the existing clinical risk stratification strategies may enhance their predictive accuracy. However, this needs to be endorsed by data derived from wide-scale clinical trials.

Prognostic value of left ventricular global longitudinal strain in mitral regurgitation: a systematic review

Conventional echocardiographic assessment may overestimate the left ventricular (LV) function in mitral regurgitation (MR). LV global longitudinal strain (GLS) is more sensitive marker to detect subclinical LV dysfunction. Multiple studies have investigated the prognostic value of LV-GLS in MR to examine its potential to determine the timing and indication of intervention. This systematic review aimed to assess the prognostic value of LV-GLS in patients with mitral regurgitation (MR) to define its clinical applicability. PUBMED and EMBASE were queried through July 2021 to identify studies investigating the prognostic value of LV-GLS in MR. A total of 24 observational studies with 5267 patients were identified. Sixteen studies investigated for primary MR, 7 studies for secondary MR, and 1 study for both. Most studies included patients who underwent intervention. There was significant heterogeneity in patient population, intervention status, follow-up period, LV-GLS cutoff value, outcomes, and statistical methods among the studies. Meta-analysis was not performed considering the significant variability. With exception to 1 study, all studies demonstrated significant association between impaired LV-GLS and worse clinical and echocardiographic outcomes in primary MR. Prognostic value of LV-GLS in secondary MR was less certain due to inconsistent findings and limited reporting. LV-GLS is a promising parameter of prognostication in primary MR and can be considered as alternative to determine the timing of intervention. However, the optimal cutoff value remains unclear. The prognostic value of LV-GLS in secondary MR is less clear. Further large-scale prospective study is warranted before its routine clinical application.

Valvular heart disease: shifting the focus to the myocardium

Adverse cardiac remodelling is the main determinant of patient prognosis in degenerative valvular heart disease (VHD). However, to give an indication for valvular intervention, current guidelines include parameters of cardiac chamber dilatation or function which are subject to variability, do not directly reflect myocardial structural changes, and, more importantly, seem to be not sensitive enough in depicting early signs of myocardial dysfunction before irreversible myocardial damage has occurred. To avoid irreversible myocardial dysfunction, novel biomarkers are advocated to help refining indications for intervention and risk stratification. Advanced echocardiographic modalities, including strain analysis, and magnetic resonance imaging have shown to be promising in providing new tools to depict the important switch from adaptive to maladaptive myocardial changes in response to severe VHD. This review, therefore, summarizes the current available evidence on the role of these new imaging biomarkers in degenerative VHD, aiming at shifting the clinical perspective from a valve-centred to a myocardium-focused approach for patient management and therapeutic decision-making.

Highlighting the role of global longitudinal strain assessment in valvular heart disease

Background

Echocardiography has been the choice for imaging modality for valvular heart disease. It is less invasive, widely available, and allows valvular structure visualization. Echocardiographic assessment often also determines the management. Left ventricular ejection fraction is the most commonly used indicator during echocardiography assessment. It shows signs of left ventricular dysfunction in patients with valve disease. However, most of the time, the ongoing process of cardiac damage may already occur even with preserved cardiac function; further deteriorated ejection fraction will show irreversible cardiac damage. There is a need for a more advanced diagnostic tool to detect early cardiac dysfunction, to prevent further damage.

Main body

Advanced echocardiography imaging using strain imaging allows a physician to evaluate cardiac function more precisely. A more sensitive parameter than left ventricular ejection fraction, global longitudinal strain, can evaluate subclinical myocardial dysfunction before the symptoms occur by evaluating complex cardiac mechanisms. Global longitudinal strain evaluation provides the chance for physicians to determine the intervention needed to prevent further deterioration and permanent cardiac dysfunction. Global longitudinal strain is proven to be beneficial in many types of valvular heart diseases, especially in mitral and aortic valve diseases. It has an excellent diagnostic and prognostic value for patients with valve disease. This review aims to present the superiority of global longitudinal strain compared to left ventricular ejection fraction in assessing cardiac function in patients with valvular heart disease. Clinical usage of global longitudinal strain in several valvular heart diseases is also presented in this review.

Conclusions

The superiority of global longitudinal strain to left ventricular ejection fraction relies on the mechanism where other strains would compensate for the deterioration of longitudinal strain, which is more vulnerable to damage, so the cardiac function is preserved. Therefore, examination of longitudinal strain would give the physician early signs of cardiac function impairment, and prompt management can be conducted.

Integration of imaging and circulating biomarkers in heart failure: a consensus document by the Biomarkers and Imaging Study Groups of the Heart Failure Association of the European Society of Cardiology

Circulating biomarkers and imaging techniques provide independent and complementary information to guide management of heart failure (HF). This consensus document by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) presents current evidence-based indications relevant to integration of imaging techniques and biomarkers in HF. The document first focuses on application of circulating biomarkers together with imaging findings, in the broad domains of screening, diagnosis, risk stratification, guidance of treatment and monitoring, and then discusses specific challenging settings. In each section we crystallize clinically relevant recommendations and identify directions for future research. The target readership of this document includes cardiologists, internal medicine specialists and other clinicians dealing with HF patients.

Speckle tracking echocardiography in primary mitral regurgitation: should we reconsider the time for intervention?

Thanks to the improvement in mitral regurgitation (MR) diagnostic and therapeutic management, with the introduction of minimally invasive techniques which have considerably reduced the individual surgical risk, the optimization of the timing for MR “open” or percutaneous surgical treatment has become a main concern which has highly raised scientific interest. In fact, the current indications for intervention in MR, especially in asymptomatic patients, rely on echocardiographic criteria with high severity cut-offs that are fulfilled only when not only mitral valve apparatus but also the cardiac chambers’ structure and function are severely impaired, which results in poor benefits for post-operative clinical outcome. This led to the need of new indices to redefine the optimal surgical timing in these patients. Speckle tracking echocardiography provides early markers of cardiac dysfunction due to subtle myocardial impairment; therefore, it could offer pivotal information in this setting. In fact, left ventricular and left atrial strains have already shown evidence about their usefulness in recognizing MR impact not only on symptoms and quality of life but also on cardiovascular events and new-onset atrial fibrillation in these patients. Moreover, right ventricular strain could be used to identify those patients with advanced cardiac damage and different grades of right ventricular dysfunction, which entails higher risks for cardiac surgery that could overweigh surgical benefits. This review aims to describe the importance of reconsidering the timing of intervention in MR and to analyze the potential additive value of speckle tracking echocardiography in this clinical setting.

Global longitudinal strain to determine optimal timing for surgery in primary mitral regurgitation: A systematic review

BACKGROUND

Primary mitral regurgitation (PMR) results in adverse remodeling changes and left ventricular (LV) dysfunction. Assessing LV function has prognostic value in predicting morbidity and mortality. Indications for surgery include parameters such as LV ejection fraction (LVEF) and systolic dimensions. Current guidelines are limited in identifying patients at optimal time for surgery. Impaired postoperative LVEF indicates poor prognostic outcomes and subsequent heart failure. Global longitudinal strain (GLS) via speckle tracking echocardiography (STE) presents as a promising parameter to detect subclinical dysfunction in asymptomatic patients.

METHODS

Following PRISMA guidelines, a literature search was conducted with Cochrane Library, PudMed, SCOPUS, and Web of Science. Key MeSH terms included "mitral regurgitation," "mitral valve insufficiency," "global longitudinal strain," "deformation," "LV-GLS," and "GLS." Inclusion criteria included (1) patients with severe PMR, (2) mixed population of symptomatic and asymptomatic patients, (3) standardized methods in assessing LV systolic function using 2D-STE, (4) valve repair or replacement surgery, and (5) patient outcomes measured after surgery. Search returned 234 papers, 12 of which met the inclusion criteria and were subsequently reviewed.

RESULTS

Baseline GLS is an independent predictor of postoperative outcomes, ranging from -17.9 to -21.7% GLS. A significant negative correlation was observed between preoperative GLS and postoperative LVEF. Impaired baseline GLS was associated with higher mortality rates. Better long-term survival rates were seen in patients who underwent early surgery.

CONCLUSION

GLS shows sensitivity in predicting long-term postoperative outcomes. Further analysis is required to determine preoperative GLS threshold to identify asymptomatic patients at the optimal time for mitral valve surgery.

Left Ventricular Longitudinal Strain in Characterization and Outcome Assessment of Mixed Aortic Valve Disease Phenotypes

OBJECTIVES

The aims of this study were to characterize the interplay between mixed aortic valve disease (MAVD) phenotypes (defined by concomitant severities of aortic stenosis and aortic regurgitation) and left ventricular global longitudinal strain (LV-GLS), and to assess the prognostic utility of LV-GLS in MAVD.

BACKGROUND

Little is known about the way LV-GLS separates MAVD phenotypes and if it is associated with their outcomes.

METHODS

This observational cohort study evaluated 783 consecutive adult patients with left ventricular ejection fraction ≥50% and MAVD, which was defined as coexisting with at least moderate aortic stenosis and at least moderate aortic regurgitation. We measured the conventional echocardiographic variables and average LV-GLS from apical long, 2- and 4-chamber views. The primary endpoint was all-cause mortality.

RESULTS

Mean age of patients was 69 ± 15 years, and 58% were male. Mean LV-GLS was -14.7 ± 2.9%. In total, 458 patients (59%) underwent aortic valve replacement at a median period of 50 days (25th to 75th percentile range: 6 to 560 days). During a median follow-up period of 5.6 years (25th to 75th percentile range: 1.8 to 9.4 years), 391 patients (50%) died. When stratified patients into tertiles according to LV-GLS values, patients with worse LV-GLS had worse outcomes (p < 0.001). LV-GLS was independently associated with mortality (hazard ratio: 1.09; 95% confidential intervals: 1.04 to 1.14; p < 0.001), with the relationship between LV-GLS and mortality being linear.

CONCLUSIONS

LV-GLS is associated with all-cause mortality. LV-GLS may be useful for risk stratification in patients with MAVD.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Global Longitudinal Strain Predicts Survival and Left Ventricular Function After Mitral Valve Surgery: A Meta-analysis

The timing for surgical treatment in patients with primary organic severe mitral valve regurgitation and preserved left ventricular ejection fraction (LVEF) systolic is a challenge since it depends upon LV end systolic dimension and LVEF which may be late markers of LV dysfunction. Echocardiography is the most important tool in the diagnosis of mechanisms, etiology, severity, and hemodynamic consequences of mitral regurgitation. The global longitudinal strain (GLS), a new and sensitive method for the detection of LV dysfunction, might be a useful method for the evaluation of preclinical systolic dysfunction. Nevertheless, its role for predicting postoperative outcomes is not well established. A meta-analysis was performed to address the role of GLS in patients with severe mitral regurgitation and preserved LVEF who underwent mitral surgery. We included studies that compared outcomes according to preoperative GLS in regard to survival and postoperative LV function. We included 2358 patients enrolled in 8 studies. Patients with reduced GLS% had worse long term survival after mitral valve surgery (hazard ratio = 1.13, 95% confidence interval [CI]: 1.02-1.26). Patients with preoperatively reduced GLS% had lower LVEF after surgery (mean difference [MD] = -5.06%, 95% CI: -8.97-1.16%) and additionally, patients who presented postoperative LVEF dysfunction had worse preoperative GLS (MD = 4.33, 95% CI: 3.89-4.76). In patients with primary mitral regurgitation, preoperative GLS is a predictor for long term survival and postoperative LVEF. It is a useful parameter to be included when considering early surgery in patients with severe mitral regurgitation and normal LVEF.

Application of strain echocardiography in valvular heart diseases

Echocardiographic strain imaging allows new insight into a complex cardiac mechanics and enables more precise evaluation of cardiac function. Hence, it has been shown to have clinical utility in a variety of valvular heart diseases. In particular, global longitudinal strain has been shown to be more sensitive to detect systolic dysfunction than left ventricular ejection fraction. In patients with valvular heart diseases, it provides both diagnostic and prognostic information in addition to standard echocardiographic and clinical parameters. In this review, we summarize current clinical application of strain echocardiography in patients with valvular heart diseases and discuss pathophysiological mechanisms that lead to respective findings in specific diseases.

Global longitudinal strain to predict left ventricular dysfunction in asymptomatic patients with severe mitral valve regurgitation: literature review

The optimal treatment strategy for asymptomatic patients with severe mitral valve regurgitation (MR) and preserved left ventricular (LV) function is challenging. This manuscript reviews the available literature on the value of left ventricular global longitudinal strain (LV-GLS) in predicting LV dysfunction after mitral valve surgery in these patients and discusses its current place in the treatment strategy. Studies were identified from Cochrane Library, SCOPUS, PubMed and Web of Science up to February 2018. The domain used was MR. The determinant was LV-GLS; other methods of deformation imaging were excluded. The examined outcome was LV dysfunction after surgery. A total of 144 articles were retrieved, of which 11 publications met the inclusion criteria, including a total of 2415 patients. Ten studies showed a significant correlation between preoperative LV-GLS and LV dysfunction postoperatively; one study reported a negative correlation. These studies suggest that LV-GLS is a predictor of LV dysfunction after surgery in asymptomatic patients with chronic MR. Hence, incorporation of LV-GLS for clinical decision-making in these patients might be of additional value. Further research is needed to confirm the role of LV-GLS in postoperative patients, and additionally in asymptomatic MR patients during a 'watchful waiting' strategy.

Clinical Applications of Echo Strain Imaging: a Current Appraisal

PURPOSE OF REVIEW

This article reviews recent advances in echocardiographic strain imaging, particularly in its ability to prognosticate in cardiovascular outcomes and impact clinical decision making.

RECENT FINDINGS

Strain has been proposed as a sensitive tool in detecting early ventricular dysfunction. Left ventricular global longitudinal strain (LV-GLS) detects subtle changes in myocardial function, often not quantifiable by ejection fraction alone. Thus, LV-GLS provides the opportunity for early decision-making, and the implementation of more effective treatments, improving outcomes in a variety of diseases such as valvular heart diseases, cardio-oncology, ischemic heart disease, cardiomyopathies, heart transplantation, and pericardial diseases and cardiomyopathies. Strain is a promising tool for the early detection of myocardial dysfunction in patients with preserved left ventricular ejection fraction and can prognosticate long-term outcomes.

Incremental Prognostic Utility of Left Ventricular Global Longitudinal Strain in Asymptomatic Patients With Significant Chronic Aortic Regurgitation and Preserved Left Ventricular Ejection Fraction

OBJECTIVES

This study sought to examine the prognostic utility of left ventricular (LV) global longitudinal strain (GLS) in asymptomatic patients with ≥III+ aortic regurgitation (AR), an indexed LV end-systolic dimension of <2.5 cm/m², and preserved left ventricular ejection fraction (LVEF).

BACKGROUND

Management of asymptomatic patients with severe chronic AR and preserved LVEF is challenging and is typically based on LV dimensions.

METHODS

We studied 1,063 such patients (age 53 ± 16 years; 77% men) seen between 2003 and 2010 (excluding those with symptoms, obstructive coronary artery disease, acute AR/dissection, aortic/mitral stenosis, more than moderate mitral regurgitation, and previous cardiac surgery). Society of Thoracic Surgeons (STS) score was calculated. The primary endpoint was mortality. Average resting LV-GLS was measured offline on 2-, 3-, and 4-chamber views using Velocity Vector Imaging (Siemens, Malvern, Pennsylvania).

RESULTS

Mean STS score, LVEF, LV-GLS, and right ventricular systolic pressure were 4.4 ± 5.0%, 57.0 ± 4.0%, -19.5 ± 0.2%, and 31.0 ± 9.0 mm Hg, respectively. In total, 671 patients (63%) underwent aortic valve surgery at a median of 42 days after the initial evaluation. At 6.8 ± 3.0 years, 146 patients (14%) had died. On multivariable Cox survival analysis, LV-GLS (hazard ratio [HR]: 1.11), STS score (HR: 1.51), indexed LV end-systolic dimension (HR: 0.50), right ventricular systolic pressure (HR: 1.33), and aortic valve surgery (HR: 0.35) were associated with longer term mortality (all p < 0.001). Sequential addition of LV-GLS and aortic valve surgery improved the C-statistic for longer term mortality for the clinical model (STS score + right ventricular systolic pressure + indexed LV end-systolic dimension) from 0.61 (95% confidence interval [CI]: 0.51 to 0.72) to 0.67 (95% CI: 0.54 to 0.87) and to 0.77 (95% CI: 0.63 to 0.90), respectively (p < 0.001 for both). A significantly higher proportion (log-rank p = 0.01) of patients with LV-GLS worse than median (-19.5%) died versus those with an LV-GLS better than median (86 of 513 [17%] vs. 60 of 550 [11%]). The risk of death at 5 years significantly increased with an LV-GLS of worse than -19%.

CONCLUSIONS

In asymptomatic patients with ≥III+ chronic AR and preserved LVEF, worsening LV-GLS was associated with longer term mortality, providing incremental prognostic value and improved reclassification.

Cardiac surgery 2016 reviewed

For the year 2016, more than 20,000 published references can be found in Pubmed when entering the search term "cardiac surgery". Publications last year have helped to more clearly delineate the fields where classic surgery and modern interventional techniques overlap. The field of coronary bypass surgery (partially compared to percutaneous coronary intervention) was enriched by five large prospective randomized trials. The value of CABG for complex coronary disease was reconfirmed and for less complex main stem lesions, PCI was found potentially equal. For aortic valve treatment, more evidence was presented for the superiority of transcatheter aortic valve implantation for patients with intermediate risk. However, the 2016 evidence argued against the liberal expansion to the low-risk field, where conventional aortic valve replacement still appears superior. For the mitral valve, many publications emphasized the significant impact of mitral valve reconstruction on survival in structural mitral regurgitation. In addition, there were many relevant and other interesting contributions from the purely operative arena in the fields of coronary revascularization, surgical treatment of valve disease, terminal heart failure (i.e., transplantation and ventricular assist devices), and aortic surgery. While this article attempts to summarize the most pertinent publications it does not have the expectation of being complete and cannot be free of individual interpretation. As in recent years, it provides a condensed summary that is intended to give the reader "solid ground" for up-to-date decision-making in cardiac surgery.

Primary mitral valve regurgitation: Update and review

Mitral regurgitation is the second most common valvular disorder requiring surgical intervention worldwide. This review summarizes the current understanding of primary, degenerative mitral regurgitation with respect to etiology, comprehensive assessment, natural history and management. The new concept of staging of the valvular disorders, newer predictors of adverse and controversy of “watchful waiting” versus “early surgical intervention” for severe, asymptomatic, primary mitral regurgitation are addressed.