Right Ventricular Failure Post-Implantation of Left Ventricular Assist Device: Prevalence, Pathophysiology, and Predictors

Acute right ventricular geometric change predicts outcomes in HeartMate 3 patients

BACKGROUND

The physiological response of the right ventricle (RV) following left ventricular assist device (LVAD) implantation is difficult to predict. We aimed to investigate RV geometric and functional changes after LVAD insertion and their effects on clinical outcomes.

METHODS

We retrospectively reviewed 188 patients who underwent HeartMate 3 implantation at our center between November 2014 and September 2021. The RV end-diastolic diameter (RVEDD) and RV end-diastolic area (RVEDA) were measured on preoperative and predischarge transthoracic echocardiography. The nonadapted group included patients with increased RVEDD and RVEDA at discharge. The composite outcome was defined as death or readmission due to worsening right heart failure.

RESULTS

There were 82 patients (44%) who had a nonadapted and 106 patients (56%) who had an adapted RV. Preoperatively, the nonadapted group had smaller RVEDD (46 vs 49 mm, p < 0.001) and RVEDA (27 vs 31 cm2, p < 0.001). At discharge, the nonadapted group had larger RVEDD (51 vs 43 mm, p < 0.001) and RVEDA (33 vs 27 cm2, p < 0.001). Kaplan-Meier analysis demonstrated worse 3-year survival (77% vs 91%, p = 0.006) and freedom from composite outcome (58% vs 85%, p < 0.001) in the nonadapted group. A multivariable Cox proportional hazards model showed that nonadaption (hazard ratio [HR] 3.09, 95% confidence interval [CI] 1.29-7.40, p = 0.01) and age (HR 3.73, 95% CI 1.42-9.77, p = 0.007) were independent predictors of composite outcome.

CONCLUSIONS

Acute RV dimensional changes after LVAD insertion may represent intrinsic RV function and may be a useful prognostic marker.

Occult right ventricular dysfunction and right ventricular-vascular uncoupling in left ventricular assist device recipients

BACKGROUND

Detecting right heart failure post left ventricular assist device (LVAD) is challenging. Sensitive pressure-volume loop assessments of right ventricle (RV) contractility may improve our appreciation of post-LVAD RV dysfunction.

METHODS

Thirteen LVAD patients and 20 reference (non-LVAD) subjects underwent comparison of echocardiographic, right heart cath hemodynamic, and pressure-volume loop-derived assessments of RV contractility using end-systolic elastance (Ees), RV afterload by effective arterial elastance (Ea), and RV-pulmonary arterial coupling (ratio of Ees/Ea).

RESULTS

LVAD patients had lower RV Ees (0.20 ± 0.08 vs 0.30 ± 0.15 mm Hg/ml, p = 0.01) and lower RV Ees/Ea (0.37 ± 0.14 vs 1.20 ± 0.54, p < 0.001) versus reference subjects. Low RV Ees correlated with reduced RV septal strain, an indicator of septal contractility, in both the entire cohort (r = 0.68, p = 0.004) as well as the LVAD cohort itself (r = 0.78, p = 0.02). LVAD recipients with low RV Ees/Ea (below the median value) demonstrated more clinical heart failure (71% vs 17%, p = 0.048), driven by an inability to augment RV Ees (0.22 ± 0.11 vs 0.19 ± 0.02 mm Hg/ml, p = 0.95) to accommodate higher RV Ea (0.82 ± 0.38 vs 0.39 ± 0.08 mm Hg/ml, p = 0.002). Pulmonary artery pulsatility index (PAPi) best identified low baseline RV Ees/Ea (≤0.35) in LVAD patients ((area under the curve) AUC = 0.80); during the ramp study, change in PAPi also correlated with change in RV Ees/Ea (r = 0.58, p = 0.04).

CONCLUSIONS

LVAD patients demonstrate occult intrinsic RV dysfunction. In the setting of excess RV afterload, LVAD patients lack the RV contractile reserve to maintain ventriculo-vascular coupling. Depression in RV contractility may be related to LVAD left ventricular unloading, which reduces septal contractility.

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.

Impact of Interventricular Interaction on Ventricular Function: Insights From Right Ventricular Pressure-Volume Analysis

BACKGROUND

Interventricular interactions may be responsible for the decline in ventricular performance observed in various disease states that primarily affect the contralateral ventricle.

OBJECTIVES

This study sought to quantify the impact of such interactions on right ventricular (RV) size and function using clinically stable individuals with left ventricular assist devices (LVADs) as a model for assessing RV hemodynamics while LV loading conditions were acutely manipulated by changing device speed during hemodynamic optimization studies (ie, ramp tests).

METHODS

The investigators recorded RV pressure-volume loops with a conductance catheter at various speeds during ramp tests in 20 clinically stable HeartMate3 recipients.

RESULTS

With faster LVAD speeds and greater LV unloading, indexed RV end-diastolic volume increased (72.28 ± 15.07 mL at low speed vs 75.95 ± 16.90 at high speed; P = 0.04) whereas indexed end-systolic volumes remained neutral. This resulted in larger RV stroke volumes and shallower end-diastolic pressure-volume relationships. Concurrently, RV end-systolic pressure decreased (31.58 ± 9.75 mL at low speed vs 29.58 ± 9.41 mL at high speed; P = 0.02), but contractility, as measured by end-systolic elastance, did not change significantly. The reduction in RV end-systolic pressure was associated with a reduction in effective arterial elastance from 0.65 ± 0.43 mm Hg/mL at low speed to 0.54 ± 0.33 mm Hg/mL at high speed (P = 0.02).

CONCLUSIONS

Interventricular interactions resulted in improved RV compliance, diminished afterload, and did not reduce RV contractility. These data challenge the prevailing view that interventricular interactions compromise RV function, which has important implications for the understanding of RV-LV interactions in various disease states, including post-LVAD RV dysfunction.

A case of progressive right ventricular failure with ventricular arrhythmia and aortic insufficiency after implantable left ventricular assist device implantation

Right ventricular failure (RVF) is a serious complication after left ventricular assist device (LVAD) implantation. In this report, a case of RVF that developed over two years after LVAD implantation is presented. The patient was a 12-year-old male with dilated phase of hypertrophic cardiomyopathy. He had no risk factors for early or late-onset RVF. However, his right ventricular function worsened after he developed ventricular arrhythmia (VA), and right ventricular dysfunction became exacerbated with an increasing frequency of VAs. He also developed moderate aortic insufficiency (AI), which became severe. Two years after implantation, he was admitted for treatment of recurrent ventricular tachycardia and became inotropic-dependent during hospitalization. Finally, he underwent successful heart transplantation 2 years and 9 months after LVAD implantation. This case suggests that vicious cycle of RV dysfunction, recurrent VAs and severe AI could lead to RVF in patients without known risk factors for RVF, even long after LVAD implantation.

Learning objective

This report shows a progressive right ventricular failure (RVF) two years after left ventricular assist device (LVAD) implantation. Although the patient had no known risk factor, vicious circle of RV dysfunction, ventricular arrhythmias (VAs) and aortic insufficiency (AI) lead to RVF. Patients with LVAD as destination therapy will increase and require long-term LVAD management. We should recognize that these patients could develop RVF even years after LVAD implantation in association with VAs and AI.

Does lateral approach preserve the right ventricular function after HeartMate 3 insertion?

OBJECTIVES

Lateral thoracotomy (LT) approach may preserve the right ventricular (RV) function after left ventricular assist device (LVAD) implantation. This study evaluated the short- and long-term RV function using echocardiography after LVAD implantation via LT or median sternotomy (sternotomy).

METHODS

The patients who underwent HeartMate 3 implantation were retrospectively reviewed. The RV function was assessed before and 1 month and 1 year after LVAD implantation. The primary and secondary outcomes were all-cause mortality and a composite of death or readmission due to RV failure, respectively.

RESULTS

Of the 195 patients, 55 (28%) underwent LT and 140 (72%) underwent sternotomy. There were no significant differences in the preoperative RV geometry or function. One month after the LVAD implantation, the LT group had a smaller RV end-diastolic dimension [42 (29-48) vs 47 (42-52) mm; P = 0.003] and RV end-diastolic area [25 (21-28) vs 29 (24-36) cm2; P < 0.001] and a greater RV fractional area change [30 (25-34)% vs 28 (23-31)%; P = 0.04] and peak systolic tissue velocity [8 (7-9) vs 7 (6-8) cm/s; P = 0.01]. Twenty-four patients died and 46 met the composite end point. Kaplan-Meier curve analysis did not reveal significant differences between LT and sternotomy in the 2-year survival (93% vs 83%; log-rank test, P = 0.28) and adverse event rate (76% vs 71%; log-rank test, P = 0.65).

CONCLUSIONS

LT approach yielded a better-preserved RV function at 1 month; however, there were no significant differences in the 2-year survival and adverse event rates.

Postoperative care after left ventricular assist device implantation: considerations for the cardiac surgical intensivist

Heart failure is a leading cause of morbidity and mortality, the incidence of which is predicted to continue to increase as the population ages. Left ventricular assist devices (LVADs) in particular have emerged as important therapies for the support of patients with advanced heart failure needing short- or long-term mechanical circulatory support. With over 5000 implantations per year, LVADs are the most commonly used durable devices worldwide. In this article, we provide an overview of the intensive care management of patients with LVADs during the early post-implantation period.

Rescuing the right ventricle: A conceptual framework to target new interventions for patients receiving a durable left ventricular assist device

Despite significant advances in durable LVAD technology, right heart failure remains a morbid and fatal condition that is difficult to predict, prevent, and successfully treat.

HFSA Expert Consensus Statement on the Medical Management of Patients on Durable Mechanical Circulatory Support

The medical management of patients supported with durable continuous flow left ventricular assist device (LVAD) support encompasses pharmacologic therapies administered in the preoperative, intraoperative, postoperative and chronic LVAD support stages. As patients live longer on LVAD support, the risks of LVAD-related complications and progression of cardiovascular and other diseases increase. Using existing data from cohort studies, registries, randomized trials and expert opinion, this Heart Failure Society of America Consensus Document on the Medical Management of Patients on Durable Mechanical Circulatory Support offers best practices on the management of patients on durable MCS, focusing on pharmacological therapies administered to patients on continuous flow LVADs. While quality data in the LVAD population are few, the utilization of guideline directed heart failure medical therapies (GDMT) and the importance of blood pressure management, right ventricular preload and afterload optimization, and antiplatelet and anticoagulation regimens are discussed. Recommended pharmacologic regimens used to mitigate or treat common complications encountered during LVAD support, including arrhythmias, vasoplegia, mucocutaneous bleeding, and infectious complications are addressed. Finally, this document touches on important potential pharmacological interactions from anti-depressants, herbal and nutritional supplements of relevance to providers of patients on LVAD support.

Differentiated impact of pulmonary hypertension on outcome after left ventricular assist device implantation and tricuspid valve repair

The present study aimed to investigate the impact of pulmonary hypertension (PH) on short-term survival after LVAD implantation with or without tricuspid annuloplasty valve repair (TVr) performed to treat regurgitation and avoid RV-failure post-LVAD insertion. Data of 24 patients receiving LVAD-implantation are assessed and compared. The primary outcome is in-hospital survival. Of 24 patients studied, 17 (70.8%) survived hospital stay: age (62.2 ± 12.3 vs 66.1 ± 8.5 years), preoperative LV-EF (15.9 ± 5.3% vs 13.6 ± 3.8%) vs. non-survivors, respectively. Survivors received preoperatively Impella (35.3% vs 0%, p = 0.037), had shorter intubation time (3.3 ± 3.5 vs 11.4 ± 11.1 days, p = 0.0053) and ICU stay (12.4 ± 9.8 vs 34.3 ± 34 days, p = 0.01) versus non-survivors. Non-survivors had more severe PH (37.0 ± 9.6 vs 29.8 ± 12.2 mmHg, p = 0.044) than survivors. Linear regression analysis revealed that cardiac operations performed concomitant with LVAD implantation increased mortality in patients with severe PH (p = 0.04), whereas isolated TVr performed concomitant with LVAD implantation did not increase mortality neither in the entire patient cohort (p = 0.569) nor in patients with severe PH (p = 0.433). LVAD with TVr improved survival in patients suffering from severe PH (vs. moderate PH), however this difference did not reach the level of significance due to the small number of patients (p = 0.08). LVAD-implantation alone improved survival of patients suffering from moderate PH (p = 0.045, vs. severe PH). Surgical correction of tricuspid regurgitation concomitant or before LVAD implantation improves early survival in patients suffering from severe PH when compared to LVAD implantation alone. Patients suffering from severe PH tend to benefit more from TVr than those suffering from moderate PH.

Hyponatremia Is a Powerful Predictor of Poor Prognosis in Left Ventricular Assist Device Patients

Serum sodium is an established prognostic marker in heart failure (HF) patients and is associated with an increased risk of morbidity and mortality. We sought to study the prognostic value of serum sodium in left ventricular assist device (LVAD) patients and whether hyponatremia reflects worsening HF or an alternative mechanism. We identified HF patients that underwent LVAD implantation between 2008 and 2019. Hyponatremia was defined as Na ≤134 mEq/L at 3 months after implantation. We assessed for differences in hyponatremia before and after LVAD implantation. We also evaluated the association of hyponatremia with all-cause mortality and recurrent HF hospitalizations. There were 342 eligible LVAD patients with a sodium value at 3 months. Among them, there was a significant improvement in serum sodium after LVAD implantation compared to preoperatively (137.2 vs. 134.7 mEq/L, P < 0.0001). Patients with and without hyponatremia had no significant differences in echocardiographic and hemodynamic measurements. In a multivariate analysis, hyponatremia was associated with a markedly increased risk of all-cause mortality (HR 3.69, 95% CI, 1.93-7.05, P < 0.001) when accounting for age, gender, co-morbidities, use of loop diuretics, and B-type natriuretic peptide levels. Hyponatremia was also significantly associated with recurrent HF hospitalizations (HR 2.11, 95% CI, 1.02-4.37, P = 0.04). Hyponatremia in LVAD patients is associated with significantly higher risk of all-cause mortality and recurrent HF hospitalizations. Hyponatremia may be a marker of ongoing neurohormonal activation that is more sensitive than other lab values, echocardiography parameters, and hemodynamic measurements.

Key questions about aortic insufficiency in patients with durable left ventricular assist devices

The development of the latest generation of durable left ventricular assist devices (LVAD) drastically decreased adverse events such as pump thrombosis or disabling strokes. However, time-related complications such as aortic insufficiency (AI) continue to impair outcomes following durable LVAD implantation, especially in the context of long-term therapy. Up to one-quarter of patients with durable LVAD develop moderate or severe AI at 1 year and its incidence increases with the duration of support. The continuous regurgitant flow within the left ventricle can compromise left ventricular unloading, increase filling pressures, decrease forward flow and can thus lead to organ hypoperfusion and heart failure. This review aims to give an overview of the epidemiology, pathophysiology, and clinical consequences of AI in patients with durable LVAD.

Impact of Pre-Operative Right Ventricular Response to Hemodynamic Optimization on Outcomes in Patients with LVADs

Background: Right ventricular failure (RVF) continues to affect patients supported with durable left ventricular assist devices (LVAD) and results in increased morbidity and mortality. Information regarding the impact of right ventricular response to pre-operative optimization on outcomes is scarce. Methods: Single-center retrospective analysis of consecutive patients who underwent first continuous flow LVAD implantation between 2006 and 2020. Patients with bi-ventricular support before LVAD or without hemodynamic data were excluded. Invasive hemodynamics at baseline and after pre-operative medical and/or temporary circulatory support were recorded. Patients were grouped in the following categories: A: No Hemodynamic RV dysfunction (RVD) at baseline; B: RVD with achievement of RV hemodynamic optimization goals; C: RVD without achievement of RV optimization goals. The main outcomes were right ventricular failure defined as inotropes >14 days after implantation, or postoperative right ventricular mechanical support, and all-cause mortality. Results: Overall, 128 patients were included in the study. The mean age was 58 ±12.5 years, 74.2% were males and, 68.7% had non-ischemic cardiomyopathy. Hemodynamic RVD was present in 70 (54.7%) of the patients at baseline. RV hemodynamic goals were achieved in 46 (79.31%) patients with RVD and in all the patients without RVD at baseline. Failure to achieve hemodynamic optimization goals was associated with a significantly higher risk of RVF after LVAD implantation (adjusted OR 4.37, 95% CI 1.14−16.76, p = 0.031) compared with no RVD at baseline and increased 1-year mortality compared with no RVD (adjusted HR 4.1, 95% CI 1.24−13.2, p = 0.02) and optimized RVD (adjusted HR 6.4, 95% CI 1.6−25.2, p = 0.008).Conclusion: Among patients with RVD, the inability to achieve hemodynamic optimization goals was associated with higher rates of RV failure and increased 1-year all-cause mortality post LVAD implantation.

Effect of levosimendan infusion prior to left ventricular assist device implantation on right ventricular failure

Objective

Investigate the safety and efficacy of preoperative levosimendan in patients undergoing left ventricular assist device (LVAD) implantation.

Methods

Consecutive patients who received LVADs (HeartMate-2, 3, HVAD) in a single tertiary medical center (2012–2018). INTERMACS profile 1 patients were excluded. The primary outcome was post-LVAD right ventricular failure (RVF) and inhospital mortality rates. The secondary outcomes included other clinical, echocardiographic and hemodynamic parameters at follow-up.

Results

Final cohort consisted of 62 patients (40[65%] in the levosimendan group and 22[35%] in the no-levosimendan group). Post-operative RVF rate and inotrope or ventilation support time were similar in the levosimendan and no-levosimendan groups (7.5% vs. 13.6%; P = 0.43, median of 51 vs. 72 h; P = 0.41 and 24 vs. 27 h; P = 0.19, respectively). Length of hospitalization, both total and in the intensive care unit, was not statistically significant (median days of 13 vs. 16; P = 0.34, and 3 vs. 4; P = 0.44, respectively). Post-operative laboratory and echocardiographic parameters and in-hospital complication rate did not differ between the groups, despite worse baseline clinical parameters in the Levosimendan group. There was no significant difference in the in-hospital and long term mortality rate (2.5% vs. 4.5%; P > 0.999 and 10% vs. 27.3% respectively; P = 0.64).

Conclusions

Levosimendan infusion prior to LVAD implantation was safe and associated with comparable results without significant improved post-operative outcomes, including RVF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01915-6.

Management of Hypertension in Patients With Ventricular Assist Devices: A Scientific Statement From the American Heart Association

Mechanical circulatory support with durable continuous-flow ventricular assist devices has become an important therapeutic management strategy for patients with advanced heart failure. As more patients have received these devices and the duration of support per patient has increased, the postimplantation complications have become more apparent, and the need for approaches to manage these complications has become more compelling. Continuous-flow ventricular assist devices, including axial-flow and centrifugal-flow pumps, are the most commonly used mechanical circulatory support devices. Continuous-flow ventricular assist devices and the native heart have a constant physiological interplay dependent on pump speed that affects pressure-flow relationships and patient hemodynamics. A major postimplantation complication is cerebrovascular vascular accidents. The causes of cerebrovascular vascular accidents in ventricular assist device recipients may be related to hypertension, thromboembolic events, bleeding from anticoagulation, or some combination of these. The most readily identifiable and preventable cause is hypertension. Hypertension management in these patients has been hampered by the fact that it is difficult to accurately measure blood pressure because these ventricular assist devices have continuous flow and are often not pulsatile. Mean arterial pressures have to be identified by Doppler or oscillometric cuff and treated. Although guidelines for hypertension management after ventricular assist device implantation are based largely on expert consensus and conventional wisdom, the mainstay of treatment for hypertension includes guideline-directed medical therapy for heart failure with reduced ejection fraction because this may reduce adverse effects associated with hypertension and increase the likelihood of favorable ventricular remodeling. The use of systemic anticoagulation in ventricular assist device recipients may at a given blood pressure increase the risk of stroke.

Six-month outcomes in postapproval HeartMate3 patients: A single-center US experience

BACKGROUND

The European CE Mark approval study and the MOMENTUM 3 trial demonstrated safety and a reduction in hemocompatibility-related adverse events with the use of HeartMate 3 (HM3) device. This single-center study investigated the real-world experience in HM3 patients since FDA approval.

METHODS

This retrospective, observational study included patients implanted with the HM3 LVAD as a primary implant between October 2017 and March 2020. Patients were divided into trial group and postapproval group. The primary endpoint was survival at 6 months. Secondary endpoints were adverse events including pump thrombosis (requiring pump exchange), stroke, renal failure, acute limb ischemia, re-exploratory for bleeding, gastrointestinal bleeding, right ventricular failure, and driveline infection.

RESULTS

A total of 189 patients were implanted with HM3 device during the study period. 174 patients met the inclusion criteria: 82 patients in the trial group and 92 patients in the postapproval group. The postapproval group had younger patients, higher preoperative mean international normalized ratio, and greater numbers of patients with bridge to transplant (BTT) indications, IINTERMACS profile 1, and use of mechanical assist devices (other than IABP) than the trial group. Other characteristics between the two groups were comparable. Overall survival at 6 months in the postapproval group was 93.3% versus 93.8% (p = .88). The postapproval group demonstrated a statistically significant lower incidence of re-explorative surgery for bleeding (10.9% vs. 46.3, p = .01) than the trial group.

CONCLUSION

In this single-center study, the real-world 6-month survival in the postapproval group was comparable to the trial results. Further studies are needed to monitor long-term outcomes.

Impact of Right Heart Failure on Clinical Outcome of Left Ventricular Assist Devices (LVAD) Implantation: Single Center Experience

The aim of this study was to examine the incidence and significance of right heart failure (RHF) in the early and late phase of left ventricular assist device (LVAD) implantation with the identification of predictive factors for the development of RHF. This was a prospective observational analytical cohort study. The study included 92 patients who underwent LVAD implantation and for whom all necessary clinical data from the follow-up period were available, as well as unambiguous conclusions by the heart team regarding pathologies, adverse events, and complications. Of the total number of patients, 43.5% died. The median overall survival of patients after LVAD implantation was 22 months. In the entire study population, survival rates were 88.04% at one month, 80.43% at six months, 70.65% at one year, and 61.96% at two years. Preoperative RHF was present in 24 patients, 12 of whom died and 12 survived LVAD implantation. Only two survivors developed early RHF (ERHF) and two late RHF (LRHF). The most significant predictors of ERHF development are brain natriuretic peptide (BNP), pre-surgery RHF, FAC < 20%, prior renal insufficiency, and total duration of ICU stay (HR: 1.002, 0.901, 0.858, 23.554, and 1.005, respectively). RHF following LVAD implantation is an unwanted complication with a negative impact on treatment outcome. The increased risk of fatal outcome in patients with ERHF and LRHF after LVAD implantation results in a need to identify patients at risk of RHF, in order to administer the available preventive and therapeutic methods.

Continuous-flow left ventricular assist device: Current knowledge, complications, and future directions

Long-term continuous-flow left ventricular assist devices have become a real alternative to heart transplantation in patients with advanced heart failure, achieving a promising 2-year event-free survival rate with new-generation devices. Currently, this technology has spread throughout the world, and any cardiologist or cardiac surgeon should be familiar with its fundamentals and its possible complications as well as the advances made in recent years. The aim of this review is to describe current knowledge, management of complications, and future directions of this novel heart-failure therapy.

Physiology of Continuous-Flow Left Ventricular Assist Device Therapy

The expanding use of continuous-flow left ventricular assist devices (CF-LVADs) for end-stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure-flow (H-Q) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF-LVAD therapy on right ventricular filling and function, through right-sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF-LVAD therapy has physiologic consequences for end-organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device-circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.

Mechanical Cardiac Circulatory Support: an Overview of the Challenges for the Anesthetist

Purpose of Review

Owing to increased utilization of Mechanical Circulatory Support (MCS) devices, patients with these devices frequently present for surgeries requiring anesthetic support. The current article provides basics of perioperative management of these devices.

Recent Findings

Use of extracorporeal membrane oxygenation (ECMO) and left ventricular assist devices (LVADs) are on the rise with recently updated management guidelines. Veno-venous ECMO utilization has been widely utilized as a salvage therapy during the COVID-19 pandemic.

Summary

Intra-Aortic Balloon Pumps continue to be one of the most frequently used devices after acute myocardial infarction. ECMO is utilized for pulmonary or cardiopulmonary support as salvage therapy. LVADs are used in patients with end-stage heart failure as a destination therapy or bridge to transplant. Each of these devices present with their own set of management challenges. Anesthetic management of patients with MCS devices requires a thorough understanding of underlying operating and hemodynamic principles.

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.

Continuous-flow left ventricular assist devices: Management in the emergency department

With an increasing number of left ventricular assist devices (LVADs) being placed every year, emergency clinicians are increasingly likely to encounter them in their practice. Patients may present to the emergency department (ED) with significant hemodynamic perturbations with an LVAD and it is imperative that emergency clinicians are able to assess and treat conditions contributing to low cardiac output states. This review describes the important aspects of the third generation of LVADs and their complications as well as common management approaches for the emergency physician.

Timing and Trends of Right Atrial Pressure and Risk of Right Heart Failure After Left Ventricular Assist Device Implantation

BACKGROUND

Elevated right atrial pressure (RAP) is associated with poor outcomes after left ventricular assist device (LVAD) implantation. However, the optimal time for RAP measurement and the importance of resolution of right heart congestion prior to LVAD implantation remain unclear.

METHODS AND RESULTS

We performed a retrospective cohort study of 134 consecutive LVAD recipients from our institution. Congestion was defined as RAP ≥ 14 mmHg and was assessed at hospital admission and implant. The primary outcome was death or right ventricular assist device (RVAD) implantation. When stratified by congestion status at admission, congested and non-congested patients had similar event-free survival rates (hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 0.6-2.6). However, when stratified at implant, congested patients had a higher rate death or RVAD implantation (HR: 2.5, 95% CI: 1.1-5.6). Patients were then divided into 4 groups based on their trajectory of congestion status: no congestion, resolved congestion, new congestion, or persistent congestion. Patients with no congestion and resolved congestion had similar outcomes, whereas patients with persistent congestion had a markedly increased rate of death or RVAD implantation (HR: 3.1, 95% CI: 1.3-7.6).

CONCLUSION

RAP at LVAD implantation is more strongly associated with postoperative outcomes than admission RAP. Patients not responsive to decongestive therapies, with persistently elevated RAP, represent a high-risk cohort for adverse outcomes following LVAD implantation.