Atrial Shunt Device Effects on Cardiac Structure and Function in Heart Failure With Preserved Ejection Fraction: The REDUCE LAP-HF II Randomized Clinical Trial

Importance

Although the results of A Study to Evaluate the Corvia Medical Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure (REDUCE LAP-HF II) trial were neutral overall, atrial shunt therapy demonstrated potential efficacy in responders (no latent pulmonary vascular disease and no cardiac rhythm management device). Post hoc analyses were conducted to evaluate the effect of shunt vs sham stratified by responder status.

Objective

To evaluate the effect of atrial shunt vs sham control on cardiac structure/function in the overall study and stratified by responder status.

Design, Setting, and Participants

This was a sham-controlled randomized clinical trial of an atrial shunt device in heart failure with preserved ejection fraction (HFpEF)/HF with mildly reduced EF (HFmrEF). Trial participants with evaluable echocardiography scans were recruited from 89 international medical centers. Data were analyzed from April 2023 to January 2024.

Interventions

Atrial shunt device or sham control.

Main Outcome Measures

Changes in echocardiographic measures from baseline to 1, 6, 12, and 24 months after index procedure.

Results

The modified intention-to-treat analysis of the REDUCE LAP-HF II trial included 621 randomized patients (median [IQR] age, 72.0 [66.0-77.0] years; 382 female [61.5%]; shunt arm, 309 [49.8%]; sham control arm, 312 [50.2%]). Through 24 months, 212 of 217 patients (98%) in the shunt arm with evaluable echocardiograms had patent shunts. In the overall trial population, the shunt reduced left ventricular (LV) end-diastolic volume (mean difference, -5.65 mL; P <.001), left atrial (LA) minimal volume (mean difference, -2.8 mL; P =.01), and improved LV systolic tissue Doppler velocity (mean difference, 0.69 cm/s; P <.001) and LA emptying fraction (mean difference, 1.88 percentage units; P =.02) compared with sham. Shunt treatment also increased right ventricular (RV; mean difference, 9.58 mL; P <.001) and right atrial (RA; mean difference, 9.71 mL; P <.001) volumes but had no effect on RV systolic function, pulmonary artery pressure, or RA pressure compared with sham. In the shunt arm, responders had smaller increases in RV end-diastolic volume (mean difference, 5.71 mL vs 15.18 mL; interaction P =.01), RV end-systolic volume (mean difference, 1.58 mL vs 7.89 mL; interaction P =.002), and RV/LV ratio (mean difference, 0.07 vs 0.20; interaction P <.001) and larger increases in transmitral A wave velocity (mean difference, 5.08 cm/s vs -1.97 cm/s; interaction P =.02) compared with nonresponders randomized to the shunt, suggesting greater ability to accommodate shunted blood through the pulmonary circulation enabling LA unloading.

Conclusions and Relevance

In this post hoc analysis of the REDUCE LAP-HF II trial, over 2 years of follow-up, atrial shunting led to reverse remodeling of left-sided chambers and increases in volume of right-sided chambers consistent with the shunt flow but no change in RV systolic function compared with sham. Changes in cardiac structure/function were more favorable in responders compared with nonresponders treated with the shunt, supporting the previously identified responder group hypothesis and mechanism, although further evaluation with longer follow-up is needed.

Trial Registration

ClinicalTrials.gov Identifier: NCT03088033.

Pulmonary arterial hypertension treatment: an individual participant data network meta-analysis

BACKGROUND AND AIMS

Effective therapies that target three main signalling pathways are approved to treat pulmonary arterial hypertension (PAH). However, there are few large patient-level studies that compare the effectiveness of these pathways. The aim of this analysis was to compare the effectiveness of the treatment pathways in PAH and to assess treatment heterogeneity.

METHODS

A network meta-analysis was performed using individual participant data of 6811 PAH patients from 20 Phase III randomized clinical trials of therapy for PAH that were submitted to the US Food and Drug Administration. Individual drugs were grouped by the following treatment pathways: endothelin, nitric oxide, and prostacyclin pathways.

RESULTS

The mean (±standard deviation) age of the sample was 49.2 (±15.4) years; 78.4% were female, 59.7% had idiopathic PAH, and 36.5% were on background PAH therapy. After covariate adjustment, targeting the endothelin + nitric oxide pathway {β: 43.7 m [95% confidence interval (CI): 32.9, 54.4]}, nitric oxide pathway [β: 29.4 m (95% CI: 22.6, 36.3)], endothelin pathway [β: 25.3 m (95% CI: 19.8, 30.8)], and prostacyclin pathway [oral/inhaled β: 19.1 m (95% CI: 14.2, 24.0), intravenous/subcutaneous β: 24.4 m (95% CI: 15.1, 33.7)] significantly increased 6 min walk distance at 12 or 16 weeks compared with placebo. Treatments also significantly reduced the likelihood of having clinical worsening events. There was significant heterogeneity of treatment effects by age, body mass index, hypertension, diabetes, and coronary artery disease.

CONCLUSIONS

Drugs targeting the three traditional treatment pathways significantly improve outcomes in PAH, with significant treatment heterogeneity in patients with some comorbidities. Randomized clinical trials are warranted to identify the most effective treatment strategies in a personalized approach.

Electrocardiographic Abnormalities and Their Association with Outcomes in Randomized Clinical Trials of Pulmonary Arterial Hypertension

Rationale PAH is a progressive disease with manifestations including right atrial enlargement, right ventricular dysfunction, dilation and hypertrophy. ECG is a non-invasive, inexpensive test that is routinely performed in clinical settings. Prior studies have described separate abnormal findings in ECGs of patients with PAH. However, the role of composite ECG findings reflective of right heart disease for risk stratification, clinical trial enrichment and management of patients with PAH has not been explored. Objectives i. Describe a pattern of right heart disease on ECG in patients with PAH. ii. Investigate the association of this pattern with clinical measures of disease severity and outcomes. Methods We harmonized individual participant data from 18 Phase-III randomized clinical trials of therapies for PAH (1998 - 2013) submitted to the FDA. Right heart disease (RHD) was defined as the presence of RV hypertrophy, right axis deviation, right atrial enlargement, or right bundle branch block on ECG. Random effects linear regression, multilevel ordinal regression (cumulative link model), and Cox proportional hazards models were used to assess the association of RHD by ECG with six-minute walk distance (6MWD), WHO functional class, and clinical worsening after a priori adjustment for age, sex, body mass index and PAH etiology. Effect modification of treatment and ECG abnormalities was assessed by including an interaction term. Results 4439 patients had baseline ECGs and 68% patients had evidence of RHD. RHD on ECG was associated with higher PVR (p<0.001) and higher mean PA pressures (p<0.001). Patients with RHD on ECG had 10 meters shorter 6MWD (p=0.005) and worse WHO functional class (p<0.001) at baseline. RHD on baseline ECG was associated with increased risk of clinical worsening (HR=1.42, 95%CI=1.21,1.67, p<0.001). Patients with RHD had greater treatment effect in terms of 6MWD, WHO-FC and time to clinical worsening compared to those without (p for interaction= 0.03, 0.001 and 0.03, respectively). Conclusion Right heart disease by ECG may be associated with a worse outcomes and potentially greater treatment effect. ECGs could be an inexpensive, widely available noninvasive method to enrich clinical trial populations in PAH.

Is low-risk status a surrogate outcome in pulmonary arterial hypertension? An analysis of three randomised trials

BACKGROUND

Targeting short-term improvements in multicomponent risk scores for mortality in patients with pulmonary arterial hypertension (PAH) could result in improved long-term outcomes. We aimed to determine whether PAH risk scores were adequate surrogates for clinical worsening or mortality outcomes in PAH randomised clinical trials (RCTs).

METHODS

We performed an individual participant data meta-analysis of RCTs selected from PAH trials provided by the US Food and Drug Administration (FDA). We calculated predicted risk using the COMPERA, COMPERA 2.0, non-invasive FPHR, REVEAL 2.0, and REVEAL Lite 2 risk scores. The primary outcome of interest was time to clinical worsening, a composite endpoint composed of any of the following events: all-cause death, hospitalisation for worsening PAH, lung transplantation, atrial septostomy, discontinuation of study treatment (or study withdrawal) for worsening PAH, initiation of parenteral prostacyclin analogue therapy, or decrease of at least 15% in 6-min walk distance from baseline, combined with either worsening of WHO functional class from baseline or the addition of an approved PAH treatment. The secondary outcome of interest was time to all-cause mortality. We assessed the surrogacy of these risk scores, parameterised as attainment of low-risk status by 16 weeks, for improvement in long-term clinical worsening and survival using mediation and meta-analysis frameworks.

FINDINGS

Of 28 trials received from the FDA, three RCTs (AMBITION, GRIPHON, and SERAPHIN; n=2508) had the data necessary to assess long-term surrogacy. The mean age was 49 years (SD 16), 1956 (78%) participants were women, 1704 (68%) were classified as White, and 280 (11%) were Hispanic or Latino. 1388 (55%) of 2503 participants with available data had idiopathic PAH and 776 (31%) of 2503 had PAH associated with connective tissue disease. In a mediation analysis, the proportions of treatment effects explained by attainment of low-risk status ranged only from 7% to 13%. In a meta-analysis of trial-regions, the treatment effects on low-risk status were not predictive of the treatment effects on time to clinical worsening (R2 values 0·01-0·19) nor the treatment effects on time to all-cause mortality (R2 values 0-0·2). A leave-one-out analysis suggested that the use of these risk scores as surrogates might lead to biased inferences regarding the effect of therapies on clinical outcomes in PAH RCTs. Results were similar when using absolute risk scores at 16 weeks as the potential surrogates.

INTERPRETATION

Multicomponent risk scores have utility for the prediction of outcomes in patients with PAH. Clinical surrogacy for long-term outcomes cannot be inferred from observational studies of outcomes. Our analyses of three PAH trials with long-term follow-up suggest that further study is necessary before using these or other scores as surrogate outcomes in PAH RCTs or clinical care.

FUNDING

Cardiovascular Medical Research and Education Fund, US National Institutes of Health.

Chronotropic Incompetence after Heart Transplantation Is Associated with Increased Mortality and Decreased Functional Capacity

INTRODUCTION

The contribution of chronotropic incompetence to reduced exercise tolerance after a heart transplant is well known, but its role as a prognostic marker of post-transplant mortality is unclear. The aim of this study is to examine the relationship between post-transplant heart rate response (HRR) and survival.

METHODS

We performed a retrospective analysis of all adult heart transplant recipients at the University of Pennsylvania between the years 2000 and 2011 who underwent a cardiopulmonary exercise test (CPET) within a year of transplant. Follow-up time and survival status were observed through October 2019, using data merged from the Penn Transplant Institute. HRR was calculated by subtracting the resting HR from the peak exercise HR. The association between HRR and mortality was analyzed using Cox proportional hazard models and Kaplan-Meier analysis. The optimal cut-off point for HRR was generated by Harrell's C statistic. Patients with submaximal exercise tests were excluded, defined by a respiratory exchange ratio (RER) cut-off of 1.05.

RESULTS

Of 277 patients with CPETs performed within a year post-transplant, 67 were excluded for submaximal exercise. In the 210 included patients, the mean follow-up time was 10.9 years (Interquartile range (IQR) 7.8-14). Resting HR and peak HR did not significantly impact mortality after adjusting for covariates. In a multivariable linear regression analysis, each 10-beat increase in heart rate response was associated with a 1.3 mL/kg/min increase in peak V_O2 and a 48 s increase in the total exercise time. Each beat/min increase in HRR was associated with a 3% reduction in the hazard of mortality (HR 0.97; 95% CI 0.96-0.99, p = 0.002). Using the optimal cut-off point generated by Harrell's C statistic, survival was significantly higher in patients with an HRR > 35 beats/min compared to those with an HRR < 35 beats/min (log rank p = 0.0012).

CONCLUSION

In heart transplant patients, a low HRR is associated with increased all-cause mortality and decreased exercise capacity. Additional studies are needed to validate whether targeting HRR in cardiac rehabilitation may improve outcomes.

Durable Left Ventricular Assist Device Outflow Graft Obstructions: Clinical Characteristics and Outcomes

PURPOSE

We report on the clinical course and management of patients supported with durable implantable LVADs who developed outflow graft obstructions at a large academic center.

METHODS

We performed a retrospective review of patients receiving LVAD support from 2012 through 2020. Patients who developed an outflow graft obstruction diagnosed by computed tomography angiography (CTA) or angiogram were identified, and patient characteristics and outcomes were reported.

RESULTS

Of the 324 patients supported by LVAD at our institution, 11 patients (3.4%) were diagnosed with outflow graft obstructions. The most common presentation was low flow alarms, which was present in 10/11 patients, and the remaining patient presented with lightheadedness. Patients had minimal LDH elevation with 8/11 presenting with less than 2-fold the upper limit of normal. Transthoracic echocardiograms were not diagnostic, but CTA enabled non-invasive diagnoses in 8/11 of the patients. Three patients with extrinsic compression of the outflow graft successfully underwent endovascular stent placement, and three patients with outflow cannula kinks received supportive care. Of the five patients diagnosed with intraluminal thromboses, one received a heart transplant, one underwent an outflow graft revision, and three received supportive care due to comorbidities.

CONCLUSION

Outflow graft obstructions remain a rare, but serious complication. The true prevalence of this entity is likely underestimated due to the non-specific clinical presentation. CTA is a pivotal non-invasive diagnostic step. Patients with external compression were successfully treated with endovascular stenting.

Association of Donors With US Public Health Service Risk Criteria and Outcomes After Adult vs Pediatric Cardiac Transplant

Importance

The United Network for Organ Sharing (UNOS) evaluates donor risk for acute transmission of HIV, hepatitis B, or hepatitis C based on US Public Health Services (PHS)-specific criteria. However, recent data regarding use and outcomes of those donors with PHS risk criteria among pediatric and adult heart transplant recipients are lacking.

Objective

To compare use and outcomes of graft from donors with PHS risk criteria vs those with a standard-risk donor (SRD) in children vs adults in a contemporary cohort.

Design, Setting, and Participants

This cohort was a nationwide analysis of heart transplants in the US that used data from the UNOS database. Participants were children (<18 years old) and adults (≥18 years old) who received a heart transplant from January 1, 2010, to December 31, 2021.

Exposures

UNOS-defined donor risk status.

Main Outcomes and Measures

Trend analysis compared changes in PHS risk criteria use among children and adults. Patient survival was analyzed using Kaplan-Meier curves with log rank and Cox proportional hazards to compare PHS risk-criteria outcomes vs SRD-criteria outcomes in children and adult heart transplant recipients. Additional analysis was performed among adults who received a PHS-risk criteria graft that was previously declined for pediatric recipients.

Results

Of 5115 pediatric transplant recipients (donor without PHS risk median [IQR] age, 5 [0-13] years and donor with PHS risk median [IQR] age, 8 [0-14] years) and 30 289 adult heart transplant recipients (donor without PHS risk median [IQR] age, 56 [46-63] years and donor with PHS risk median [IQR] age, 57 [47-63] years), PHS risk criteria comprised 8% in children vs 25% in adults. PHS criteria are being increasingly used over the past decade with the proportion of recipients transplanted with PHS risk-criteria donors being approximately 3 times greater among adult recipients than children recipients. Pediatric recipients of a PHS risk-criteria donor had greater pretransplant ventilatory support, whereas adult recipients of a PHS risk-criteria donor had greater pretransplant extracorporeal membrane oxygenation use. Patient survival was similar between pediatric recipients of PHS risk-criteria grafts vs SRD-criteria grafts and slightly higher among adult recipients of PHS risk-criteria grafts vs SRD-criteria grafts. The 1778 adult recipients who received a PHS criteria-risk donor that was previously declined for pediatric recipients had similar patient survival recipients compared with SRD-criteria donors (HR, 0.92; 95% CI, 0.81-1.03; P = .18).

Conclusions and Relevance

In the current era, a 3-fold greater proportion of adult recipients receive a PHS risk-criteria graft compared with children despite similar posttransplant patient survival. The ongoing organ donor shortage underscores the need for consideration of PHS risk criteria where these donors remain underused.

Symptom phenotypes in Pulmonary Arterial Hypertension: The PAH “Symptome”

Women with pulmonary arterial hypertension (PAH) experience multiple symptoms, including dyspnea, fatigue, and sleep disturbance, that impair their health‐related quality of life (HRQOL). However, we know little about phenotypic subgroups of patients with PAH with similar, concurrent, multiple symptoms. The objectives of this study were to define the “symptome” by symptom cluster phenotypes and compare characteristics such as biomarkers, cardiac structure and function (echocardiography), functional capacity (6‐min walk distance), and HRQOL between the groups. This cross‐sectional study included 60 women with PAH. Subjects completed an assessment battery: Pulmonary Arterial Hypertension Symptom Scale, Pittsburgh Sleep Quality Index, Multidimensional Dyspnea Profile, Patient‐Reported Outcomes Measurement Information System (PROMIS®) Physical Function, PROMIS® Sleep‐Related Impairment, and the emPHasis‐10. Subjects also underwent transthoracic echocardiography, phlebotomy, 6‐min walk distance, and actigraphy. The three symptoms of dyspnea, fatigue, and sleep disturbance were used to define the symptom clusters. Other PAH symptoms, plasma and serum biomarkers, cardiac structure and function (echocardiography), exercise capacity (6‐min walk distance), sleep (actigraphy), and HRQOL were compared across phenotypes. The mean age was 50 ± 18 years, 51% were non‐Hispanic white, 32% were non‐Hispanic Black and 40% had idiopathic PAH. Cluster analysis identified Mild (n = 28, 47%), Moderate (n = 20, 33%), and Severe Symptom Cluster Phenotypes (n = 12, 20%). There were no differences for age, race, or PAH etiology between the phenotypes. WHO functional class (p < 0.001), norepinephrine levels (p = 0.029), right atrial pressure (p = 0.001), physical function (p < 0.001), sleep onset latency (p = 0.040), and HRQOL (p < 0.001) all differed significantly across phenotypes. We identified three distinctive symptom cluster phenotypes (Mild, Moderate, and Severe) for women with PAH that also differed by PAH‐related symptoms, physical function, right atrial pressure, norepinephrine levels, and HRQOL. These phenotypes could suggest targeted interventions to improve symptoms and HRQOL in those most severely affected.

BMI and Treatment Response in Patients With Pulmonary Arterial Hypertension

Background

Obesity is increasingly prevalent in pulmonary arterial hypertension (PAH) but is associated with improved survival, creating an “obesity paradox” in PAH. It is unknown if the improved outcomes could be attributable to obese patients deriving a greater benefit from PAH therapies.

Research Question

Does BMI modify treatment effectiveness in PAH?

Study Design and Methods

Using individual participant data, a meta-analysis was conducted of phase III, randomized, placebo-controlled trials of treatments for PAH submitted for approval to the U.S. Food and Drug Administration from 2000 to 2015. Primary outcomes were change in 6-min walk distance (6MWD) and World Health Organization (WHO) functional class.

Results

A total of 5,440 participants from 17 trials were included. Patients with overweight and obesity had lower baseline 6MWD and were more likely to be WHO functional class III or IV. Treatment was associated with a 27.01-m increase in 6MWD (95% CI, 21.58-32.45; P < .001) and lower odds of worse WHO functional class (OR, 0.58; 95% CI, 0.48-0.70; P < .001). For every 1 kg/m² increase in BMI, 6MWD was reduced by 0.66 m (P = .07); there was no significant effect modification of treatment response in 6MWD according to BMI (P for interaction = .34). Higher BMI was not associated with odds of WHO functional class at end of follow-up; however, higher BMI attenuated the treatment response such that every 1 kg/m² increase in BMI increased odds of worse WHO functional class by 3% (OR, 1.03; P for interaction = .06).

Interpretation

Patients with overweight and obesity had lower baseline 6MWD and worse WHO functional class than patients with normal weight with PAH. Higher BMI did not modify the treatment response for change in 6MWD, but it attenuated the treatment response for WHO functional class. PAH trials should include participants representative of all weight groups to allow for assessment of treatment heterogeneity and mechanisms.

Risk Stratification of Patients with Pulmonary Arterial Hypertension: The Role of Echocardiography

Background: Given the morbidity and mortality associated with pulmonary arterial hypertension (PAH), risk stratification approaches that guide therapeutic management have been previously employed. However, most patients remain in the intermediate-risk category despite initial therapy. Herein, we sought to determine whether echocardiographic parameters could improve the risk stratification of intermediate-risk patients. Methods: Prevalent PAH patients previously enrolled in observational studies at 3 pulmonary hypertension centers were included in this study. A validated PAH risk stratification approach was used to stratify patients into low-, intermediate-, and high-risk groups. Right ventricular echocardiographic parameters were used to further stratify intermediate-risk patients into intermediate-low- and intermediate-high-risk groups based on transplant-free survival. Results: From a total of 146 patients included in our study, 38 patients died over a median follow-up of 2.5 years. Patients with intermediate-/high-risk had worse echocardiographic parameters. Tricuspid annular plane systolic excursion (TAPSE) and the degree of tricuspid regurgitation (TR) were highly associated with survival (p < 0.01, p = 0.04, respectively) and were subsequently used to further stratify intermediate-risk patients. Among intermediate-risk patients, survival was worse for patients with TAPSE < 19 mm compared to those with TAPSE ≥ 19 mm (estimated one-year survival 74% vs. 96%, p < 0.01) and for patients with moderate/severe TR compared to those with no/trace/mild TR (estimated one-year survival 70% vs. 93%, p < 0.01). Furthermore, among intermediate-risk patients, those with both TAPSE < 19 mm and moderate/severe TR had an estimated one-year survival (56%) similar to that of high-risk patients (56%), and those with both TAPSE ≥ 19 mm and no/trace/mild TR had an estimated one-year survival (97%) similar to that of low-risk patients (95%). Conclusions: Echocardiography, a routinely performed, non-invasive imaging modality, plays a pivotal role in discriminating distinct survival phenotypes among prevalent intermediate-risk PAH patients using TAPSE and degree of TR. This can potentially help guide subsequent therapy.

Safety and Effectiveness of Intravenous Iron Therapy in Patients Supported by Durable Left Ventricular Assist Devices

Aims: While it is common practice to use intravenous (IV) iron in patients with left ventricular assist devices (LVADs) and iron deficiency, there is insufficient evidence regarding outcomes in this patient population. We evaluated the safety and effectiveness of IV iron therapy in patients supported by LVADs with iron deficiency. Methods: We performed a retrospective analysis of iron deficient patients on continuous LVAD support at a large academic center between 2008 and 2019. Patients were divided into two cohorts based on IV iron sucrose treatment. The primary endpoint was hemoglobin at 12 weeks. Secondary endpoints were mean corpuscular volume (MCV) and New York Heart Association (NYHA) class at 12 weeks. Safety endpoints included hospitalization, infection, pump thrombosis, arrhythmia, and gastrointestinal bleed. Models were weighted by the inverse probability of receiving IV iron using a propensity score, and endpoints were adjusted for their corresponding baseline values. Results: Among 213 patients, 70 patients received IV iron and 143 patients did not. Hemoglobin at 12 weeks was significantly greater among those treated (intergroup difference: 0.6 g/dL; 95% CI, 0.1 to 1.1; p = 0.01), while MCV was similar in both groups (intergroup difference: 0.7 μm³; 95% CI, −1.3 to 2.7; p = 0.50). NYHA class distribution at 12 weeks was significantly different (odds ratio for improvement: 2.84; 95% CI, 1.42 to 4.68; p = 0.003). The hazards of adverse events in each group were similar. Conclusions: In patients with LVADs and iron deficiency, treatment with IV iron sucrose was safe and associated with improvements in functional status and hemoglobin.

Left Ventricular Assist Device as a Bridge to Recovery: Single Center Experience of Successful Device Explantation

Continuous-flow left ventricular assist devices (CF-LVAD) have been shown to enhance reverse remodeling and myocardial recovery in certain patients allowing for device removal. We sought to analyze the characteristics and describe outcomes of patients who underwent CF-LVAD explantation at a large academic center. We retrospectively identified all patients who underwent CF-LVAD explants due to recovery from 2006 to 2019. Patient baseline characteristics and data on pre- and postexplant evaluation were collected and analyzed. Of 421 patients who underwent CF-LVAD implantation, 13 underwent explantation (3.1%). Twelve HeartMate II and one HeartWare LVAD were explanted. All patients had nonischemic cardiomyopathy. Median time from heart failure diagnosis to LVAD implant was 12 months (interquartile range [IQR], 2-44) and the median time supported on LVAD was 22 months (IQR, 11-28). Two patients died within 30 days of explant. Three additional patients died during the follow-up period and all were noted to be nonadherent to medical therapy. After a mean follow-up duration of 5 years, overall survival was 52%. Mean pre-explant ejection fraction was 49%, which decreased at most recent follow-up to 32%. Mean pre-explant left ventricular internal diameter in diastole (LVIDD) was 4.37 cm and increased to 5.52 cm at most recent follow-up. Continuous-flow left ventricular assist device explantation is feasible and safe in select patients.

Predicting, Recognizing, and Treating Right Heart Failure in Patients Undergoing Durable LVAD Therapy

Despite advancing technology, right heart failure after left ventricular assist device implantation remains a significant source of morbidity and mortality. With the UNOS allocation policy change, a larger proportion of patients proceeding to LVAD are destination therapy and consist of an overall sicker population. Thus, a comprehensive understanding of right heart failure is critical for ensuring the ongoing success of durable LVADs. The purpose of this review is to describe the effect of LVAD implantation on right heart function, review the diagnostic and predictive criteria related to right heart failure, and discuss the current evidence for management and treatment of post-LVAD right heart failure.

Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure

BACKGROUND

In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of an atrial shunt device did not provide overall clinical benefit for patients with heart failure with preserved or mildly reduced ejection fraction. However, prespecified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial volume, and sex. Shunt implantation reduces left atrial pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). On the basis of these results, we hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance during exercise, might be harmed by shunt implantation, and conversely that patients without PVD might benefit.

METHODS

REDUCE LAP-HF II enrolled 626 patients with heart failure, ejection fraction ≥40%, exercise pulmonary capillary wedge pressure ≥25 mm Hg, and resting pulmonary vascular resistance <3.5 Wood units who were randomized 1:1 to atrial shunt device or sham control. The primary outcome-a hierarchical composite of cardiovascular death, nonfatal ischemic stroke, recurrent HF events, and change in health status-was analyzed using the win ratio. Latent PVD was defined as pulmonary vascular resistance ≥1.74 Wood units (highest tertile) at peak exercise, measured before randomization.

RESULTS

Compared with patients without PVD (n=382), those with latent PVD (n=188) were older, had more atrial fibrillation and right heart dysfunction, and were more likely to have elevated left atrial pressure at rest. Shunt treatment was associated with worse outcomes in patients with PVD (win ratio, 0.60 [95% CI, 0.42, 0.86]; P=0.005) and signal of clinical benefit in patients without PVD (win ratio, 1.31 [95% CI, 1.02, 1.68]; P=0.038). Patients with larger right atrial volumes and men had worse outcomes with the device and both groups were more likely to have pacemakers, heart failure with mildly reduced ejection fraction, and increased left atrial volume. For patients without latent PVD or pacemaker (n=313; 50% of randomized patients), shunt treatment resulted in more robust signal of clinical benefit (win ratio, 1.51 [95% CI, 1.14, 2.00]; P=0.004).

CONCLUSIONS

In patients with heart failure with preserved or mildly reduced ejection fraction, the presence of latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.

Right Ventricular Global Longitudinal Strain as a Predictor of Acute and Early Right Heart Failure Post Left Ventricular Assist Device Implantation

Early right heart failure (RHF) occurs in up to 40% of patients following left ventricular assist device (LVAD) implantation and is associated with increased morbidity and mortality. The most recent report from the Mechanical Circulatory Support-Academic Research Consortium (MCS-ARC) working group subdivides early RHF into early acute RHF and early postimplant RHF. We sought to determine the effectiveness of right ventricular (RV) longitudinal strain (LS) in predicting RHF according to the new MCS-ARC definition. We retrospectively analyzed clinical and echocardiographic data of patients who underwent LVAD implantation between 2015 and 2018. RVLS in the 4-chamber (4ch), RV outflow tract, and subcostal views were measured on pre-LVAD echocardiograms. Fifty-five patients were included in this study. Six patients (11%) suffered early acute RHF, requiring concomitant RVAD implantation intraoperatively. Twenty-two patients (40%) had postimplant RHF. RVLS was significantly reduced in patients who developed early acute and postimplant RHF. At a cutoff of -9.7%, 4ch RVLS had a sensitivity of 88.9% and a specificity of 77.8% for predicting RHF and area under the receiver operating characteristic curve of 0.86 (95% confidence interval 0.76-0.97). Echocardiographic RV strain outperformed more invasive hemodynamic measures and clinical parameters in predicting RHF.

Novel Risk Model to Predict Emergency Department Associated Mortality for Patients Supported With a Ventricular Assist Device: The Emergency Department-Ventricular Assist Device Risk Score

Background The past decade has seen tremendous growth in patients with ambulatory ventricular assist devices. We sought to identify patients that present to the emergency department (ED) at the highest risk of death. Methods and Results This retrospective analysis of ED encounters from the Nationwide Emergency Department Sample includes 2010 to 2017. Using a random sampling of patient encounters, 80% were assigned to development and 20% to validation cohorts. A risk model was derived from independent predictors of mortality. Each patient encounter was assigned to 1 of 3 groups based on risk score. A total of 44 042 ED ventricular assist device patient encounters were included. The majority of patients were male (73.6%), <65 years old (60.1%), and 29% presented with bleeding, stroke, or device complication. Independent predictors of mortality during the ED visit or subsequent admission included age ≥65 years (odds ratio [OR], 1.8; 95% CI, 1.3-4.6), primary diagnoses (stroke [OR, 19.4; 95% CI, 13.1-28.8], device complication [OR, 10.1; 95% CI, 6.5-16.7], cardiac [OR, 4.0; 95% CI, 2.7-6.1], infection [OR, 5.8; 95% CI, 3.5-8.9]), and blood transfusion (OR, 2.6; 95% CI, 1.8-4.0), whereas history of hypertension was protective (OR, 0.69; 95% CI, 0.5-0.9). The risk score predicted mortality areas under the curve of 0.78 and 0.71 for development and validation. Encounters in the highest risk score strata had a 16-fold higher mortality compared with the lowest risk group (15.8% versus 1.0%). Conclusions We present a novel risk score and its validation for predicting mortality of patients with ED ventricular assist devices, a high-risk, and growing, population.

Mental health disorders and emergency resource use and outcomes in ventricular assist device supported patients

There are limited data describing the prevalence of mental health disorders (MHDOs) in patients with ventricular assist devices (VADs), or associations between MHDOs and resource use or outcomes. We used the Nationwide Emergency Department Sample administrative database to analyze 44,041 ED encounters for VAD-supported adults from 2010 to 2017, to assess the relationship between MHDOs and outcomes in this population. MHDO diagnoses were present for 23% of encounters, and were associated with higher charges and rates of admission, but lower mortality.

ISHLT consensus document on lung transplantation in patients with connective tissue disease: Part II: Cardiac, surgical, perioperative, operative, and post-operative challenges and management statements

Patients with connective tissue disease (CTD) present unique surgical, perioperative, operative, and postoperative challenges related to the often underlying severe pulmonary hypertension and right ventricular dysfunction. The International Society for Heart and Lung Transplantation-supported consensus document on lung transplantation in patients with CTD standardization addresses the surgical challenges and relevant cardiac involvement in the perioperative, operative, and postoperative management in patients with CTD.

Coronavirus disease 2019 in heart transplant recipients: Risk factors, immunosuppression, and outcomes

Background

COVID-19 continues to inflict significant morbidity and mortality, particularly on patients with preexisting health conditions. The clinical course, outcomes, and significance of immunosuppression regimen in heart transplant recipients with COVID-19 remains unclear.

Methods

We included the first 99 heart transplant recipients at participating centers with COVID-19 and followed patients until resolution. We collected baseline information, symptoms, laboratory studies, vital signs, and outcomes for included patients. The association of immunosuppression regimens at baseline with severe disease were compared using logistic regression, adjusting for age and time since transplant.

Results

The median age was 60 years, 25% were female, and 44% were white. The median time post-transplant to infection was 5.6 years. Overall, 15% died, 64% required hospital admission, and 7% remained asymptomatic. During the course of illness, only 57% of patients had a fever, and gastrointestinal symptoms were common. Tachypnea, oxygen requirement, elevated creatinine and inflammatory markers were predictive of severe course. Age ≥ 60 was associated with higher risk of death and the use of the combination of calcineurin inhibitor, antimetabolite, and prednisone was associated with more severe disease compared to the combination of calcineurin inhibitor and antimetabolite alone (adjusted OR = 7.3, 95% CI 1.8-36.2). Among hospitalized patients, 30% were treated for secondary infection, acute kidney injury was common and 17% required new renal replacement therapy.

Conclusions

We present the largest study to date of heart transplant patients with COVID-19 showing common atypical presentations and a high case fatality rate of 24% among hospitalized patients and 16% among symptomatic patients.

Multimodality assessment of heart failure with preserved ejection fraction skeletal muscle reveals differences in the machinery of energy fuel metabolism

AIMS

Skeletal muscle (SkM) abnormalities may impact exercise capacity in patients with heart failure with preserved ejection fraction (HFpEF). We sought to quantify differences in SkM oxidative phosphorylation capacity (OxPhos), fibre composition, and the SkM proteome between HFpEF, hypertensive (HTN), and healthy participants.

METHODS AND RESULTS

Fifty-nine subjects (20 healthy, 19 HTN, and 20 HFpEF) performed a maximal-effort cardiopulmonary exercise test to define peak oxygen consumption (VO_{2, peak} ), ventilatory threshold (VT), and VO₂ efficiency (ratio of total work performed to O₂ consumed). SkM OxPhos was assessed using Creatine Chemical-Exchange Saturation Transfer (CrCEST, n = 51), which quantifies unphosphorylated Cr, before and after plantar flexion exercise. The half-time of Cr recovery (t_{1/2, Cr} ) was taken as a metric of in vivo SkM OxPhos. In a subset of subjects (healthy = 13, HTN = 9, and HFpEF = 12), percutaneous biopsy of the vastus lateralis was performed for myofibre typing, mitochondrial morphology, and proteomic and phosphoproteomic analysis. HFpEF subjects demonstrated lower VO_2,peak , VT, and VO₂ efficiency than either control group (all P < 0.05). The t_{1/2, Cr} was significantly longer in HFpEF (P = 0.005), indicative of impaired SkM OxPhos, and correlated with cycle ergometry exercise parameters. HFpEF SkM contained fewer Type I myofibres (P = 0.003). Proteomic analyses demonstrated (a) reduced levels of proteins related to OxPhos that correlated with exercise capacity and (b) reduced ERK signalling in HFpEF.

CONCLUSIONS

Heart failure with preserved ejection fraction patients demonstrate impaired functional capacity and SkM OxPhos. Reductions in the proportions of Type I myofibres, proteins required for OxPhos, and altered phosphorylation signalling in the SkM may contribute to exercise intolerance in HFpEF.

Characteristics and Outcomes of COVID-19 in Patients on Left Ventricular Assist Device Support

Supplemental Digital Content is available in the text.

Background:

The coronavirus disease 2019 (COVID-19) pandemic continues to afflict millions of people worldwide. Patients with end-stage heart failure and left ventricular assist devices (LVADs) may be at risk for severe COVID-19 given a high prevalence of complex comorbidities and functional impaired immunity. The objective of this study is to describe the clinical characteristics and outcomes of COVID-19 in patients with end-stage heart failure and durable LVADs.

Methods:

The Trans-CoV-VAD registry is a multi-center registry of LVAD and cardiac transplant patients in the United States with confirmed COVID-19. Patient characteristics, exposure history, presentation, laboratory data, course, and clinical outcomes were collected by participating institutions and reviewed by a central data repository. This report represents the participation of the first 9 centers to report LVAD data into the registry.

Results:

A total of 40 patients were included in this cohort. The median age was 56 years (interquartile range, 46–68), 14 (35%) were women, and 21 (52%) were Black. Among the most common presenting symptoms were cough (41%), fever, and fatigue (both 38%). A total of 18% were asymptomatic at diagnosis. Only 43% of the patients reported either subjective or measured fever during the entire course of illness. Over half (60%) required hospitalization, and 8 patients (20%) died, often after lengthy hospitalizations.

Conclusions:

We present the largest case series of LVAD patients with COVID-19 to date. Understanding these characteristics is essential in an effort to improve the outcome of this complex patient population.

No survival benefit associated with waiting for non-lung donor heart transplants for adult recipients with congenital heart disease

BACKGROUND

Adults with congenital heart disease (CHD) awaiting heart transplant (HT) have higher mortality and waitlist removal due to clinical deterioration than those without CHD. The selective use of non-lung donors (NLD) to recover donor pulmonary vasculature to assist in graft implantation may be a contributing factor and is supported by consensus statements despite the recent use of pericardium or graft material as an alternative in pulmonary vascular reconstruction. The impact of selecting NLD for CHD recipients on wait time and mortality has not been evaluated.

METHODS/RESULTS

In the United Network for Organ Sharing (UNOS) Registry, 1271 HT recipients age ≥ 18 with CHD were identified between 1987 and 2016, 68% of which had NLDs. Prior to HT, NLD recipients were significantly less likely to be listed UNOS Status 1A, require mechanical ventilation, or intra-aortic balloon pump support. There was no difference in mean waitlist time (254 vs. 278 days, p = .31), 1-year mortality (82% vs. 80%, p = .81; adjusted odds ratio 1.32, 95% confidence interval [CI] 0.96-1.83, p = .08), or overall mortality (adjusted hazard ratio 1.08, 95% CI 0.86-1.36, p = .48) between recipients from NLD and concomitant lung donors.

CONCLUSIONS

Adult CHD patients who are less critically ill or listed at a lower status are more likely to receive HT from NLD. There is no overall mortality benefit associated with this practice. While specific cases may necessitate waiting for NLD, programs need to re-evaluate whether this should remain a more widespread practice among CHD patients.

An Increasing Burden of Disease: Emergency Department Visits Among Patients With Ventricular Assist Devices From 2010 to 2017

Background With a growing population of patients supported by ventricular assist devices (VADs) and the improvement in survival of this patient population, understanding the healthcare system burden is critical to improving outcomes. Thus, we sought to examine national estimates of VAD-related emergency department (ED) visits and characterize their demographic, clinical, and outcomes profile. Additionally, we tested the hypotheses that resource use increased and mortality improved over time. Methods and Results This retrospective database analysis uses encounter-level data from the 2010 to 2017 Nationwide Emergency Department Sample. The primary outcome was mortality. From 2010 to 2017, >880 million ED visits were evaluated, with 44 042 VAD-related ED visits identified. The annual mean visits were 5505 (SD 4258), but increased 16-fold from 2010 to 2017 (824 versus 13 155). VAD-related ED visits frequently resulted in admission (72%) and/or death (3.0%). Median inflation-adjusted charges were $25 679 (interquartile range, $7450, $63 119) per encounter. The most common primary diagnoses were cardiac (22%), and almost 30% of encounters were because of bleeding, stroke, or device complications. From 2010 to 2017, admission and mortality decreased from 82% to 71% and 3.4% to 2.4%, respectively (P for trends <0.001, both). Conclusions We present the first study using national-level data to characterize the growing ED resource use and financial burden of patients supported by VAD. During the past decade, admission and mortality rates decreased but remain substantial; in 2017 ≈1 in every 40 VAD ED encounters resulted in death, making it critical that clinical decision-making be optimized for patients with VAD to maximize good outcomes.

A Modified Grading System for Early Right Heart Failure Matches Functional Outcomes and Survival After Left Ventricular Assist Devices

Early right heart failure (ERHF) remains a common complication after continuous-flow left ventricular assist device (cf-LVAD) and has been associated with increased mortality. The specific criteria used to define ERHF remain somewhat arbitrary. Correlating the degree of ERHF with outcomes after LVAD could inform a more clinically relevant definition. We identified 196 patients who underwent first durable cf-LVAD between 2008 and 2015 at a single center. Postimplant ERHF was graded as absent, mild (requiring inotropic support for 14-20 days), moderate (inotropes for ≥ 21 days), or severe (requiring unplanned RVAD at any time during the index hospitalization). ERHF was associated with clinical outcomes including 1 year survival and New York Heart Association (NYHA) class and 6 minute walk distance (6MWD) at 3 and 6 months. Survival was assessed using the Kaplan-Meier method with log-rank testing and multivariate Cox proportional-hazards modeling. Compared to patients without ERHF, those with mild ERHF had similar 1 year survival (hazard ratio [HR] 0.69, 95% confidence interval [CI]: 0.26-1.80, p = 0.45), while mortality was substantially increased in patients with moderate (HR 2.65, 95% CI: 1.27-5.54, p = 0.009) and severe ERHF (HR 8.16, 95% CI: 3.97-16.76, p < 0.0001). The severity of ERHF was associated with 6MWD at both 3 months (p = 0.001) and 6 months (p = 0.013). The relationship between ERHF and postimplant survival and functional status persisted in multivariate modeling. A simple, modified grading system for ERHF severity is strongly associated with 1 year survival and functional capacity after cf-LVAD. These results argue against using a binary definition for ERHF and suggest the need to modify definition of ERHF severity.

Greater admissions, mortality and cost of heart failure in adults with congenital heart disease

OBJECTIVE

Limited contemporary data exist regarding outcomes and resource use among adults with congenital heart disease and heart failure (ACHD-HF). This study compared outcomes, emergency department (ED) and hospital resource use, and advanced heart failure (HF) therapies in ACHD-HF versus non-ACHD with HF (HF-non-ACHD).

METHODS

The Nationwide Emergency Department Sample and Nationwide Inpatient Sample were used to analyse outcomes and resource use among ACHD-HF ED visits and hospitalisations from 2006 to 2016. ACHD-HF was stratified by single-ventricle (SV) and two-ventricle (2V) disease.

RESULTS

A total of 76 557 ACHD-HF visits (3.6% SV physiology) and 31 137 414 HF-non-ACHD visits were analysed. ACHD-HFs were younger (SV 33 years (IQR 25-44), 2V 62 years (IQR 45-76); HF-non-ACHD 74 years (IQR 63-83); p<0.001). ACHD-HFs had higher ED admissions (78% vs 70%, p<0.001), longer hospital length of stay (5 days (IQR 2-8) vs 4 days (IQR 2-7), p<0.001) and greater hospital costs ($49K (IQR 2K-121K) vs $32K (17K-66K), p<0.001). Mortality was significantly higher among ACHD-HFs with SV physiology (6.6%; OR 1.6, 95% CI 1.1 to 2.3) or 2V physiology (6.3%; OR 1.4, 95% CI 1.3 to 1.5) versus HF-non-ACHD (5.5%). ACHF-HF hospitalisations increased more (46% vs 6% HF-non-ACHD) over a 10-year period, but the proportion receiving ventricular assist device (VAD) (ACHD-HF -2% vs HF-non-ACHD 294%) or transplant (ACHD-HF -37% vs HF-non-ACHD 73%) decreased.

CONCLUSION

ACHD-HFs have significant ED and hospital resource use that has increased over the past 10 years. However, advanced HF therapies (VAD and transplantation) are less commonly used compared with those without adult congenital heart disease.

Risk factors for 30-day readmission in adults hospitalized for pulmonary hypertension

Readmissions for pulmonary hypertension are poorly understood and understudied. We sought to determine national estimates and risk factors for 30-day readmission after pulmonary hypertension-related hospitalizations. We utilized the Healthcare Cost and Utilization Project Nationwide Readmission Database, which has weighted estimates of roughly 35 million discharges in the US. Adult patients with primary International Classification of Disease, Ninth Revision, Clinical Modification diagnosis codes of 416.0 and 416.8 for primary and secondary pulmonary hypertension with an index admission between 2012 and 2014 and any readmission within 30 days of the index event were identified. Predictors of 30-day readmission were identified using multivariable logistic regression with adjustment for covariates. Results showed that the national estimate for Primary Pulmonary Hypertension vs Secondary Pulmonary Hypertension-related index events between 2012 and 2014 with 30-day readmission was 247 vs 2550 corresponding to a national readmission risk estimate of 17% vs 18.3%, respectively. The presence of fluid and electrolyte disorders, renal failure, and alcohol abuse were associated with increased risk of readmission in Primary Pulmonary Hypertension, while factors associated with Secondary Pulmonary Hypertension readmissions included anemia, congestive heart failure, lung disease, fluid and electrolyte disorders, renal failure, diabetes, and liver disease. The median cost of Primary Pulmonary Hypertension admissions and readmissions were $46,132 (IQR: $25,384–$85,647) and $41,604.50 (IQR: $22,481.50–$84,420.50), respectively. The median costs of Secondary Pulmonary Hypertension admissions and readmissions were $34,893 (IQR: $19,670–$66,143) and $36,279 (IQR: $19,059–$74,679), respectively. In conclusion, approximately 19% of Primary Pulmonary Hypertension and Secondary Pulmonary Hypertension hospitalizations result in 30-day readmission, with significant costs accrued during the index hospitalization and readmission. With evolving clinical terminology and diagnostic codes, future study will need to better clarify underlying factors associated with readmissions amongst pulmonary hypertension sub-types, and identify methods and procedures to minimize readmission risk.

SCUBE1 Controls BMPR2-Relevant Pulmonary Endothelial Function: Implications for Diagnostic Marker Development in Pulmonary Arterial Hypertension

Utilizing publicly available ribonucleic acid sequencing data, we identified SCUBE1 as a BMPR2-related gene differentially expressed between induced pluripotent stem cell-endothelial cells derived from pulmonary arterial hypertension (PAH) patients carrying pathogenic BMPR2 mutations and control patients without mutations. Endothelial SCUBE1 expression was decreased by known triggers of PAH, and its down-regulation recapitulated known BMPR2-associated endothelial pathophenotypes in vitro. Meanwhile, SCUBE1 concentrations were reduced in plasma obtained from PAH rodent models and patients with PAH, whereas plasma concentrations were tightly correlated with hemodynamic markers of disease severity. Taken together, these data implicate SCUBE1 as a novel contributor to PAH pathogenesis with potential therapeutic, diagnostic, and prognostic applications.

Ranolazine Improves Right Ventricular Function in Patients With Precapillary Pulmonary Hypertension: Results From a Double-Blind, Randomized, Placebo-Controlled Trial

INTRODUCTION

A major outcome determinant in patients with precapillary pulmonary hypertension (PH) is right ventricular (RV) function. We studied the effect of ranolazine on RV function over 6 months using cardiovascular magnetic resonance (CMR) imaging in patients with precapillary PH (groups I, III, and IV).

METHODS AND RESULTS

We enrolled patients with PH and RV dysfunction (CMR imaging ejection fraction [EF] of <45%) in a longitudinal, randomized, double-blinded, placebo controlled, multicenter study of ranolazine treatment. All enrolled patients were on stable PH-specific therapy. Enrolled patients were assessed using CMR imaging, New York Heart Association functional class, N-terminal pro brain natriuretic peptide, 6-minute walk test, and quality of life health outcomes at baseline and repeated at the end of treatment. The primary outcome was change in RVEF after 6 months of treatment. Analysis of covariance was used to analyze the longitudinal changes taking into account baseline values, age, and sex, based on per protocol population. Twenty-two patients were enrolled, and 9 patients completed follow-up CMR imaging after ranolazine treatment and 6 completed placebo treatment. There was significant increase in RVEF at end of treatment compared with baseline in the ranolazine group adjusted for baseline values, age, and sex. There were no statistically significant changes in secondary outcomes such as changes in New York Heart Association functional class, 6-minute walk distance, N-terminal pro brain natriuretic peptide, or quality of life measures. Ranolazine treated patients experienced a higher number of adverse events, but only one was discontinued owing to side effects.

CONCLUSIONS

Ranolazine may improve RV function in patients with precapillary PH. Larger studies are needed to confirm the beneficial effects of ranolazine.

The effect of transfusion of blood products on ventricular assist device support outcomes

AIMS

Perioperative blood transfusions are common among patients undergoing left ventricular assist device (LVAD) implantation. The association between blood product transfusion at the time of LVAD implantation and mortality has not been described.

METHODS AND RESULTS

This was a retrospective cohort study of all patients who underwent continuous flow LVAD implantation at a single, large, tertiary care, academic centre, from 2008 to 2014. We assessed used of packed red blood cells (pRBCs), platelets, and fresh frozen plasma (FFP). Outcomes of interest included all-cause mortality and acute right ventricular (RV) failure. Standard regression techniques were used to examine the association between blood product exposure and outcomes of interest. A total of 170 patients were included in this study (mean age: 56.5 ± 15.5 years, 79.4% men). Over a median follow-up period of 11.2 months, for every unit of pRBC transfused, the hazard for mortality increased by 4% [hazard ratio (HR) 1.04; 95% CI 1.02-1.07] and odds for acute RV failure increased by 10% (odds ratio 1.10; 95% CI 1.05-1.16). This association persisted for other blood products including platelets (HR for mortality per unit 1.20; 95% CI 1.08-1.32) and FFP (HR for mortality per unit 1.08; 95% CI 1.04-1.12). The most significant predictor of perioperative blood product exposure was a lower pre-implant haemoglobin.

CONCLUSIONS

Perioperative blood transfusions among patients undergoing LVAD implantation were associated with a higher risk for all-cause mortality and acute RV failure. Of all blood products, FFP use was associated with worst outcomes. Future studies are needed to evaluate whether pre-implant interventions, such as intravenous iron supplementation, will improve the outcomes of LVAD candidates by decreasing need for transfusions.

A comprehensive echocardiographic method for risk stratification in pulmonary arterial hypertension

QUESTION ADDRESSED

Echocardiography is not currently considered as providing sufficient prognostic information to serve as an integral part of treatment goals in pulmonary arterial hypertension (PAH). We tested the hypothesis that incorporation of multiple parameters reflecting right heart function would improve the prognostic value of this imaging modality.

METHODS AND MAIN RESULTS

We pooled individual patient data from a total of 517 patients (mean age 52±15 years, 64.8% females) included in seven observational studies conducted at five European and United States academic centres. Patients were subdivided into three groups representing progressive degrees of right ventricular dysfunction based on a combination of echocardiographic measurements, as follows. Group 1 (low risk): normal tricuspid annular plane systolic excursion (TAPSE) and nonsignificant tricuspid regurgitation (TR) (n=129); group 2 (intermediate risk): normal TAPSE and significant TR or impaired TAPSE and nondilated inferior vena cava (IVC) (n=256); group 3 (high risk): impaired TAPSE and dilated IVC (n=132). The 5-year cumulative survival rate was 82% in group 1, 63% in group 2 and 43% in group 3. Low-risk patients had better survival rates than intermediate-risk patients (log-rank Chi-squared 12.25; p<0.001) and intermediate-risk patients had better survival rates than high-risk patients (log-rank Chi-squared 26.25; p<0.001). Inclusion of other parameters such as right atrial area and pericardial effusion did not provide added prognostic value.

ANSWER TO THE QUESTION

The proposed echocardiographic approach integrating the evaluation of TAPSE, TR grade and IVC is effective in stratifying the risk for all-cause mortality in PAH patients, outperforming the prognostic parameters suggested by current guidelines.

Treatment With Impella Increases the Risk of De Novo Aortic Insufficiency Post Left Ventricular Assist Device Implant

BACKGROUND

Impella (Abiomed Inc, Danvers, MA) is a temporary mechanical support device positioned across the aortic valve, and can be used to support patient before LVAD implantation. There are no data on the incidence of aortic insufficiency (AI) in patients supported with Impella as a bridge to durable LVAD implantation. We sought to assess the incidence of AI in patients with Impella support as a bridge to durable left ventricular assist device (LVAD) implantation.

METHODS

We reviewed all patients undergoing primary LVAD implantation at the University of Pennsylvania from January 2015 onward, comparing those supported with Impella as temporary mechanical support with those supported by either venoarterial extracorporeal life support or an intra-aortic balloon pump. We reviewed transthoracic echocardiography preoperatively, as well as at 1 week, 1, 3, 6, 9, and 12 months after LVAD implantation.

RESULTS

A total of 215 echocardiograms were analyzed in 41 patients. Eleven patients were supported with Impella before LVAD implant-6 patients with Impella alone (5 with Impella CP, 1 with Impella 5.0) and 5 with Impella in conjunction with venoarterial extracorporeal life support (2 with Impella 2.5, 2 with Impella CP, and 1 with Impella 5.0). After LVAD implant, mild or moderate AI developed in 82% of patients supported with Impella (9 of 11) compared with 43% of those without Impella (13 of 30) (P = .038).

CONCLUSIONS

Patients supported by Impella as a bridge to durable LVAD have a higher risk of developing AI. Further studies are needed to assess this risk as the use of the Impella increases.

Outcomes of catheter-directed versus systemic thrombolysis for the treatment of pulmonary embolism: A real-world analysis of national administrative claims

Catheter-directed thrombolysis (CDT) and systemic thrombolysis (ST) are used to treat intermediate/high-risk pulmonary embolism (PE) in the absence of comparative safety and effectiveness data. We utilized a large administrative database to perform a comparative safety and effectiveness analysis of catheter-directed versus systemic thrombolysis. From the Optum^® Clinformatics^® Data Mart private-payer insurance claims database, we identified 100,744 patients hospitalized with PE between 2004 and 2014. We extracted demographic characteristics, high-risk PE features, components of the Elixhauser Comorbidity Index, and outcomes including intracranial hemorrhage (ICH), all-cause bleeding, and mortality among all patients receiving CDT and ST. We used propensity score methods to compare outcomes between matched cohorts adjusted for observed confounders. A total of 1915 patients (1.9%) received either CDT (n = 632) or ST (n = 1283). Patients in the CDT group had fewer high-risk features including less shock (5.4 vs 11.1%; p < 0.001) and cardiac arrest (6.8 vs 11.0%; p = 0.004). In 1:1 propensity-matched groups, ICH rates were 1.9% in both the CDT and ST groups (p = 1.0). All-cause bleeding was higher in the CDT group (15.9 vs 8.7%; p < 0.001), while in-hospital mortality was lower (6.5 vs 10.0%; p = 0.02). Among a nationally representative cohort of patients with PE at higher risk for mortality, CDT was associated with similar ICH rates, increased all-cause bleeding, and lower short and intermediate-term mortality when compared with ST. The competing risks and benefits of CDT in real-world practice suggest the need for large-scale randomized clinical trials with appropriate comparator arms.

Pulmonary Hypertension in Heart Failure Patients

The development of pulmonary hypertension (PH) in patients with heart failure is associated with increased morbidity and mortality. In this article, the authors examine recent changes to the definition of PH in the setting of left heart disease (PH-LHD), and discuss its epidemiology, pathophysiology and prognosis. They also explore the complexities of diagnosing PH-LHD and the current evidence for the use of medical therapies, promising clinical trials and the role of left ventricular assist device and transplantation.

Peripheral Determinants of Oxygen Utilization in Heart Failure With Preserved Ejection Fraction: Central Role of Adiposity

•

ΔAVo₂ during exercise is a complex metric that incorporates into its calculation skeletal muscle blood flow and DmO₂ across the skeletal muscle capillary membrane.

•

Although ΔAVo₂ was reduced in patients with HFpEF during both systemic and local (forearm) exercise, there was no difference in forearm DmO₂ among subjects with HFpEF, those with hypertension, and healthy control subjects; therefore, abnormalities in forearm DmO₂ cannot explain the reduced forearm ΔAVo₂ seen in subjects with HFpEF.

•

Local forearm exercise performance predicted about one-third of the variability in systemic aerobic capacity, demonstrating that peripheral factors are important in determining whole-body exercise tolerance.

•

Degree of adiposity strongly correlated with ΔAVo₂ during both local and whole-body exercise, suggesting that adipose tissue may play an active role in limiting exercise capacity in subjects with HFpEF.

The aim of this study was to determine the arteriovenous oxygen content difference (ΔAVo₂) in adult subjects with and without heart failure with preserved ejection fraction (HFpEF) during systemic and forearm exercise. Subjects with HFpEF had reduced ΔAVo₂. Forearm diffusional conductance for oxygen, a lumped conductance parameter that incorporates all impediments to the movement of oxygen from red blood cells in skeletal muscle capillaries into the mitochondria within myocytes, was estimated. Forearm diffusional conductance for oxygen was not different among adults with HFpEF, those with hypertension, and healthy control subjects; therefore, diffusional conductance cannot explain the reduced forearm ΔAVo₂. Instead, adiposity was strongly associated with ΔAVo₂, suggesting an active role for adipose tissue in reducing exercise capacity in patients with HFpEF.

Serum Albumin Is a Marker of Myocardial Fibrosis, Adverse Pulsatile Aortic Hemodynamics, and Prognosis in Heart Failure With Preserved Ejection Fraction

Background

Data regarding the phenotypic correlates and prognostic value of albumin in heart failure with preserved ejection fraction (HFpEF) are scarce. The goal of the current study is to determine phenotypic correlates (myocardial hypertrophy, myocardial fibrosis, detailed pulsatile hemodynamics, and skeletal muscle mass) and prognostic implications of serum albumin in HFpEF.

Methods and Results

We studied 118 adults with HFpEF. All‐cause death or heart‐failure–related hospitalization was ascertained over a median follow‐up of 57.6 months. We measured left ventricular mass, myocardial extracellular volume, and axial muscle areas using magnetic resonance imaging. Pulsatile arterial hemodynamics were assessed with a combination of arterial tonometry and phase‐contrast magnetic resonance imaging. Subjects with lower serum albumin exhibited a higher body mass index, and a greater proportion of black ethnicity and diabetes mellitus. A low serum albumin was associated with higher myocardial extracellular volume (52.3 versus 57.4 versus 39.3 mL in lowest to highest albumin tertile, respectively; P=0.0023) and greater N‐terminal pro B‐type natriuretic peptide levels, but not with a higher myocardial cellular volume (123 versus 114 versus 102 mL; P=0.13). Lower serum albumin was also associated with an increased forward wave amplitude and markedly increased pulsatile power in the aorta. Serum albumin was a strong predictor of death or heart failure hospitalization even after adjustment for N‐terminal pro B‐type natriuretic peptide levels and the Meta‐Analysis Global Group in Chronic Heart Failure (MAGGIC) risk score (adjusted standardized hazard ratio=0.56; 95% CI=0.37–0.83; P<0.0001).

Conclusions

Serum albumin is associated with myocardial fibrosis, adverse pulsatile aortic hemodynamics, and prognosis in HFpEF. This readily available clinical biomarker can enhance risk stratification in HFpEF and identifies a subgroup with specific pathophysiological abnormalities.

Right ventricular outflow tract velocity time integral-to-pulmonary artery systolic pressure ratio: a non-invasive metric of pulmonary arterial compliance differs across the spectrum of pulmonary hypertension

Pulmonary arterial compliance (PAC), invasively assessed by the ratio of stroke volume to pulmonary arterial (PA) pulse pressure, is a sensitive marker of right ventricular (RV)-PA coupling that differs across the spectrum of pulmonary hypertension (PH) and is predictive of outcomes. We assessed whether the echocardiographically derived ratio of RV outflow tract velocity time integral to PA systolic pressure (RVOT-VTI/PASP) (a) correlates with invasive PAC, (b) discriminates heart failure with preserved ejection-associated PH (HFpEF-PH) from pulmonary arterial hypertension (PAH), and (c) is associated with functional capacity. We performed a retrospective cohort study of patients with PAH (n = 70) and HFpEF-PH (n = 86), which was further dichotomized by diastolic pressure gradient (DPG) into isolated post-capillary PH (DPG < 7 mmHg; Ipc-PH, n = 54), and combined post- and pre-capillary PH (DPG ≥ 7 mm Hg; Cpc-PH, n = 32). Of the 156 patients, 146 had measurable RVOT-VTI or PASP and were included in further analysis. RVOT-VTI/PASP correlated with invasive PAC overall (ρ = 0.61, P < 0.001) and for the PAH (ρ = 0.38, P = 0.002) and HFpEF-PH (ρ = 0.63, P < 0.001) groups individually. RVOT-VTI/PASP differed significantly across the PH spectrum (PAH: 0.13 [0.010–0.25] vs. Cpc-PH: 0.20 [0.12–0.25] vs. Ipc-PH: 0.35 [0.22–0.44]; P < 0.001), distinguished HFpEF-PH from PAH (AUC = 0.72, 95% CI = 0.63–0.81) and Cpc-PH from Ipc-PH (AUC = 0.78, 95% CI = 0.68–0.88), and remained independently predictive of 6-min walk distance after multivariate analysis (standardized β-coefficient = 27.7, 95% CI = 9.2–46.3; P = 0.004). Echocardiographic RVOT-VTI/PASP is a novel non-invasive metric of PAC that differs across the spectrum of PH. It distinguishes the degree of pre-capillary disease within HFpEF-PH and is predictive of functional capacity.

Abstract 106: Predicting Pulmonary Hypertension Readmission Using Machine Learning Models

Objectives: Pulmonary hypertension (PH) is increasingly recognized but understudied. We sought to determine predictors of 30-day readmission after PH-related hospitalization using Driverless Artificial Intelligence (DAI) algorithm.

Methods: We utilized the 2012-2014 Healthcare Cost and Utilization Project Nationwide Readmission Database (NRD) that accounts for weighted estimates of roughly 35 million discharges in the United States. Adult patients with primary ICD-9-CM diagnosis codes of 416.0 and 416.8 for primary and secondary PH with an index admission and any readmission within 30-days of the index event were identified. We assessed predictors of all cause 30-day readmission from clinical, hospital and 29 AHRQ comorbidity measures using predictive modeling to provide interpretable risk factors globally at population level and locally associated with each discharge. The risk prediction model was developed using DAI algorithm and results compared to models based on LIME GLM, Random Forest, and Decision Tree. Overall model performance was assessed using concordance statistic.

Results: Data from patients with 14,659 admissions and 2797 30-day readmissions were used to train the model. After data processing, the final model included 3674 variables. The Random Forest model had the best performance with c-statistic of 0.70 and surrogate models compared at AUCs of 0.51(Decision Tree), 0.62 (LIME) and (DAI) 0.59. Global features that mainly important to the overall prediction of DAI model were deficiency anemia, APR-DRG severity risk, APR-DRG mortality risk, renal failure and CHF.

Conclusion: Using predictive models with high predictive power, interpretable risk factors and prediction accuracy may enable health care systems to accurately target high-risk PH patients and prevent recurrent readmissions.

EXPRESS: Statement on imaging and pulmonary hypertension from the Pulmonary Vascular Research Institute (PVRI)

Pulmonary hypertension (PH) is highly heterogeneous and despite treatment advances it remains a life-shortening condition. There have been significant advances in imaging technologies, but despite evidence of their potential clinical utility, practice remains variable, dependent in part on imaging availability and expertise. This statement summarizes current and emerging imaging modalities and their potential role in the diagnosis and assessment of suspected PH. It also includes a review of commonly encountered clinical and radiological scenarios, and imaging and modeling-based biomarkers. An expert panel was formed including clinicians, radiologists, imaging scientists, and computational modelers. Section editors generated a series of summary statements based on a review of the literature and professional experience and, following consensus review, a diagnostic algorithm and 55 statements were agreed. The diagnostic algorithm and summary statements emphasize the key role and added value of imaging in the diagnosis and assessment of PH and highlight areas requiring further research.

Cardiopulmonary Exercise Testing-A Valuable Tool, Not Gatekeeper When Referring Patients With Adult Congenital Heart Disease for Transplant Evaluation

INTRODUCTION

Treatment of patients with adult congenital heart disease (ACHD) with advanced therapies including heart transplant (HT) is often delayed due to paucity of objective prognostic markers for the severity of heart failure (HF). While the utility of Cardiopulmonary Exercise Testing (CPET) in non-ACHD patients has been well-defined as it relates to prognosis, CPET for this purpose in ACHD is still under investigation.

METHODS

We performed a retrospective cohort study of 20 consecutive patients with ACHD who underwent HT between March 2010 and February 2016. Only 12 of 20 patients underwent CPET prior to transplantation. Demographics, standard measures of CPET interpretation, and 30-day and 1-year post transplantation outcomes were collected.

RESULTS

Patient Characteristics. Twenty patients with ACHD were transplanted at a median of 40 years of age (range: 23-57 years). Of the 12 patients who underwent CPET, 4 had undergone Fontan procedures, 4 had tetralogy of Fallot, 3 had d-transposition of the great arteries, and 1 had Ebstein anomaly. Thirty-day and one-year survival was 100%. All tests included in the analysis had a peak respiratory quotient _1.0. The median peak oxygen consumption per unit time (_VO2) for all diagnoses was 18.2 mL/kg/min (46% predicted), ranging from 12.2 to 22.6.

CONCLUSION

There is a paucity of data to support best practices for patients with ACHD requiring transplantation. While it cannot be proven based on available data, it could be inferred that outcomes would have been worse or perhaps life sustaining options unavailable if providers delayed referral because of the lack of attainment of CPET-specific thresholds.

Increased Pulmonary-Systemic Pulse Pressure Ratio Is Associated With Increased Mortality in Group 1 Pulmonary Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterised by remodelling of the pulmonary vasculature leading to right ventricular (RV) failure. The failing RV, through interventricular uncoupling, deleteriously impacts the left ventricle and overall cardiac efficiency. We hypothesised that the ratio of the pulmonary artery pulse pressure to the systemic pulse pressure ("pulmonary-systemic pulse pressure ratio", or PS-PPR) would be associated with mortality in PAH.

METHODS

We conducted a retrospective analysis of 262 patients in the National Institute of Health Primary Pulmonary Hypertension Registry (NIH-PPH). We evaluated the association between the PS-PPR and mortality after adjustment for the Pulmonary Hypertension Connection (PHC) risk equation.

RESULTS

Among 262 patients (mean age 37.5±15.8years, 62.2% female), median PS-PPR was 1.04 (IQR 0.79-1.30). In the Cox proportional hazards regression model, each one unit increase in the PS-PPR was associated with more than a two-fold increase in mortality during follow-up (HR 2.06, 95% CI 1.40-3.02, p=0.0002), and this association of PS-PPR with mortality remained significant in the multivariable Cox model adjusted for the PHC risk equation, mean pulmonary artery pressure, and body mass index (BMI) (adjusted HR 1.81, 95% CI 1.13-2.88, p=0.01). Furthermore, PS-PPR in the upper quartile (>1.30) versus quartiles 1-3 was associated with a 68% increase in mortality after adjustment for these same covariates (adjusted HR 1.68, 95% CI 1.13-2.50, p=0.01).

CONCLUSIONS

Pulmonary-systemic pulse pressure ratio, a marker of biventricular efficiency, is associated with survival in PAH even after adjustment for the PHC risk equation. Further studies are needed on the wider applications of PS-PPR in PAH patients.