Cardiogenic Shock in Older Adults: A Focus on Age-Associated Risks and Approach to Management: A Scientific Statement From the American Heart Association.

Cardiogenic shock continues to portend poor outcomes, conferring short-term mortality rates of 30% to 50% despite recent scientific advances. Age is a nonmodifiable risk factor for mortality in patients with cardiogenic shock and is often considered in the decision-making process for eligibility for various therapies. Older adults have been largely excluded from analyses of therapeutic options in patients with cardiogenic shock. As a result, despite the association of advanced age with worse outcomes, focused strategies in the assessment and management of cardiogenic shock in this high-risk and growing population are lacking. Individual programs oftentimes develop upper age limits for various interventional strategies for their patients, including heart transplantation and durable left ventricular assist devices. However, age as a lone parameter should not be used to guide individual patient management decisions in cardiogenic shock. In the assessment of risk in older adults with cardiogenic shock, a comprehensive, interdisciplinary approach is central to developing best practices. In this American Heart Association scientific statement, we aim to summarize our contemporary understanding of the epidemiology, risk assessment, and in-hospital approach to management of cardiogenic shock, with a unique focus on older adults.

Outcomes of Patients Transferred to Tertiary Care Centers for Treatment of Cardiogenic Shock: A Cardiogenic Shock Working Group Analysis.

BACKGROUND: Consensus recommendations for cardiogenic shock (CS) advise transfer of patients in need of advanced options beyond the capability of "spoke" centers to tertiary/"hub" centers with higher capabilities. However, outcomes associated with such transfers are largely unknown beyond those reported in individual health networks. OBJECTIVES: To analyze a contemporary, multicenter CS cohort with the aim of comparing characteristics and outcomes of patients between transfer (between spoke and hub centers) and nontransfer cohorts (those primarily admitted to a hub center) for both acute myocardial infarction (AMI-CS) and heart failure-related HF-CS. We also aim to identify clinical characteristics of the transfer cohort that are associated with in-hospital mortality. METHODS: The Cardiogenic Shock Working Group (CSWG) registry is a national, multicenter, prospective registry including high-volume (mostly hub) CS centers. Fifteen U.S. sites contributed data for this analysis from 2016-2020. RESULTS: Of 1890 consecutive CS patients enrolled into the CSWG registry, 1028 (54.4%) patients were transferred. Of these patients, 528 (58.1%) had heart failure-related CS (HF-CS), and 381 (41.9%) had CS related to acute myocardial infarction (AMI-CS). Upon arrival to the CSWG site, transfer patients were more likely to be in SCAI stages C and D, when compared to nontransfer patients. Transfer patients had higher mortality rates (37% vs 29%, < 0.001) than nontransfer patients; the differences were driven primarily by the HF-CS cohort. Logistic regression identified increasing age, mechanical ventilation, renal replacement therapy, and higher number of vasoactive drugs prior to or within 24 hours after CSWG site transfer as independent predictors of mortality among HF-CS patients. Conversely, pulmonary artery catheter use prior to transfer or within 24 hours of arrival was associated with decreased mortality rates. Among transfer AMI-CS patients, BMI > 28 kg/m2, worsening renal failure, lactate > 3 mg/dL, and increasing numbers of vasoactive drugs were associated with increased mortality rates. CONCLUSION: More than half of patients with CS managed at high-volume CS centers were transferred from another hospital. Although transfer patients had higher mortality rates than those who were admitted primarily to hub centers, the outcomes and their predictors varied significantly when classified by HF-CS vs AMI-CS.

Association of Hemometabolic Trajectory and Mortality: Insights From the Cardiogenic Shock Working Group Registry.

Cardiogenic shock (CS) is a hemodynamic syndrome that can progress to systemic metabolic derangements and end-organ dysfunction. Prior studies have reported hemodynamic parameters at the time of admission to be associated with mortality but hemodynamic trajectories in CS have not been well described. We studied the association between hemodynamic profiles and their trajectories and in-hospital mortality in patients with CS due to heart failure (HF-CS) and acute myocardial infarction (MI-CS). Using data from the large multicenter Cardiogenic Shock Working Group (CSWG) registry, we analyzed hemodynamic data obtained at the time of pulmonary artery catheter (PAC) insertion (dataset at baseline) and at PAC removal or death (dataset at final time point). Univariable regression analyses for prediction of in-hospital mortality were conducted for baseline and final hemodynamic values, as well as the interval change (delta-P). Data was further analyzed based on CS etiology and survival status. A total of 2260 patients with PAC data were included (70% male, age 61 ± 14 years, 61% HF-CS, 27% MI-CS). In-hospital mortality was higher in the MI-CS group (40.1%) compared with HF-CS (22.4%, P < .01). In the HF-CS cohort, survivors exhibited lower right atrial pressure (RAP), pulmonary artery pressure (PAP), cardiac output/index (CO/CI), lactate, and higher blood pressure (BP) than nonsurvivors at baseline. In this cohort, during hospitalization, improvement in metabolic (aspartate transaminase, lactate), BP, hemodynamic (RAP, pulmonary artery pulsatility index [PAPi], pulmonary artery compliance for right-sided profile and CO/CI for left-sided profile), had association with survival. In the MI-CS cohort, a lower systolic BP and higher PAP at baseline were associated with odds of death. Improvement in metabolic (lactate), BP, hemodynamic (RAP, PAPi for right-sided profile and CO/CI for left-sided profile) were associated with survival. In a large contemporary CS registry, hemodynamic trajectories had a strong association with short-term outcomes in both cohorts. These findings suggest the clinical importance of timing and monitoring hemodynamic trajectories to tailor management in patients with CS.

Plasma Cell-Free DNA Predicts Survival and Maps Specific Sources of Injury in Pulmonary Arterial Hypertension.

BACKGROUND: Cell-free DNA (cfDNA) is a noninvasive marker of cellular injury. Its significance in pulmonary arterial hypertension (PAH) is unknown. METHODS: Plasma cfDNA was measured in 2 PAH cohorts (A, n=48; B, n=161) and controls (n=48). Data were collected for REVEAL 2.0 (Registry to Evaluate Early and Long-Term PAH Disease Management) scores and outcome determinations. Patients were divided into the following REVEAL risk groups: low (≤6), medium (7-8), and high (≥9). Total cfDNA concentrations were compared among controls and PAH risk groups by 1-way analysis of variance. Log-rank tests compared survival between cfDNA tertiles and REVEAL risk groups. Areas under the receiver operating characteristic curve were estimated from logistic regression models. A sample subset from cohort B (n=96) and controls (n=16) underwent bisulfite sequencing followed by a deconvolution algorithm to map cell-specific cfDNA methylation patterns, with concentrations compared using t tests. RESULTS: In cohort A, median (interquartile range) age was 62 years (47-71), with 75% female, and median (interquartile range) REVEAL 2.0 was 6 (4-9). In cohort B, median (interquartile range) age was 59 years (49-71), with 69% female, and median (interquartile range) REVEAL 2.0 was 7 (6-9). In both cohorts, cfDNA concentrations differed among patients with PAH of varying REVEAL risk and controls (analysis of variance P≤0.002) and were greater in the high-risk compared with the low-risk category (P≤0.002). In cohort B, death or lung transplant occurred in 14 of 54, 23 of 53, and 35 of 54 patients in the lowest, middle, and highest cfDNA tertiles, respectively. cfDNA levels stratified as tertiles (log-rank: P=0.0001) and REVEAL risk groups (log-rank: P<0.0001) each predicted transplant-free survival. The addition of cfDNA to REVEAL improved discrimination (area under the receiver operating characteristic curve, 0.72-0.78; P=0.02). Compared with controls, methylation analysis in patients with PAH revealed increased cfDNA originating from erythrocyte progenitors, neutrophils, monocytes, adipocytes, natural killer cells, vascular endothelium, and cardiac myocytes (Bonferroni adjusted P<0.05). cfDNA concentrations derived from erythrocyte progenitor cells, cardiac myocytes, and vascular endothelium were greater in patients with PAH with high-risk versus low-risk REVEAL scores (P≤0.02). CONCLUSIONS: Circulating cfDNA is elevated in patients with PAH, correlates with disease severity, and predicts worse survival. Results from cfDNA methylation analyses in patients with PAH are consistent with prevailing paradigms of disease pathogenesis.

Pulmonary Artery Catheter Use and Risk of In-hospital Death in Heart Failure Cardiogenic Shock.

BACKGROUND: Pulmonary artery catheters (PACs) are increasingly used to guide management decisions in cardiogenic shock (CS). The goal of this study was to determine if PAC use was associated with a lower risk of in-hospital mortality in CS owing to acute heart failure (HF-CS). METHODS AND RESULTS: This multicenter, retrospective, observational study included patients with CS hospitalized between 2019 and 2021 at 15 US hospitals participating in the Cardiogenic Shock Working Group registry. The primary end point was in-hospital mortality. Inverse probability of treatment-weighted logistic regression models were used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CI), accounting for multiple variables at admission. The association between the timing of PAC placement and in-hospital death was also analyzed. A total of 1055 patients with HF-CS were included, of whom 834 (79%) received a PAC during their hospitalization. In-hospital mortality risk for the cohort was 24.7% (n = 261). PAC use was associated with lower adjusted in-hospital mortality risk (22.2% vs 29.8%, OR 0.68, 95% CI 0.50-0.94). Similar associations were found across SCAI stages of shock, both at admission and at maximum SCAI stage during hospitalization. Early PAC use (≤6 hours of admission) was observed in 220 PAC recipients (26%) and associated with a lower adjusted risk of in-hospital mortality compared with delayed (≥48 hours) or no PAC use (17.3% vs 27.7%, OR 0.54, 95% CI 0.37-0.81). CONCLUSIONS: This observational study supports PAC use, because it was associated with decreased in-hospital mortality in HF-CS, especially if performed within 6 hours of hospital admission. CONDENSED ABSTRACT: An observational study from the Cardiogenic Shock Working Group registry of 1055 patients with HF-CS showed that pulmonary artery catheter (PAC) use was associated with a lower adjusted in-hospital mortality risk (22.2% vs 29.8%, odds ratio 0.68, 95% confidence interval 0.50-0.94) compared with outcomes in patients managed without PAC. Early PAC use (≤6 hours of admission) was associated with a lower adjusted risk of in-hospital mortality compared with delayed (≥48 hours) or no PAC use (17.3% vs 27.7%, odds ratio 0.54, 95% confidence interval 0.37-0.81).

Timelines of adverse event journeys of LVAD patients.

OBJECTIVE: The INTERMACS Events data set contains an expansive collection of temporal evidence of the course of adverse events (AEs) of >15 000 patients that have received a left ventricular assist device (LVAD). The chronology of AEs may contain insightful information of the "AE journeys" of LVAD patients. The purpose of this study is to investigate the timelines of AEs within the INTERMACS database. METHODS: Descriptive statistics were applied to 86 912 recorded AEs of 15 820 patients with a continuous flow-LVAD between 2008 to 2016, extracted from INTERMACS registry. The characteristics of the timelines of AE journeys were investigated by posing six descriptive research questions. RESULTS: The analysis revealed several time-related characteristics and patterns of the AE journey after LVAD including the most common time of occurrences of AEs after surgery, duration of AEs journeys, the time of first and last AEs, and the time gaps between AEs. CONCLUSION: The INTERMACS Event dataset is a valuable resource for research about the timeline of AE journeys of patients who received an LVAD. It is necessary for future studies to first explore and consider the time-related characteristics of the data set such as diversity and sparsity to effectively choose an appropriate scope of time and time granularity and to acknowledge potential challenges.

Aspirin and Hemocompatibility Events With a Left Ventricular Assist Device in Advanced Heart Failure: The ARIES-HM3 Randomized Clinical Trial.

IMPORTANCE: Left ventricular assist devices (LVADs) enhance quality and duration of life in advanced heart failure. The burden of nonsurgical bleeding events is a leading morbidity. Aspirin as an antiplatelet agent is mandated along with vitamin K antagonists (VKAs) with continuous-flow LVADs without conclusive evidence of efficacy and safety. OBJECTIVE: To determine whether excluding aspirin as part of the antithrombotic regimen with a fully magnetically levitated LVAD is safe and decreases bleeding. DESIGN, SETTING, and PARTICIPANTS: This international, randomized, double-blind, placebo-controlled study of aspirin (100 mg/d) vs placebo with VKA therapy in patients with advanced heart failure with an LVAD was conducted across 51 centers with expertise in treating patients with advanced heart failure across 9 countries. The randomized population included 628 patients with advanced heart failure implanted with a fully magnetically levitated LVAD (314 in the placebo group and 314 in the aspirin group), of whom 296 patients in the placebo group and 293 in the aspirin group were in the primary analysis population, which informed the primary end point analysis. The study enrolled patients from July 2020 to September 2022; median follow-up was 14 months. Intervention: Patients were randomized in a 1:1 ratio to receive aspirin (100 mg/d) or placebo in addition to an antithrombotic regimen. MAIN OUTCOMES AND MEASURES: The composite primary end point, assessed for noninferiority (-10% margin) of placebo, was survival free of a major nonsurgical (>14 days after implant) hemocompatibility-related adverse events (including stroke, pump thrombosis, major bleeding, or arterial peripheral thromboembolism) at 12 months. The principal secondary end point was nonsurgical bleeding events. RESULTS: Of the 589 analyzed patients, 77% were men; one-third were Black and 61% were White. More patients were alive and free of hemocompatibility events at 12 months in the placebo group (74%) vs those taking aspirin (68%). Noninferiority of placebo was demonstrated (absolute between-group difference, 6.0% improvement in event-free survival with placebo [lower 1-sided 97.5% CI, -1.6%]; P < .001). Aspirin avoidance was associated with reduced nonsurgical bleeding events (relative risk, 0.66 [95% confidence limit, 0.51-0.85]; P = .002) with no increase in stroke or other thromboembolic events, a finding consistent among diverse subgroups of patient characteristics. CONCLUSIONS AND RELEVANCE: In patients with advanced heart failure treated with a fully magnetically levitated LVAD, avoidance of aspirin as part of an antithrombotic regimen, which includes VKA, is not inferior to a regimen containing aspirin, does not increase thromboembolism risk, and is associated with a reduction in bleeding events. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04069156.

Center Variability in Patient Outcomes Following HeartMate 3 Implantation: An Analysis of the MOMENTUM 3 Trial.

BACKGROUND: As left ventricular assist device (LVAD) survival rates continue to improve, evaluating site-specific variability in outcomes can facilitate identifying targets for quality-improvement initiative opportunities in the field. METHODS: Deidentified center-specific outcomes were analyzed for HeartMate 3 (HM3) patients enrolled in the MOMENTUM 3 pivotal and continued access protocol trials. Centers < 25th percentile for HM3 volumes were excluded. Variability in risk-adjusted center mortality was assessed at 90 days and 2 years (conditional upon 90-day survival). Adverse event (AE) rates were compared across centers. RESULTS: In the 48 included centers (1958 patients), study-implant volumes ranged between 17 and 106 HM3s. Despite similar trial-inclusion criteria, patient demographics varied across sites, including age quartile ((Q)1-Q3:57-62 years), sex (73%-85% male), destination therapy intent (60%-84%), and INTERMACS profile 1-2 (16%-48%). Center mortality was highly variable, nadiring at ≤ 3.6% (≤ 25th percentile) and peaking at ≥ 10.4% (≥ 75th percentile) at 90 days and ≤ 10.2% and ≥ 18.7%, respectively, at 2 years. Centers with low mortality rates tended to have lower 2-year AE rates, but no center was a top performer for all AEs studied. CONCLUSIONS: Mortality and AEs were highly variable across MOMENTUM 3 centers. Studies are needed to improve our understanding of the drivers of outcome variability and to ascertain best practices associated with high-performing centers across the continuum of intraoperative to chronic stages of LVAD support.

Outcomes in Patients With LVADs Undergoing Simultaneous Heart-Kidney Transplantation.

BACKGROUND: Multiple studies have shown better outcomes for simultaneous heart-kidney transplant (sHKT) than for isolated orthotopic heart transplant (iOHT) in recipients with chronic kidney disease (CKD). However, outcomes in patients supported by durable left ventricular assist devices (LVADs) have not been well studied. METHODS: Patients with durable LVADs and stage 3 or higher CKD (eGFR < 60 mL/min/1.73 m2) undergoing iOHT or sHKT between 2008 and 2020 were identified from the United Network for Organ Sharing registry. A Kaplan-Meier survival analysis with associated log-rank test was conducted to compare post-transplant survival rates. Multivariable modeling was used to identify risk-adjusted predictors of 1 year post-transplant mortality. RESULTS: We identified 4375 patients; 366 underwent sHKT, and 4009 underwent iOHT. The frequency of sHKT increased during the study period. The 1-year post-transplant survival rate was worse in patients after sHKT than in patients after iOHT (80.3% vs 88.3%; P < 0.001) and persisted up to 5 years post-transplant (P = 0.001). sHKT recipients were more likely to require dialysis after transplantation and had longer hospital lengths of stay (P < 0.001). Multivariable analysis showed that sHKT remained an independent risk factor for mortality at 1 year (OR 1.58; P = 0.002). CONCLUSIONS: sHKT is becoming more common in patients with durable LVADs. Compared with iOHT, patients with sHKTs have worse short- and long-term survival rates and are more likely to require post-transplant dialysis.

Selection and management considerations to enhance outcomes in patients supported by left ventricular assist devices.

PURPOSE OF REVIEW: Left ventricular assist devices (LVADs) are life-saving therapies for patients in end-stage heart failure (HF) with reduced ejection fraction regardless of candidacy for heart transplantation. Multiple clinical trials have demonstrated improved morbidity and mortality with LVADs when compared to medical therapy alone. However, the uptake of LVADs as a therapeutic option in a larger section of end-stage HF patients remains limited, partly due to associated adverse events and re-hospitalization. RECENT FINDINGS: Accurate assessment and staging of HF patients is crucial to guide appropriate use of LVADs. Innovative methods to risk stratify patients and manage cardiac and noncardiac comorbidities can translate to improved outcomes in LVAD recipients. Inclusion of quality of life metrics and measurements of adverse events can better inform heart failure cardiologists to help identify ideal LVAD candidates. Addition of machine learning algorithms to this process may guide patient selection to improve outcomes. SUMMARY: Patient selection and assessment of reversible medical comorbidities are critical to the postoperative success of LVAD implantation. Identifying patients most likely to benefit and least likely to experience adverse events should be a priority.

Role of medical management of cardiogenic shock in the era of mechanical circulatory support.

PURPOSE OF REVIEW: The goal of this review is to summarize the current knowledge on the role of medical management of cardiogenic shock in the era of mechanical circulatory support based on important lessons from clinical trials and routine clinical practice, with a focus on providing practical recommendations that can improve contemporary in-hospital management. RECENT FINDINGS: Despite an increasing number of invasive therapies being used to manage cardiogenic shock, evidence-based treatment regimens known to improve outcomes are limited. Medical management of cardiogenic shock includes pharmacological interventions aimed at optimizing determinants of cardiac output-contractility, preload, afterload, and heart rate. In this regard, inotropes and vasopressors remain cornerstone therapies for the management of cardiogenic shock. Norepinephrine has shown potential vasopressor advantage with compared with dopamine, and although milrinone and dobutamine are both considered appropriate first-line inotropes, there is limited data to guide selection, and a recent randomized clinical trial found no significant differences in the treatment of cardiogenic shock. SUMMARY: In the absence of an evidence-based management approach to cardiogenic shock, clinical guidelines are based on expert opinion and routine clinical practice patterns. Further studies focusing on clinical outcomes among specific cardiogenic shock phenotypes are needed to better assess the clinical efficacy of these agents.

Enrichment Benefits of Risk Algorithms for Pulmonary Arterial Hypertension Clinical Trials.

Rationale: Event-driven primary endpoints are increasingly used in pulmonary arterial hypertension clinical trials, substantially increasing required sample sizes and trial lengths. The U.S. Food and Drug Administration advocates the use of prognostic enrichment of clinical trials by preselecting a patient population with increased likelihood of experiencing the trial's primary endpoint.Objectives: This study compares validated clinical scales of risk (Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension, the French score, and Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management [REVEAL] 2.0) to identify patients who are likely to experience a clinical worsening event for trial enrichment.Methods: Baseline data from three pulmonary arterial hypertension clinical trials (AMBITION [a Study of First-Line Ambrisentan and Tadalafil Combination Therapy in Subjects with Pulmonary Arterial Hypertension], SERAPHIN [Study of Macitentan on Morbidity and Mortality in Patients with Symptomatic Pulmonary Arterial Hypertension], and GRIPHON [Selexipag in Pulmonary Arterial Hypertension]) were pooled and standardized. Receiver operating curves were used to measure each algorithm's performance in predicting clinical worsening within the pooled placebo cohort. Power simulations were conducted to determine sample size and treatment time reductions for multiple enrichment strategies. A cost analysis was performed to illustrate potential financial savings by applying enrichment to GRIPHON.Measurements and Main Results: All risk algorithms were compared using area under the receiver operating curve and substantially outperformed prediction per New York Heart Association Functional Class. The REVEAL 2.0's risk grouping provided the greatest time and sample size savings in AMBITION and GRIPHON for all enrichment strategies but lacked appropriate inputs (i.e., N-terminal-proB-type natriuretic peptide) to perform as well in SERAPHIN. Cost analysis applied to GRIPHON demonstrated the greatest financial benefit by enrolling patients with a REVEAL score ≥8.Conclusions: This preliminary study demonstrates the feasibility of risk algorithms for pulmonary arterial hypertension trial enrichment and a need for further investigation.

Artificial Intelligence and Mechanical Circulatory Support.

Advances in machine learning algorithms and computing power have fueled a rapid increase in artificial intelligence research in health care, including mechanical circulatory support. In this review, we highlight the needs for artificial intelligence in the mechanical circulatory support field and summarize existing artificial intelligence applications in 3 areas: identifying patients appropriate for mechanical circulatory support therapy, predicting risks after mechanical circulatory support device implantation, and monitoring for adverse events. We address the challenges of incorporating artificial intelligence in daily clinical practice and recommend demonstration of artificial intelligence tools' clinical efficacy, reliability, transparency, and equity to drive implementation.

Estimation of Stressed Blood Volume in Patients With Cardiogenic Shock From Acute Myocardial Infarction and Decompensated Heart Failure.

BACKGROUND: Sympathetically mediated redistribution of blood from the unstressed venous reservoir to the hemodynamically active stressed compartment is thought to contribute to congestion in cardiogenic shock (CS). We used a novel computational method to estimate stressed blood volume (SBV) in CS and assess its relationship with clinical outcomes. METHODS AND RESULTS: Hemodynamic parameters including estimated SBV (eSBV) were compared among patients from the Cardiogenic Shock Working Group registry with a complete set of hemodynamic data. eSBV was compared across shock etiologies (acute myocardial infarction and CS (AMI-CS) vs heart failure with CS (HF-CS), Society for Cardiovascular Angiography and Interventions stage, and between survivors and nonsurvivors. Among 528 patients with patients analyzed, the mean eSBV was 2423 mL/70 kg and increased with increasing Society for Cardiovascular Angiography and Interventions stage (B, 2029 mL/70 kg; C, 2305 mL/70 kg; D, 2496 mL/70 kg; E, 2707 mL/70 kg; P < .001). The eSBV was significantly greater among patients with HF-CS who died compared with survivors (2733 vs 2357 mL/70 kg; P < .001), whereas no significant difference was observed between outcome groups in AMI-CS (2501 mL/70 kg vs 2384 mL/70 kg; P = .19). CONCLUSIONS: eSBV is a novel integrated index of congestion which correlates with shock severity. eSBV was higher in patients with HF-CS who died; no difference was observed in patients with AMI-CS, suggesting that congestion may play a more significant role in the deterioration of patients with HF-CS.

Right Ventricular Pressure-Volume Analysis During Left Ventricular Assist Device Speed Optimization Studies: Insights Into Interventricular Interactions and Right Ventricular Failure.

BACKGROUND: Interventricular interaction, which refers to the impact of left ventricular (LV) function on right ventricular (RV) function and vice versa, has been implicated in the pathogenesis of RV failure in LV assist device (LVAD) recipients. We sought to understand more about interventricular interaction by quantifying changes in the RV systolic and diastolic function with varying LVAD speeds. METHODS AND RESULTS: Four patients (ages 22-69 years, 75% male, and 25% with ischemic cardiomyopathy) underwent a protocolized hemodynamic ramp test within 12 months of LVAD implantation where RV pressure-volume loops were recorded with a conductance catheter. The end-systolic PV relationship and end-diastolic PV relationship were compared using the V20 and V10 indices (volumes at which end-systolic PV relationship and end-diastolic PV relationship reach a pressure of 20 and 10 mm Hg, respectively). The ∆V20 and ∆V10 refer to the change in V20 and V10 from the minimum to maximum LVAD speeds. RV PV loops demonstrated variable changes in systolic and diastolic function with increasing LVAD speed. The end-systolic PV relationship changed in 1 patient (patient 2, ∆V20 = 23.5 mL), reflecting a decrease in systolic function with increased speed, and was unchanged in 3 patients (average ∆V20 = 7.4 mL). The end-diastolic PV relationship changed with increasing speed in 3 of 4 patients (average ∆V10 = 12.5 mL), indicating an increase in ventricular compliance, and remained unchanged in one participant (patient 1; ∆V10 = 4.0 mL). CONCLUSIONS: Interventricular interaction can improve RV compliance and impair systolic function, but the overall effect on RV performance in this pilot investigation is heterogeneous. Further research is required to understand which patient characteristics and hemodynamic parameters influence the net impact of interventricular interaction.

Right Ventricular Dysfunction Is Common and Identifies Patients at Risk of Dying in Cardiogenic Shock.

BACKGROUND: Understanding the prognostic impact of right ventricular dysfunction (RVD) in cardiogenic shock (CS) is a key step toward rational diagnostic and treatment algorithms and improved outcomes. Using a large multicenter registry, we assessed (1) the association between hemodynamic markers of RVD and in-hospital mortality, (2) the predictive value of invasive hemodynamic assessment incorporating RV evaluation, and (3) the impact of RVD severity on survival in CS. METHODS AND RESULTS: Inpatients with CS owing to acute myocardial infarction (AMI) or heart failure (HF) between 2016 and 2019 were included. RV parameters (right atrial pressure, right atrial/pulmonary capillary wedge pressure [RA/PCWP], pulmonary artery pulsatility index [PAPI], and right ventricular stroke work index [RVSWI]) were assessed between survivors and nonsurvivors, and between etiology and SCAI stage subcohorts. Multivariable logistic regression analysis determined hemodynamic predictors of in-hospital mortality; the resulting models were compared with SCAI staging alone. Nonsurvivors had a significantly higher right atrial pressure and RA/PCWP and lower PAPI and RVSWI than survivors, consistent with more severe RVD. Compared with AMI, patients with HF had a significantly lower RA/PCWP (0.58 vs 0.66, P = .001) and a higher PAPI (2.71 vs 1.78, P < .001) and RVSWI (5.70 g-m/m2 vs 4.66 g-m/m2, P < .001), reflecting relatively preserved RV function. Paradoxically, multiple RVD parameters (PAPI, RVSWI) were associated with mortality in the HF but not the AMI cohort. RVD was more severe with advanced SCAI stage, although its prognostic value was progressively diluted in stages D and E. Multivariable modelling incorporating the RA/PCWP improved the predictive value of SCAI staging (area under the curve [AUC] 0.78 vs 0.73, P < .001), largely driven by patients with HF (AUC 0.82 vs 0.71, P < .001). CONCLUSIONS: RVD is associated with poor outcomes in CS, with key differences across etiology and shock severity. Further studies are needed to assess the usefulness of RVD assessment in guiding therapy.

Risk stratification in pulmonary arterial hypertension using Bayesian analysis.

BACKGROUND: Current risk stratification tools in pulmonary arterial hypertension (PAH) are limited in their discriminatory abilities, partly due to the assumption that prognostic clinical variables have an independent and linear relationship to clinical outcomes. We sought to demonstrate the utility of Bayesian network-based machine learning in enhancing the predictive ability of an existing state-of-the-art risk stratification tool, REVEAL 2.0. METHODS: We derived a tree-augmented naïve Bayes model (titled PHORA) to predict 1-year survival in PAH patients included in the REVEAL registry, using the same variables and cut-points found in REVEAL 2.0. PHORA models were validated internally (within the REVEAL registry) and externally (in the COMPERA and PHSANZ registries). Patients were classified as low-, intermediate- and high-risk (<5%, 5-20% and >10% 12-month mortality, respectively) based on the 2015 European Society of Cardiology/European Respiratory Society guidelines. RESULTS: PHORA had an area under the curve (AUC) of 0.80 for predicting 1-year survival, which was an improvement over REVEAL 2.0 (AUC 0.76). When validated in the COMPERA and PHSANZ registries, PHORA demonstrated an AUC of 0.74 and 0.80, respectively. 1-year survival rates predicted by PHORA were greater for patients with lower risk scores and poorer for those with higher risk scores (p<0.001), with excellent separation between low-, intermediate- and high-risk groups in all three registries. CONCLUSION: Our Bayesian network-derived risk prediction model, PHORA, demonstrated an improvement in discrimination over existing models. This is reflective of the ability of Bayesian network-based models to account for the interrelationships between clinical variables on outcome, and tolerance to missing data elements when calculating predictions.

Bionic women and men - Part 2: Arterial stiffness in heart failure patients implanted with left ventricular assist devices.

NEW FINDINGS: What is the topic of this review? This review discusses how implantation of continuous flow left ventricular assist devices impact arterial stiffness and outcome. What advances does it highlight? Not all patients implanted with continuous flow left ventricular assist devices show an increase in arterial stiffness. However, in those patients where arterial stiffness increases, levels of composite outcome (stroke, gastrointestinal bleeding, pump thrombosis and death) is significantly higher than those who's arterial stiffness does not increase. ABSTRACT: In parallel with the major advances in clinical care, technological advancements and implantation of mechanical circulatory support in patients with severe heart failure have resulted in these patients living longer. However, these patients are still at increased risk of stroke and gastrointestinal bleeding. The unique continuous flow produced by various left ventricular assist devices (LVADs) has been suggested as one potential reason for this increased risk of stroke and gastrointestinal bleeding. Furthermore, these continuous-flow (CF) devices challenge our understanding of circulatory blood pressure and flow regulation in relationship to organ health. In healthy pulsatile and dynamic systems, arterial stiffness is a major independent risk factor for stroke. However, to date, there are limited data regarding the impact of CF-LVAD therapy on arterial stiffness. The purpose of this report is to discuss the variable impact of CF-LVAD therapy on arterial stiffness and attempt to highlight some potential mechanisms linking these associations in this unique population.

Bionic women and men - Part 1: Cardiovascular lessons from heart failure patients implanted with left ventricular assist devices.

NEW FINDINGS: What is the topic of this review? Patients with advanced heart failure who are implanted with left ventricular assist devices (LVADs) present an opportunity to understand the human circulation under extreme conditions. What advances does it highlight? LVAD patients have a unique circulation that is characterized by a reduced or even absent arterial pulse. The remarkable survival of these patients is accompanied by circulatory complications, including stroke, gastrointestinal bleeding and right-heart failure. Understanding the mechanisms related to the complications in LVAD patients will help the patients and also advance our fundamental understanding of the human circulation in general. ABSTRACT: Some humans with chronic, advanced heart failure are surgically implanted with a left ventricular assist device (LVAD). Because the LVAD produces a continuous flow, a palpable pulse is often absent in these patients. This allows for a unique investigation of the human circulation and has created a controversy around the 'need' for a pulse. The medical debate has also generated a more generic, fundamental discussion into what is 'normal' arterial physiology and health. The comprehensive study and understanding of the arterial responses to drastically altered haemodynamics due to continuous-flow LVADs, at rest and during activity, presents an opportunity to significantly increase our current understanding of the fundamental components of arterial regulation (flow, blood pressure, sympathetic activity, endothelial function, pulsatility) in a way that could never have been studied previously. In a series of four articles, we summarize the talks presented at the symposium entitled 'Bionic women and men - Physiology lessons from implantable cardiac devices' presented at the 2019 Annual Meeting of The Physiological Society in Aberdeen, UK. The articles highlight the novel questions generated by physiological phenomena observed in LVAD patients and propose future areas of interest within the field of cardiovascular physiology.

Bionic women and men - Part 4: Cardiovascular, cerebrovascular and exercise responses among patients supported with left ventricular assist devices.

NEW FINDINGS: LVAD patients are predisposed to hypertension which may increase the risk of stroke. Hypertension may result from markedly elevated levels of sympathetic nerve activity, which occurs through a baroreceptor-mediated pathway in response to chronic exposure to a non-physiologic (and reduced) pulse. Cerebral autoregulatory processes appear to be preserved in the absence of a physiologic pulse. Nevertheless, the rate of ischemic/embolic and hemorrhagic stroke is unacceptably high and is a major cause of morbidity and mortality in these patients. Despite normalization of a resting cardiac output, LVAD patients suffer from persistent, severe reductions in functional capacity. ABSTRACT: Current generation left ventricular assist devices (LVADs) have led to significant improvements in survival compared to medical therapy alone, when used for management of patients with advanced heart failure. However, there are a number of side-effects associated with LVAD use, including hypertension, gastrointestinal bleeding, stroke, as well as persistent and severe limitations in functional capacity despite normalization of a resting cardiac output. These issues are, in large part, related to chronic exposure to a non-physiologic pulse, which contributes to a hyperadrenergic environment characterized by markedly elevated levels of sympathetic nerve activity through a baroreceptor-mediated pathway. In addition, these machines are unable to participate in, or contribute to, normal cardiovascular/autonomic reflexes that attempt to modulate flow through the body. Efforts to advance device technology and develop biologically sensitive devices may resolve these issues, and lead to further improvements in quality-of-life, functional capacity, and ultimately, survival, for the patients they support.