Systematic Left Ventricular Assist Device Implant Eligibility with Non-Invasive Assessment: The SIENA Protocol

Cardiac replacement therapy: Critical issues and future perspectives of heart transplantation and artificial heart

Diagnostic and therapeutic advances in the cardiovascular field have caused a progressive reduction in mortality from acute causes, with an ever-increasing chronicity of cardiovascular pathologies. In recent years, mechanical supports have played a fundamental role, allowing the patient to be stabilized in the most critical phase of acute heart failure (AHF) and acting as a "bridge" for definitive therapies. Heart transplantation (HTx) is the gold-standard treatment for end-stage HF, but it is burdened by a series of critical issues that limit its use, first of all the shortage of grafts. It also requires the patient to take immunosuppressive therapy for life, which exposes him to a greater risk of infectious and oncological diseases. For these reasons, in the last years, mechanical supports are increasingly used as "destination therapy", alternatively to HTx. However, also mechanical supports are not free from critical issues that limit their use. In this review we aim to analyze critical issues and future perspectives of advanced HF therapies.

The Role of Speckle Tracking Echocardiography in the Evaluation of Advanced-Heart-Failure Patients

Health care is currently showing a fall in heart failure (HF) incidence and prevalence, particularly in developed countries, but with only a subset receiving appropriate therapy to protect the heart against maladaptive processes such as fibrosis and hypertrophy. Appropriate markers of advanced HF remain unidentified, which would help in choosing the most suitable therapy and avoid major compliance problems. Speckle tracking echocardiography (STE) is a good choice, being a non-invasive imaging technique which is able to assess cardiac deformation in a variety of conditions. Several multicenter studies and meta-analyses have demonstrated the clinical application and accuracy of STE in early and late stages of HF, as well as its association with both left ventricular (LV) filling pressures and myocardial oxygen consumption. Furthermore, STE assists in assessing right ventricular free-wall longitudinal strain (RVFWLS), which is a solid predictor of right ventricle failure (RVF) following LV assist device (LVAD) implantation. However, STE is known for its limitations; despite these, it has been shown to explain symptoms and signs and also to be an accurate prognosticator. The aim of this review is to examine the advantages of STE in the early evaluation of myocardial dysfunction and its correlation with right heart catheterization (RHC) parameters, which should have significant clinical relevance in the management of HF patients.

Right ventricular dysfunction in left ventricular assist device candidates: is it time to change our prospective?

The use of left ventricular assist devices (LVAD) has significantly increased in the last years, trying to offer a therapeutic alternative to heart transplantation, in light also to the significant heart donor shortage compared to the growing advanced heart failure population. Despite technological improvements in the devices, LVAD-related mortality is still fairly high, with right heart failure being one of the predominant predictors. Therefore, many efforts have been made toward a thorough right ventricular (RV) evaluation prior to LVAD implant, considering clinical, laboratory, echocardiographic, and invasive hemodynamic parameters. However, there is high heterogeneity regarding both which predictor is the strongest as well as the relative cut-off values, and a consensus has not been reached yet, increasing the risk of facing patients in which the distinction between good or poor RV function cannot be surely reached. In parallel, due to technological development and availability of mechanical circulatory support of the RV, LVADs are being considered even in patients with suboptimal RV function. The aim of our review is to analyze the current evidence regarding the role of RV function prior to LVAD and its evaluation, pointing out the extreme variability in parameters that are currently assessed and future prospective regarding new diagnostic tools. Finally, we attempt to gather the available information on the therapeutic strategies to use in the peri-operative phase, in order to reduce the incidence of RV failure, especially in patients in which the preoperative evaluation highlighted some conflicting results with regard to ventricular function.

Monitoring of the right ventricular responses to pressure overload: prognostic value and usefulness of echocardiography for clinical decision-making

Regardless of whether pulmonary hypertension (PH) results from increased pulmonary venous pressure in left-sided heart diseases or from vascular remodeling and/or obstructions in pre-capillary pulmonary vessels, overload-induced right ventricular (RV) dysfunction and its final transition into right-sided heart failure is a major cause of death in PH patients. Being particularly suited for non-invasive monitoring of the right-sided heart, echocardiography has become a useful tool for optimizing the therapeutic decision-making and evaluation of therapy results in PH. The review provides an updated overview on the pathophysiological insights of heart-lung interactions in PH of different etiology, as well as on the diagnostic and prognostic value of echocardiography for monitoring RV responses to pressure overload. The article focuses particularly on the usefulness of echocardiography for predicting life-threatening aggravation of RV dysfunction in transplant candidates with precapillary PH, as well as for preoperative prediction of post-operative RV failure in patients with primary end-stage left ventricular (LV) failure necessitating heart transplantation or a LV assist device implantation. In transplant candidates with refractory pulmonary arterial hypertension, a timely prediction of impending RV decompensation can contribute to reduce both the mortality risk on the transplant list and the early post-transplant complications caused by severe RV dysfunction, and also to avoid combined heart-lung transplantation. The review also focuses on the usefulness of echocardiography for monitoring the right-sided heart in patients with acute respiratory distress syndrome, particularly in those with refractory respiratory failure requiring extracorporeal membrane oxygenation support. Given the pathophysiologic particularity of severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection to be associated with a high incidence of thrombotic microangiopathy-induced increase in the pulmonary resistance, echocardiography can improve the selection of temporary mechanical cardio-respiratory support strategies and can therefore contribute to the reduction of mortality rates. On the whole, the review aims to provide a theoretical and practical basis for those who are or intend in the future to be engaged in this highly demanding field.

Clinical impact of the right ventricular impairment in patients following transcatheter aortic valve replacement

The right ventricular (RV) impairment can predict clinical adverse events in patients following transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS). Limited reports have compared impact of the left ventricular (LV) and RV disorders. This retrospective study evaluated two-year major adverse cardiac and cerebrovascular events (MACCE) in patients following TAVR for severe AS. RV sphericity index was calculated as the ratio between RV mid-ventricular and longitudinal diameters during the end-diastolic phase. Of 239 patients, 2-year MACCE were observed in 34 (14%). LV ejection fraction was 58 ± 11%. Tricuspid annular plane systolic excursion (TAPSE) and RV sphericity index were 20 ± 3 mm and 0.36 (0.31-0.39). Although the univariate Cox regression analysis demonstrated that both LV and RV parameters predicted the outcomes, LV parameters no longer predicted them after adjustment. Lower TAPSE (adjusted hazard ratio per 1 mm, 0.84; 95% confidence interval, 0.75-0.93) and higher RV sphericity index (adjusted hazard ratio per 0.1, 1.94; 95% confidence interval, 1.17-3.22) were adverse clinical predictors. In conclusion, the RV structural and functional disorders predict two-year MACCE, whereas the LV parameters do not. Impact of LV impairment can be attenuated after development of RV disorders.

Right ventricular myocardial work for the prediction of early right heart failure and long-term mortality after left ventricular assist device implant

AIMS

Right heart failure (RHF) after left ventricular assist device (LVAD) implant is burdened by high morbidity and mortality rates and should be prevented by appropriate patient selection. Adequate right ventricular function is of paramount importance but its assessment is complex and cannot disregard afterload. Myocardial work (MW) is a non-invasive Speckle Tracking Echocardiography-derived method to estimate pressure-volume loops. The aim of this study was to evaluate the performance of right ventricular myocardial work to predict RHF and long-term mortality after LVAD implant.

METHODS AND RESULTS

Consecutive patients from May 2017 to February 2022 undergoing LVAD implant were retrospectively reviewed. Patients without a useful echocardiographic exam prior to LVAD implant were excluded. MW analysis was performed. The primary endpoints were early RHF (<30 days from LVAD implant) and death at latest available follow-up. We included 23 patients (mean age 64 ± 8 years, 91% men). Median follow-up was 339 days (IQR: 30-1143). Early RHF occurred in six patients (26%). A lower right ventricular global work efficiency [RVGWE, OR 0.86, 95% confidence intervals (CI) 0.76-0.97, P = 0.014] was associated with the occurrence of early RHF. Among MW indices, the performance for early RHF prediction was greatest for RVGWE [area under the curve (AUC) 0.92] and a cut-off of 77% had a 100% sensitivity and 82% specificity. At long-term follow-up, death occurred in 4 of 14 patients (28.6%) in the RVGWE > 77% group and in 6 of 9 patients (66.7%) in the RVGWE < 77% group (HR 0.25, 95% CI 0.07-0.90, P = 0.033).

CONCLUSION

RVGWE was a predictor of early RHF after LVAD implant and brought prognostic value in terms of long-term mortality.

Prediction, prevention, and management of right ventricular failure after left ventricular assist device implantation: A comprehensive review

Left ventricular assist devices (LVADs) are increasingly common across the heart failure population. Right ventricular failure (RVF) is a feared complication that can occur in the early post-operative phase or during the outpatient follow-up. Multiple tools are available to the clinician to carefully estimate the individual risk of developing RVF after LVAD implantation. This review will provide a comprehensive overview of available tools for RVF prognostication, including patient-specific and right ventricle (RV)-specific echocardiographic and hemodynamic parameters, to provide guidance in patient selection during LVAD candidacy. We also offer a multidisciplinary approach to the management of early RVF, including indications and management of right ventricular assist devices in this setting to provide tools that help managing the failing RV.

Update on the Practical Role of Echocardiography in Selection, Implantation, and Management of Patients Requiring Left Ventricular Assist Device Therapy

PURPOSE OF REVIEW

Echocardiography is a valuable tool for management of patients with a left ventricular assist device (LVAD). We present an updated review on the practical applications of the role of echocardiography for pre- and postoperative evaluation of patients selected.

RECENT FINDINGS

The LVAD is a temporary or permanent option for patients with advanced heart failure who are unresponsive to other therapy. Use of the device has its own risks, and implantation remains a complex procedure. Transthoracic and transesophageal echocardiography are useful tools for patient evaluation and monitoring both peri- and postoperatively, as we previously presented. Assessment of left and right ventricular function, complications such as thrombus formation or intracardiac shunting, and valvular disease are all important in this assessment. This also aids in predicting postoperative complications. Placement of the device is confirmed intraoperatively, and subsequent ramp studies are used to determine optimal device settings. Right ventricular (RV) failure is the most common postoperative complication and preoperative evaluation of its function is crucial. Studies suggest that tricuspid annular plane systolic excursion, RV fractional area change, and RV global longitudinal strain are strong predictors of RV failure; LV ejection fraction, size, and end-diastolic diameter are also important markers. Aortic regurgitation and mitral stenosis must always be corrected prior to LVAD placement. However, direct visualization before and after implantation, especially to rule out potential contraindications such as thrombi, cannot be overemphasized. Ramp studies remain an integral part of device optimization and may result in greater myocardial recovery than previously realized.

Clinical, echocardiographic and hemodynamic predictors of right heart failure after LVAD placement

Right ventricular failure (RVF) after left ventricular assist device (LVAD) implant is associated with increasing morbidity and mortality. The aim of this study was to identify the best predictors of RVF post LVAD-implant among biochemical, haemodynamic and echocardiographic parameters. From 2009 to 2019, 38 patients who underwent LVAD implantation at our centre were prospectively enrolled. Preoperative clinical, laboratory, echocardiographic and haemodynamic parameters were reported. Overall, eight patients (21%) developed RVF over time, which revealed to be strongly related to overall mortality. Pulmonary artery pulsatility index (PAPi) resulted to be the most significant right heart catheterization index in discriminating RVF vs no RVF patients [(1.32 ± 0.26 vs. 3.95 ± 3.39 respectively) p = 0.0036]. Regarding transthoracic echocardiography, RVF was associated with reduced free wall right ventricular longitudinal strain (fw-RVLS) (- 7.9 ± 1.29 vs. - 16.14 ± 5.83) (p < 0.009), which was superior to other echocardiographic determinants of RVF. Among laboratory values, N-terminal pro-brain natriuretic peptide (NT-proBNP) was strongly increased in RVF patients [(10,496.13 pg/ml ± 5272.96 pg/ml vs. 2865, 5 pg/ml ± 2595.61 pg/ml) p = 0.006]. PAPi, NT-proBNP and fwRVLS were the best pre-operative predictors of RVF, a post-LVAD implant complication which was confirmed to have a great impact on survival. In particular, fwRVLS has been proven to be the strongest independent predictor.

Cardiac Reverse Remodelling by 2D and 3D Echocardiography in Heart Failure Patients Treated with Sacubitril/Valsartan

In terms of sacubitril/valsartan (S/V)-induced changes in heart failure with reduced ejection fraction (HFrEF) via three-dimensional (3D) transthoracic echocardiography (TTE) and S/V effects based on HF aetiology, data are lacking. We prospectively enrolled 51 HFrEF patients (24 ischaemic, 27 non-ischaemic). At baseline and at 6-month follow-up (6MFU) after S/V treatment optimisation, we assessed the N-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac remodelling by two-dimensional (2D) and 3DTTE. In non-ischaemic patients, 2D and 3DTTE showed an improvement in left ventricular (LV) size and biventricular function at 6MFU vs. baseline: 3D-LV end-diastolic volume (EDV) 103 ± 30 vs. 125 ± 32 mL/m² (p < 0.05), 3D-LV ejection fraction (EF) 40 ± 9 vs. 32 ± 5% (p < 0.05), right ventricular (RV) 3D-EF 48.4 ± 6.5 vs. 44.3 ± 7.5% (p < 0.05); only the 3D method detected RV size reduction: 3D-RVEDV 63 ± 27 vs. 71 ± 30 mL/m² (p < 0.05). In ischaemic patients, only 3DTTE showed biventricular size and LV function improvement: 3D-LVEDV 112 ± 29 vs. 121 ± 27 mL/m² (p < 0.05), 3D-LVEF 35 ± 6 vs. 32 ± 5% (p < 0.05), 3D-RVEDV 57 ± 11 vs. 63 ± 14 mL/m² (p < 0.05); RV function did not ameliorate. In both ischaemic and non-ischaemic patients, diastolic function and NT-proBNP significantly improved. In HFrEF patients treated with S/V, 3DTTE helps to ascertain subtle changes in heart chambers’ size and function, which have a major impact on HFrEF prognosis. S/V has significantly different effects on LV function in non-ischaemic vs. ischaemic patients.

Ablation therapy for ventricular arrhythmias in patients with LVAD: Multiple faces of an electrophysiological challenge

Left ventricular assist device implantation is a recognized treatment option for patients with advanced heart failure refractory to medical therapy and can be used both as bridge to transplantation and as destination therapy. The risk of ventricular arrhythmias is common after left ventricular assist device implantation and is influenced by pre-, peri and post-operative determinants. The management of ventricular arrhythmias can be a challenge when they become refractory to medication or to device therapy and their impact on prognosis can be detrimental despite the mechanical support. In this setting, catheter ablation is being increasingly recognized as a feasible option for patients in which standard therapeutic strategies fail, but also with preventive purpose. Catheter ablation is being increasingly considered for the management of ventricular arrhythmias in patients with left ventricular assist device despite complex clinical and technical peculiarities due to the characteristics of the mechanical support. Much conflicting data exist regarding the predictors of success of the procedure and the rate of recurrence. In this review we discuss the latest evidences regarding catheter ablation of ventricular arrhythmias in this subset of patients, focusing on clinical characteristics, arrhythmia etiology, technical aspects and postprocedural features which must be considered by the electrophysiologist.

Traditional and Novel Imaging of Right Ventricular Function in Patients with Heart Failure and Reduced Ejection Fraction

PURPOSE OF REVIEW

This review attempts to summarize the role of standard and advanced echocardiographic techniques together with CMR in the evaluation of the RV in HF, providing an outlook on the recent evidence.

RECENT FINDINGS

In the last decade, there has been growing interest in the study of the RV, and it is now widely established that RV function is a strong predictor of mortality, in several cardiovascular diseases, in particular in the setting of heart failure (HF). The evaluation of RV function might be particularly challenging, which justifies the necessity of multi-modality imaging. The echocardiographic assessment remains the mainstay technique even though it might be complex, due to RV crescent shape and its position in the chest, requiring both qualitative and quantitative parameters. Cardiac magnetic resonance (CMR) represents a complementary exam which is particularly useful when precise structural and functional assessment are needed, considering the most recently developed sequences. Despite the technological improvement attested over the last years, there is still no universally accepted parameter that univocally defines RV function, hence the necessity to evaluate several parameters, combining different imaging techniques.

Echocardiography for left ventricular assist device implantation and evaluation: an indispensable tool

Echocardiography is an indispensable tool in the evaluation, placement, management and follow-up of patients with left ventricular assist devices (LVAD). While transoesophageal echocardiography is the ideal tool in guiding the implantation procedure, transthoracic echocardiography is essential during the initial evaluation, patient selection and in the post-operative follow-up. This review attempts to summarize which parameters the echocardiographic assessment should focused on during each step. In particular, during the pre-operative assessment, it is of paramount importance to assess the presence of aortic regurgitation and most importantly to evaluate right ventricular function, since it is one of the strongest predictor of post-implant right ventricular failure. During the procedure, through transoesophageal echocardiography, it is possible to confirm the correct placement of the inflow cannula, to assess right ventricular function and to guide the choice of the right pump speed. Transthoracic echocardiographic is an essential part in the patient's follow-up once the LVAD has been implanted, in order to attest the onset of possible complications.

Survival in acute heart failure in intensive cardiac care unit: a prospective study

The aim of this study is to identify the best predictors of mortality among clinical, biochemical and advanced echocardiographic parameters in acute heart failure (AHF) patients admitted to coronary care unit (CCU). AHF is a clinical condition characterized by high mortality and morbidity. Several studies have investigated the potential prognostic factors that could help the risk assessment of cardiovascular events in HF patients, but at the moment it has not been found a complete prognostic score (including clinical, laboratory and echocardiographic parameters), univocally used for AHF patients. Patients (n = 118) admitted to CCU due to AHF de novo or to an exacerbation of chronic heart failure were enrolled. For each patient, clinical and biochemical parameters were reported as well as the echocardiographic data, including speckle tracking echocardiography analysis. These indexes were then related to intra- and extrahospital mortality. At the end of the follow-up period, the study population was divided into two groups, defined as 'survivors' and 'non-survivors'. From statistical analysis, C-reactive protein (CRP) (AUC = 0.75), haemoglobin (AUC = 0.71), creatinine clearance (AUC = 0.74), left atrial strain (AUC = 0.73) and freewall right ventricular strain (AUC = 0.76) showed the strongest association with shortterm mortality and they represented the items of the proposed risk score, whose cut-off of 3 points is able to discriminate patients at higher risk of mortality. AHF represents one of the major challenges in CCU. The use of a combined biochemical and advanced echocardiographic score, assessed at admission, could help to better predict mortality risk, in addition to commonly used indexes.

Ventricular systolic dysfunction with and without altered myocardial contractility: Clinical value of echocardiography for diagnosis and therapeutic decision-making

The inability of one of the two or both ventricles to contract normally and expel sufficient blood to meet the functional demands of the body results from a complex interplay between intrinsic abnormalities and extracardiac factors that limit ventricular pump function and is a major cause for heart failure (HF). Even if impaired myocardial contractile function was the primary cause for ventricular dysfunction, with the progression of systolic dysfunction, additionally developed diastolic dysfunction can also contribute to the severity of HF. Although at the first sight, the diagnosis of systolic HF appears quite easy because it is usually defined by reduction of the ejection fraction (EF), in reality this issue is far more complex because ventricular pumping performance depends not only on myocardial contractility, but also largely on loading conditions (preload and afterload), being also influenced by valvular function, ventricular interdependence, pericardial constraint, synchrony of ventricular contrac-tion and heart rhythm. Conventional echocardiography (ECHO) combined with new imaging techniques such as tissue Doppler and tissue tracking can detect early subclinical alteration of ventricular systolic function. However, no single ECHO parameter reveals alone the whole picture of systolic dysfunction. Multiparametric ECHO evaluation and the use of integrative approaches using ECHO-parameter combinations which include also the ventricular loading conditions appeared particularly useful especially for differentiation between primary (myocardial damage-induced) and secondary (hemodynamic overload-induced) systolic dysfunction. This review summarizes the available evidence on the usefulness and limitations of comprehensive evaluation of LV and RV systolic function by using all the currently available ECHO techniques.

Dental management of patients with congestive heart failure before and after implantation of ventricular assist devices: linking the missing protocol

Objectives: There are no studies that have reviewed the pre- and post-operative dental protocols for the management of congestive heart failure (CHF) patients before and after implantation of the left ventricular assist device (LVAD). The aim of the present study was to review the pre- and post-operative dental protocols reported in indexed literature related to the management of CHF patients before and after implantation of ventricular assist devices (VAD). Design: The addressed focused question was "Is there a protocol for the dental management of end-stage CHF patients before and after VAD implantation?" Indexed databases were searched using various keywords. Letters to the Editor, review articles, and commentaries/expert opinions were excluded. Results: Seven studies were included and processed for data extraction. The number of participants ranged between 1 and 32 individuals, with age ranging between 14 and 66 years. Dental extractions were performed in 5 studies, and in 2 studies scaling and root planing was done for the treatment of periodontal diseases. One study assessed odontogenic infective foci and other lesions of the oral soft and hard tissues as a preoperative protocol. Six of the 7 studies did not report a dental therapeutic protocol, which was followed for the pre and/or post-LVAD implantation. Conclusions: It is recommended that standardized protocols should be adopted that allow the delivery of safe and effective pre- and postoperative dental care to VAD patients. Such protocols may help influence the morbidity and mortality rates and simultaneously improve the overall quality of life in vulnerable patients.

LEFT VENTRICULAR EJECTION FRACTION: COMPARISON BETWEEN TRUE VOLUME-BASED MEASUREMENTS AND AREA-BASED ESTIMATES

Left ventricular ejection fraction (LVEF) is a critical measure of cardiac health commonly acquired in clinical practice, which serves as the basis for cardiovascular therapeutic treatment. Ultrasound (US) imaging of the heart is the most common, least expensive, reliable and non-invasive modality to assess LVEF. Cardiologists, in practice, persistently use 2D US images to provide visual estimates of LVEF, which are based on 2D information embedded in the US images by examining the area changes in LV blood pool between diastole and systole. There has been some anecdotal evidence that visual estimation of the LVEF based on the area changes of the LV blood pool significantly underestimate true LVEF. True LVEF should be calculated based on changes in LV volumes between diastole and systole. In this project, we utilized both idealized models of the LV geometry - a truncated prolate spheroid (TPS) and a paraboloid model - to represent the LV anatomy. Cross-sectional areas and volumes of simulated LV shapes using both models were calculated to compare the LVEF. Further, a LV reconstruction algorithm was employed to build the LV blood pool volume in both systole and diastole from multi-plane 2D US imaging data. Our mathematical models yielded an area-based LVEF of 41 4.7% and a volume-based LVEF of 55 ±5.7%, while the 3D recon-struction model showed an area-based LVEF of 35 11.9% and a volume-based LVEF of 48.0 ± 14.0%. In summary, the area-based LVEF using all three models ±underestimate the volume-based LVEF using corresponding models by 13% to 14%. This preliminary study confirms both mathematically and empirically that area-based LVEF estimates indeed underestimate the true volume-based LVEF measurements and suggests that true volumetric measurements of the LV blood pool must be computed to correctly assess cardiac LVEF.

Evaluation of the right ventricle by echocardiography: particularities and major challenges

INTRODUCTION

Compared with the left ventricle (LV), the right ventricle (RV) is less suited for evaluation by echocardiography (ECHO). Nevertheless, RV ECHO-assessment has currently emerged as an important diagnostic tool with meaningful prognostic value and essential contribution to therapeutic decisions. Although significant progress has been made, including generation of higher-quality normative data, validation of several two-dimensional measurements and improvements in three-dimensional ECHO-techniques, many challenges in RV ECHO-assessment still persist. Areas covered: This review discusses the particular challenges and limits in obtaining accurate measurements of RV anatomical and functional parameters and focuses primarily on the difficulties in proper interpretation of the highly load dependent RV ECHO-parameters which complicates the use of this valuable diagnostic and surveillance technique. Expert commentary: There is increasing evidence that RV assessment in relation with its actual loading conditions by ECHO-derived composite variables, which either incorporate a certain functional parameter and load, or incorporate measures which reflect the relationship between RV dilation and RV load, considering also the right atrial pressure (i.e. 'load adaptation index'), is particularly suited for clinical decision-making. Load dependency of RV ECHO-parameters must be taken into consideration especially in patients with advanced RV dysfunction scheduled for LV assist device implantation or lung transplantation.