Novel Role for Cardiolipin as a Target of Therapy to Mitigate Myocardial Injury Caused by Venoarterial Extracorporeal Membrane Oxygenation.

BACKGROUND: Cardiolipin is a mitochondrial-specific phospholipid that maintains integrity of the electron transport chain (ETC) and plays a central role in myocardial ischemia/reperfusion injury. Tafazzin is an enzyme that is required for cardiolipin maturation. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) use to provide hemodynamic support for acute myocardial infarction has grown exponentially, is associated with poor outcomes, and is under active clinical investigation, yet the mechanistic effect of VA-ECMO on myocardial damage in acute myocardial infarction remains poorly understood. We hypothesized that VA-ECMO acutely depletes myocardial cardiolipin and exacerbates myocardial injury in acute myocardial infarction. METHODS: We examined cardiolipin and tafazzin levels in human subjects with heart failure and healthy swine exposed to VA-ECMO and used a swine model of closed-chest myocardial ischemia/reperfusion injury to evaluate the effect of VA-ECMO on cardiolipin expression, myocardial injury, and mitochondrial function. RESULTS: Cardiolipin and tafazzin levels are significantly reduced in the left ventricles of individuals requiring VA-ECMO compared with individuals without VA-ECMO before heart transplantation. Six hours of exposure to VA-ECMO also decreased left ventricular levels of cardiolipin and tafazzin in healthy swine compared with sham controls. To explore whether cardiolipin depletion by VA-ECMO increases infarct size, we performed left anterior descending artery occlusion for a total of 120 minutes followed by 180 minutes of reperfusion in adult swine in the presence and absence of MTP-131, an amphipathic molecule that interacts with cardiolipin to stabilize the inner mitochondrial membrane. Compared with reperfusion alone, VA-ECMO activation beginning after 90 minutes of left anterior descending artery occlusion increased infarct size (36±8% versus 48±7%; P<0.001). VA-ECMO also decreased cardiolipin and tafazzin levels, disrupted mitochondrial integrity, reduced electron transport chain function, and promoted oxidative stress. Compared with reperfusion alone or VA-ECMO before reperfusion, delivery of MTP-131 before VA-ECMO activation reduced infarct size (22±8%; P=0.03 versus reperfusion alone and P<0.001 versus VA-ECMO alone). MTP-131 restored cardiolipin and tafazzin levels, stabilized mitochondrial function, and reduced oxidative stress in the left ventricle. CONCLUSIONS: We identified a novel mechanism by which VA-ECMO promotes myocardial injury and further identify cardiolipin as an important target of therapy to reduce infarct size and to preserve mitochondrial function in the setting of VA-ECMO for acute myocardial infarction.

Unloading the Left Ventricle in Venoarterial ECMO: In Whom, When, and How?

Venoarterial extracorporeal membrane oxygenation provides cardiorespiratory support to patients in cardiogenic shock. This comes at the cost of increased left ventricle (LV) afterload that can be partly ascribed to retrograde aortic flow, causing LV distension, and leads to complications including cardiac thrombi, arrhythmias, and pulmonary edema. LV unloading can be achieved by using an additional circulatory support device to mitigate the adverse effects of mechanical overload that may increase the likelihood of myocardial recovery. Observational data suggest that these strategies may improve outcomes, but in whom, when, and how LV unloading should be employed is unclear; all techniques require balancing presumed benefits against known risks of device-related complications. This review summarizes the current evidence related to LV unloading with venoarterial extracorporeal membrane oxygenation.

Guide to Lung-Protective Ventilation in Cardiac Patients.

The incidence of acute respiratory insufficiency has continued to increase among patients admitted to modern-day cardiovascular intensive care units. Positive pressure ventilation (PPV) remains the mainstay of treatment for these patients. Alterations in intrathoracic pressure during PPV has distinct effects on both the right and left ventricles, affecting cardiovascular performance. Lung-protective ventilation (LPV) minimizes the risk of further lung injury through ventilator-induced lung injury and, hence, an understanding of LPV and its cardiopulmonary interactions is beneficial for cardiologists.

Increased Spironolactone Dosing in Acute Heart Failure Alters Potassium Homeostasis but Does Not Enhance Decongestion.

BACKGROUND: The ATHENA-HF clinical trial found no improvements in natriuretic peptide levels or clinical congestion when spironolactone 100 mg/day for 96 hours was used in addition to usual treatment for acute heart failure. METHODS: We performed a post hoc analysis of ATHENA-HF to determine whether spironolactone treatment induced any detectable pharmacodynamic effect and whether patients with potentially greater aldosterone activity experienced additional decongestion. Trial subjects previously treated with spironolactone were excluded. We first examined for changes in renal potassium handling. Using the baseline serum potassium level as a surrogate marker of spironolactone activity, we then divided each treatment arm into tertiles of baseline serum potassium and explored for differences in laboratory and clinical congestion outcomes. RESULTS: Among spironolactone-naïve patients, the change in serum potassium did not differ after 24 hours or 48 hours but was significantly larger with spironolactone treatment compared to placebo at 72 hours (0.23±0.55 vs 0.03±0.60 mEq/L, P=0.042) and 96 hours (0.32±0.51 vs 0.13±0.72 mEq/L, P=0.046). While potassium supplementation was similar at treatment start and 24 hours, spironolactone-treated patients required substantially less potassium replacement at 48 hours (24% vs 36%; P=0.048), 72 hours (21% vs 37%; P=0.013), and 96 hours (11% vs 38%; P<0.001). When the treatment arms were divided into tertiles of baseline serum potassium, there were no differences in the 96-hour log N-terminal pro-B-type natriuretic peptide, net fluid loss, urine output, or dyspnea relief between any of the potassium groups, with no effect modification by treatment exposure. CONCLUSIONS: Spironolactone 100 mg/day for 96 hours in patients receiving intravenous loop diuresis for acute heart failure has no clear added decongestive ability but does meaningfully limit potassium wasting.

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.

Prognostic Implications of Quantifying Vasoactive Medications in Cardiogenic Shock.

None.

Left ventricular unloading in patients supported with veno-arterial extra corporeal membrane oxygenation; an international EuroELSO survey.

INTRODUCTION: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) improves end-organ perfusion in cardiogenic shock but may increase afterload, which can limit cardiac recovery. Left ventricular (LV) unloading strategies may aid cardiac recovery and prevent complications of increased afterload. However, there is no consensus on when and which unloading strategy should be used. METHODS: An online survey was distributed worldwide via the EuroELSO newsletter mailing list to describe contemporary international practice and evaluate heterogeneity in strategies for LV unloading. RESULTS: Of 192 respondents from 43 countries, 53% routinely use mechanical LV unloading, to promote ventricular recovery and/or to prevent complications. Of those that do not routinely unload, 65% cited risk of complications as the reason. The most common indications for unplanned unloading were reduced arterial line pulsatility (68%), pulmonary edema (64%) and LV dilatation (50%). An intra-aortic balloon pump was the most frequently used device for unloading followed by percutaneous left ventricular assist devices. Echocardiography was the most frequently used method to monitor the response to unloading. CONCLUSIONS: Significant variation exists with respect to international practice of ventricular unloading. Further research is required that compares the efficacy of different unloading strategies and a randomized comparison of routine mechanical unloading versus unplanned unloading.

Escalating and De-escalating Temporary Mechanical Circulatory Support in Cardiogenic Shock: A Scientific Statement From the American Heart Association.

The use of temporary mechanical circulatory support in cardiogenic shock has increased dramatically despite a lack of randomized controlled trials or evidence guiding clinical decision-making. Recommendations from professional societies on temporary mechanical circulatory support escalation and de-escalation are limited. This scientific statement provides pragmatic suggestions on temporary mechanical circulatory support device selection, escalation, and weaning strategies in patients with common cardiogenic shock causes such as acute decompensated heart failure and acute myocardial infarction. The goal of this scientific statement is to serve as a resource for clinicians making temporary mechanical circulatory support management decisions and to propose standardized approaches for their use until more robust randomized clinical data are available.

Interpretation of the central aortic pressure waveform in elderly patients with aortic stenosis.

The central aortic pressure waveform, while simple in form, is complex in its physiological interpretation. Although general agreement has been reached on the contour and mechanisms responsible for pressure waveforms in the ascending aorta of healthy humans, in recent years there has been increasing interest in the contour of the pressure wave in elderly patients with aortic valve stenosis (AS). As aortic valve leaflets succumb to fibrosis and calcification, they increase opposition to forward flow. This results in a protracted pressure rise and manifests as the classical finding of pulsus parvus et tardus. Equally, changes to arterial properties (including elasticity and geometry) and pulse wave velocity (PWV) with age, heart failure, or hypertension can cause profound changes to the contour. Increased accessibility of methods to measure the central aortic pressure waveform, as well as the rapid uptake of transcatheter aortic valve implantation technologies, has created a renewed focus on better understanding of characteristic perturbations to the waveform in elderly patients with AS. In this review, we investigate the evolution of our understanding of the central aortic pressure waveform in varying AS disease states to highlight the importance of the physiological and biological basis for alterations in this waveform.

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).

SCAI stage reclassification at 24 h predicts outcome of cardiogenic shock: Insights from the Altshock-2 registry.

BACKGROUND: Cardiogenic shock (CS) includes several phenotypes with heterogenous hemodynamic features. Timely prognostication is warranted to identify patients requiring treatment escalation. We explored the association of the updated Society for Cardiovascular Angiography and Interventions (SCAI) stages classification with in-hospital mortality using a prospective national registry. METHODS: Between March 2020 and February 2022 the Altshock-2 Registry has included 237 patients with CS of all etiologies at 11 Italian Centers. Patients were classified according to their admission SCAI stage (assigned prospectively and independently updated according to the recently released version). In-hospital mortality was evaluated for association with both admission and 24-h SCAI stages. RESULTS: The overall in-hospital mortality was 38%. Of the 237 patients included and staged according to the updated SCAI classification, 20 (8%) had SCAI shock stage B, 131 (55%) SCAI stage C, 61 (26%) SCAI stage D and 25 (11%) SCAI stage E. In-hospital mortality stratified according to the SCAI classification at 24 h was 18% for patients in SCAI stage B, 27% for SCAI stage C, 63% for SCAI stage D and 100% for SCAI stage E. Both the revised SCAI stages on admission and at 24 h were associated with in-hospital mortality, but the classification potential slightly increased at 24-h. After adjusting for age, sex, lactate level, eGFR, CVP, inotropic score and mechanical circulatory support [MCS], SCAI classification at 24 h was an independent predictor of in-hospital mortality. CONCLUSIONS: In the Altshock-2 registry the utility of SCAI shock stages to identify risk of in-hospital mortality increased at 24 h after admission. Escalation of treatment (either pharmacological or with MCS) should be tailored to achieve prompt clinical improvement within the first 24 h after admission. Registration: http://www. CLINICALTRIALS: gov; Unique identifier: NCT04295252.

Peripheral artery disease and extracorporeal membrane oxygenation: Examining a high-risk cohort over time.

OBJECTIVE: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a resource-intensive approach for the management of refractory cardiogenic shock. Within this population exists a substantial cohort of patients with peripheral artery disease (PAD), which independently increases the risk of complications and all-cause mortality. We studied 10-year national trends of the impact of PAD among VA-ECMO recipients to better understand the prevalence of PAD and implications on outcomes in this vulnerable population. METHODS: This 10-year retrospective, propensity score-matched study identified all adult patients (≥18) who underwent VA-ECMO between 2009 and 2018, from a large US database (National Inpatient Sample). Patients with an ICD diagnosis of PAD were identified. The primary endpoints of in-hospital mortality, bleeding complications and major limb loss (above- or below-knee amputation) were compared between patients with PAD to those without. RESULTS: A total of 6768 patients were identified, of which 342 (5.3%) had PAD. The median age at admission was significantly higher in PAD patients [64 years vs. 55 years; p < .01], as was male gender [71% vs. 64%; p < .01]. Patients with PAD had higher rates of smoking (38.9% vs. 23.3%), hypertension (71.1% vs. 50%), diabetes (37.4% vs. 27.0%), chronic kidney disease (30.1% vs. 18.0%), coronary artery disease (76.0% vs. 35.0%) and dyslipidemia (76.0% vs. 35.0); all p < .01. After propensity-matching 2:1 for comorbidities, PAD patients were found to have significantly greater overall complications, including in-hospital mortality, bleeding, surgical wound infections, pseudoaneurysms, and major adverse limb events [71.9% vs. 63.9%; p < .01]. Subgroup analysis revealed greater in-hospital mortality [62.2% vs. 55.3%; p < .05], major amputations [4.1% vs. 0.3%; p < .01] and blood transfusions [32.2% vs. 26.2%; p < .05] in PAD patients. Over 2014-2018, the non-PAD group demonstrated statistically discernable trends in a 51.1% decrease in overall complications and a 28.1% increase in survival to discharge (all p < .01). Over the same time period the PAD cohort experienced a modest, nonsignificant, decrease in complications [7.0%, p = .40] and a decrease in those surviving to discharge [47.1% vs. 40.5%, p = .91]. CONCLUSION: Patients with PAD on VA-ECMO are sicker at baseline and experience significantly greater major amputations and higher in-hospital mortality. They have not benefitted from the considerable decrease in complication rates and increase in survival to discharge over time as compared to their non-PAD counterparts. These findings demonstrate the substantial frailty of the PAD population within an already high-risk cohort, and highlight the need for better procedural approaches and innovative technologies.

Cardiogenic Shock Integrated PHenotyping for Event Reduction: A Pilot Metabolomics Analysis.

Cardiogenic shock (CS) portends a dismal prognosis if hypoperfusion triggers uncontrolled inflammatory and metabolic derangements. We sought to investigate metabolomic profiles and temporal changes in IL6, Ang-2, and markers of glycocalyx perturbation from admission to discharge in eighteen patients with heart failure complicated by CS (HF-CS). Biological samples were collected from 18 consecutive HF-CS patients at admission (T0), 48 h after admission (T1), and at discharge (T2). ELISA analytical techniques and targeted metabolomics were performed Seven patients (44%) died at in-hospital follow-up. Among the survivors, IL-6 and kynurenine were significantly reduced at discharge compared to baseline. Conversely, the amino acids arginine, threonine, glycine, lysine, and asparagine; the biogenic amine putrescine; multiple sphingolipids; and glycerophospholipids were significantly increased. Patients with HF-CS have a metabolomic fingerprint that might allow for tailored treatment strategies for the patients' recovery or stabilization.

Mechanical Circulatory Support in COVID-19.

Despite aggressive care, patients with cardiopulmonary failure and COVID-19 experience unacceptably high mortality rates. The use of mechanical circulatory support devices in this population offers potential benefits but confers significant morbidity and novel challenges for the clinician. Thoughtful application of this complex technology is of the utmost importance and should be done in a multidisciplinary fashion by teams familiar with mechanical support devices and aware of the particular challenges provided by this complex patient population.

Invasive Management of Acute Myocardial Infarction Complicated by Cardiogenic Shock: A Scientific Statement From the American Heart Association.

Cardiogenic shock (CS) remains the most common cause of mortality in patients with acute myocardial infarction. The SHOCK trial (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock) demonstrated a survival benefit with early revascularization in patients with CS complicating acute myocardial infarction (AMICS) 20 years ago. After an initial improvement in mortality related to revascularization, mortality rates have plateaued. A recent Society of Coronary Angiography and Interventions classification scheme was developed to address the wide range of CS presentations. In addition, a recent scientific statement from the American Heart Association recommended the development of CS centers using standardized protocols for diagnosis and management of CS, including mechanical circulatory support devices (MCS). A number of CS programs have implemented various protocols for treating patients with AMICS, including the use of MCS, and have published promising results using such protocols. Despite this, practice patterns in the cardiac catheterization laboratory vary across health systems, and there are inconsistencies in the use or timing of MCS for AMICS. Furthermore, mortality benefit from MCS devices in AMICS has yet to be established in randomized clinical trials. In this article, we outline the best practices for the contemporary interventional management of AMICS, including coronary revascularization, the use of MCS, and special considerations such as the treatment of patients with AMICS with cardiac arrest.

Primary left ventricular unloading with delayed reperfusion in patients with anterior ST-elevation myocardial infarction: Rationale and design of the STEMI-DTU randomized pivotal trial.

BACKGROUND: Despite successful primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI), myocardial salvage is often suboptimal, resulting in large infarct size and increased rates of heart failure and mortality. Unloading of the left ventricle (LV) before primary PCI may reduce infarct size and improve prognosis. STUDY DESIGN AND OBJECTIVES: STEMI-DTU (NCT03947619) is a prospective, randomized, multicenter trial designed to compare mechanical LV unloading with the Impella CP device for 30 minutes prior to primary PCI to primary PCI alone without LV unloading. The trial aims to enroll approximately 668 subjects, with a potential sample size adaptation, with anterior STEMI with a primary end point of infarct size as a percent of LV mass evaluated by cardiac magnetic resonance at 3-5 days after PCI. The key secondary efficacy end point is a hierarchical composite of the 1-year rates of cardiovascular mortality, cardiogenic shock ≥24 hours after PCI, use of a surgical left ventricular assist device or heart transplant, heart failure, intra-cardiac defibrillator or chronic resynchronization therapy placement, and infarct size at 3 to 5 days post-PCI. The key secondary safety end point is Impella CP-related major bleeding or major vascular complications within 30 days. Clinical follow-up is planned for 5 years. CONCLUSIONS: STEMI-DTU is a large-scale, prospective, randomized trial evaluating whether mechanical unloading of the LV by the Impella CP prior to primary PCI reduces infarct size and improves prognosis in patients with STEMI compared to primary PCI alone without LV unloading.

Improved outcomes in patients with severely depressed LVEF undergoing percutaneous coronary intervention with contemporary practices.

BACKGROUND: Contemporary practices for hemodynamically supported high-risk percutaneous coronary intervention have evolved over the last decade. This study sought to compare outcomes of the prospective, multicenter, PROTECT III study to historic patients treated with Impella in the PROTECT II randomized controlled trial. METHODS: Of 1,134 patients enrolled in PROTECT III from March 2017 to March 2020, 504 were "PROTECT II-like" (met eligibility for PROTECT II randomized controlled trial) and are referred to as PROTECT III for comparative analysis. Major adverse cardiac and cerebrovascular events (MACCE), comprising all-cause mortality, stroke/transient ischemic attack, myocardial infarction, and repeat revascularization, were compared at hospital discharge and 90 days. RESULTS: Compared with PROTECT II (N = 216), PROTECT III patients were less often Caucasian (77.1% vs 83.8%, P = .045), with less prior CABG (13.7% vs 39.4%; P < .001) and prior myocardial infarction (40.7% vs 69.3%; P < .001). More PROTECT III patients underwent rotational atherectomy (37.1% vs 14.8%, P < .001) and duration of support was longer (median 1.6 vs 1.3 hours; p<0.001), with greater improvement achieved in myocardial ischemia jeopardy scores (7.0±2.4 vs 4.4±2.9; P < .001) and SYNTAX scores (21.4±10.8 vs 15.7±9.5; P < .001). In-hospital bleeding requiring transfusion was significantly lower in PROTECT III (1.8% vs 9.3%; P < .001), as was procedural hypotension (2.2% vs 10.1%; P < .001) and cardiopulmonary resuscitation or ventricular arrhythmia (1.6% vs 6.9%; P < .001). At 90 days, MACCE was 15.1% and 21.9% in PROTECT III and PROTECT II, respectively (p=0.037). Following propensity score matching, Kaplan-Meier analysis showed improved 90-day MACCE rates in PROTECT III (10.4% vs 16.9%, P = .048). CONCLUSIONS: The PROTECT III study demonstrates improved completeness of revascularization, less bleeding, and improved 90-day clinical outcomes compared to PROTECT II for Impella-supported high-risk percutaneous coronary intervention among patients with severely depressed LVEF.

Intra-aortic Balloon Pump for Acute-on-Chronic Heart Failure Complicated by Cardiogenic Shock.

The intra-aortic balloon pump (IABP) is widely implanted as temporary mechanical circulatory support for cardiogenic shock (CS). However, its use is declining following the results of the IABP-SHOCK II trial, which failed to show a clinical benefit of the IABP in acute coronary syndrome (ACS)-related CS. Acute-on-chronic heart failure has become an increasingly recognized, distinct cause of CS (HF-CS). The pathophysiology of HF-CS differs from that of ACS-CS because it typically represents the progression from a state of congestion (with relatively preserved cardiac output) to a low-output state with hypoperfusion. The IABP is a volume-displacement pump that promotes forward flow from a high-capacitance reservoir to low-capacitance vessels, improving peripheral perfusion and decreasing left ventricular afterload in the setting of high filling pressures. The IABP can improve ventricular-vascular coupling and, therefore, myocardial energetics. Additionally, many patients with HF-CS are candidates for cardiac replacement therapies (left ventricular assist device or heart transplantation) and, therefore, may benefit from a bridge strategy that stabilizes the hemodynamics and end-organ function in preparation for more durable therapies. Notably, the new United Network for Organ Sharing donor heart allocation system has recently prioritized patients on IABP support. This review describes the role of IABP in the treatment of HF-CS. It also briefly discusses new strategies for vascular access as well as fully implantable versions for longer duration of support.

Variability in reporting of key outcome predictors in acute myocardial infarction cardiogenic shock trials.

BACKGROUND: Among acute myocardial infarction patients with cardiogenic shock (AMICS), a number of key variables predict mortality, including cardiac arrest (CA) and shock classification as proposed by Society for Cardiovascular Angiography and Intervention (SCAI). Given this prognostic importance, we examined the frequency of reporting of high risk variables in published randomized controlled trials (RCTs) of AMICS patients. METHODS: We identified 15 RCTs enrolling 2,500 AMICS patients and then reviewed rates of CA, baseline neurologic status, right heart catheterization data, lactate levels, inotrope and vasopressor requirement, hypothermia, mechanical ventilation, left ventricular ejection fraction (LVEF), mechanical circulatory support, and specific cause of death based on the primary manuscript and Data in S1. RESULTS: A total of 2,500 AMICS patients have been enrolled in 15 clinical trials over 21 years with only four trials enrolling >80 patients. The reporting frequency and range for key prognostic factors was: neurologic status (0% reported), hypothermia (28% reported, prevalence 33-75%), specific cause of death (33% reported), cardiac index and wedge pressure (47% reported, range 1.6-2.3 L min-1  m-2 and 15-24 mmHg), lactate (60% reported, range 4-7.7 mmol/L), LVEF (73% reported, range 25-45%), CA (80% reported, prevalence 0-92%), MCS (80% reported, prevalence 13-100%), and mechanical ventilation (93% reported, prevalence 35-100%). This variability was reflected in the 30-day mortality which ranged from 20-73%. CONCLUSIONS: In a comprehensive review of seminal RCTs in AMICS, important predictors of outcome were frequently not reported. Future efforts to standardize CS trial data collection and reporting may allow for better assessment of novel therapies for AMICS.

Vasopressors independently associated with mortality in acute myocardial infarction and cardiogenic shock.

BACKGROUND: Increasing vasopressor dose is associated with increasing mortality in patients presenting with acute myocardial infarction and cardiogenic shock (AMICS). It is unknown whether the use of vasopressors is independently harmful or if their use is secondary to decreasing intrinsic cardiac power output (CPO). Mechanical circulatory support (MCS) devices enhance CPO. We sought to evaluate the independent impact of increasing vasopressor dose on survival in the National Cardiogenic Shock Initiative (NCSI). METHODS: The NCSI is a single arm prospective trial evaluating outcomes associated with the use of MCS using Impella in patients with AMICS. Early initiation of MCS placement before percutaneous coronary intervention (PCI) and rapid de-escalation of vasopressors guided by systematic use of invasive hemodynamic measures led to 70% in-hospital survival for the first 300 patients enrolled from July 2016 to December 2019 in 57 U.S. sites. RESULTS: Hemodynamic measures were obtained immediately after MCS and PCI. Survival curves were constructed based on CPO and use of vasopressors. For patients with CPO ≤0.6 W, survival was 77.3%, 45.0%, and 35.3% when 0, 1, or ≥ 2 vasopressors were used (p = 0.02). Similarly, for patients with CPO >0.6 W survival was 81.7%, 72.6%, and 56.8%, respectively (p = 0.01). Logistic regression analysis demonstrated that increasing vasopressor requirements were independently associated with increasing mortality (p = 0.02). CONCLUSION: Increasing vasopressor requirement is associated with increased mortality in AMICS independent of underlying CPO. Methods to decrease the need for vasopressors may enhance survival in AMICS.