Preoperative risk factors for right ventricular failure after implantable left ventricular assist device insertion

Concomitant tricuspid valve surgery in patients with significant tricuspid regurgitation undergoing left ventricular assist device implantation: A systematic review and meta-analysis

BACKGROUND

Significant tricuspid regurgitation (TR) is a predictor of right heart failure (RHF) and increased mortality following left ventricular assist device (LVAD) implantation, however the benefit of tricuspid valve surgery (TVS) at the time of LVAD implantation remains unclear. This study compares early and late mortality and RHF outcomes in patients with significant TR undergoing LVAD implantation with and without concomitant TVS.

METHODS

A systematic search of four electronic databases was conducted for studies comparing patients with moderate or severe TR undergoing LVAD implantation with or without concomitant TVS. Meta-analysis was performed for primary outcomes of early and late mortality and RHF. Secondary outcomes included rate of stroke, renal failure, hospital and ICU length of stay. An overall survival curve was constructed using aggregated, reconstructed individual patient data from Kaplan-Meier (KM) curves.

RESULTS

Nine studies included 575 patients that underwent isolated LVAD and 308 patients whom received concomitant TVS. Both groups had similar rates of severe TR (46.5% vs. 45.6%). There was no significant difference seen in risk of early mortality (RR 0.90; 95% CI, 0.57-1.42; p = 0.64; I2 = 0%) or early RHF (RR 0.82; 95% CI, 0.66-1.19; p = 0.41; I2 = 57) and late outcomes remained comparable between both groups. The aggregated KM curve showed isolated LVAD to be associated with overall increased survival (HR 1.42; 95% CI, 1.05-1.93; p = 0.023).

CONCLUSIONS

Undergoing concomitant TVS did not display increased benefit in terms of early or late mortality and RHF in patients with preoperative significant TR. Further data to evaluate the benefit of concomitant TVS stratified by TR severity or by other predictors of RHF will be beneficial.

Quantitative Evaluation of Right Ventricular Workload Based on the Stroke Work Index in Patients after Right Ventricular Outflow Tract Reconstruction

The evaluation of right ventricular workload is sometimes complicated in patients after right ventricular outflow tract reconstruction (RVOTR) because both stenotic and regurgitation lesions are involved. In this study, we modified the right ventricular stroke work index (RVSWI) and evaluated the relationship between the modified RVSWI (mRVSWI) and patient prognosis after RVOTR.We enrolled 69 patients who underwent RVOTR (the RVOTR group), including those who needed early reoperation (early reoperation subgroup) and those who did not (follow-up subgroup), and 13 age-matched control participants (control group). Based on the catheterization results 1 year after RVOTR, we compared the mRVSWI between these groups. Additionally, we evaluated the influence of the mRVSWI on the reoperation avoidance rate and survival.The mRVSWI in the RVOTR group was significantly greater than that in the control group (17.7 ± 8.6 vs. 11.0 ± 2.7 g·m/m2, p = 0.008). The mRVSWI in the early reoperation subgroup was significantly greater than that in the follow-up subgroup (32.5 ± 11.1 vs. 15.8 ± 6.0 g·m/m2, p < 0.0001). In the follow-up subgroup, patients with an mRVSWI higher than the upper limit of normal (16.4 g·m/m2) had a greater rate of reoperation than did the other patients (p = 0.0013). One patient died suddenly, and her mRVSWI was consistently high throughout her life.We established the mRVSWI as an index that integrates the pressure and volume load on the right ventricle. Our results indicate the utility of the mRVSWI for predicting patient prognosis after RVOTR.

Blood flow kinetic energy is a novel marker for right ventricular global systolic function in patients with left ventricular assist device therapy

Objectives

Right ventricular (RV) failure remains a major concern in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implantation. We aimed to measure the kinetic energy of blood in the RV outflow tract (KE-RVOT) - a new marker of RV global systolic function. We also aimed to assess the relationship of KE-RVOT to other echocardiographic parameters in all subjects and assess the relationship of KE-RVOT to hemodynamic parameters of RV performance in HF patients.

Methods

Fifty-one subjects were prospectively enrolled into 4 groups (healthy controls, NYHA Class II, NYHA Class IV, LVAD patients) as follows: 11 healthy controls, 32 HF patients (8 NYHA Class II and 24 Class IV), and 8 patients with preexisting LVADs. The 24 Class IV HF patients included 21 pre-LVAD and 3 pre-transplant patients. Echocardiographic parameters of RV function (TAPSE, St', Et', IVA, MPI) and RV outflow color-Doppler images were recorded in all patients. Invasive hemodynamic parameters of RV function were collected in all Class IV HF patients. KE-RVOT was derived from color-Doppler imaging using a vector flow mapping proprietary software. Kruskal-Wallis test was performed for comparison of KE-RVOT in each group. Correlation between KE-RVOT and echocardiographic/hemodynamic parameters was assessed by linear regression analysis. Receiver operating characteristic curves for the ability of KE-RVOT to predict early phase RV failure were generated.

Results

KE-RVOT (median ± IQR) was higher in healthy controls (55.10 [39.70 to 76.43] mW/m) than in the Class II HF group (22.23 [15.41 to 35.58] mW/m, p < 0.005). KE-RVOT was further reduced in the Class IV HF group (9.02 [5.33 to 11.94] mW/m, p < 0.05). KE-RVOT was lower in the LVAD group (25.03 [9.88 to 38.98] mW/m) than the healthy controls group (p < 0.005). KE-RVOT had significant correlation with all echocardiographic parameters and no correlation with invasive hemodynamic parameters. RV failure occurred in 12 patients who underwent LVAD implantation in the Class IV HF group (1 patient was not eligible due to death immediately after the LVAD implantation). KE-RVOT cut-off value for prediction of RV failure was 9.15 mW/m (sensitivity: 0.67, specificity: 0.75, AUC: 0.66).

Conclusions

KE-RVOT, a novel noninvasive measure of RV function, strongly correlates with well-established echocardiographic markers of RV performance. KE-RVOT is the energy generated by RV wall contraction. Therefore, KE-RVOT may reflect global RV function. The utility of KE-RVOT in prediction of RV failure post LVAD implantation requires further study.

Impact of right ventricular reserve on exercise capacity and quality of life in patients with left ventricular assist device

Although measuring right ventricular (RV) function during exercise is more informative than assessing it at rest, the relationship between RV reserve function, exercise capacity, and health-related quality of life (HRQoL) in patients with left ventricular assist devices (LVAD) remains unresolved. We aimed to investigate whether RV reserve assessed by the change in RV stroke work index (RVSWI) during exercise is correlated with exercise capacity and HRQoL in patients with LVAD. We prospectively assessed 24 consecutive patients with LVAD who underwent invasive right heart catheterization in the supine position. Exercise capacity and HRQoL were assessed using the 6-min walk distance (6 MWD) and peak oxygen consumption (V̇o₂) in cardiopulmonary exercise testing, and the EuroQol visual analog scale (EQ-VAS), respectively. The patients were divided into two groups according to the median ΔRVSWI (change from rest to peak exercise). Patients with lower ΔRVSWI had significantly lower changes in cardiac index and absolute value of RV dP/dt than those with higher ΔRVSWI. The ΔRVSWI was positively correlated with 6 MWD (r = 0.59, P = 0.003) and peak V̇o₂ (r = 0.56, P = 0.006). In addition, ΔRVSWI was positively correlated with the EQ-VAS (r = 0.44, P = 0.030). In contrast, there was no significant correlation between RVSWI at rest and 6 MWD (r = -0.34, P = 0.88), peak V̇o₂ (r = 0.074, P = 0.74), or EQ-VAS (r = 0.127, P = 0.56). Our findings suggest that the assessment of RV reserve function is useful for risk stratification in patients with LVAD.NEW & NOTEWORTHY The change in right ventricular stroke work index (RVSWI) during exercise, not RVSWI at rest, was associated with exercise capacity and HRQoL. Our findings suggest that the assessment of change in RVSWI during exercise as a surrogate of RV reserve function may aid in risk stratification of patients with LVAD.

Biventricular assist devices and total artificial heart: Strategies and outcomes

In contrast to the advanced development of the left ventricular assist device (LVAD) therapy for advanced heart failure, the mechanical circulatory support (MCS) with biventricular assist device (BVAD) and total artificial heart (TAH) options remain challenging. The treatment strategy of BVAD and TAH therapy largely depends on the support duration. For example, an extracorporeal centrifugal pump, typically referred to as a temporary surgical extracorporeal right ventricular assist device, is implanted for the short term with acute right ventricular failure following LVAD implantation. Meanwhile, off-label use of a durable implantable LVAD is a strategy for long-term right ventricular support. Hence, this review focuses on the current treatment strategies and clinical outcomes based on each ventricle support duration. In addition, the issue of heart failure post-heart transplantation (post-HT) is explored. We will discuss MCS therapy options for post-HT recipients.

Supporting the "forgotten" ventricle: The evolution of percutaneous RVADs

Right heart failure (RHF) can occur as the result of an acute or chronic disease process and is a challenging clinical condition for surgeons and interventionalists to treat. RHF occurs in approximately 0.1% of patients after cardiac surgery, in 2-3% of patients following heart transplantation, and in up to 42% of patients after LVAD implantation. Regardless of the cause, RHF portends high morbidity and mortality and is associated with longer hospital stays and higher healthcare costs. The mainstays of traditional therapy for severe RHF have included pharmacological support, such as inotropes and vasopressors, and surgical right ventricular (RV) assist devices. However, in recent years catheter-based mechanical circulatory support (MCS) strategies have offered novel solutions for addressing RHF without the morbidity of open surgery. This manuscript will review the pathophysiology of RHF, including the molecular underpinnings, gross structural mechanisms, and hemodynamic consequences. The evolution of techniques for supporting the right ventricle will be explored, with a focus on various institutional experiences with percutaneous ventricular assist devices.

Hemodynamic reserve predicts early right heart failure after LVAD implantation

BACKGROUND

Early right heart failure (RHF) remains a major source of morbidity and mortality after left ventricular assist device (LVAD) implantation, yet efforts to predict early RHF have proven only modestly successful. Pharmacologic unloading of the left ventricle may be a risk stratification approach allowing for assessment of right ventricular and hemodynamic reserve.

METHODS

We performed a multicenter, retrospective analysis of patients who had undergone continuous-flow LVAD implantation from October 2011 to April 2020. Only those who underwent vasodilator testing with nitroprusside during their preimplant right heart catheterization were included (n = 70). Multivariable logistic regression was used to determine independent predictors of early RHF as defined by Mechanical Circulatory Support-Academic Research Consortium.

RESULTS

Twenty-seven patients experienced post-LVAD early RHF (39%). Baseline clinical characteristics were similar between patients with and without RHF. Patients without RHF, however, achieved higher peak stroke volume index (SVI) (30.1 ± 8.8 vs 21.7 ± 7.4 mL/m2; p < 0.001; AUC: 0.78; optimal cut-point: 22.1 mL/m2) during nitroprusside administration. Multivariable analysis revealed that peak SVI was significantly associated with early RHF, demonstrating a 16% increase in risk of early RHF per 1 ml/m2 decrease in SVI. A follow up cohort of 10 consecutive patients from July 2020 to October 2021 resulted in all patients being categorized appropriately in regards to early RHF versus no RHF according to peak SVI.

CONCLUSION

Peak SVI with nitroprusside administration was independently associated with post-LVAD early RHF while resting hemodynamics were not. Vasodilator testing may prove to be a strong risk stratification tool when assessing LVAD candidacy though additional prospective validation is needed.

Right heart failure after left ventricular assist device: From mechanisms to treatments

Left ventricular assist device (LVAD) therapy is a lifesaving option for patients with medical therapy-refractory advanced heart failure. Depending on the definition, 5-44% of people supported with an LVAD develop right heart failure (RHF), which is associated with worse outcomes. The mechanisms related to RHF include patient, surgical, and hemodynamic factors. Despite significant progress in understanding the roles of these factors and improvements in surgical techniques and LVAD technology, this complication is still a substantial cause of morbidity and mortality among LVAD patients. Additionally, specific medical therapies for this complication still are lacking, leaving cardiac transplantation or supportive management as the only options for LVAD patients who develop RHF. While significant effort has been made to create algorithms aimed at stratifying risk for RHF in patients undergoing LVAD implantation, the predictive value of these algorithms has been limited, especially when attempts at external validation have been undertaken. Perhaps one of the reasons for poor performance in external validation is related to differing definitions of RHF in external cohorts. Additionally, most research in this field has focused on RHF occurring in the early phase (i.e., ≤1 month) post LVAD implantation. However, there is emerging recognition of late-onset RHF (i.e., > 1 month post-surgery) as a significant cause of morbidity and mortality. Late-onset RHF, which likely has a unique physiology and pathogenic mechanisms, remains poorly characterized. In this review of the literature, we will describe the unique right ventricular physiology and changes elicited by LVADs that might cause both early- and late-onset RHF. Finally, we will analyze the currently available treatments for RHF, including mechanical circulatory support options and medical therapies.

Characterization and Development of Universal Ventricular Assist Device: Computational Fluid Dynamics Analysis of Advanced Design

We are developing a universal, advanced ventricular assist device (AVAD) with automatic pressure regulation suitable for both left and right ventricular support. The primary goal of this computational fluid dynamics (CFD) study was to analyze the biventricular performance of the AVAD across its wide range of operating conditions. An AVAD CFD model was created and validated using in vitro hydraulic performance measurements taken over conditions spanning both left ventricular assist device (LVAD) and right ventricular assist device (RVAD) operation. Static pressure taps, placed throughout the pump, were used to validate the CFD results. The CFD model was then used to assess the change in hydraulic performance with varying rotor axial positions and identify potential design improvements. The hydraulic performance was simulated and measured at rotor speeds from 2,300 to 3,600 revolutions/min and flow rates from 2.0 to 8.0 L/min. The CFD-predicted hydraulic pressure rise agreed well with the in vitro measured data, within 6.5% at 2300 rpm and within 3.5% for the higher rotor speeds. The CFD successfully predicted wall static pressures, matching experimental values within 7%. High degree of similarity and circumferential uniformity in the pump's flow fields were observed over the pump operation as an LVAD and an RVAD. A secondary impeller axial clearance reduction resulted in a 10% decrease in peak flow residence time and lower static pressures on the secondary impeller. These lower static pressures suggest a reduction in the upwards rotor forces from the secondary impeller and a desired increase in the pressure sensitivity of the pump. The CFD analyses supported the feasibility of the proposed AVAD's use as an LVAD or an RVAD, over a wide range of operating conditions. The CFD results demonstrated the operability of the pump in providing the desired circumferential flow similarity over the intended range of flow/speed conditions and the intended functionality of the AVAD's automated pressure regulation.

Outcomes of Ambulatory Heart Failure Patients Managed With an Intra-aortic Balloon Pump Before Left Ventricular Assist Device Implantation

Patients are admitted to the hospital for hemodynamic optimization before left ventricular assist device (LVAD) implantation. The aim of this study was to evaluate the clinical outcomes of hemodynamic optimization using an intra-aortic balloon pump (IABP) in ambulatory heart failure patients before LVAD placement. This retrospective single-center study included 199 noninotrope-dependent patients who underwent durable LVAD implantation between January 1, 2007 and April 10, 2017. Invasive hemodynamic as well as the primary composite end-point of stage 2 or 3 acute kidney injury, right ventricular failure, and 30-day mortality were compared between patients with and without an IABP. Median age was 64 (interquartile range [IQR], 57-71) years and 165 (82.9%) were male; 72 (36.2%) received an IABP. Patients treated with an IABP had worse baseline exercise capacity and hemodynamic parameters. Patients with an IABP had greater relative reduction in pulmonary artery mean pressure (-16% vs. -2%; p ≤ 0.001). The primary composite end-point was not different between patients who had an IABP and those who did not (20.8% vs. 20.5%; p = 0.952), as were each of the individual end-points. Despite worse baseline hemodynamic parameters and exercise capacity, ambulatory heart failure patients who received an IABP before LVAD implantation had more favorable reductions in pulmonary artery pressures without an increase in the composite end-point. These results suggest that IABP use before LVAD implantation may mitigate the risk of postoperative complications in ambulatory patients.

Impact of tricuspid regurgitation on late right ventricular failure in left ventricular assist device patients ~can prophylactic tricuspid annuloplasty prevent late right ventricular failure? ~

BACKGROUND

In this study, we evaluated the prevalence of tricuspid regurgitation (TR) worsening in patients with left ventricular assist devices (LVADs) and its impact on late right ventricular (RV) failure.

METHODS

We enrolled 147 patients of the 184 patients who underwent continuous-flow LVAD implantations from 2005 to March 2018. The prevalence of postoperative TR worsening and late RV failure were retrospectively evaluated.

RESULTS

Concomitant tricuspid annuloplasty (TAP) was performed in 28 of 41 patients (68%) with preoperative TR greater than or equal to moderate (TR group) and in 23 of 106 patients (22%) with preoperative TR less than or equal to mild (non-TR group). Regarding the TR-free rates, despite receiving or not receiving concomitant TAP, there was no significant difference between the 2 groups (TR group: p = 0.37; non-TR group: p = 0.42). Of the 9 patients with postoperative TR greater than or equal to moderate, late RV failure developed in 3 patients, with TR worsening after RV failure in each case. During follow-up, 16 patients (11%) had late RV failure. As for the late RV failure-free rates, despite receiving or not receiving concomitant TAP, there was no significant difference between the 2 groups (TR group: p = 0.37; non-TR group: p = 0.96).

CONCLUSIONS

TR prognosis was preferable regardless of a patient receiving concomitant TAP; however, the presence of postoperative TR seemed to unrelated to late RV failure. Prophylactic TAP might not be necessary to prevent late RV failure.

Dynamic Assessment of Pulmonary Artery Pulsatility Index Provides Incremental Risk Assessment for Early Right Ventricular Failure After Left Ventricular Assist Device

BACKGROUND

The pulmonary artery pulsatility index (PAPi) has been studied to predict right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation, but only as a single time point before LVAD implantation. Multiple clinical factors and therapies impact RV function in pre-LVAD patients. Thus, we hypothesized that serial PAPi measurements during cardiac intensive care unit (CICU) optimization before LVAD implantation would provide incremental risk stratification for early RVF after LVAD implantation.

METHODS AND RESULTS

Consecutive patients who underwent sequential pulmonary artery catherization with cardiac intensive care optimization before durable LVAD implantation were included. Serial hemodynamics were reviewed retrospectively across the optimization period. The optimal PAPi was defined by the initial PAPi + the PAPi at optimized hemodynamics. RVF was defined as need for a right ventricular assist device or prolonged inotrope use (>14 days postoperatively). Patients with early RVF had significantly lower mean optimal PAPi (3.5 vs 7.5, P < .001) compared with those who did not develop RVF. After adjusting for established risk factors of early RVF after LVAD implantation, the optimal PAPi was independently and incrementally associated with early RVF after LVAD implantation (odds ratio 0.64, 95% confidence interval 0.532-0.765, P < .0001).

CONCLUSIONS

Optimal PAPi achieved during medical optimization before LVAD implantation provides independent and incremental risk stratification for early RVF, likely identifying dynamic RV reserve.

Right ventricular failure after left ventricular assist device implantation: a review of the literature

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation remains a major complication which may significantly impair patient outcome. The genesis of RVF is, however, multifactorial, and the mechanisms underlying such a condition have not been fully elucidated, making its prevention challenging and the course not always predictable. Although preoperative risks factors can be associated with RV impairment, the physiologic changes after the LV support, can still hamper the function of the RV. Current medical treatment options are limited and sometimes, patients with a severe post-LVAD RVF may be unresponsive to pharmacological therapy and require more aggressive treatment, such as temporary RV support. We retrieved 11 publications which we assessed and divided in groups based on the RV support [extracorporeal membrane oxygenation (ECMO), right ventricular assist device (RVAD), TandemHeart with ProtekDuo cannula]. The current review comprehensively summarizes the main studies of the literature with particular attention to the RV physiology and its changes after the LVAD implantation, the predictors and prognostic score as well as the different modalities of temporary mechanical cardio-circulatory support, and its effects on patient prognosis for RVF in such a setting. In addition, it provides a decision making of the pre-, intra and post-operative management in high- and moderate- risk patients.

Impact of right ventricular stroke work index on predicting hospital readmission and functional status of patients with advanced heart failure

INTRODUCTION AND AIMS

The prognosis of chronic heart failure with reduced ejection fraction (HFrEF) has been studied extensively, but factors predicting cardiac decompensation are poorly defined. Right ventricular stroke work index (RVSWI), an invasive measure of right ventricular (RV) systolic function, is a well-known prognostic marker of RV failure after left ventricular assist device insertion and after lung transplantation. Thus, the aim of this study was to assess whether there is a relationship between RVSWI, HFrEF hospital readmission due to cardiac decompensation, and prognosis.

METHODS

We prospectively enrolled 132 consecutive patients with HFrEF. Right heart catheterization was performed and RVSWI values were calculated in all patients. The relationship between RVSWI values and readmission and prognosis was analyzed.

RESULTS

During a median follow-up of 20±7 months, 33 patients were readmitted due to cardiac decompensation in the survivor group, and 18 patients died due to cardiac causes. There was no difference between patients who died and survived in terms of RVSWI values. Among patients with decompensation, mean RVSWI was significantly lower than in patients with stable HFrEF (6.0±2.2 g/m²/beat vs. 8.8±3.5 g/m²/beat, p<0.001). On correlation analysis, RVSWI was negatively correlated with NYHA functional class. RVSWI was also identified as an independent risk factor for cardiac decompensation in Cox regression survival analysis.

CONCLUSIONS

We showed that RVSWI predicts cardiac decompensation and correlates with functional class in advanced stage HFrEF. Our data suggest the value of combining information on right heart hemodynamics with assessment of RV function when defining the risk of patients with advanced HFrEF.

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.

Total artificial heart: surgical technique in the patient with normal cardiac anatomy

Heart failure is a complex, growing problem with significant morbidity and mortality. Though heart transplantation remains the gold standard treatment for end-stage heart failure, there remains a national shortage of donor hearts. Mechanical circulatory support has provided an additional option for clinicians to support patients for the purposes of bridging patients to transplantation or to be used for destination therapy purposes. Despite generally favorable outcomes with univentricular support, in a subset of patients with biventricular heart failure, an isolated left ventricular assist device is not sufficient. Right ventricular failure has a negative impact on patient survival if not identified and treated promptly. The Total Artificial Heart (TAH) is the only Food and Drug Administration (FDA) approved artificial heart used for bridging patients to transplantation. Outcomes in patients who undergo implantation of the TAH at experienced centers have been good and reproducible.

Right ventricle failure in patients treated with left ventricular assist device

This review article aim to highlight the right ventricular function peri left ventricular assist device implantation, and to assess the incidence, physiopathology, predictors, management and prognosis, of right ventricular failure post-implant.

Usefulness of right ventricular contraction pressure index to predict short-term mortality and right heart failure in patients who underwent continuous-flow left ventricular assist device implantation

Background:

Right ventricular stroke work index is a useful but invasively measured parameter that can be used to predict right heart failure following continuous-flow left ventricular assist device implantation. Right ventricular contraction pressure index is a novel parameter that was developed to measure right ventricular stroke work index with echocardiography. We aimed to investigate the clinical usefulness of right ventricular contraction pressure index to predict short-term mortality and right heart failure in patients who underwent continuous-flow left ventricular assist device implantation.

Methods:

A total of 49 patients who participated in institutional advanced heart failure registry and underwent continuous-flow left ventricular assist device implantation with a bridge-to-candidacy indication were analyzed retrospectively. Right ventricular contraction pressure index was calculated using offline measurements. Demographic, clinical and outcome data were obtained from the registry data. Patients were grouped according to right ventricular contraction pressure index quartiles.

Results:

Patients within the lowest right ventricular contraction pressure index quartile had a trend toward higher short-term mortality (46.2%, p = 0.056) and combined short-term mortality and definitive right heart failure (53.8%, p = 0.054) at 15th day postoperatively. Similarly, short-term survival or survival free of definite right heart failure were significantly lower in the lowest right ventricular contraction pressure index quartile (log-rank p = 0.045 and log-rank p = 0.03, respectively). In a proportional hazards model that included echocardiographic parameters, right ventricular contraction pressure index was an independent predictor for short-term mortality (odds ratio: 6.777, 95% confidence interval: 1.118–41.098, p = 0.037), but not for combined short-term mortality and definite right heart failure. No such associations were found for long-term mortality. Right ventricular contraction pressure index had a statistically significant correlation with invasively measured pulmonary capillary wedge pressure, pulmonary vascular resistance, mean pulmonary pressure, and right ventricular stroke work index.

Conclusion:

Right ventricular contraction pressure index was found as a useful parameter for determining short-term postoperative mortality in patients undergoing continuous-flow left ventricular assist device implantation.

Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association

Background and Purpose:

The diverse causes of right-sided heart failure (RHF) include, among others, primary cardiomyopathies with right ventricular (RV) involvement, RV ischemia and infarction, volume loading caused by cardiac lesions associated with congenital heart disease and valvular pathologies, and pressure loading resulting from pulmonic stenosis or pulmonary hypertension from a variety of causes, including left-sided heart disease. Progressive RV dysfunction in these disease states is associated with increased morbidity and mortality. The purpose of this scientific statement is to provide guidance on the assessment and management of RHF.

Methods:

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through September 2017. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or reference to contemporary clinical practice recommendations.

Results:

Chronic RHF is associated with decreased exercise tolerance, poor functional capacity, decreased cardiac output and progressive end-organ damage (caused by a combination of end-organ venous congestion and underperfusion), and cachexia resulting from poor absorption of nutrients, as well as a systemic proinflammatory state. It is the principal cause of death in patients with pulmonary arterial hypertension. Similarly, acute RHF is associated with hemodynamic instability and is the primary cause of death in patients presenting with massive pulmonary embolism, RV myocardial infarction, and postcardiotomy shock associated with cardiac surgery. Functional assessment of the right side of the heart can be hindered by its complex geometry. Multiple hemodynamic and biochemical markers are associated with worsening RHF and can serve to guide clinical assessment and therapeutic decision making. Pharmacological and mechanical interventions targeting isolated acute and chronic RHF have not been well investigated. Specific therapies promoting stabilization and recovery of RV function are lacking.

Conclusions:

RHF is a complex syndrome including diverse causes, pathways, and pathological processes. In this scientific statement, we review the causes and epidemiology of RV dysfunction and the pathophysiology of acute and chronic RHF and provide guidance for the management of the associated conditions leading to and caused by RHF.

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.

Short- and long-term mechanical cardiac assistance

With the increase in high risk patients undergoing cardiac surgery and the substantial mortality among patients waiting for cardiac transplantation, the need for mechanical circulatory support is growing. Several devices are currently available, ranging from the intra-aortic balloon pump to fully implantable ventricular assist devices. Each system has its own features, and proper patient selection as well as the timing of implantation is sometimes difficult. Algorithms for stepwise management in subgroups of patients remain controversial and the concepts of weaning patients after myocardial recovery during mechanical circulatory support need further evaluation for their long-term effects. Future identification of valuable prognostic and risk factors may help in decision-making and allow for improved survival of these often very ill patients. In this report we review the concepts of mechanical circulatory support at our institution with emphasis on a detailed overview of technical features of extracorporeal life support.

Frequency and Consequences of Right-Sided Heart Failure After Continuous-Flow Left Ventricular Assist Device Implantation

Postoperative right-sided heart failure (RHF) is a common complication after continuous-flow left ventricular assist device implantation. Studies have examined RHF in the perioperative period, but few have assessed late-onset RHF. We analyzed the incidence of early and late RHF in patients with HeartMate II and HeartWare left ventricular assist devices and associated morbidity, mortality, and independent predictors of RHF. We retrospectively analyzed records of 526 patients with chronic heart failure who underwent continuous-flow left ventricular assist device implantation; 147 (27.9%) developed RHF (early RHF, n = 87, 16.5%; late RHF, n = 74, 14.4%). We examined demographics, postoperative complications, and long-term survival rate. Patients with RHF or late RHF had higher mortality (p <0.001) than those without RHF. Patients with RHF had a higher incidence of acute kidney injury (20.4% vs 11.9%, p = 0.01). Device type did not affect the incidence of early, late, or overall RHF. Patients with severe RHF requiring right ventricular assist device support had a low success of bridge to transplantation (11.1% vs 33.3%, p = 0.02). In Cox regression models, RHF was an independent predictor of mortality (hazard ratio = 1.69, 95% confidence interval = 1.28 to 2.22, p <0.001), but no predictive variables of RHF were identified. RHF was significantly associated with increased mortality and a higher incidence of postoperative acute kidney injury. RHF decreased the success rate of bridging patients to transplantation when a right ventricular assist device was required.

Treatment and Prognosis of Pulmonary Hypertension in the Left Ventricular Assist Device Patient

This review will discuss the medical management of pulmonary hypertension in patients with left ventricular assist devices. Although much has been written on the management of primary pulmonary hypertension, also called pulmonary arterial hypertension, this review will instead focus on the treatment of pulmonary hypertension secondary to left heart disease. The relevant pharmacotherapy can be divided into medications for treating heart failure, such as diuretics and β-blockers, and medications for treating pulmonary hypertension. We also discuss important preoperative considerations in patients with pulmonary hypertension; the relationships between left ventricular assist devices, pulmonary hemodynamics, and right heart failure; as well as optimal perioperative and long-term postoperative medical management of pulmonary hypertension.

Perioperative Care of the Patient With the Total Artificial Heart

Advanced heart failure continues to be a leading cause of morbidity and mortality despite improvements in pharmacologic therapy. High demand for cardiac transplantation and shortage of donor organs have led to an increase in the utilization of mechanical circulatory support devices. The total artificial heart is an effective biventricular assist device that may be used as a bridge to transplant and that is being studied for destination therapy. This review discusses the history, indications, and perioperative management of the total artificial heart with emphasis on the postoperative concerns.

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

In patients with end-stage left ventricular (LV) heart failure who receive LV assist device (LVAD) implantation, right ventricular (RV) failure represents a possible critical complication that heavily affects morbidity and mortality. Several clinical, laboratory, hemodynamic, and echocardiographic variables have been found to be associated with RV failure occurrence after surgery. Different models and risk scores have been proposed, with poor results. No accordance has ever been reached about RV pre-operative evaluation, and time has come to introduce a standardized systematic protocol for LVAD suitability assessment according to RV function. We analyzed imaging parameters associated with LVAD implantation-related RV failure, in order to identify the minimum number for pre-operative reliable prediction of post-operative RV failure. A few echocardiographic parameters have been identified as the most reliable, or promising, and reproducible tools in this field: free-wall RV longitudinal strain, RV fractional area change, RV sphericity index, and RV ejection fraction with 3D-echocardiography. We propose the Systematic LVAD Implant Eligibility with Non-invasive Assessment protocol–the SIENA protocol–as a new and simple way of pre-operative evaluation of patients candidates to LVAD implantation.

Does Gender Influence the Likelihood or Types of Complications Following Cardiac Surgery?

Over 410,000 cardiac surgeries are performed in American women each year. Women having coronary artery bypass graft (CABG) and valve surgery do so at an older age and with more cardiovascular risk factors than men. Women's smaller body size may also increase risk by increasing the technical difficulty of surgical procedures. Female CABG patients appear to have higher perioperative mortality and cardiac morbidity, although studies of neurologic outcomes in female CABG patients have produced equivocal findings. Women undergoing CABG tend to consume more hospital resources than men do in terms of blood transfusion, mechanical ventilation, and length of intensive care unit and overall hospital stay. With regard to valve surgery, women appear to have worse outcomes than men if the surgery is combined with a CABG operation. Women and men undergoing isolated aortic valve surgery have similar mortality, but little is known about gender differences in mitral and tricuspid valve surgery outcomes. Women who require heart transplantation tend to have idiopathic cardiomyopathy rather than the ischemic cardiomyopathy that is more common in male heart transplant candidates. Although female heart transplant recipients seem to have a stronger immunologic response after transplantation, which manifests in more frequent acute rejection episodes, it is not clear whether this increases women's mortality risk. Men appear to have a greater incidence of posttransplant vasculopathy than women. Further research is needed to identify risk factors for perioperative morbidity and mortality in women undergoing cardiac surgery and to develop medical interventions to mitigate these risks.

Current Status of Mechanical Circulatory Assistance

Mechanical circulatory support has become an increasingly used management strategy for patients with both acute and chronic ventricular failure. This article briefly reviews the current state of mechanical circulatory support with a focus on indications, contraindications, and complications of currently available devices. Perioperative considerations for ventricular assist device implantation are discussed, including the decision-making process underlying the use of univentricular versus biventricular support, specific anesthetic considerations, and the role of transesophageal echocardiography where ventricular assist devices are concerned. The anesthetic considerations for the patient already supported by a ventricular assist device presenting for noncardiac surgery are also reviewed. The work concludes with a discussion of the rationale behind the next generation of continuous flow devices currently in human clinical trials.

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.