Assessment of right ventricular dysfunction predictors before the implantation of a left ventricular assist device in end-stage heart failure patients using echocardiographic measures (ARVADE): Combination of left and right ventricular echocardiographic variables

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.

The Role of Artificial Intelligence and Machine Learning in the Prediction of Right Heart Failure after Left Ventricular Assist Device Implantation: A Comprehensive Review

One of the most challenging and prevalent side effects of LVAD implantation is that of right heart failure (RHF) that may develop afterwards. The purpose of this study is to review and highlight recent advances in the uses of AI in evaluating RHF after LVAD implantation. The available literature was scanned using certain key words (artificial intelligence, machine learning, left ventricular assist device, prediction of right heart failure after LVAD) was scanned within Pubmed, Web of Science, and Google Scholar databases. Conventional risk scoring systems were also summarized, with their pros and cons being included in the results section of this study in order to provide a useful contrast with AI-based models. There are certain interesting and innovative ML approaches towards RHF prediction among the studies reviewed as well as more straightforward approaches that identified certain important predictive clinical parameters. Despite their accomplishments, the resulting AUC scores were far from ideal for these methods to be considered fully sufficient. The reasons for this include the low number of studies, standardized data availability, and lack of prospective studies. Another topic briefly discussed in this study is that relating to the ethical and legal considerations of using AI-based systems in healthcare. In the end, we believe that it would be beneficial for clinicians to not ignore these developments despite the current research indicating more time is needed for AI-based prediction models to achieve a better performance.

Interventricular-Septal Output While Supported on Left Ventricular Assist Device Therapy

The effects of left ventricular unloading on septal function in patients with left ventricular assist devices (LVADs) have not been well characterized in vivo. The purpose of this study was to evaluate the relationship between markers of septal function with echocardiography in relationship to RV dysfunction and late RV failure after LVAD implantation. A retrospective study was conducted of patients supported on centrifugal-flow LVADs implanted over a 10-year period. Echocardiographic data were collected pre-operatively and up to 2 years after implantation. Interventricular septum (IVS) measurements were taken at end-systole and end-diastole. Interventricular-septal output (ISO) was calculated using the formula: (IVSs-IVSd)×heart rate. A total of 110 patients were included. An immediate and sustained reduction in both lateral annulus systolic velocity (RVS') and TAPSE were observed after implant ( p < 0.0001). However, ISO gradually decreased over time ( p < 0.0001). While ISO was not predictive of late RV failure, a decrease in ISO by 25% or greater from pre-implant to hospital discharge was associated with late RV failure (OR 4.8; 95% CI, 1.4-16.5; p = 0.012) even after adjusting for relevant clinical variables ( p ≤ 0.01 for each model). RV function is known to be influenced by mechanical ventricular interdependence and we demonstrate that measurement of ISO may be a useful marker in assessing RV dysfunction and predicting RV failure in patients following LVAD implantation.

Comparison of Cadmium Zinc Telluride ECG-gated SPECT equilibrium radionuclide angiocardiography to magnetic resonance imaging to measure right ventricular volumes and ejection fraction in patients with cardiomyopathy

AIMS

The objective of this study was to determine the accuracy of right ventricular function (RVF) assessed by Cadmium Zinc Telluride ECG-gated SPECT equilibrium radionuclide angiocardiography (CZT-ERNA).

METHODS AND RESULTS

Twenty-one consecutive patients with cardiomyopathy (aged 54 ± 19 years; 62% male) were included. RV ejection fraction (EF) and volumes were analyzed by CZT-ERNA and compared with values obtained by cardiac magnetic resonance imaging (CMR). Mean values were not different between CZT-ERNA and MRI for RVEF (48.1 ± 10.4% vs 50.8 ± 10.0%; P = .23). Significant correlations (P < .0001) were observed between CZT-ERNA and MRI for RVEF, RV end-diastolic volume, and end-systolic volume (r = 0.81, r = 0.93, and r = 0.96, respectively). Bland-Altman analysis showed a mean difference (bias) between CZT-ERNA and MRI for RVEF of -2.69% (95% CI - 5.35 to - 0.42) with good agreement between the 2 techniques (limits of agreement, -14.3 to 8.99). Intraobserver and interobserver reproducibility of RVF measured by CZT-ERNA was high.

CONCLUSION

CZT-ERNA provides accurate, reproducible assessment of RVF and appears as a good alternative to cardiac magnetic resonance for the evaluation of the magnitude of RVF in patients with cardiomyopathy.

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.

Prediction of right ventricular failure after left ventricular assist device implantation in patients with heart failure: a meta-analysis comparing echocardiographic parameters

OBJECTIVES

Between 10% and 40% of patients who receive a left ventricular assistance device (LVAD) suffer from right ventricular failure (RVF) shortly after the device is implanted. Patients with post-LVAD RVF tend to have poor outcomes. Only a few predictive factors concerning the right ventricle (RV) have been investigated. Our goal was to search for non-invasive variables that correlate with RV function, focusing on echocardiographic parameters of the RV.

METHODS

We selected 3 parameters: tricuspid annular plane systolic excursion, right ventricular fractional area change and right ventricular global longitudinal strain. We searched the literature and pooled relevant studies in a meta-analysis. Finally, we performed a statistical analysis to confirm whether each parameter was a reliable predictor of RVF after LVAD implantation.

RESULTS

We retained 19 articles involving a total of 1561 patients. We found a pooled standardized mean deviation of -0.13 cm for the tricuspid annular plane systolic excursion, with the lower and upper tails of -0.21 and -0.04 cm, respectively. Concerning the right ventricular fractional area change, the averaged standardized mean deviation was equal to -2.61%, with the lower and upper extremities of -4.12% and -1.09%, respectively. Finally, regarding the global longitudinal strain, the standardized mean deviation was equal to -2.06% with an uncertainty value between -3.23% and -0.88%.

CONCLUSIONS

The tricuspid annular plane systolic excursion could be a reliable parameter in RVF prediction. The right ventricular fractional area change and global longitudinal strain are likely to be stronger predictors of RVF after LVAD implantation. Prospective studies should be carried out to confirm this observation.

Defining Vasoplegia Following Durable, Continuous Flow Left Ventricular Assist Device Implantation

This study aimed to develop a definition of vasoplegia that reliably predicts clinical outcomes. Vasoplegia was evaluated using data from the electronic health record for each 15-minute interval for 72 hours following cardiopulmonary bypass. Standardized definitions considered clinical features (systemic vascular resistance [SVR], mean arterial pressure [MAP], cardiac index [CI], norepinephrine equivalents [NEE]), threshold strategy (criteria occurring in any versus all measurements in an interval), and duration (criteria occurring over multiple consecutive versus separated intervals). Minor vasoplegia was MAP < 60 mm Hg or SVR < 800 dynes⋅sec⋅cm with CI > 2.2 L/min/m and NEE ≥ 0.1 µg/kg/min. Major vasoplegia was MAP < 60 mm Hg or SVR < 700 dynes⋅sec⋅cm with CI > 2.5 L/min/m and NEE ≥ 0.2 µg/kg/min. The primary outcome was incidence of vasoplegia for eight definitions developed utilizing combinations of these criteria. Secondary outcomes were associations between vasoplegia definitions and three clinical outcomes: time to extubation, time to intensive care unit discharge, and nonfavorable discharge. Minor vasoplegia detected anytime within a 15-minute period (MINOR_ANY_15) predicted the highest incidence of vasoplegia (61%) and was associated with two of three clinical outcomes: 1 day delay to first extubation (95% CI: 0.2 to 2) and 7 day delay to first intensive care unit discharge (95% CI: 1 to 13). The MINOR_ANY_15 definition should be externally validated as an optimal definition of vasoplegia.

Development of tricuspid regurgitation and right ventricular performance after implantation of centrifugal left ventricular assist devices

Background

Tricuspid regurgitation (TR) after left ventricular assist device (LVAD) implantation is associated with a poor prognosis. This study evaluates the development of TR and right ventricular (RV) performance after LVAD implantation.

Methods

Retrospective analysis of patients who underwent LVAD implantation between March 2018 and June 2019. Patients who underwent concomitant tricuspid valve surgery and patients with congenital heart disease were excluded.

Results

A total of 155 patients underwent LVAD implantation. Fourteen patients were excluded. Of the remaining patients, thirty-one died during the first six months, six were lost to follow-up and two underwent transplantation. 102 patients presented at 6.3 months (5.8 to 7.0). Patients were supported with HeartWare HVAD (74%) or HeartMate 3 (26%). 50.4% were rated as INTERMACS profile 1 or 2. At six months, systolic pulmonary artery pressure dropped from 36 to 21 mmHg (P<0.001). Tricuspid annular plane systolic excursion decreased from 17.3 to 14.3 mm (P<0.001), RV fractional area change did not change (P=0.839). Twenty-two patients (22%) presented with moderate-to-severe or severe (ms-s) TR pre-operatively. Of these, eighteen (81%) showed improvement to ≤ moderate TR. At follow-up twelve patients presented with ms-s TR. Of these, only four patients (33%) had been diagnosed with ms-s TR pre-operatively. There were no differences in pre-operative echocardiographic or clinical parameters between the twelve patients with ms-s late TR and the other ninety patients in the cohort.

Conclusions

TR can show an impressive improvement with LVAD support. Longitudinal RV function decreases; this appears to be compensated by transverse shortening. Late TR can develop independently from pre-operative parameters including TR.

Assessment of right ventricular function following left ventricular assist device (LVAD) implantation-The role of speckle-tracking echocardiography: A meta-analysis

BACKGROUND

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation is associated with worse outcomes. Prediction of RVF is difficult with routine transthoracic echocardiography (TTE), while speckle-tracking echocardiography (STE) showed promising results. We performed systematic review and meta-analysis of published literature.

METHODS

We queried multiple databases to compile articles reporting preoperative or intraoperative right ventricle global longitudinal strain (RVGLS) or right ventricle free wall strain (RVFWS) in LVAD recipients. The standard mean difference (SMD) in RVGLS and RVFWS in patients with and without RVF postoperatively was pooled using random-effects model.

RESULTS

Seventeen studies were included. Patients with RVF had significantly lower RVGLS and RVFWS as compared to non-RVF patients; SMD: 2.79 (95% CI: -4.07 to -1.50; P: <.001) and -3.05 (95% CI: -4.11 to -1.99; P: <.001), respectively. The pooled odds ratio (OR) for RVF per percentage increase of RVGLS and RVFWS were 1.10 (95 CI: 0.98-1.25) and 1.63 (95% CI 1.07-2.47), respectively. In a subgroup analysis, TTE-derived GLS and FWS were significantly lower in RVF patients as compared to non-RVF patients; SMD of -3.97 (95% CI: -5.40 to -2.54; P: <.001) and -3.05 (95% CI: -4.11 to -1.99; P: <.001), respectively. There was no significant difference between RVF and non-RVF groups in TEE-derived RVGLS and RVFWS.

CONCLUSION

RVGLS and RVFWS were lower in patients who developed RVF as compared to non-RVF patients. In a subgroup analysis, TTE-derived RVGLS and RVFWS were reduced in RVF patients as compared to non-RVF patients. This difference was not reported with TEE.

Current perspectives on mechanical circulatory support

Mechanical circulatory support gained a significant value in the armamentarium of heart failure therapy because of the increased awareness of the prevalence of heart failure and the tremendous advances in the field of mechanical circulatory support during the last decades. Current device technologies already complement a heart transplant as the gold standard of treatment for patients with end-stage heart failure refractory to conservative medical therapy. This article reviews important aspects of mechanical circulatory support therapy and focuses on currently debated issues.

Right Ventricular Strain to Assess Early Right Heart Failure in the Left Ventricular Assist Device Candidate

PURPOSE OF REVIEW

Right heart failure (RHF) following left ventricular assist device implantation (LVAD) remains the primary cause of postoperative mortality and morbidity, and prediction of RHF is the main interest of the transplantation community. In this review, we outline the role and impact of right ventricular strain in the evaluation of the right ventricle function before LVAD implantation.

RECENT FINDINGS

Accumulating data suggest that measurement of right ventricular longitudinal strain (RVLS) has a critical role in predicting RHF preoperatively and may improve morbidity and mortality following LVAD implantation. However, the significant intraobserver, interobserver variability, the lack of multicenter, prospective studies, and the need for a learning curve remain the most critical limitations in the clinical practice at present. This review highlighted the importance of right ventricular strain in the diagnosis of RHF preoperatively and revealed that RVLS might have a crucial clinical measurement for the selection and management of LVAD patients in the future with the more extensive multicenter studies.

Risk factors of in-hospital mortality in adult postcardiotomy cardiogenic shock patients successfully weaned from venoarterial extracorporeal membrane oxygenation

OBJECTIVE

Mortality of adult postcardiotomy cardiogenic shock patients after successfully weaned from venoarterial extracorporeal membrane oxygenation remains high. The objective of this study is to identify the risk factors associated with mortality after successfully weaning from venoarterial extracorporeal membrane oxygenation in adult postcardiotomy cardiogenic shock patients.

METHODS

All consecutive patients who were successfully weaned from venoarterial extracorporeal membrane oxygenation between January 2011 and December 2016 at the Beijing Anzhen Hospital were analyzed retrospectively. Multivariate logistic regression was performed to identify risk factors associated with in-hospital mortality after successfully weaning from venoarterial extracorporeal membrane oxygenation.

RESULTS

In total, 212 (58.4%) of 363 postcardiotomy cardiogenic shock patients were successfully weaned from venoarterial extracorporeal membrane oxygenation. The non-survivors had a longer duration of extracorporeal membrane oxygenation than the survivors (120.0 (98.0, 160.50) vs. 100.0 (77.0, 126.0), p = 0.000). Variables associated with mortality of patients successfully weaned from extracorporeal membrane oxygenation by univariable analysis were age, diabetes, vasoactive inotropic score pre-extracorporeal membrane oxygenation, vasoactive inotropic score at weaning, left ventricular ejection fraction at weaning, central venous pressure at weaning, sequential organ failure assessment score pre-extracorporeal membrane oxygenation, sequential organ failure assessment at weaning, survival after venoarterial ECMO pre-extracorporeal membrane oxygenation, and survival after venoarterial ECMO at weaning. In the multivariate analysis, sequential organ failure assessment score at weaning (odds ratio = 1.889, 95% confidence interval = 1.460-2.455, p < 0.001) was an independent risk factor for in-hospital mortality of patients successfully weaned from venoarterial extracorporeal membrane oxygenation. The cumulative 30-day survival rate in patients with a sequential organ failure assessment score < 7 was significantly (p < 0.001) higher than in patients with a sequential organ failure assessment score ⩾ 7 (87% vs. 56.7%, p < 0.001).

CONCLUSION

Vasoactive inotropic score, left ventricular ejection fraction, central venous pressure, and sequential organ failure assessment score at weaning were associated with in-hospital mortality for postcardiotomy cardiogenic shock patients successfully weaned from venoarterial extracorporeal membrane oxygenation. Sequential organ failure assessment score might help clinicians to predict in-hospital mortality for patients successfully weaned from venoarterial extracorporeal membrane oxygenation.

Intraoperative Hemodynamic and Echocardiographic Measurements Associated With Severe Right Ventricular Failure After Left Ventricular Assist Device Implantation

BACKGROUND

Severe right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation increases morbidity and mortality. We investigated the association between intraoperative right heart hemodynamic data, echocardiographic parameters, and severe versus nonsevere RVF.

METHODS

A review of LVAD patients between March 2013 and March 2016 was performed. Severe RVF was defined by the need for a right ventricular mechanical support device, inotropic, and/or inhaled pulmonary vasodilator requirements for >14 days. From a chart review, the right ventricular failure risk score was calculated and right heart hemodynamic data were collected. Pulmonary artery pulsatility index (PAPi) [(pulmonary artery systolic pressure - pulmonary artery diastolic pressure)/central venous pressure (CVP)] was calculated for 2 periods: (1) 30 minutes before cardiopulmonary bypass (CPB) and (2) after chest closure. Echocardiographic data were recorded pre-CPB and post-CPB by a blinded reviewer. Univariate logistic regression models were used to examine the performance of hemodynamic and echocardiographic metrics.

RESULTS

A total of 110 LVAD patients were identified. Twenty-five did not meet criteria for RVF. Of the remaining 85 patients, 28 (33%) met criteria for severe RVF. Hemodynamic factors associated with severe RVF included: higher CVP values after chest closure (18 ± 9 vs 13 ± 5 mm Hg; P = .0008) in addition to lower PAPi pre-CPB (1.2 ± 0.6 vs 1.7 ± 1.0; P = .04) and after chest closure (0.9 ± 0.5 vs 1.5 ± 0.8; P = .0008). Post-CPB echocardiographic findings associated with severe RVF included: larger right atrial diameter major axis (5.4 ± 0.9 vs 4.9 ± 1.0 cm; P = .03), larger right ventricle end-systolic area (22.6 ± 8.4 vs 18.5 ± 7.9 cm; P = .03), lower fractional area of change (20.2 ± 10.8 vs 25.9 ± 12.6; P = .04), and lower tricuspid annular plane systolic excursion (0.9 ± 0.2 vs 1.1 ± 0.3 cm; P = .008). Right ventricular failure risk score was not a significant predictor of severe RVF. Post-chest closure CVP and post-chest closure PAPi discriminated severe from nonsevere RVF better than other variables measured, each with an area under the curve of 0.75 (95% CI, 0.64-0.86).

CONCLUSIONS

Post-chest closure values of CVP and PAPi were significantly associated with severe RVF. Echocardiographic assessment of RV function post-CPB was weakly associated with severe RVF.

Left Ventricular Assist Devices (LVADS): History, Clinical Application and Complications

Congestive heart failure is a major cause of morbidity and mortality as well as a major health care cost in the developed world. Despite the introduction of highly effective heart failure medical therapies and simple devices such as cardiac resynchronization therapy that reduce mortality, improve cardiac function and quality of life, there remains a large number of patients who do not respond to these therapies or whose heart failure progresses despite optimal therapy. For these patients, cardiac transplantation is an option but is limited by donor availability as well as co-morbidities which may limit survival post-transplant. For these patients, left ventricular assist devices (LVADs) offer an alternative that can improve survival as well as exercise tolerance and quality of life. These devices have continued to improve as technology has improved with substantially improved durability of the devices and fewer post-implant complications. Pump thrombosis, stroke, gastrointestinal bleeding and arrhythmias post-implant have become less common with the newest devices, making destination therapy where ventricular assist device are implanted permanently in patients with advanced heart failure, a reality and an appropriate option for many patients. This may offer an opportunity for long term survival in many patients. As the first of the totally implantable devices are introduced and go to clinical trials, LVADs may be introduced that may truly be alternatives to cardiac transplantation in selected patients. Post-implant right ventricular failure remains a significant complication and better ways to identify patients at risk as well as to manage this complication must be developed.

Utility of Novel Cardiorenal Biomarkers in the Prediction and Early Detection of Congestive Kidney Injury Following Cardiac Surgery

Acute Kidney Injury (AKI) in the context of right ventricular failure (RVF) is thought to be largely congestive in nature. This study assessed the utility of biomarkers high sensitivity cardiac troponin T (hs-cTnT), N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP), and neutrophil gelatinase-associated lipocalin (NGAL) for prediction and early detection of congestive AKI (c-AKI) following cardiac surgery. This prospective nested case-control study recruited 350 consecutive patients undergoing elective cardiac surgery requiring cardiopulmonary bypass. Cases were patients who developed (1) AKI (2) new or worsening RVF, or (3) c-AKI. Controls were patients free of these complications. Biomarker levels were measured at baseline after anesthesia induction and immediately postoperatively. Patients with c-AKI had increased mean duration of mechanical ventilation and length of stay in hospital and in the intensive care unit (p < 0.01). For prediction of c-AKI, baseline NT-proBNP yielded an area under the curve (AUC) of 0.74 (95% CI, 0.60–0.89). For early detection of c-AKI, postoperative NT-proBNP yielded an AUC of 0.78 (0.66–0.91), postoperative hs-cTnT yielded an AUC of 0.75 (0.58–0.92), and ∆hs-cTnT yielded an AUC of 0.80 (0.64–0.96). The addition of baseline creatinine to ∆hs-cTnT improved the AUC to 0.87 (0.76–0.99), and addition of diabetes improved the AUC to 0.93 (0.88–0.99). Δhs-cTnT alone, or in combination with baseline creatinine or diabetes, detects c-AKI with high accuracy following cardiac surgery.

Prevention and Treatment of Right Ventricular Failure During Left Ventricular Assist Device Therapy

Left ventricular assist devices (LVAD) are increasingly used for the treatment of end-stage heart failure. Right ventricular (RV) failure after LVAD implantation is an increasingly common clinical problem, occurring in patients early after continuous flow LVAD implant. RV failure is associated with a substantial increase in post-LVAD morbidity and mortality. RV failure can be predicted using preoperative hemodynamic, clinical, and echocardiographic variables and a variety of risk prediction algorithms. However, RV failure may also develop due to unanticipated intraoperative or perioperative factors. Early recognition and treatment are critical in terms of mitigating the impact of RV failure on post-LVAD outcomes.

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.

Mechanical Circulatory Support in the Treatment of Advanced Heart Failure

According to the Centers for Disease Control, heart failure (HF) remains a pervasive condition with high morbidity and mortality, affecting 5.8 million people in the United States and 23 million worldwide. For patients with refractory end-stage HF, heart transplantation is the "gold standard" for definitive treatment. However, the demand for heart transplantation has consistently exceeded the availability of donor hearts, with approximately 2331 orthotopic heart transplantations performed in the United States in 2015 despite an estimated 100 000 to 250 000 patients with New York Heart Association class IIIB or IV symptoms that are refractory to medical treatment, making such patients potential transplant candidates. As such, the need for mechanical circulatory support (MCS) to treat patients with end-stage HF has become paramount. In this review, we focus on the history, advancements, and current use of durable MCS device therapy in the treatment of advanced heart failure.

Impact of Right Ventricular Performance in Patients Undergoing Extracorporeal Membrane Oxygenation Following Cardiac Surgery

BACKGROUND

Extracorporeal membrane oxygenation following cardiac surgery safeguards end-organ oxygenation but unfavorably alters cardiac hemodynamics. Along with the detrimental effects of cardiac surgery to the right heart, this might impact outcome, particularly in patients with preexisting right ventricular (RV) dysfunction. We sought to determine the prognostic impact of RV function and to improve established risk-prediction models in this vulnerable patient cohort.

METHODS AND RESULTS

Of 240 patients undergoing extracorporeal membrane oxygenation support following cardiac surgery, 111 had echocardiographic examinations at our institution before implantation of extracorporeal membrane oxygenation and were thus included. Median age was 67 years (interquartile range 60-74), and 74 patients were male. During a median follow-up of 27 months (interquartile range 16-63), 75 patients died. Fifty-one patients died within 30 days, 75 during long-term follow-up (median follow-up 27 months, minimum 5 months, maximum 125 months). Metrics of RV function were the strongest predictors of outcome, even stronger than left ventricular function (P<0.001 for receiver operating characteristics comparisons). Specifically, RV free-wall strain was a powerful predictor univariately and after adjustment for clinical variables, Simplified Acute Physiology Score-3, tricuspid regurgitation, surgery type and duration with adjusted hazard ratios of 0.41 (95%CI 0.24-0.68; P=0.001) for 30-day mortality and 0.48 (95%CI 0.33-0.71; P<0.001) for long-term mortality for a 1-SD (SD=-6%) change in RV free-wall strain. Combined assessment of the additive EuroSCORE and RV free-wall strain improved risk classification by a net reclassification improvement of 57% for 30-day mortality (P=0.01) and 56% for long-term mortality (P=0.02) compared with the additive EuroSCORE alone.

CONCLUSIONS

RV function is strongly linked to mortality, even after adjustment for baseline variables and clinical risk scores. RV performance improves established risk prediction models for short- and long-term mortality.

Echocardiographic assessment of the right ventricle: Impact of the distinctly load dependency of its size, geometry and performance

Right ventricular (RV) size, shape and function are distinctly load-dependent and pulmonary load is an important determinant of RV function in patients with congestive heart failure (CHF) due to primary impaired left ventricular function and in those with pre-capillary pulmonary hypertension (PH). In a pressure overloaded RV, not only dilation and aggravation of tricuspid regurgitation, but also systolic dysfunction leading to RV failure (RVF) can occur already before the development of irreversible alterations in RV myocardial contractility. This explains RV ability for reverse remodeling and functional improvement in patients with post-capillary and pre-capillary PH of a different etiology, after normalization of loading conditions. There is increasing evidence that RV evaluation by echocardiography in relation with its loading conditions can improve the decision-making process and prognosis assessments in clinical praxis. Recent approaches to evaluate the RV in relation with its actual loading conditions by echo-derived composite variables which either incorporate a certain functional parameter (i.e. tricuspid annulus peak systolic excursion, stroke volume, RV end-systolic volume index, velocity of myocardial shortening) and load, or incorporate measures which reflect the relationship between RV load and RV dilation, also taking the right atrial pressure into account (i.e. "load adaptation index"), appeared particularly suited and therefore also potentially useful for evaluation of RV contractile function. Special attention is focused on the usefulness of RV echo-evaluation in relation to load for proper decision making before ventricular assist-device implantation in patients with CHF and for optimal timing of listing procedures to transplantation in patients with end-stage pre-capillary PH.