Treatment Strategies and Outcomes of Right Ventricular Failure Post Left Ventricular Assist Device Implantation: An INTERMACS Analysis

Right heart failure (RHF) management after left ventricular assist device (LVAD) implantation includes inotropes, right ventricular mechanical support, and heart transplantation. The purpose of this study is to compare different RHF treatment strategies in patients with a magnetically levitated centrifugal LVAD. A total of 6,632 Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) patients from 2013 to 2020 were included. Of which, 769 (69.6%) patients (group 1) were supported with inotropes (≥14 days post-LVAD implantation), 233 (21.1%) patients (group 2) were supported with temporary right ventricular assist device (RVAD) that was implanted during LVAD implant, 77 (7.0%) patients (group 3) with durable centrifugal RVAD implanted during the LVAD implant, and 26 (2.4%) patients (group 4) were supported with RVAD (temporary or permanent), which was implanted at a later stage. Groups 1 and 4 had higher survival rates in comparison with group 2 (hazard ratio [HR] = 0.513, 95% confidence intervals [CIs] = 0.402-0.655, p < 0.001, versus group 1) and group 3 (HR = 0.461, 95% CIs = 0.320-0.666, p < 0.001, versus group 1). Patients in group 3 showed higher heart transplantation rates at 12 and 36 months as compared with group 1 (40.4% and 46.6% vs. 21.9% and 37.4%, respectively), group 2 (40.4% and 46.6% vs. 25.8% and 39.3%, respectively), and group 4 (40.4% and 46.6% vs. 3.8% and 12.0%, respectively). Severe RHF post-LVAD is associated with poor survival. Patients with LVAD who during the perioperative period are in need of right ventricular temporary or durable mechanical circulatory support constitute a group at particular risk. Improvement of devices tailored for right ventricular support is mandatory for further evolution of the field.

Right Heart Reserve Function Assessed With Fluid Loading Predicts Late Right Heart Failure After Left Ventricular Assist Device Implantation

BACKGROUND

A left ventricular assist device (LVAD) is an effective therapeutic option for advanced heart failure. Late right heart failure (LRHF) is a complication after LVAD implantation that is associated with increasing morbidity and mortality; however, the assessment of right heart function, including right heart reserve function after LVAD implantation, has not been established. We focused on a fluid-loading test with right heart catheterization to evaluate right heart preload reserve function and investigate its impact on LRHF.

METHODS

Patients aged > 18 years who received a continuous-flow LVAD between November 2007 and December 2022 at our institution, and underwent right heart catheterization with saline loading (10 mL/kg for 15 minutes) 1 month after LVAD implantation, were included.

RESULTS

Overall, 31 cases of LRHF or death (right heart failure [RHF] group) occurred in 149 patients. In the RHF vs the non-RHF groups, the pulmonary artery pulsatility index (PAPi) at rest (1.8 ± 0.89 vs 2.5 ± 1.4, P = 0.02) and the right ventricular stroke work index (RVSWi) change ratio with saline loading (0.96 ± 0.32 vs 1.1 ± 0.20, P = 0.03) were significantly different. The PAPi at rest and the RVSWi change ratio with saline loading were identified as postoperative risks for LRHF and death. The cohort was divided into 3 groups based on whether the PAPi at rest and the RVSWi change ratio were low. The event-free curve differed significantly among the 3 groups (P < 0.001).

CONCLUSIONS

Hemodynamic assessment with saline loading can evaluate the right ventricular preload reserve function of patients with an LVAD. A low RVSWi change with saline loading was a risk factor for LRHF following LVAD implantation.

Left Atrial Decompression With the HeartMate3 in Heart Failure With Preserved Ejection Fraction: Virtual Fitting and Hemodynamic Analysis

Effective treatment of heart failure with preserved ejection fraction (HFpEF) remains an unmet medical need. Although left atrial decompression using mechanical circulatory support devices was previously suggested, the heterogeneous HFpEF population and the lack of tailored devices have prevented the translation into clinical practice. This study aimed to evaluate the feasibility of left atrial decompression in HFpEF patients with a HeartMate 3 (HM3, Abbott Inc, Chicago, USA) in silico and in vitro . Anatomic compatibility of the HM3 pump was assessed by virtual device implantation into the left atrium through the left atrial appendage (LAA) and left atrial posterior wall (LAPW) of 10 HFpEF patients. Further, the efficacy of left atrial decompression was investigated experimentally in a hybrid mock loop, replicating the hemodynamics of an HFpEF phenotype at rest and exercise conditions. Virtual implantation without substantial intersection with surrounding tissues was accomplished through the LAA in 90% and 100% through the LAPW. Hemodynamic analysis in resting conditions demonstrated normalization of left atrial pressures without backflow at a pump speed of around 5400 rpm, whereas a range of 6400-7400 rpm was required during exercise. Therefore, left atrial decompression with the HM3 may be feasible in terms of anatomic compatibility and hemodynamic efficacy.

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.

Late Right Heart Failure After Left Ventricular Assist Device Implantation: Contemporary Insights and Future Perspectives

Late right heart failure (RHF) is increasingly recognized in patients with long-term left ventricular assist device (LVAD) support and is associated with decreased survival and increased incidence of adverse events such as gastrointestinal bleeding and stroke. Progression of right ventricular (RV) dysfunction to clinical syndrome of late RHF in patients supported with LVAD is dependent on the severity of pre-existing RV dysfunction, persistent or worsening left- or right-sided valvular heart disease, pulmonary hypertension, inadequate or excessive left ventricular unloading, and/or progression of the underlying cardiac disease. RHF likely represents a continuum of risk with early presentation and progression to late RHF. However, de novo RHF develops in a subset of patients leading to increased diuretic requirement, arrhythmias, renal and hepatic dysfunction, and heart failure hospitalizations. The distinction between isolated late RHF and RHF due to left-sided contributions is lacking in registry studies and should be the focus of future registry data collection. Potential management strategies include optimization of RV preload and afterload, neurohormonal blockade, LVAD speed optimization, and treatment of concomitant valvular disease. In this review, the authors discuss definition, pathophysiology, prevention, and management of late RHF.

Right heart failure after left ventricular assist device implantation: a persistent problem

Left ventricular assist device (LVAD) is an option for bridge-to-transplant or destination therapy for patients with end-stage heart failure. Right heart failure (RHF) remains a complication after LVAD implantation that portends high morbidity and mortality, despite advances in LVAD technology. Definitions of RHF vary, but generally include the need for inotropic or pulmonary vasodilator support, or potential right ventricular (RV) mechanical circulatory support. This review covers the complex pathophysiology of RHF related to underlying myocardial dysfunction, interventricular dependence, and RV afterload, as well as treatment strategies to curtail this challenging problem.

Left ventricular assist device in cardiac amyloidosis: friend or foe?

The prevalence of cardiac amyloidosis has progressively increased over the last years, being recognized as a significant cause of heart failure. In fact, the management of advanced heart failure is a cornerstone treatment of amyloid cardiomyopathy due to the frequent delay in its diagnosis. Left ventricular assist devices (LVADs) have been gaining importance in the scenario of end-stage heart failure, representing an alternative to heart transplant. However, only few studies have investigated the role of LVAD in restrictive cardiomyopathies such as cardiac amyloidosis, since there are several problems to consider. In fact, both anatomical factors and the restrictive physiology of this condition make LVAD implant a relevant challenge in this subset of patients. Furthermore, due to the systemic involvement of amyloidosis, several factors have to be considered after LVAD implant, such as an increased risk of bleeding and right ventricular failure. This review attempts to summarize the current evidence of LVAD in cardiac amyloidosis, especially focusing on the challenges that this cardiomyopathy imposes both to the implant and to its management thereafter.

Prognostic value of TAPSE/PASP ratio in right ventricular failure after left ventricular assist device implantation: Experience from a tertiary center

Background

In this study, we aimed to investigate the prognostic value of the tricuspid annular plane systolic excursion (TAPSE)/ pulmonary arterial systolic pressure (PASP) ratio in right ventricular failure patients undergoing left ventricular assist device implantation.

Methods

Between February 2013 and February 2020, a total of 75 heart failure patients (65 males, 10 females; median age: 54 years; range, 21 to 66 years) were retrospectively analyzed. The prognostic value of TAPSE/PASP ratio was assessed using the multivariate Cox regression models and confirmed using the Kaplan-Meier analyses.

Results

Forty-one (55.4%) patients had an ischemic heart failure etiology. The indication for assist device implantation was bridge to transplant in 64 (85.3%) patients. The overall survival rates at one, three, and five years following left ventricular assist device implantation were 82.7%, 68%, and 49.3%, respectively. Right ventricular failure was observed in 24 (32%) patients during follow-up. In the multivariate analysis, TAPSE/PASP was found to be independently associated with postoperative right ventricular failure (HR: 1.63; 95% CI: 1.49-2.23). A TAPSE/PASP of 0.34 mm/mmHg was found to be the most accurate predictor value, with lower ratios correlating with right ventricular failure. The Kaplan-Meier analysis showed a better overall survival using a TAPSE/PASP ≥ of 0.34 mm/mmHg (p<0.001).

Conclusion

A lower TAPSE/PASP ratio, particularly lower values than 0.34 mm/mmHg, strongly predicts right ventricular failure after left ventricular assist device implantation in patients with advanced heart failure.

A Computational Hemodynamics Approach to Left Ventricular Assist Device (LVAD) Optimization Validated in a Large Patient Cohort

With increasing use of left ventricular assist devices (LVAD) it is critical to devise strategies to optimize LVAD speed while controlling mean arterial pressure (MAP) and flow according to patient physiology. The complex interdependency between LVAD speed, MAP, and flow frequently makes optimization difficult under clinical conditions. We propose a method to guide this procedure in silico, narrowing the conditions to test clinically. A computational model of the circulatory network that simulates HF and LVAD support, incorporating LVAD pressure-flow curves was applied retrospectively to anonymized patient hemodynamics data from the University of Washington Medical Center. MAP management on 61 patient-specific computational models with a target of 70 mm Hg, resulting flow for a given LVAD speed was analyzed, and compared to a target output of 5 L/min. Before performing virtual MAP management, 51% had a MAP>70 mm Hg and CO>5 L/min, and 33% had a MAP>70 mm Hg and CO<5 L/min. After changing systemic resistance to meet the MAP target (without adjusting LVAD speed), 84% of cases resulted in CO higher than 5 L/min, with a median CO of 6.79 L/min, using the computational predictive model. Blood pressure management alone is insufficient in meeting both MAP and CO targets, due to the risk of hypervolemia, and requires appropriate LVAD speed optimization to achieve both targets, while preserving right heart health. Such computational tools can narrow down conditions to be tested for each patient, providing significant insight into the pump-patient interplay. LVAD hemodynamic optimization has the potential to reduce complications and improve outcomes.

Right Heart Failure Following Left Ventricular Device Implantation: Natural History, Risk Factors, and Outcomes: An Analysis of the STS INTERMACS Database

BACKGROUND

Our current understanding of right heart failure (RHF) post-left ventricular assist device (LVAD) is lacking. Recently, a new Interagency Registry for Mechanically Assisted Circulatory Support definition of RHF was introduced. Based on this definition, we investigated natural history, risk factors, and outcomes of post-LVAD RHF.

METHODS

Patients implanted with continuous flow LVAD between June 2, 2014, and June 30, 2016 and registered in the Interagency Registry for Mechanically Assisted Circulatory Support/Society of Thoracic Surgeons Database were included. RHF incidence and predictors, and survival after RHF were assessed. The manifestations of RHF which were separately analyzed were elevated central venous pressure, peripheral edema, ascites, and use of inotropes.

RESULTS

Among 5537 LVAD recipients (mean 57±13 years, 49% destination therapy, support 18.9 months) prevalence of 1-month RHF was 24%. Of these, RHF persisted at 12 months in 5.3%. In contrast, de novo RHF, first identified at 3 months, occurred in 5.1% and persisted at 12 months in 17% of these, and at 6 months occurred in 4.8% and persisted at 12 months in 25%. Higher preimplant blood urea nitrogen (ORs,1.03-1.09 per 5 mg/dL increase; P<0.0001), previous tricuspid valve repair/replacement (ORs, 2.01-10.09; P<0.001), severely depressed right ventricular systolic function (ORs,1.17-2.20; P=0.004); and centrifugal versus axial LVAD (ORs,1.15-1.78; P=0.001) represented risk factors for RHC incidence at 3 months. Patients with persistent RHF at 3 months had the lowest 2-year survival (57%) while patients with de novo RHF or RHF which resolved by 3 months had more favorable survival outcomes (75% and 78% at 2 years, respectively; P<0.001).

CONCLUSIONS

RHF at 1 or 3 months post-LVAD was a common and frequently transient condition, which, if resolved, was associated with relatively favorable prognosis. Conversely, de novo, late RHF post-LVAD (>6 months) was more frequently a persistent disorder and associated with increased mortality. The 1-, 3-, and 6-month time points may be used for RHF assessment and risk stratification in LVAD recipients.

The right ventricular involvement in dilated cardiomyopathy: prevalence and prognostic implications of the often-neglected child

Dilated cardiomyopathy (DCM) is a primary heart muscle disease characterized by left or biventricular systolic impairment. Historically, most of the clinical attention has been devoted to the evaluation of left ventricular function and morphology, while right ventricle (RV) has been for many years the forgotten chamber. Recently, progresses in cardiac imaging gave clinicians precious tools for the evaluation of RV, raising the awareness of the importance of biventricular assessment in DCM. Indeed, RV involvement is far from being uncommon in DCM, and the presence of right ventricular dysfunction (RVD) is one of the major negative prognostic determinants in DCM patients. However, some aspects such as the possible role of specific genetic mutations in determining the biventricular phenotype in DCM, or the lack of specific treatments able to primarily counteract RVD, still need research. In this review, we summarized the current knowledge on RV involvement in DCM, giving an overview on the epidemiology and pathogenetic mechanisms implicated in determining RVD. Furthermore, we discussed the imaging techniques to evaluate RV function and the role of RV failure in advanced heart failure.

Late-onset right ventricular failure after continuous-flow left ventricular assist device implantation: case presentation and review of the literature

With the widespread use of implantable left ventricular assist device (LVAD), right ventricular failure (RVF) has become a serious problem that becomes apparent several weeks or later after LVAD implantation. However, there are no marked preoperative signs of RVF. This is called late-onset RVF and is currently a major problem leading to long-term complications following implantable LVAD use. Pathogenically, this could be the result of left ventricular suction by LVAD that causes the septum shift to the left ventricular side. This causes a change in morphology of the right ventricle, resulting in impaired right ventricular function. Aortic insufficiency and ventricular arrhythmia, which are also important as long-term complications after LVAD implantation, are considered to be closely involved in the onset and progression of RVF. Once late-onset RVF develops, exercise capacity declines and inotrope administration may be required. Late-onset RVF was also reported to be significantly associated with increased mortality. Several predictors of RVF have been proposed such as preoperative left ventricular diastolic dimension <64 mm, tricuspid valve annulus diameter ≥41 mm, and so on. However, some reports identified no predictors. The basic treatment strategy for late-onset RVF is to optimize volume status by administering diuretics and ensuring inotrope as needed. β-blockers and antiarrhythmic agents often need to be reduced in terms of dosage or even discontinued because these might reduce right ventricular function. Although their efficacy is unclear, pulmonary vasodilators may be used to reduce right ventricular afterload. It is better to decrease the rotation speed of LVAD to minimize the displacement of the septum; however, this is often difficult because the required flow rate cannot be secured. Progress in the prevention and management of late-onset RVF is required because the number of patients who require longer-term LVAD support will increase with the spread of LVAD use as destination therapy.

Long-Term renal function after implantation of continuous-flow left ventricular assist devices: A single center study

Background

Implantable continuous-flow left ventricular assist device (LVAD) improve renal function in advanced heart failure. However, the long-term effects of LVAD on renal function have not been investigated thoroughly. We aimed to assess long-term renal function in patients with LVAD support and to identify predictors for late deterioration in renal function (LDRF).

Methods

One hundred patients underwent LVAD implantation as a bridge to transplant at the University of Tokyo Hospital between May 2011 and December 2018. We assessed renal function at intervals (preoperative, 1, 6, 12, 18, 24 and 30 months after LVAD implantation). We divided patients into two groups: “with LDRF,” whose renal function at 30 months had decreased by >25% compared with preoperatively (n = 14), and “without LDRF” (n = 55).

Results

Renal function improved at 1 month, returned to preoperative levels at 6 months, and remained there up to 30 months after LVAD implantation. However, renal function impairment became evident in patients with LDRF 18 months after LVAD implantation. A ratio of right atrial pressure/pulmonary artery wedge pressure > 0.57 and left ventricular dimension diastole ≤ 67 mm were preoperative independent risk factors for LDRF. In addition, the incidence of perioperative acute kidney injury, ventricular arrhythmia, aortic insufficiency, and late right ventricular failure was significantly higher in patients with LDRF.

Conclusion

LDRF after LVAD implantation corresponded to several risk factors, including a small left ventricle and LVAD-related complications, such as right ventricular failure.

Consensus Report on Destination Therapy in Japan - From the DT Committee of the Council for Clinical Use of Ventricular Assist Device Related Academic Societies

Destination therapy (DT) is the indication to implant a left ventricular assist device (LVAD) in a patient with stage D heart failure who is not a candidate for heart transplantation. The implantable LVAD has been utilized in Japan since 2011 under the indication of bridge to transplant (BTT). After almost 10 year lag, DT has finally been approved and reimbursed in May 2021 in Japan. To initiate the DT program in Japan, revision of the LVAD indication from BTT is necessary. Also, in-depth discussion of caregiver issues as well as end-of-life care is indispensable. For that purpose, we assembled a DT committee of multidisciplinary members in August 2020, and started monthly discussions via web-based communication during the COVID-19 pandemic. This is a summary of the consensus reached after 6 months' discussion, and we have included as many relevant topics as possible. Clinical application of DT has just started, and we are willing to revise this consensus to meet the forthcoming issues raised during real-world clinical experience.

Risk assessment in patients with left ventricular systolic dysfunction following transcatheter aortic valve replacement

BACKGROUND

Mortality following transcatheter aortic valve replacement (TAVR) in patients with post-procedural left ventricular systolic dysfunction remains high. We investigated clinical variables associating with worse clinical outcomes following TAVR in patients with systolic dysfunction.

METHODS

We retrospectively investigated 2588 patients with severe aortic stenosis who received TAVR and were enrolled in the optimized transcatheter valvular intervention (OCEAN-TAVI) multicenter registry (UMIN000020423). The association between the clinical variables following TAVR and 2-year cardiovascular mortality was investigated among those with post-TAVR left ventricular ejection fraction less than 50%.

RESULTS

A total of 298 patients (median 85 years old, 131 men) were included. The presence of moderate or greater tricuspid regurgitation following TAVR was independently associated with 2-year mortality (adjusted hazard ratio 3.41, 95% confidence interval 1.15-10.1), and significantly discriminated 2-year cardiovascular mortality (30% vs. 12%, p = 0.001). No patients with any improvement in tricuspid regurgitation had cardiovascular death.

CONCLUSION

Following TAVR, the existence of significant tricuspid regurgitation was associated with cardiovascular mortality in patients with heart failure with reduced ejection fraction.

Markers of Right Ventricular Dysfunction Predict Maximal Exercise Capacity After Left Ventricular Assist Device Implantation

Although left ventricular assist device (LVAD) improves functional capacity, on average LVAD patients are unable to achieve the aerobic capacity of normal healthy subjects or mild heart failure patients. The aim of this study was to examine if markers of right ventricular (RV) function influence maximal exercise capacity. This was a single-center prospective study that enrolled 20 consecutive HeartWare ventricular assist device patients who were admitted at the Freeman Hospital (Newcastle upon Tyne, United Kingdom) for a heart transplant assessment from August 2017 to October 2018. Mean peak oxygen consumption (Peak VO2) was 14.0 ± 5.0 ml/kg/min, and mean peak age and gender-adjusted percent predicted oxygen consumption (%VO2) was 40.0% ± 11.5%. Patients were subdivided into two groups based on the median peak VO2, so each group consisted of 10 patients (50%). Right-sided and pulmonary pressures were consistently higher in the group with poorer exercise tolerance. Patients with poor exercise tolerance (peak VO2 below the median) had higher right atrial pressures at rest (10.6 ± 6.4 vs. 4.3 mmHg ± 3.2; p = 0.02) and the increase with passive leg raising was significantly greater than those with preserved exercise tolerance (peak VO2 above the median). Patients with poor functional capacity also had greater RV dimensions (4.4 cm ± 0.5 vs. 3.7 cm ± 0.5; p = 0.02) and a higher incidence of significant tricuspid regurgitation (moderate or severe tricuspid regurgitation in five patients in the poor exercise capacity group vs. none in the preserved exercise capacity group; p = 0.03). In conclusion, echocardiographic and hemodynamic markers of RV dysfunction discriminate between preserved and nonpreserved exercise capacity in HeartWare ventricular assist device patients.

Winter LVAD implantation is associated with adverse clinical outcomes

BACKGROUND

The seasonal variation of incidence and severity of heart failure is well known. However, the impact of seasonal variation on clinical outcomes following left ventricular assist device (LVAD) implantation remains unknown.

METHODS

We retrospectively reviewed consecutive patients who received LVAD implantation between January 2014 and December 2016 along with their first year of post-implant outcomes. Clinical outcomes were compared between those with winter LVAD implantation (between October and March) and those with non-winter LVAD implantation.

RESULTS

168 patients with a median age of 57 years and 130 males were included. There was no seasonal difference in the number of LVAD implantations. One-year survival free from major adverse events was significantly lower in the winter implant group (n = 88) compared to the non-winter group (n = 80) (44% vs 61%) with an adjusted hazard ratio of 1.81 (95% confidence interval 1.11-2.90, p = 0.014), largely due to a higher rate of heart failure readmission in the winter implant patients (incidence rate ratio 2.29, 95% confidence interval 0.89-5.84).

CONCLUSION

Patients who underwent LVAD implantation during the winter season had a higher heart failure readmission rate. A detailed mechanism and therapeutic strategy given our findings warrant further investigation.

Detailed mechanism and impact of new-onset late right heart failure during LVAD support

Not applicable.

Implication of Hemodynamic Assessment during Durable Left Ventricular Assist Device Support

Durable left ventricular assist device therapy has improved survival in patients with advanced heart failure refractory to conventional medical therapy, although the readmission rates due to device-related comorbidities remain high. Left ventricular assist devices are designed to support a failing left ventricle through relief of congestion and improvement of cardiac output. However, many patients still have abnormal hemodynamics even though they may appear to be clinically stable. Furthermore, such abnormal hemodynamics are associated with an increased risk of future adverse events including recurrent heart failure, gastrointestinal bleeding, stroke, and pump thrombosis. Correction of residual hemodynamic derangements post-implantation may be a target in improving longitudinal clinical outcomes during left ventricular assist device support. Automatic and timely device speed adjustments considering a patients' hemodynamic status (i.e., with a smart pump) are potential improvements in forthcoming devices.

Associations between hemodynamic parameters at rest and exercise capacity in patients with implantable left ventricular assist devices

BACKGROUND

Hemodynamic parameters at rest are known to correlate poorly with peak oxygen uptake (VO₂) in heart failure. However, we hypothesized that hemodynamic parameters at rest could predict exercise capacity in patients with left ventricular assist device (LVAD), because LVAD pump rotational speed does not respond during exercise. Therefore, we investigated the relationships between hemodynamic parameters at rest (measured with right heart catheterization) and exercise capacity (measured with cardiopulmonary exercise testing) in patients with implantable LVAD.

METHODS

We performed a retrospective medical record review of patients who received implantable LVAD at our institution from November 2013 to December 2017.

RESULTS

A total of 20 patients were enrolled in this study (15 males; mean age, 45.8 years; median duration of LVAD support, 356 days). The mean peak VO₂ and cardiac index (CI) were 13.5 mL/kg/min and 2.6 L/min/m², respectively. CI and hemoglobin level were significantly associated with peak VO₂ (CI: r = 0.632, p = 0.003; hemoglobin: r = 0.520, p = 0.019). In addition, pulmonary capillary wedge pressure, right atrial pressure, and right ventricular stroke work index were also significantly associated with peak VO₂. In multiple linear regression analysis, CI and hemoglobin level remained independent predictors of peak VO₂ (CI: β = 0.559, p = 0.006; hemoglobin: β = 0.414, p = 0.049).

CONCLUSIONS

CI at rest and hemoglobin level are associated with poor exercise capacity in patients with LVAD.

Longitudinal Trajectories of Hemodynamics Following Left Ventricular Assist Device Implantation

BACKGROUND

Continuous-flow left ventricular assist devices (LVADs) improve the hemodynamics of patients with advanced heart failure. However, the longitudinal trajectories of hemodynamics in patients after LVAD implantation remain unknown. The aim of this study was to investigate the trends of hemodynamic parameters following LVAD implantation.

METHODS AND RESULTS

We retrospectively reviewed patients who underwent LVAD implantation between April 2014 and August 2018. We collected hemodynamic parameters from right heart catheterizations. Of 199 consecutive patients, we enrolled 150 patients who had both pre- and postimplant right heart catheterizations. They had 3 (2, 4) postimplant right heart catheterizations during a follow-up of 2.3 (1.3, 3.1) years. The mean age was 57 ± 13 years, and 102 patients (68%) were male. Following LVAD implantation, pulmonary arterial pressure and pulmonary capillary wedge pressure decreased, and cardiac index increased significantly, then remained unchanged throughout follow-up. Right atrial pressure decreased initially and then gradually increased to preimplant values. The pulmonary artery pulsatility index decreased initially and returned to preimplant values, then progressively decreased over longer follow-up. Subgroup analysis showed significant differences in the trajectories of the pulmonary artery pulsatility index based on gender.

CONCLUSIONS

Despite improvement in left-side filling pressures and cardiac index following LVAD implantation, right atrial pressure increased and the pulmonary artery pulsatility index decreased over time, suggesting progressive right ventricular dysfunction.

Comparative Analysis of Established Risk Scores and Novel Hemodynamic Metrics in Predicting Right Ventricular Failure in Left Ventricular Assist Device Patients

BACKGROUND

Right ventricular failure (RVF) portends poor outcomes after left ventricular assist device (LVAD) implantation. Although numerous RVF predictive models have been developed, there are few independent comparative analyses of these risk models.

METHODS AND RESULTS

RVF was defined as use of inotropes for >14 days, inhaled pulmonary vasodilators for >48 hours or unplanned right ventricular mechanical support postoperatively during the index hospitalization. Risk models were evaluated for the primary outcome of RVF by means of logistic regression and receiver operating characteristic curves. Among 93 LVAD patients with complete data from 2011 to 2016, the Michigan RVF score (C = 0.74 [95% CI 0.61-0.87]; P = .0004) was the only risk model to demonstrate significant discrimination for RVF, compared with newer risk scores (Utah, Pitt, EuroMACS). Among individual hemodynamic/echocardiographic metrics, preoperative right ventricular dysfunction (C = 0.72 [95% CI 0.58-0.85]; P = .0022) also demonstrated significant discrimination of RVF. The Michigan RVF score was also the best predictor of in-hospital mortality (C = 0.67 [95% CI 0.52-0.83]; P = .0319) and 3-year survival (Kaplan-Meier log-rank 0.0135).

CONCLUSIONS

In external validation analysis, the more established Michigan RVF score-which emphasizes preoperative hemodynamic instability and target end-organ dysfunction-performed best, albeit modestly, in predicting RVF and demonstrated association with in-hospital and long-term mortality.

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.

Clinical implications of hemodynamic assessment during left ventricular assist device therapy

Left ventricular assist devices (LVADs) significantly improve outcomes of advanced heart failure patients. However, patients continue to have high readmission rates due to complications ranging from bleeding, thrombosis, heart failure, and infection. Considering that the hallmark benefit of LVAD therapy is improvement in hemodynamics (cardiac unloading and increased cardiac output), hemodynamic assessment on LVAD support is key to better understand these difficult complications and may serve as a tool to resolving them. In this review, we will discuss the hemodynamic changes following LVAD implantation, and the implications and prognostic impact of hemodynamic optimization on outcomes and complications.

Indication of Ventricular Assist Device Therapy in Patients with INTERMACS Profile 4-7

Optimal timing of ventricular assist device (VAD) therapy has been discussed mainly among patients with heart failure dependent on inotrope infusion, but little is known about the indication of VAD therapy among less sick ambulatory patients. Considering recent improvement of VAD therapy outcome, now is the best time to discuss the expansion of VAD indication into less sick population. In this review, we will investigate optimal candidates for VAD therapy especially among ambulatory populations on the basis of recent evidence.

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.

Novel Scoring System to Predict Ineligibility for Bridge to Implantable Left Ventricular Assist Device as Destination Therapy Before Extracorporeal Ventricular Assist Device Implantation - For the Coming Era of Destination Therapy in Japan

BACKGROUND

Although destination therapy (DT) is now expected to be a promising strategy for those who are not suitable for heart transplantation in Japan, there has not been any investigation into ineligibility for bridging to implantable left ventricular assist device (I-LVAD) as DT among patients with extracorporeal LVAD.

METHODS AND RESULTS

We retrospectively studied 85 patients who had received an extracorporeal LVAD. To assess ineligibility for a bridge to I-LVAD for DT, we defined DT ineligibility (DTI) as BiVAD requirement, death within 6 months, and persistent end-organ dysfunction (medium or high J-VAD risk score) at 6 months after extracorporeal LVAD implantation. DTI was recorded for 32 patients. Uni/multivariate analysis showed that smaller left ventricular diastolic dimension (<64 mm; [odds ratio (OR) 4.522]), continuous hemodiafiltration (OR 4.862), past history of cardiac surgery (OR 6.522), and low serum albumin level (<3.1 g/dl; OR 10.064) were significant predictors of DTI. By scoring 2, 2, 3, 4 points, respectively, considering each OR, we constructed a novel scoring system for DTI (DTI score), which stratified patients into 3 risk strata: low (0-3 points), medium (4-6 points), and high (7-11 points), from the view point of DTI risk (low 8%, medium 46%, high 93%, respectively).

CONCLUSIONS

DTI score is a promising tool for predicting ineligibility for I-LVAD as DT before extracorporeal VAD implantation.

High pulmonary vascular resistance in addition to low right ventricular stroke work index effectively predicts biventricular assist device requirement

Although the right ventricular stroke work index (RVSWI) is a good index for RV function, a low RVSWI is not necessarily an indicator for the need for a right ventricular assist device at the time of left VAD implantation. We here aimed to determine a more precise indicator for the need for a biventricular assist device (BiVAD). In total, 116 patients (mean age, 38 ± 14 years), who underwent hemodynamic assessments preoperatively including 12 BiVAD patients, and had been followed at our institute from 2003 to 2015, were included. Multivariate logistic regression analysis indicated that RVSWI and pulmonary vascular resistance (PVR) were independent predictors of BiVAD requirement (P < 0.05 for both). In addition, all patients were classified into 4 groups: (1) normal (RVSWI > 5 g/m, PVR < 3.7 WU), (2) pulmonary hypertension (RVSWI > 5, PVR > 3.7), (3) RV failure (RVSWI < 5, PVR < 3.7), and (4) both pulmonary hypertension and RV failure (RVSWI < 5, PVR > 3.7), and examined. Most of the patients in Group 4 (75 %), with acutely depressed hemodynamics and inflammatory responses in the myocardium, required BiVAD. Overall, patients with BiVAD had a worse survival rate as compared with those with LVAD alone. In conclusion, high PVR in addition to low RVSWI effectively predicts BiVAD requirement.

Quality of Life and Influential Factors in Patients Implanted With a Left Ventricular Assist Device

BACKGROUND

Improving quality of life (QOL) has become an important goal in left ventricular assist device (LVAD) therapy. We aimed (1) to assess the effect of an implantable LVAD on patients' QOL, (2) to compare LVAD patients' QOL to that of patients in different stages of heart failure (HF), and (3) to identify factors associated with patients' QOL.

METHODS AND RESULTS

The QOL of 33 Japanese implantable LVAD patients was assessed using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and Short-form 8 (SF-8), before and at 3 and 6 months afterwards. After LVAD implantation, QOL significantly improved [MLHFQ, SF-8 physical component score (PCS), SF-8 mental component score (MCS), all P<0.05]. Implanted LVAD patients had a better QOL than extracorporeal LVAD patients (n=33, 32.1±21.9 vs. n=17, 47.6±18.2), and Stage D HF patients (n=32, 51.1±17.3), but the score was comparable to that of patients who had undergone a heart transplant (n=13). In multiple regression analyses, postoperative lower albumin concentration and right ventricular failure were independently associated with poorer PCS. Female sex and postoperative anxiety were 2 of the independent factors for poorer MCS (all P<0.05).

CONCLUSIONS

Having an implantable LVAD improves patients' QOL, which is better than that of patients with an extracorporeal LVAD. Both clinical and psychological factors are influence QOL after LVAD implantation.

Perioperative Hypoalbuminemia Affects Improvement in Exercise Tolerance After Left Ventricular Assist Device Implantation

BACKGROUND

Although survival rates have improved for patients receiving implantable continuous flow left ventricular assist devices (I-CF LVAD), postoperative exercise tolerance levels are not necessarily satisfactory.

METHODS AND RESULTS

We enrolled 51 patients who had received an I-CF LVAD and underwent follow-up between 2006 and 2014; all patients underwent cardiopulmonary exercise testing 3 months following surgery: 26 (51%) patients achieved peak oxygen consumption (PV̇O2) ≥14 ml·kg(-1)·min(-1)and had significantly lower readmission rates for cardiovascular events than those with PV̇O2<14 ml·kg(-1)·min(-1)during 2 years of LVAD treatment (17 vs. 43%, P=0.033). Uni- and multivariate logistic regression analyses showed that the preoperative serum albumin (S-ALB) level was an independent predictor for PV̇O2≥14 ml·kg(-1)·min(-1)at 3 months (P=0.023, odds ratio 6.132). Patients with persistently normal S-ALB levels during the perioperative period had the lowest preoperative serum C-reactive protein level (S-CRP, 0.7±0.9 mg/dl), and the majority (77%) showed improved exercise tolerance. Conversely, patients with persistently low S-ALB levels during this period had the highest preoperative S-CRP level (2.8±1.2 mg/dl) and did not achieve the test endpoint.

CONCLUSIONS

Both pre- and postoperative low S-ALB impedes recovery of exercise tolerance after I-CF LVAD surgery, and this may be attributable to inflammatory responses caused by heart failure.

Biventricular failure with low pulmonary vascular resistance was managed by left ventricular assist device alone without right-sided mechanical support

How to manage preoperative right ventricular dysfunction (RVD) in heart failure patients without cardiogenic shock remains as a matter to be debated because implantable biventricular assist device treatment has not been established thus far. We here presented a patient with significant RVD indicated by low RV stroke work index (0.3 g/m) and RV dilatation as well as low pulmonary vascular resistance (PVR, 0.8 Wood Unit), who was managed by the introduction of pimobendan and sildenafil after the implantation of DuraHeart and tricuspid annuloplasty without right VAD, although his New York Heart Association symptom remained class III. Preoperative low PVR may be a key for successful LVAD treatment alone without right VAD in patients with INTERMACS profile 3 suffering RVD.