The management of heart failure cardiogenic shock: an international RAND appropriateness panel

BACKGROUND

Observational data suggest that the subset of patients with heart failure related CS (HF-CS) now predominate critical care admissions for CS. There are no dedicated HF-CS randomised control trials completed to date which reliably inform clinical practice or clinical guidelines. We sought to identify aspects of HF-CS care where both consensus and uncertainty may exist to guide clinical practice and future clinical trial design, with a specific focus on HF-CS due to acute decompensated chronic HF.

METHODS

A 16-person multi-disciplinary panel comprising of international experts was assembled. A modified RAND/University of California, Los Angeles, appropriateness methodology was used. A survey comprising of 34 statements was completed. Participants anonymously rated the appropriateness of each statement on a scale of 1 to 9 (1-3 as inappropriate, 4-6 as uncertain and as 7-9 appropriate).

RESULTS

Of the 34 statements, 20 were rated as appropriate and 14 were rated as inappropriate. Uncertainty existed across all three domains: the initial assessment and management of HF-CS; escalation to temporary Mechanical Circulatory Support (tMCS); and weaning from tMCS in HF-CS. Significant disagreement between experts (deemed present when the disagreement index exceeded 1) was only identified when deliberating the utility of thoracic ultrasound in the immediate management of HF-CS.

CONCLUSION

This study has highlighted several areas of practice where large-scale prospective registries and clinical trials in the HF-CS population are urgently needed to reliably inform clinical practice and the synthesis of future societal HF-CS guidelines.

Fulminant myocarditis proven by early biopsy and outcomes

BACKGROUND AND AIMS

While endomyocardial biopsy (EMB) is recommended in adult patients with fulminant myocarditis, the clinical impact of its timing is still unclear.

METHODS

Data were collected from 419 adult patients with clinically suspected fulminant myocarditis admitted to intensive care units across 36 tertiary centres in 15 countries worldwide. The diagnosis of myocarditis was histologically proven in 210 (50%) patients, either by EMB (n = 183, 44%) or by autopsy/explanted heart examination (n = 27, 6%), and clinically suspected cardiac magnetic resonance imaging confirmed in 96 (23%) patients. The primary outcome of survival free of heart transplantation (HTx) or left ventricular assist device (LVAD) at 1 year was specifically compared between patients with early EMB (within 2 days after intensive care unit admission, n = 103) and delayed EMB (n = 80). A propensity score-weighted analysis was done to control for confounders.

RESULTS

Median age on admission was 40 (29-52) years, and 322 (77%) patients received temporary mechanical circulatory support. A total of 273 (65%) patients survived without HTx/LVAD. The primary outcome was significantly different between patients with early and delayed EMB (70% vs. 49%, P = .004). After propensity score weighting, the early EMB group still significantly differed from the delayed EMB group in terms of survival free of HTx/LVAD (63% vs. 40%, P = .021). Moreover, early EMB was independently associated with a lower rate of death or HTx/LVAD at 1 year (odds ratio of 0.44; 95% confidence interval: 0.22-0.86; P = .016).

CONCLUSIONS

Endomyocardial biopsy should be broadly and promptly used in patients admitted to the intensive care unit for clinically suspected fulminant myocarditis.

Early renal recovery after acute kidney injury in patients on venoarterial extracorporeal membrane oxygenation: A retrospective study

PURPOSE

The impact of VA-ECMO on early renal recovery (within 7 days after ECMO onset) in patients with pre-ECMO acute kidney injury and cardiogenic shock is unknown.

MATERIAL AND METHODS

This retrospective single-center study included adult patients with cardiogenic shock rescued by VA-ECMO and severe AKI occurring before ECMO implantation (pre-ECMO AKI). Patients with early renal recovery (defined as at least a 50% decrease in peak serum creatinine or weaning from renal replacement therapy) were compared to patients without early renal recovery.

RESULTS

During 7 years, 145 patients with severe pre-ECMO AKI were included. Eighty-two patients had no early renal recovery whereas 63 had early renal recovery within 7 days after VA-ECMO onset. The median time to early renal recovery was 4 (3,6) days. Nephrotoxic antibiotics (HR = 0.35 [95% CI, 0.21-0.59], p < 0.001), median fluid balance during the first 7 days of VA-ECMO (HR = 0.77 [95% CI, 0.64-0.93], p = 0.008), pre-ECMO AKI stage 3 (HR = 0.36 [95% CI, 0.20-0.64], p < 0.001) and median vasoactive-inotropic score (HR = 0.99 [95% CI, 0.98,1.00], p = 0.035) were independently associated with no early renal recovery.

CONCLUSIONS

Only 43% of patients with severe pre-ECMO AKI had early renal recovery after VA-ECMO initiation.

Performance analysis of a STEMI network: prognostic impact of the type of first medical contact facility

INTRODUCTION AND OBJECTIVES

Prognosis in ST-elevation myocardial infarction (STEMI) is determined by delay in primary percutaneous coronary intervention (PPCI). The impact of first medical contact (FMC) facility type on reperfusion delays and mortality remains controversial.

METHODS

We performed a prospective registry of primary coronary intervention (PCI)-treated STEMI patients (2010-2020) in the Codi Infart STEMI network. We analyzed 1-year all-cause mortality depending on the FMC facility type: emergency medical service (EMS), community hospital (CH), PCI hospital (PCI-H), or primary care center (PCC).

RESULTS

We included 18 332 patients (EMS 34.3%; CH 33.5%; PCI-H 12.3%; PCC 20.0%). Patients with Killip-Kimball classes III-IV were: EMS 8.43%, CH 5.54%, PCI-H 7.51%, PCC 3.76% (P <.001). All comorbidities and first medical assistance complications were more frequent in the EMS and PCI-H groups (P <.05) and were less frequent in the PCC group (P <.05 for most variables). The PCI-H group had the shortest FMC-to-PCI delay (median 82 minutes); the EMS group achieved the shortest total ischemic time (median 151 minutes); CH had the longest reperfusion delays (P <.001). In an adjusted logistic regression model, the PCI-H and CH groups were associated with higher 1-year mortality, OR, 1.22 (95%CI, 1.00-1.48; P=.048), and OR, 1.17 (95%CI 1.02-1.36; P=.030), respectively, while the PCC group was associated with lower 1-year mortality than the EMS group, OR, 0.71 (95%CI 0.58-0.86; P <.001).

CONCLUSIONS

FMC with PCI-H and CH was associated with higher adjusted 1-year mortality than FMC with EMS. The PCC group had a much lower intrinsic risk and was associated with better outcomes despite longer revascularization delays.

The current clinical practice for management of post-infarction ventricular septal rupture: a European survey

Aims

Many historical and recent reports showed that post-infarction ventricular septal rupture (VSR) represents a life-threatening condition and the strategy to optimally manage it remains undefined. Therefore, disparate treatment policies among different centres with variable results are often described. We analysed data from European centres to capture the current clinical practice in VSR management.

Methods and results

Thirty-nine centres belonging to eight European countries participated in a survey, filling a digital form of 38 questions from April to October 2022, to collect information about all the aspects of VSR treatment. Most centres encounter 1-5 VSR cases/year. Surgery remains the treatment of choice over percutaneous closure (71.8% vs. 28.2%). A delayed repair represents the preferred approach (87.2%). Haemodynamic conditions influence the management in almost all centres, although some try to achieve patients stabilization and delayed surgery even in cardiogenic shock. Although 33.3% of centres do not perform coronarography in unstable patients, revascularization approaches are widely variable. Most centres adopt mechanical circulatory support (MCS), mostly extracorporeal membrane oxygenation, especially pre-operatively to stabilize patients and achieve delayed repair. Post-operatively, such MCS are more often adopted in patients with ventricular dysfunction.

Conclusion

In real-life, delayed surgery, regardless of the haemodynamic conditions, is the preferred strategy for VSR management in Europe. Extracorporeal membrane oxygenation is becoming the most frequently adopted MCS as bridge-to-operation. This survey provides a useful background to develop dedicated, prospective studies to strengthen the current evidence on VSR treatment and to help improving its currently unsatisfactory outcomes.

Mechanical complications in STEMI: prevalence and mortality trends in the primary PCI era. The Ruti-STEMI registry

INTRODUCTION AND OBJECTIVES

Mechanical complications confer a dreadful prognosis in ST-elevation myocardial infarction (STEMI). Their prevalence and prognosis are not well-defined in the current era of primary percutaneous coronary intervention (pPCI) reperfusion networks. We aimed to analyze prevalence and mortality trends of post-STEMI mechanical complications over 2 decades, before and after the establishment of pPCI networks.

METHODS

Prospective, consecutive registry of STEMI patients within a region of 850 000 inhabitants over 2 decades: a pre-pPCI period (1990-2000) and a pPCI period (2007-2017). We analyzed the prevalence of mechanical complications, including ventricular septal rupture, papillary muscle rupture, and free wall rupture (FWR). Twenty eight-day and 1-year mortality trends were compared between the 2 studied decades.

RESULTS

A total of 6033 STEMI patients were included (pre-pPCI period, n=2250; pPCI period, n=3783). Reperfusion was supported by thrombolysis in the pre-pPCI period (99.1%) and by pPCI in in the pPCI period (95.7%). Mechanical complications developed in 135 patients (2.2%): ventricular septal rupture in 38 patients, papillary muscle rupture in 24, and FWR in 73 patients. FWR showed a relative reduction of 60% in the pPCI period (0.8% vs 2.0%, P<.001), without significant interperiod changes in the other mechanical complications. After multivariate adjustment, FWR remained higher in the pre-pPCI period (OR, 1.93; 95%CI, 1.10-3.41; P=.023). At 28 days and 1 year, mortality showed no significant changes in all the mechanical complications studied.

CONCLUSIONS

The establishment of regional pPCI networks has modified the landscape of mechanical complications in STEMI. FWR is less frequent in the pPCI era, likely due to reduced transmural infarcts.

Acute LDL-C reduction post ACS: strike early and strike strong: from evidence to clinical practice. A clinical consensus statement of the Association for Acute CardioVascular Care (ACVC), in collaboration with the European Association of Preventive Cardiology (EAPC) and the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

After experiencing an acute coronary syndrome (ACS), patients are at a high risk of suffering from recurrent ischaemic cardiovascular events, especially in the very early phase. Low density lipoprotein-cholesterol (LDL-C) is causally involved in atherosclerosis and a clear, monotonic relationship between pharmacologic LDL-C lowering and a reduction in cardiovascular events post-ACS has been shown, a concept termed 'the lower, the better'. Current ESC guidelines suggest an LDL-C guided, step-wise initiation and escalation of lipid-lowering therapy (LLT). Observational studies consistently show low rates of guideline-recommended LLT adaptions and concomitant low rates of LDL-C target goal achievement, leaving patients at residual risk, especially in the vulnerable post-ACS phase. In addition to the well-established 'the lower, the better' approach, a 'strike early and strike strong' approach in the early post-ACS phase with upfront initiation of a combined lipid-lowering approach using high-intensity statins and ezetimibe seems reasonable. We discuss the rationale, clinical trial evidence and experience for such an approach and highlight existing knowledge gaps. In addition, the concept of acute initiation of PCSK9 inhibition in the early phase is reviewed. Ultimately, we focus on hurdles and solutions to provide high-quality, evidence-based follow-up care in post-ACS patients.

Time course, factors related to, and prognostic impact of venoarterial extracorporeal membrane flow in cardiogenic shock

AIMS

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is currently one of the most used devices in refractory cardiogenic shock. However, there is a lack of evidence on how to set the 'optimal' flow. We aimed to describe the evolution of VA-ECMO flows in a cardiogenic shock population and determine the risk factors of 'high-ECMO flow'.

METHODS AND RESULTS

A 7 year database of patients supported with VA-ECMO was used. Based on the median flow during the first 48 h of the VA-ECMO run, patients were classified as 'high-flow' or 'low-flow', respectively, when median ECMO flow was ≥3.6 or <3.6 L/min. Outcomes included rates of ventilator-associated pneumonia, ECMO-related complications, days on ECMO, days on mechanical ventilation, intensive care unit and hospitalization lengths of stay, and in-hospital and 60 day mortality. Risk factors of high-ECMO flow were assessed using univariate and multivariate cox regression. The study population included 209 patients on VA-ECMO, median age was 51 (40-59) years, and 78% were males. The most frequent aetiology leading to cardiogenic shock was end-stage dilated cardiomyopathy (57%), followed by acute myocardial infarction (23%) and fulminant myocarditis (17%). Among the 209 patients, 105 (50%) were classified as 'high-flow'. This group had a higher rate of ischaemic aetiology (16% vs. 30%, P = 0.023) and was sicker at admission, in terms of worse Simplified Acute Physiology Score II score [40 (26-58) vs. 56 (42-74), P < 0.001], higher lactate [3.6 (2.2-5.8) mmol/L vs. 5.2 (3-9.7) mmol/L, P < 0.001], and higher aspartate aminotransferase [97 (41-375) U/L vs. 309 (85-939) U/L, P < 0.001], among others. The 'low-flow' group had less ventilator-associated pneumonia (40% vs. 59%, P = 0.007) and less days on mechanical ventilation [4 (1.5-7.5) vs. 6 (3-12) days, P = 0.009]. No differences were found in lengths of stay or survival according to the ECMO flow. The multivariate analysis showed that risk factors independently associated with 'high-flow' were mechanical ventilation at cannulation [odds ratio (OR) 3.9, 95% confidence interval (CI) 2.1-7.1] and pre-ECMO lactate (OR 1.1, 95% CI 1.0-1.2).

CONCLUSIONS

In patients with refractory cardiogenic shock supported with VA-ECMO, sicker patients had higher support since early phases, presenting thereafter higher rates of ventilator-associated pneumonia but similar survival compared with patients with lower flows.

Impact of COVID-19 on mechanical complications in ST elevation myocardial infarction

Background

Mechanical complications (MC) give a poor prognosis for ST elevation myocardial infarction (STEMI). Its prevalence had decreased in the era of primary angioplasty, at the expense of free wall rupture (FWR).

Purpose

To analyse the prevalence of post-STEMI MC for two periods, before and after the COVID-19 pandemic.

Methods

Unicentric prospective registration of patients with STEMI admitted between January-2018 and December-2021. They are classified into two groups according to the onset of the pandemic by COVID-19: Pre-COVID: January-2018 to December-2019, and Post-COVID: January-2020 to December-2021. The prevalence of post-STEMI MC is analysed, including ventricular septal rupture (VSR), papillary muscle rupture (PMR) and FWR, and 30-day mortality.

Results

1507 consecutive patients with STEMI (Pre-COVID n=775, Post-COVID n=732) are included. Age 62.9 years vs 63.3 years (p=0.5097). Men 78.1% Vs 79.5% (p=0.493). No differences in cardiovascular risk factors, previous heart infarction or anterior wall STEMI. Primary angioplasty was similar in both groups (92%). The Post-COVID group has a higher prevalence of Killip>I (21.7% vs 17.2% p=0.025) and LVEF ≤40% (27.2% vs 20% p=0.001), and longer symptom onset to balloon dilatation interval (316 min vs 257 min p=0.0004). MC are most developed in Post-COVID (2.6% vs 1.2% p=0.039), at the expense of FWR (1.91% vs 0.3% p=0.001). No significant changes in VSR and PMR prevalence or 30-day mortality. Multivariate analysis identifies the independent predictors of FWR: Age (OR 1.05, p=0.024), Primary angioplasty (OR 0.09, p<0.001), and Post-COVID (OR 6.8, p=0.013).

Conclusions

The COVID-19 pandemic is independently associated with a higher prevalence of FWR, probably due to delayed reperfusion.

Funding Acknowledgement

Type of funding sources: None.

Non-STEMI vs. STEMI Cardiogenic Shock: Clinical Profile and Long-Term Outcomes

Cardiogenic shock (CS) is a severe complication of acute myocardial infarction (AMI). In AMI-CS, the ST segment deviation on ECG may be elevated (STEMI-CS) or non-elevated (NSTEMI-CS), which may influence prognosis. Our aim was to analyze the clinical profile, acute-phase prognosis, and long-term outcomes of CS relative to the ST pattern on admission. In a prospective registry of 4647 AMI patients admitted to the intensive cardiac care unit of a university hospital between 2010 and 2019, we compared the clinical characteristics, 30-days case fatality, and long-term outcomes of AMI-CS, based on the presence of ST-segment deviation. AMI-CS developed in 239 (5.1%) patients (26.4% women): 190 (79.5%) STEMI-CS and 49 (20.5%) NSTEMI-CS. The mean age was 69.7 years. The STEMI-CS patients had larger infarcts and more mechanical complications than the NSTEMI-CS patients. The NSTEMI-CS patients had a greater prevalence of hypertension, diabetes, peripheral vascular disease, previous cardiovascular comorbidities, three-vessel disease, and left main disease than the STEMI-CS patients. The STEMI-CS patients had higher 30-day mortality than the NSTEMI-CS (59.5% vs. 36.7%; p = 0.004), even after multivariable adjustment (HR 1.91; 95% CI 1.16–3.14), but no differences in mortality were observed at 3 years. In conclusion, the 30-day case-fatality is higher in STEMI-CS, but the long-term outcome is similar in both groups.

Venoarterial extracorporeal membrane oxygenation flow or dobutamine to improve microcirculation during ECMO for refractory cardiogenic shock

PURPOSE

Venoarterial extracorporeal membrane oxygenation (VA ECMO) effectively supports refractory cardiogenic shock (rCS), and sustains macro- and microcirculations. We investigated the respective impact of increasing VA ECMO flow or dobutamine dose on microcirculation in stabilized VA ECMO-treated patients with rCS.

METHODS

In this prospective interventional study, we included consecutive intubated patients, with ECMO-supported rCS and hemodynamic stability, able to tolerate stepwise incremental dobutamine doses (from 5 to 20 gamma/kg/min) or ECMO flows (progressive increase by 25% above baseline ECMO flow. Baseline was defined as the lowest VA ECMO flow and dobutamine 5 μg/kg/min (DOBU₅) to maintain mean arterial pressure (MAP) ≥ 65 mmHg. Macro- and microcirculations were evaluated after 30 min at each level.

RESULTS

Fourteen patients were included. Macro- and microcirculations were assessed 2 [2-5] days post-ECMO onset. Dobutamine-dose increments did not modify any microcirculation parameters. Only the De Backer score tended to be reduced (p = 0.08) by ECMO-flow increments whereas other microcirculation parameters were not affected. These findings did not differ between patients successfully weaned-off ECMO (n = 6) or not.

CONCLUSIONS

When macrocirculation has already been restored in patients with ECMO-supported rCS, increasing dobutamine (above 5 μg/kg/min) or ECMO flow did not further improve microcirculation.

Circulating virome and inflammatory proteome in patients with ST-elevation myocardial infarction and primary ventricular fibrillation

Primary ventricular fibrillation (PVF) is a life-threatening complication of ST-segment elevation myocardial infarction (STEMI). It is unclear what roles viral infection and/or systemic inflammation may play as underlying triggers of PVF, as a second hit in the context of acute ischaemia. Here we aimed to evaluate whether the circulating virome and inflammatory proteome were associated with PVF development in patients with STEMI. Blood samples were obtained from non-PVF and PVF STEMI patients at the time of primary PCI, and from non-STEMI healthy controls. The virome profile was analysed using VirCapSeq-VERT (Virome Capture Sequencing Platform for Vertebrate Viruses), a sequencing platform targeting viral taxa of 342,438 representative sequences, spanning all virus sequence records. The inflammatory proteome was explored with the Olink inflammation panel, using the Proximity Extension Assay technology. After analysing all viral taxa known to infect vertebrates, including humans, we found that non-PVF and PVF patients only significantly differed in the frequencies of viruses in the Gamma-herpesvirinae and Anelloviridae families. In particular, most showed a significantly higher relative frequency in non-PVF STEMI controls. Analysis of systemic inflammation revealed no significant differences between the inflammatory profiles of non-PVF and PVF STEMI patients. Inflammatory proteins associated with cell adhesion, chemotaxis, cellular response to cytokine stimulus, and cell activation proteins involved in immune response (IL6, IL8 CXCL-11, CCL-11, MCP3, MCP4, and ENRAGE) were significantly higher in STEMI patients than non-STEMI controls. CDCP1 and IL18-R1 were significantly higher in PVF patients compared to healthy subjects, but not compared to non-PVF patients. The circulating virome and systemic inflammation were not associated with increased risk of PVF development in acute STEMI. Accordingly, novel strategies are needed to elucidate putative triggers of PVF in the setting of acute ischaemia, in order to reduce STEMI-driven sudden death burden.

Impact of the COVID-19 pandemic on hospitalizations for acute coronary syndromes: a multinational study

BACKGROUND

COVID-19 has challenged the health system organization requiring a fast reorganization of diagnostic/therapeutic pathways for patients affected by time-dependent diseases such as acute coronary syndromes (ACS).

AIM

To describe ACS hospitalizations, management, and complication rate before and after the COVID-19 pandemic was declared.

DESIGN

Ecological retrospective study. Methods: We analyzed aggregated epidemiological data of all patients > 18 years old admitted for ACS in twenty-nine hub cardiac centers from 17 Countries across 4 continents, from December 1st, 2019 to April 15th, 2020. Data from December 2018 to April 2019 were used as historical period.

RESULTS

A significant overall trend for reduction in the weekly number of ACS hospitalizations was observed (20.2%; 95% confidence interval CI [1.6, 35.4] P = 0.04). The incidence rate reached a 54% reduction during the second week of April (incidence rate ratio: 0.46, 95% CI [0.36, 0.58]) and was also significant when compared to the same months in 2019 (March and April, respectively IRR: 0.56, 95%CI [0.48, 0.67]; IRR: 0.43, 95%CI [0.32, 0.58] p < 0.001). A significant increase in door-to-balloon, door-to-needle, and total ischemic time (p <0.04 for all) in STEMI patents were reported during pandemic period. Finally, the proportion of patients with mechanical complications was higher (1.98% vs. 0.98%; P = 0.006) whereas GRACE risk score was not different.

CONCLUSIONS

Our results confirm that COVID-19 pandemic was associated with a significant decrease in ACS hospitalizations rate, an increase in total ischemic time and a higher rate of mechanical complications on a international scale.

P–492 Knowledge about reproductive health among cohort of oocyte donors in Spain

Study question

What degree of reproductive health knowledge have oocyte donors?

Summary answer

The results of this study reveal that although oocyte donors are aware of the risks of possible fertility disorders, reproductive health knowledge is insufficient

What is known already

Sterility affects approximately 15% of the population of reproductive age, that is, young people. However, the information that young people have about fertility is scarce. Gamete donors are a group especially involved in reproductive issues since they help many people to solve their fertility problems and must undergo numerous tests before being accepted as such. However, there are no studies in Spain that deal with the knowledge that young people and, more specifically, donors, have about reproductive health and fertility

Study design, size, duration

A prospective, cross-sectional multicenter study including oocyte donors at ten fertility clinics performing gamete donation treatment in Spain. During a 2-month period (September-October 2020), 63 donors aged between 19 and 35 years old were recruited consecutively and a total of 63 oocyte donors were included as sample population. Most of them (78%) had not donated before

Participants/materials, setting, methods

54% oocyte donors had secondary education and 43% have achieved university studies. Participants anonymously completed a questionnaire containing 41 questions divided into three sections: sociodemographic characteristics (11 items), knowledge on fertility and reproduction (22 items) and with a Likert scale, response to determine general reproductive health information as well as known risks for fertility disorders (8 items).

Besides descriptive statistics, statistical analysis was performed with Chi square test. p &lt; 0.05 was considered significant

Main results and the role of chance

In the survey 96.8% of the participants reported that they had already known the tests for fertility disorders.

The increasing age of the women was correctly assessed by the participants of the study as a decisive risk factor for fertility, but it was found that exact knowledge was lacking: the decrease of a woman’s fertility by 39.7% was stated to occur on average at the age of 35–40 and by 30% at 40–45. Nevertheless, 66% of donors considered that fertility preservation should be carried out before the age of 35.

61.1% of the non-university donors reported that fertility can drop as a woman ages due to the decreasing number and quality of the remaining eggs. Among university donors, this percentage increases to 92,6% (p:0,034). Merely 47% of the participants informed what they understood that ovarian reserve is and 47.6% of donors believed that women create new eggs every month.

Regarding the known risk factors for fertility, lifestyle was mentioned most frequently by all participants (91,2%), followed by chemo/radiotherapy (83,8%) and smoking, alcohol, and drugs (82,4%). Concerning the influence of the body mass index on fertility, differences were found between non-university (61%) and university donors (88,9%) (p:0,012).

Limitations, reasons for caution

Financial compensation has been found to be a motivating factor for oocyte donors and therefore one could question the representativeness of the participating oocyte donors. It would be of great interest to explore the significance of the financial compensation further.

Wider implications of the findings: The present study reveals an existing requirement for information among oocyte donors, which is not only important for the success of prevention plans but also provides a foundation for possible strategies for the prevention of fertility disorder.

Trial registration number

Not applicable

Awake venoarterial extracorporeal membrane oxygenation for refractory cardiogenic shock

BACKGROUND 

Venoarterial-extracorporeal membrane oxygenation (VA-ECMO) is currently one of the first-line therapies for refractory cardiogenic shock (CS), but its applicability is undermined by the high morbidity associated with its complications, especially those related to mechanical ventilation (MV). We aimed to assess the prognostic impact of keeping patients in refractory CS awake at cannulation and during the VA-ECMO run.

METHODS 

A 7-year database of patients given peripheral VA-ECMO support was used to conduct a propensity-score (PS)-matched analysis to balance their clinical profiles. Patients were classified as 'awake ECMO' or 'non-awake ECMO', respectively, if invasive MV was used during ≤50% or >50% of the VA-ECMO run. Primary outcomes included ventilator-associated pneumonia and ECMO-related complication rates, and secondary outcomes were 60-day and 1-year mortality. A multivariate logistic-regression analysis was used to identify whether MV at cannulation was independently associated with 60-day mortality.

RESULTS 

Among 231 patients included, 91 (39%) were 'awake' and 140 (61%) 'non-awake'. After PS-matching adjustment, the 'awake ECMO' group had significantly lower rates of pneumonia (35% vs. 59%, P = 0.017), tracheostomy, renal replacement therapy, and less antibiotic and sedative consumption. This strategy was also associated with reduced 60-day (20% vs. 41%, P = 0.018) and 1-year mortality rates (31% vs. 54%, P = 0.021) compared to the 'non-awake' group, respectively. Lastly, MV at ECMO cannulation was independently associated with 60-day mortality.

CONCLUSION 

An 'awake ECMO' management in VA-ECMO-supported CS patients is feasible, safe, and associated with improved short- and long-term outcomes.

Current status and needs for changes in critical care training: the voice of the young cardiologists

AIMS

The implementation of the 2013 European Society of Cardiology (ESC) Core Curriculum guidelines for acute cardiovascular care (acc) training among European countries is unknown. We aimed to evaluate the current status of acc training among cardiology trainees and young cardiologists (<40 years) from ESC countries.

METHODS AND RESULTS

The survey (March-July 2019) asked about details of cardiology training, self-confidence in acc technical and non-technical skills, access to training opportunities, and needs for further training in the field. Overall 614 young doctors, 31 (26-43) years old, 55% males were surveyed. Place and duration of acc training differed between countries and between centres in the same country. Although the majority of the respondents (91%) had completed their acc training, the average self-confidence to perform invasive procedures and to manage acc clinical scenarios was low-44% (27.3-70.4). The opportunities for simulation-based learning were scarce-18% (5.8-51.3), as it was previous leadership training (32%) and knowledge about key teamwork principles was poor (48%). The need for further acc training was high-81% (61.9-94.3). Male gender, higher level of training centres, professional qualifications of respondents, longer duration of acc/intensive care training, debriefings, and previous leadership training as well as knowledge about teamwork were related to higher self-confidence in all investigated aspects.

CONCLUSIONS

The current cardiology training program is burdened by deficits in acc technical/non-technical skills, substantial variability in programs across ESC countries, and a clear gender-related disparity in outcomes. The forthcoming ESC Core Curriculum for General Cardiology is expected to address these deficiencies.

Trends in Short- and Long-Term ST-Segment-Elevation Myocardial Infarction Prognosis Over 3 Decades: A Mediterranean Population-Based ST-Segment-Elevation Myocardial Infarction Registry

Background Coronary artery disease remains a major cause of death despite better outcomes of ST-segment-elevation myocardial infarction (STEMI). We aimed to analyze data from the Ruti-STEMI registry of in-hospital, 28-day, and 1-year events in patients with STEMI over the past 3 decades in Catalonia, Spain, to assess trends in STEMI prognosis. Methods and Results Between February 1989 and December 2017, a total of 7589 patients with STEMI were admitted consecutively. Patients were grouped into 5 periods: 1989 to 1994 (period 1), 1995 to 1999 (period 2), 2000 to 2004 (period 3), 2005 to 2009 (period 4), and 2010 to 2017 (period 5). We used Cox regression to compare 28-day and 1-year STEMI mortality and in-hospital complication trends across these periods. Mean patient age was 61.6±12.6 years, and 79.3% were men. The 28-day all-cause mortality declined from period 1 to period 5 (10.4% versus 6.0%; P<0.001), with a 40% reduction after multivariable adjustment (hazard ratio [HR], 0.6; 95% CI, 0.46-0.80; P<0.001). One-year all-cause mortality declined from period 1 to period 5 (11.7% versus 9.0%; P=0.001), with a 24% reduction after multivariable adjustment (HR, 0.76; 95% CI, 0.60-0.98; P=0.036). A significant temporal reduction was observed for in-hospital complications including postinfarct angina (-78%), ventricular tachycardia (-57%), right ventricular dysfunction (-48%), atrioventricular block (-45%), pericarditis (-63%), and free wall rupture (-53%). Primary ventricular fibrillation showed no significant downslope trend. Conclusions In-hospital STEMI complications and 28-day and 1-year mortality rates have dropped markedly in the past 30 years. Reducing ischemia-driven primary ventricular fibrillation remains a major challenge.

Venoarterial extracorporeal membrane oxygenation to rescue sepsis-induced cardiogenic shock: a retrospective, multicentre, international cohort study

BACKGROUND

Patients with sepsis-induced cardiomyopathy with cardiogenic shock have a high mortality. This study assessed venoarterial extracorporeal membrane oxygenation (VA-ECMO) support for sepsis-induced cardiogenic shock refractory to conventional treatments.

METHODS

In this retrospective, multicentre, international cohort study, we compared outcomes of 82 patients (aged ≥18 years) with septic shock who received VA-ECMO at five academic ECMO centres, with 130 controls (not receiving ECMO) obtained from three large databases of septic shock. All patients had severe myocardial dysfunction (cardiac index 3 L/min per m2 or less or left ventricular ejection fraction [LVEF] 35% or less) and severe haemodynamic compromise (inotrope score at least 75 μg/kg per min or lactic acidaemia at least 4 mmol/L) at time of inclusion. The primary endpoint was survival at 90 days. A propensity score-weighted analysis was done to control for confounders.

FINDINGS

At baseline, patients treated with VA-ECMO had more severe myocardial dysfunction (mean cardiac index 1·5 L/min per m2vs 2·2 L/min per m2, LVEF 17% vs 27%), more severe haemodynamic impairment (inotrope score 279 μg/kg per min vs 145 μg/kg per min, lactataemia 8·9 mmol/L vs 6·5 mmol/L), and more severe organ failure (Sequential Organ Failure Assessment score 17 vs 13) than did controls, with p<0·0001 for each comparison. Survival at 90 days for patients treated with VA-ECMO was significantly higher than for controls (60% vs 25%, risk ratio [RR] for mortality 0·54, 95% CI [0·40-0·70]; p<0·0001). After propensity score weighting, ECMO remained associated with improved survival (51% vs 14%, adjusted RR for mortality 0·57, 95% CI [0·35-0·93]; p=0·0029). Lactate and catecholamine clearance were also significantly enhanced in patients treated with ECMO. Among the 49 survivors treated with ECMO, 32 who had been treated at the largest centre reported satisfactory Short Form-36 evaluated health-related quality of life at 1-year follow-up.

INTERPRETATION

Patients with severe sepsis-induced cardiogenic shock treated with VA-ECMO had a large and significant improvement in survival compared with controls not receiving ECMO. However, despite the careful propensity-weighted analysis, we cannot rule out unmeasured confounders.

FUNDING

None.

Comorbidity and low use of new antiplatelets in acute coronary syndrome

INTRODUCTION

Despite the use of the new generation P2Y12 inhibitors (Ticagrelor and Prasugrel) with aspirin is the recommended therapy in acute NSTE-ACS patients, their current use in clinical practice remains quite low and might be related, among several variables, with increased comorbidity burden. We aimed to assess the prevalence of these treatments and whether their use could be associated with comorbidity.

METHOD

A multicentric prospective registry was conducted at 8 Cardiac Intensive Care Units (October 2017-April 2018) in patients admitted with non ST elevation myocardial infarction. Antithrombotic treatment was recorded and the comorbidity risk was assessed using the Charlson Comorbidity Index. We created a multivariate model to identify the independent predictors of the use of new inhibitors of P2Y12.

RESULTS

A total of 629 patients were included, median age 67 years, 23.2% women, 359 patients (57.1%) treated with clopidogrel and 40.6% with new P2Y12 inhibitors: ticagrelor (228 patients, 36.2%) and prasugrel (30 patients, 4.8%). Among the patients with very high comorbidity (Charlson Score > 6) clopidogrel was the drug of choice (82.6%), meanwhile in patients with low comorbility (Charlson Score 0-1) was the ticagrelor or prasugrel (63.6%). Independent predictors of the use of ticagrelor or prasugrel were a low Charlson Comorbidity Index, a low CRUSADE score and the absence of prior bleeding.

CONCLUSION

Antiplatelet treatment with Ticagrelor or Pasugrel was low in patients admitted with NSTE-ACS. Comorbidity calculated with Charlson Comorbidity Index was a powerful predictor of the use of new generation P2Y12 inhibitors in this population.

Transitioning from a coronary to a critical cardiovascular care unit: trends over the past three decades

BACKGROUND

Coronary care units were established in the 1960s to reduce acute-phase mortality in acute coronary syndrome. In the 21st century, the original coronary care unit concept has evolved into an intensive cardiovascular care unit. The aim of this study was to analyse trend changes in characteristics and mortality of patients admitted to a coronary care unit over the past three decades.

METHOD

Between February 1989 and December 2017, a total of 18,334 patients was consecutively admitted to the coronary care unit of a university hospital in Barcelona. Data were analysed in five time frames: 1989-1994, 1995-1999, 2000-2004, 2005-2009 and 2010-2017. We analysed demographic profile, diagnoses at admission and trend changes in mortality across periods.

RESULTS

During the periods, the patients' ages and comorbidities increased. Diagnoses at admission have evolved. Acute coronary syndrome cases declined from the first to the last period (72.6% vs. 62.8%) while heart failure (6.0% vs. 8.6%) and malignant arrhythmias (0.8% vs. 4.0%) increased significantly. Overall, coronary care unit mortality decreased 34% from the first to the last period (6.8% vs. 4.5%, P<0.001). Furthermore, the cause of death has changed, those due to acute coronary syndrome declining (66.7% vs. 45.5%), and death from malignant arrhythmias increasing (1.9% vs. 16.2%) from the first to the last period.

CONCLUSIONS

Although acute coronary syndrome remained the main diagnosis, heart failure and arrhythmias have increased. Despite the aging and comorbidities, overall mortality in the coronary care unit decreased by 34% in the past three decades. Deaths due to acute coronary syndrome have declined, whereas those due to malignant arrhythmias have increased.

Prevalence and prognostic impact of subclinical pulmonary congestion at discharge in patients with acute heart failure

Aims

Residual pulmonary congestion at hospital discharge can worsen the outcomes in patients with heart failure (HF) and can be detected by lung ultrasound (LUS). The aim of this study was to analyse the prevalence of subclinical pulmonary congestion at discharge and its impact on prognosis in patients admitted for acute HF.

Methods and results

This is a post‐hoc analysis of the LUS‐HF trial. LUS was performed by the investigators in eight chest zones with a pocket device. Physical exam was subsequently performed by the treating physicians. Primary outcome was a combined endpoint of rehospitalization, unexpected visit for HF worsening or death at 6‐ month follow‐up. Subclinical pulmonary congestion at discharge was defined as the presence of ≥5 B‐lines in LUS in absence of rales in the auscultation employing the area under the ROC curve. At discharge, 100 patients (81%) did not show clinical signs of pulmonary congestion. Of these, 41 had ≥5 B‐lines. Independent factors related with the presence of subclinical pulmonary congestion were anaemia, higher New York Heart Association (NYHA) class, and N terminal pro brain natriuretic peptide (NT‐proBNP). After adjusting by propensity score analysis including age, renal insufficiency, atrial fibrillation, NYHA class, NT‐proBNP levels, clinical congestion, and the trial intervention, the presence of subclinical pulmonary congestion at discharge was a risk factor for the occurrence of the primary outcome (hazard ratio 2.63; 95% confidence interval: 1.08–6.41; P = 0.033).

Conclusions

Up to 40% of patients considered ‘dry’ according to pulmonary auscultation presents subclinical congestion at hospital discharge that can be detected by LUS and implies a worse prognosis at 6‐ month follow‐up. Comorbidities, high values of natriuretic peptides, and higher NYHA class are the factors related with its presence.

Fulminant Versus Acute Nonfulminant Myocarditis in Patients With Left Ventricular Systolic Dysfunction

BACKGROUND

Fulminant myocarditis (FM) is a form of acute myocarditis characterized by severe left ventricular systolic dysfunction requiring inotropes and/or mechanical circulatory support. A single-center study found that a patient with FM had better outcomes than those with acute nonfulminant myocarditis (NFM) presenting with left ventricular systolic dysfunction, but otherwise hemodynamically stable. This was recently challenged, so disagreement still exists.

OBJECTIVES

This study sought to provide additional evidence on the outcome of FM and to ascertain whether patient stratification based on the main histologic subtypes can provide additional prognostic information.

METHODS

A total of 220 patients (median age 42 years, 46.3% female) with histologically proven acute myocarditis (onset of symptoms <30 days) all presenting with left ventricular systolic dysfunction were included in a retrospective, international registry comprising 16 tertiary hospitals in the United States, Europe, and Japan. The main endpoint was the occurrence of cardiac death or heart transplantation within 60 days from admission and at long-term follow-up.

RESULTS

Patients with FM (n = 165) had significantly higher rates of cardiac death and heart transplantation compared with those with NFM (n = 55), both at 60 days (28.0% vs. 1.8%, p = 0.0001) and at 7-year follow-up (47.7% vs. 10.4%, p < 0.0001). Using Cox multivariate analysis, the histologic subtype emerged as a further variable affecting the outcome in FM patients, with giant cell myocarditis having a significantly worse prognosis compared with eosinophilic and lymphocytic myocarditis. In a subanalysis including only adults with lymphocytic myocarditis, the main endpoints occurred more frequently in FM compared with in NFM both at 60 days (19.5% vs. 0%, p = 0.005) and at 7-year follow up (41.4% vs. 3.1%, p = 0.0004).

CONCLUSIONS

This international registry confirms that patients with FM have higher rates of cardiac death and heart transplantation both in the short- and long-term compared with patients with NFM. Furthermore, we provide evidence that the histologic subtype of FM carries independent prognostic value, highlighting the need for timely endomyocardial biopsy in this condition.

Destination Therapy with Left Ventricular Assist Devices in Non-transplant Centres: The Time is Right

For almost half a century, cardiac transplant has been the only long-term treatment for patients with end-stage heart failure. Implantable left ventricular assist devices (LVADs) have emerged as a new treatment option for advanced heart failure as destination therapy for patients either too old or not suitable for transplant. A meta-analysis presenting head-to-head comparisons of cardiac transplant versus LVAD as destination therapy (LVAD-DT) found no difference in 1-year mortality rates between LVAD-DT and cardiac transplant (OR 1.49; 95% CI [0.48–4.66]; I2=82.8%). Moreover, a recent subanalysis from the Interagency Registry for Mechanically Assisted Circulatory Support found similar outcomes after LVAD-DT implantation in both transplant and non-transplant centres. The time is right for LVAD-DT in non-transplant centres, provided multidisciplinary heart failure teams and expertise are in place.

2422Outcome of histologically-proven fulminant versus acute non-fulminant myocarditis with left ventricular systolic dysfunction. Evidence from the International Registry on Acute Myocarditis

Background

Fulminant myocarditis (FM) is a form of acute myocarditis characterized by severe left ventricular (LV) dysfunction requiring inotropes and/or mechanical circulatory support. Based on a retrospective single-center study published in 2000, patients with FM were considered to have better outcomes than those affected by acute non-fulminant myocarditis (NFM) presenting with LV systolic dysfunction (LVSD). Recently, this tenet was challenged, though substantial disagreement still exists.

Purpose

Aim of the present study is to provide additional evidence on the outcome of FM and to ascertain if patient stratification based on the main histologic subtypes can provide additional prognostic information.

Methods

Two hundred and twenty patients (median age 42 years, 46.3% female) with histologically proven acute myocarditis (onset of symptoms <30 days) presenting with LVSD were included in a retrospective, international registry comprising 16 tertiary hospitals in the United States, Europe, and Japan. The primary endpoint was the occurrence of cardiac death or heart transplant (HTx) within 60 days from admission and at long-term follow-up.

Results

Patients with FM (N=165) had significantly higher rates of cardiac death and HTx compared with those with NFM (N=55), both at 60 days (28.0% vs. 1.8%, p=0.0001) and at 7-year follow up (47.7% vs. 10.4%, p<0.0001; Figure). At Cox-multivariate analysis, the histologic subtype emerged as a further variable affecting outcome in FM patients, with giant cell myocarditis having a significantly worse prognosis compared with eosinophilic and lymphocytic myocarditis both at 60 days (62.5% vs. 26.3% vs. 21.0%) and at 3 years (81.3% vs. 39.9% vs. 37.3%, overall p<0.0001). In a sub-analysis including only adults with lymphocytic myocarditis, the main endpoints occurred more frequently in FM compared with NFM both at 60 days (19.5% vs. 0%, p=0.005) and up to 7 years (41.4% vs. 3.1%, p=0.0004).

Outcome of FM vs NFM

Conclusions

The results of this international registry confirm that patients with FM have higher rates of cardiac death and HTx both in the short and long-term compared with patients with NFM. Furthermore, we provide evidence that the histologic subtype of FM carries independent prognostic value, highlighting the need for timely endomyocardial biopsy in this condition.

Acknowledgement/Funding

None

Risk-adjusted early invasive strategy in patients with non-ST-segment elevation acute coronary syndrome in Intensive Cardiac Care Units

OBJECTIVE

Current guidelines recommend a risk-adjusted early invasive strategy (EIS) in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). The present study assesses the application if this strategy, the conditioning factors and prognostic impact upon patients with NSTEACS admitted to Intensive Cardiac Care Units (ICCU).

DESIGN

A prospective cohort study was carried out.

SETTING

The ICCUs of 8 hospitals in Catalonia (Spain).

PATIENTS

Consecutive patients with NSTEACS between October 2017 and March 2018. The risk profile was defined by the European Society of Cardiology criteria.

INTERVENTIONS

EIS was defined as the performance of coronary angiography within the first 6hours in patients at very high-risk or within 24hours in high-risk patients.

OUTCOME VARIABLES

Mortality or readmission at 6 months.

RESULTS

A total of 629 patients were included (mean age 66.6 years), of whom 225 (35.9%) were at very high risk, and 392 (62.6%) at high risk. Most patients (96.2%) underwent an invasive strategy. EIS was performed in 284 patients (45.6%), especially younger patients with fewer comorbidities. These patients had a shorter ICCU and hospital stay, as well as a lesser incidence of ACS, revascularization and death or readmission at 6 months. After adjusting for confounders, the association between EIS and death or readmission at 6 months remained significant (hazard ratio: .66, 95% confidence interval .45-.97; P=.035).

CONCLUSIONS

The EIS was performed in a minority of NSTEACS admitted to ICCU, being associated with better outcomes.

Fulminant giant-cell myocarditis on mechanical circulatory support: Management and outcomes of a French multicentre cohort

AIMS

Giant-cell myocarditis (GCM) is a rare and often fatal form of myocarditis. Only a few reports have focused on fulminant forms. We describe the clinical characteristics, management and outcomes of GCM patients rescued by mechanical circulatory support (MCS).

METHODS AND RESULTS

The clinical features, diagnoses, treatments and outcomes of MCS-treated patients in refractory cardiogenic shock secondary to fulminant GCM admitted to eight French intensive care units (2002-2016) were analysed. We also conducted a systematic review of this topic. Thirteen patients (median age 44 [range 21-76]years, Simplified Acute Physiology Score II 55 [40-79]) in severe cardiogenic shock (median [range] left ventricular ejection fraction 15% [15-35%] and blood lactate 4 mmol/L) were placed on MCS 4 [0-28]days after hospital admission. Severe arrhythmic disturbances were frequent (77%), with six (46%) patients experiencing an electrical storm prior to MCS. Venoarterial extracorporeal membrane oxygenation was the first MCS option for 11 (85%) patients. GCM was diagnosed in five (38%) patients before transplant or death and treated with immunosuppressants; infections were the main complication (80%). Four patients died on MCS and no patient presented long-term survival free from heart transplant (nine patients, 69%). All transplanted patients were alive 1year later and no GCM recurrence was reported after median follow-up of 42 [12-145]months.

CONCLUSION

Outcomes of fulminant GCMs may differ from those of milder forms. In this context, heart transplant might likely be the only long-term survival option.

To be or not to be on ECMO: can survival prediction models solve the question?

Over the past decade, there has been growing interest in extracorporeal membrane oxygenation (ECMO) as a rescue therapy for patients with severe acute respiratory distress syndrome (ARDS) and cardiogenic shock. Although survival of ECMO-treated patients has improved recently, the incidence of ECMO-related complications such as bleeding and nosocomial infections remains unacceptably high. In addition, patients often experience long-term physiological and psychological sequelae. Hence, identifying patients who will most likely benefit from ECMO is crucial. Because the technique exposes patients to complications and is associated with high costs and resource utilisation, prediction models have been developed to assist clinicians in identifying patients that would most likely survive after ECMO treatment. In addition, these prediction models enable comparison of risk-adjusted outcomes, both over time and between centres. Our review explores the latest predictive survival models developed for ECMO-treated severe cardiogenic shock and ARDS patients.

BDNF and AMPA receptors in the cNTS modulate the hyperglycemic reflex after local carotid body NaCN stimulation

The application of sodium cyanide (NaCN) to the carotid body receptors (CBR) (CBR stimulation) induces rapid blood hyperglycemia and an increase in brain glucose retention. The commissural nucleus tractus solitarius (cNTS) is an essential relay nucleus in this hyperglycemic reflex; it receives glutamatergic afferents (that also release brain derived neurotrophic factor, BDNF) from the nodose-petrosal ganglia that relays CBR information. Previous work showed that AMPA in NTS blocks hyperglycemia and brain glucose retention after CBR stimulation. In contrast, BDNF, which attenuates glutamatergic AMPA currents in NTS, enhances these glycemic responses. Here we investigated the combined effects of BDNF and AMPA (and their antagonists) in NTS on the glycemic responses to CBR stimulation. Microinjections of BDNF plus AMPA into the cNTS before CBR stimulation in anesthetized rats, induced blood hyperglycemia and an increase in brain arteriovenous (a-v) of blood glucose concentration difference, which we infer is due to increased brain glucose retention. By contrast, the microinjection of the TrkB antagonist K252a plus AMPA abolished the glycemic responses to CBR stimulation similar to what is observed after AMPA pretreatments. In BDNF plus AMPA microinjections preceding CBR stimulation, the number of c-fos immunoreactive cNTS neurons increased. In contrast, in the rats microinjected with K252a plus AMPA in NTS, before CBR stimulation, c-fos expression in cNTS decreased. The expression of AMPA receptors GluR2/3 did not change in any of the studied groups. These results indicate that BDNF in cNTS plays a key role in the modulation of the hyperglycemic reflex initiated by CBR stimulation.

Mixing effects in the crystallization of supercooled quantum binary liquids

By means of Raman spectroscopy of liquid microjets, we have investigated the crystallization process of supercooled quantum liquid mixtures composed of parahydrogen (pH2) or orthodeuterium (oD2) diluted with small amounts of neon. We show that the introduction of the Ne impurities affects the crystallization kinetics in terms of a significant reduction of the measured pH2 and oD2 crystal growth rates, similarly to what found in our previous work on supercooled pH2-oD2 liquid mixtures [Kühnel et al., Phys. Rev. B 89, 180201(R) (2014)]. Our experimental results, in combination with path-integral simulations of the supercooled liquid mixtures, suggest in particular a correlation between the measured growth rates and the ratio of the effective particle sizes originating from quantum delocalization effects. We further show that the crystalline structure of the mixtures is also affected to a large extent by the presence of the Ne impurities, which likely initiate the freezing process through the formation of Ne-rich crystallites.

Nitric oxide in the solitary tract nucleus (STn) modulates glucose homeostasis and FOS-ir expression after carotid chemoreceptor stimulation

We evaluate in rats the role of NO in the solitary tract nucleus (STn) after an anoxic stimulus to carotid body chemoreceptor cells (CChrc) with cyanide (NaCN), on the hyperglycemic reflex with glucose retention by the brain (BGR) and FOS expression (FOS-ir) in the STn. The results suggest that nitroxidergic pathways in the STn may play an important role in glucose homeostasis. A NO donor such as sodium nitroprusside (NPS) in the STn before CChrc stimulation increased arterial glucose level and significantly decreased BGR. NPS also induced a higher FOS-ir expression in STn neurons when compared to neurons in control rats that only received artificial cerebrospinal fluid (aCSF) before CChrc stimulation. In contrast, a selective NOS inhibitor such as Nomega-nitro-L-arginine methyl ester (L-NAME) in the STn before CChrc stimulation resulted in an increase of both, systemic glucose and BGR above control values. In this case, the number of FOS-ir positive neurons in the STn decreased when compared to control or to NPS experiments. FOS-ir expression in brainstem cells suggests that CChrc stimulation activates nitroxidergic pathways in the STn to regulate peripheral and central glucose homeostasis. The study of these functionally defined cells will be important to understand brain glucose homeostasis.

Low-temperature inelastic collisions between hydrogen molecules and helium atoms

Inelastic H(2):He collisions are studied from the experimental and theoretical points of view between 22 and 180 K. State-to-state cross sections and rates are calculated at the converged close-coupling level employing recent potential energy surfaces (PES): The MR-PES [J. Chem. Phys. 100, 4336 (1994)], and the MMR-PES and BMP-PESs [J. Chem. Phys. 119, 3187 (2003)]. The fundamental rates k(2-->0) and k(3-->1) for H(2):He collisions are assessed experimentally on the basis of a master equation describing the time evolution of rotational populations of H(2) in the vibrational ground state. These populations are measured in the paraxial region of supersonic jets of H(2)+He mixtures by means of high-sensitivity and high spatial resolution Raman spectroscopy. Good agreement between theory and experiment is found for the k(2-->0) rate derived from the MR-PES, but not for the BMP-PES. For the k(3-->1) rate, which is about one-third to one-half of k(2-->0), the result is less conclusive. The experimental k(3-->1) rate is compatible within experimental error with the values calculated from both PESs. In spite of this uncertainty, the global consistence of experiment and theory in the framework of Boltzmann equation supports the MR-PES and MMR-PESs, and the set of gas-dynamic equations employed to describe the paraxial region of the jet at a molecular level.