Need For Mechanical Support Research Articles

Degenerative disc disease: analysis of treatments, tissue, and market

The prevalence of intervertebral thinning discs and the degradation of spinal discs as a whole has created a new market and area of research to find a solution to this age-related problem. The loss of the cartilage cushioning two vertebrae is called degenerative disc disease, or DDD. DDD can impact a patient’s quality of life greatly – putting them in severe pain, limiting mobility, and decreasing their ability to perform daily activities. The market for DDD treatment shows promising growth, both globally and in the US. Most of the drugs and devices that are currently on the market aim to alleviate pain or reduce inflammation, addressing the symptoms of DDD rather than regenerating the lost disc tissue. However, there are many new treatments that are in development or are being tested in clinical trials that could satisfy this need. In the context of tissue engineering, regeneration of the intervertebral disc is a prime target. A scaffold could fulfill the need for mechanical support in between the vertebrae and growth factors and cells could stimulate the regrowth of the injured tissue.

P194 DESTRUCTIVE AORTIC VALVE ENDOCARDITIS WITH INVOLVEMENT OF THE MITRO–AORTIC CURTAIN: A SUCCESSFUL “UFO” PROCEDURE

Abstract Infective endocarditis is a relatively rare disease with an estimated mean incidence of 3.6–7.0 cases per 100,000 subject–years. Aortic bicuspid disease, the most frequent congenital anomaly, is one of the main risk factors. Heart failure, uncontrolled infection (fistulas, abscesses, persistently positive blood cultures) and systemic embolization are among the most feared complications of endocarditis: these cases constitute an indication for emergency/urgent cardiac surgery. An example of extremely demolitive surgery is the Commando or "UFO" procedure, which consists in the double replacement of the aortic valve and the mitral valve with reconstruction of the mitro–aortic junction. The clinical case concerns a 36–year–old man who went to the emergency room for high fever with shivering. Having been found positive blood cultures for MSSA and having emerged mitro–aortic vegetation by echocardiogram, a diagnosis of infective endocarditis was made. During hospitalization, multi–organ cardioembolic phenomena (e.g. splenic, cerebral) with hemorrhagic cerebral infarction occurred: therefore, in accordance with current guidelines, a conservative treatment was temporarily opted for. However, in the following days the deterioration of the clinical–haemodynamic picture was such as to require emergency cardiac surgery. The patient was thus subjected to Commando or UFO procedure with reconstruction of the mitral–aortic junction. Severe bi–ventricular dysfunction was found for the first time at post–operative echocardiographic control, with the need for mechanical support to the circulation (AV ECMO, Impella). The remainder of the hospitalization was characterized by a progressive recovery of ventricular function (LVEF 16% to 44%), therefore patient was discharged in discrete hemodynamic compensation, despite the multiorgan sequelae (hepatic, neurological, renal).

A primer for the student joining the adult cardiac surgery service tomorrow: Primer 1 of 7

A primer for the student joining the adult cardiac surgery service tomorrow: Primer 1 of 7

Long-term milrinone therapy in children with dilated cardiomyopathy.

The aim of this study was to assess the safety and efficacy of long-term milrinone therapy in children with acute decompensated heart failure due to dilated cardiomyopathy (DCM). A single-centre retrospective study of all children ≤18 years with acute decompensated heart failure and DCM who received continuous long-term (≥7 consecutive days) intravenous milrinone between January 2008 and January 2022. The 47 patients had a median age of 3.3 months [interquartile range (IQR) 1.0-18.1], weight of 5.7kg [IQR 4.3-10.1] and fractional shortening of 11.9% [±4.7]. Idiopathic DCM (n=19) and myocarditis (n=18) were the most common diagnoses. The median milrinone infusion duration was 27 days [IQR 10-50, range 7-290]. No adverse events necessitated milrinone termination. Nine patients required mechanical circulatory support. Median follow-up was 4.2 years [IQR 2.7-8.6]. On initial admission, four patients died, six were transplanted and 79% [37/47] were discharged home. The 18 readmissions resulted in five more deaths and four transplantations. Cardiac function recovered in 60% [28/47], as measured by normalised fractional shortening. Long-term intravenous milrinone is safe and effective in paediatric acute decompensated DCM. Combined with conventional heart failure therapies, it can act as a bridge to recovery and thereby potentially reduce the need for mechanical support or heart transplantation.

Efficacy of Intraoperative Low Dose Intravenous Amiodarone in Pharmacologic Cardioversion in Patients with Preoperative Atrial Fibrillation Presenting for Mitral Valve Replacement Surgery Randomized Control Trial.

Atrial fibrillation (AF) is the most common form of dysrhythmia observed in the clinical field, causing multiple morbidities, such as thromboembolic complications. Hence, the maintenance of sinus rhythm is superior to rate control. This study tests the efficacy of single- and low-dose amiodarone on the persistence of AF after surgery before transfer to the intensive care unit. A double-blinded, randomized controlled trial assessed 113 patients who underwent mitral valve surgery with preoperative chronic AF. Patients were divided into two groups: the control group (N = 55) who received 50 mL of 5% dextrose over 10 min after general anesthesia induction, and the amiodarone group (N = 58) who received 1 mg/kg of amiodarone diluted in 50 mL of 5% dextrose over 10 min shortly after anesthesia induction. The amiodarone group had a statistically significant successful conversion of preoperative AF to normal sinus rhythm in 40 patients (72.73%). The control group demonstrated spontaneous conversion from AF to a normal sinus rhythm in seven patients (12.73%). The sinus rhythm was maintained in 60% of patients (36), as four patients reverted to AF during the hospital stay despite the initial normal sinus rhythm after the operation. In contrast, 53 (96.36%) patients in the control group were discharged from the hospital with a controlled rate of AF. In addition, low-dose amiodarone caused a statistically significant reduction in heart rates at 10, 30, and 60 min after declamping, extended throughout the first 24 h with mean heart rates of 97.233±7.311, 99.509±8.482, and 97.940±7.715 bpm, respectively. In comparison, the control group had heart rates of 115.382±7.547, 115.055±13.919, and 113.618±8.765 bpm at these times. The mean postoperative heart rate at the end of the first 24 h was 97.793±7.189 bpm in the amiodarone group and 113.036±9.737 bpm in the control group. No mortality or need for mechanical support was recorded in either group. Single and low-dose intraoperative intravenous amiodarone during mitral valve surgery may be practical to aid in pharmacological cardioversion of patients with preoperative chronic AF presenting for mitral valve surgery.

Nonplatelet thromboxane generation is associated with impaired cardiovascular performance and mortality in heart failure.

Nonplatelet thromboxane generation, stimulated largely by oxidative stress, is a novel mortality risk factor in individuals with coronary artery disease. Though inversely associated with left ventricular ejection fraction (LVEF), a potential role in the pathobiology of heart failure (HF) remains poorly defined. Nonplatelet thromboxane generation and oxidative stress were assessed by measuring urine thromboxane-B2 metabolites (TXB2-M) and 8-isoPGF2α by ELISA in 105 subjects taking aspirin and undergoing right heart catheterization for evaluation of HF, valve disease, or after transplantation. Multivariable logistic regression and survival analyses were used to define associations of TXB2-M to invasive measures of cardiovascular performance and 4-year clinical outcomes. TXB2-M was elevated (>1,500 pg/mg creatinine) in 46% of subjects and correlated with HF severity by New York Heart Association (NYHA) functional class and brain natriuretic peptide level, modestly with LVEF, but not with HF etiology. There was no association of oxidative stress to HF type or etiology but a trend with NYHA functional class. Multiple invasive hemodynamic parameters independently associated with TXB2-M after adjustment for oxidative stress, age, sex, and race with pulmonary effective arterial elastance (Ea pulmonary), reflective of right ventricular afterload, being the most robust on hierarchical analysis. Similar to Ea pulmonary, elevated urinary TXB2-M is associated with increased risk of death (adjusted HR = 2.15, P = 0.037) and a combination of death, transplant, or mechanical support initiation (adjusted HR = 2.0, P = 0.042). Nonplatelet TXA2 thromboxane generation is independently associated with HF severity reflected by invasive measures of cardiovascular performance, particularly right ventricular afterload, and independently predicted long-term mortality risk.NEW & NOTEWORTHY Nonplatelet thromboxane generation in heart failure is independently associated with risk of death, transplant, or need for mechanical support. Measurement of urine thromboxane metabolites using a clinically available assay may be a useful surrogate for invasive measurement of cardiovascular hemodynamics and performance that could provide prognostic information and facilitate tailoring of therapy in patients with heart failure. Inhibiting thromboxane generation or its biological effects is a potential strategy for improving cardiovascular performance and outcomes in heart failure.

Association Between Right Ventricular Dysfunction and Adverse Outcomes in Peripartum Cardiomyopathy: Insights From the BRO-HF Quebec Cohort Study

BackgroundPeripartum cardiomyopathy (PPCM) is associated with severe morbidity and mortality, and the significance of right ventricular (RV) involvement is unclear. We sought to determine whether RV systolic dysfunction or dilatation is associated with adverse clinical outcomes in women with PPCM. MethodsWe conducted a multicentre retrospective cohort study examining the association between echocardiographic RV systolic dysfunction or dilatation at the time of PPCM diagnosis and clinical outcomes. Clinical endpoints of interest were the need for mechanical support, recovery of left ventricular ejection fraction at follow-up, and a combined endpoint of hospitalization for heart failure, cardiac transplant, or death. ResultsA total of 67 women, median age 30 years (interquartile range: 7), were diagnosed with PPCM between 1994 and 2015 in 17 participating centres. Twin pregnancies occurred in 11%; 62% of women were multiparous; and 24% had preeclampsia. RV systolic function was impaired in 18 (27%) and dilated in 8 (12%). Seven women required ventricular assistance, and 8 experienced the composite outcome during follow-up (25 [interquartile range 61] months). RV dysfunction was associated with the need for mechanical support (odds ratio 10.10 (95% confidence interval: 1.86-54.81), P = 0.007), but neither RV dysfunction nor dilatation was associated with left ventricular ejection fraction recovery, the need for cardiac transplant, heart failure hospitalization, or death. ConclusionsRV dysfunction is associated with the need for mechanical support in women with PPCM. These findings may improve risk stratification of complications and clinical management.

The Role of Perioperative Levosimendan in Patients with Reduced Ejection Fraction undergoing Cardiac surgery in Reducing Post-operative Hemodynamic Support

BACKGROUND: Acute perioperative left ventricular dysfunction is a major complication affecting patients subjected to cardiac surgery and is associated with increased mortality. Levosimendan as a “calcium sensitizers” with inodilator effect improves myocardial contractility by sensitizing troponin C to calcium without increasing myocardial oxygen consumption and without impairing relaxation and diastolic function. AIM: The aim of this study was to evaluate the effect of perioperative levosimendan compared to the conventional management used in the patient with poor left ventricular function undergoing cardiac surgery to reduce the need of post-operative pharmacological and mechanical circulatory support. METHODS: It is prospective observational studies were patients undergoing cardiac surgery divided into two groups of 25 patients each. The first group received conventional management while the other group received levosimendan additionally duration and type of post-operative pharmacological support, duration of mechanical ventilation, durations of ICU and hospital stays, and major outcomes, and data about the need of mechanical support were collected. RESULTS: In the levosimendan, fewer patients required vasoactive agents post-surgery (Noradrenaline) compared to the conventional group, yet the use of inotropic support (adrenaline) in the 2nd day and the need of mechanical circulatory support was equal in both groups. The mortality was equal in both groups. CONCLUSION: Perioperative levosimendan may reduce the need of vasoactive agents postoperatively, but it does not reduce the need of inotropic nor mechanical support.

Relationship between donor fraction cell-free DNA and clinical rejection in heart transplantation.

Clinical rejection (CR) defined as decision to treat clinically suspected rejection with change in immunotherapy based on clinical presentation with or without diagnostic biopsy findings is an important part of care in heart transplantation. We sought to assess the utility of donor fraction cell-free DNA (DF cfDNA) in CR and the utility of serial DF cfDNA in CR patients in predicting outcomes of clinical interest. Patients with heart transplantation were enrolled in two sequential, multi-center, prospective observational studies. Blood samples were collected for surveillance or clinical events. Clinicians were blinded to the results of DF cfDNA. A total of 835samples from 269subjects (57% pediatric) were included for this analysis, including 28samples associated with CR were analyzed. Median DF cfDNA was 0.43 (IQR 0.15, 1.36)% for CR and 0.10 (IQR 0.07, 0.16)% for healthy controls (p<.0001). At cutoff value of 0.13%, the area under curve (AUC) was 0.82, sensitivity of 0.86, specificity of 0.67, and negative predictive value of 0.99. There was serial decline in DF cfDNA post-therapy, however, those with cardiovascular events (cardiac arrest, need for mechanical support or death) showed significantly higher levels of DF cfDNA on Day 0 (2.11 vs 0.31%) and Day 14 (0.51 vs 0.22%) compared to those who did not have such an event (p<.0001). DF cfDNA has excellent agreement with clinical rejection and, importantly, serial measurement of DF cfDNA predict clinically significant outcomes post treatment for rejection in these patients.

The role of intraoperative pulmonary arterial catheterization data in determining the need for extracorporeal membrane oxygenation in lung transplantation.

Background This study aims to investigate predictive factors of identification of the need of patients for extracorporeal membrane oxygenation support during lung transplantation. Methods A total of 63 patients (49 males, 14 females, mean age: 44.9±14.4 years; range, 14 to 64 years) who underwent lung transplantation in our institution between December 2016 and December 2019 were retrospectively analyzed. Demographic characteristics and perioperative clinical data of patients were recorded. After induction and pulmonary artery catheterization, cardiac output, mean pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac index, pulmonary vascular resistance, systemic vascular resistance, and right atrial pressure were measured using the thermodilution technique. Results Thirty-three of the patients received extracorporeal membrane oxygenation support during surgery. The right atrial pressure (p<0.001), pulmonary capillary wedge pressure (p<0.002), mean pulmonary artery pressure (p<0.001), and pulmonary vascular resistance (p<0.001) were statistically significantly higher in the patients who required extracorporeal membrane oxygenation support intraoperatively. The systemic vascular resistance (p<0.032) was statistically significantly lower in the patients who required extracorporeal membrane oxygenation support intraoperatively. A mean pulmonary artery pressure of >39 mmHg (p<0.02) and a right atrial pressure of >12 mmHg (p<0.047) were independent risk factors for ECMO support intraoperatively during lung transplantation. Conclusion Predicting the need of intraoperative extracorporeal membrane oxygenation support is of utmost importance in timing the need for mechanical support, protecting the new graft from high mechanical ventilator pressures, and adequately maintaining hemodynamic stability.

A systematic approach to weaning from extracorporeal membrane oxygenation in patients with refractory cardiac failure.

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is commonly used to provide haemodynamic support for patients with severe cardiac failure. However, timing ECMO weaning remains challenging. We aimed to examine if an integrative weaning approach based on predefined haemodynamic, respiratory and echocardiographic criteria is associated with successful weaning. All patients weaned from ECMO between April 2017 and April 2019 at Aarhus University Hospital, Denmark, were consecutively enrolled. Predefined haemodynamic, respiratory and echocardiographic criteria were assessed before and during ECMO flow reduction. A weaning attempt was commenced in haemodynamic stable patients and patients remaining stable at minimal flow were weaned from ECMO. Comparisons were made between patients who met the criteria for weaning at first attempt and patients who did not meet these criteria. Patients completing a full weaning attempt with no further need for mechanical support within 24h were defined as successfully weaned. A total of 38 patients were included in the study, of whom 26 (68%) patients met the criteria for weaning. Among these patients, 25 (96%) could be successfully weaned. Successfully weaned patients were younger and had less need for inotropic support and ECMO duration was shorter. Fulfilling the weaning criteria was associated with successful weaning and both favourable 30-d survival and survival to discharge. An integrative weaning approach based on haemodynamic, respiratory and echocardiographic criteria may strengthen the clinical decision process in predicting successful weaning in patients receiving ECMO for refractory cardiac failure.

Myocardial involvement in children with post-COVID multisystem inflammatory syndrome: a cardiovascular magnetic resonance based multicenter international study\u2014the CARDOVID registry

BackgroundRecent evidence shows an association between coronavirus disease 2019 (COVID-19) infection and a severe inflammatory syndrome in children. Cardiovascular magnetic resonance (CMR) data about myocardial injury in children are limited to small cohorts. The aim of this multicenter, international registry is to describe clinical and cardiac characteristics of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 using CMR so as to better understand the real extent of myocardial damage in this vulnerable cohort.Methods and resultsHundred-eleven patients meeting the World Health Organization criteria for MIS-C associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), having clinical cardiac involvement and having received CMR imaging scan were included from 17 centers. Median age at disease onset was 10.0 years (IQR 7.0–13.8). The majority of children had COVID-19 serology positive (98%) with 27% of children still having both, positive serology and polymerase chain reaction (PCR). CMR was performed at a median of 28 days (19–47) after onset of symptoms. Twenty out of 111 (18%) patients had CMR criteria for acute myocarditis (as defined by the Lake Louise Criteria) with 18/20 showing subepicardial late gadolinium enhancement (LGE). CMR myocarditis was significantly associated with New York Heart Association class IV (p = 0.005, OR 6.56 (95%-CI 1.87–23.00)) and the need for mechanical support (p = 0.039, OR 4.98 (95%-CI 1.18–21.02)). At discharge, 11/111 (10%) patients still had left ventricular systolic dysfunction.ConclusionNo CMR evidence of myocardial damage was found in most of our MIS-C cohort. Nevertheless, acute myocarditis is a possible manifestation of MIS-C associated with SARS-CoV-2 with CMR evidence of myocardial necrosis in 18% of our cohort. CMR may be an important diagnostic tool to identify a subset of patients at risk for cardiac sequelae and more prone to myocardial damage.Clinical trial registration: The study has been registered on ClinicalTrials.gov, Identifier NCT04455347, registered on 01/07/2020, retrospectively registered.

Atrial Fibrillation is related with higher in-hospital morality in acute myocardial infarction (AMI) patients from K-ACTIVE registry

Abstract Background The prognostic significance of atrial fibrillation (AF) on in-hospital mortality in acute myocardial infarction (AMI) patients is not fully understood in Japanese patients. Methods To elucidate the clinical significance of AF on in-hospital mortality in AMI patients, we analyzed the Japanese observational prospective multicenter registry of acute myocardial infarction (K-ACTIVE: Kanagawa ACuTe cardio Vacular rEgistry), which spans October 2016 to December 2019. Results A total of 3482 patients included 336 patients with AF and 3146 patients with sinus rhythm. Table 1 shows patient baseline characteristics. Patients with AF were significantly older than those with sinus rhythm (75 vs 67, P&amp;lt;0.0001). Prevalence of hypertension and hemodialysis were significantly greater in patients with AF than patients with sinus rhythm while prevalence of dyslipidemia and smoking were significantly less in patients with AF than patients with sinus rhythm. Table 2 shows characteristics of AMI. There were no significant difference in prevalence of STEMI, area of MI, Peak CK/CK-MB and prevalence of multivessel disease. However, patients with AF showed lower systolic blood pressure, faster heart rate, worse Killip category, greater prevalence of OHCA. Need of mechanical support including IABP/ECMO were greater in patients with AF than patients with sinus rhythm. In-hospital mortality was significantly higher in patients with AF than in patients with sinus rhythm (Figure, 10.4% versus 5.2%, P=0.0005). This trend didn't change even after adjustment with age and sex (Odds ratio 1.6 95% confidence interval 1.1–2.4, P=0.02). Conclusion AF was associated with higher in-hospital mortality in Japanese AMI patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported by JSPS KAKENHI Grant Number JP15K09101.

Differences in Baseline Characteristics and Outcomes in Young Caucasians and African Americans with Acute Myocardial Infarction

BackgroundThe incidence of acute myocardial infarction (AMI) in young patients is increasing. While race-related differences in clinical characteristics and outcomes for older AMI patients have been well-studied, such differences in young patients are unknown. MethodsWe performed a retrospective review of charts of Caucasian and African American (AA) patients <50 years of age, presenting with AMI between 2010 and 2017 in an urban, community hospital in Detroit, Michigan. ResultsA total of 271 patients were identified with 156 being AAs (57.5%). Mean age was 43 years which was similar in both groups. AAs with AMI were 2.2 times more likely to be women and to have a history of diabetes and 1.2 times more likely to have BMI >30 kg/m2. History of coronary artery disease (1.8-fold) and hypertension (1.5-fold) were also more common in AAs. Overall presenting features were similar, other than that AAs presented more often with non-ST-elevation MI and tended to present less often with cardiac arrest. No differences were observed in the angiographic findings or in-hospital outcomes in the two groups, with the exception of lower need of mechanical support in AAs. ConclusionsIn conclusion, our data provide important, not previously described information on race-related differences in history, presentation, clinical and angiographic features and outcomes in AAs compared with Caucasians younger than 50 with AMI. These findings may have implications for tailoring specific preventive strategies to decrease the incidence of AMI and its associated adverse events in both racial groups.

Predictors of survival in patients with acute coronary syndrome undergoing percutaneous coronary intervention of unprotected left main coronary artery stenosis.

Aim of this study was to investigate predictors of survival in unstable patients with high SYNTAX-1-score. In significant unprotected left main coronary artery (ULMCA) stenosis, treatment options include percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG). While CABG is recommended for stable patients with ULMCA stenosis and a SYNTAX-1-score > 32, PCI may be preferable in unstable or high operative risk patients. Retrospective single-center all-comers registry study. A total of 142 patients underwent ULMCA-PCI (~72.9 years, 23.2% females, 54.2% survival in 2-year follow-up), 84 of whom had a SYNTAX-1 > 32 (37.4 ± 12.8). Patients in the high-SYNTAX-1-group (score > 32) were more often in an acute condition compared to low-SYNTAX-2-group (score ≤ 32) including acute myocardial infarction (76.2% vs. 57.4%, p = .024), cardiogenic shock (48.2% vs. 14.8%, p = .001), or need for mechanical support (36.1% vs. 11.1%, p = .001). Survival was predicted by the acute condition including cardiogenic shock (OR 0.06 and 0.05) and myocardial infarction (OR 0.03 and 0.34) in both groups. Performance of the SYNTAX-1-score was limited in our patient collective in both groups (c-index 0.65 vs. 0.63) while SYNTAX-2-PCI-score performed better (c-index 0.67 vs. 0.67). EuroScore II had the best discriminative ability (c-index 0.87 vs. 0.78). The majority of patients undergoing ULMCA-PCI presented in acute conditions with high SYNTAX-1-score, and is therefore underrepresented in clinical trials. Prognosis was best predicted by the acute condition and the EuroScore II. These data suggest that therapy in unstable patients should be guided by clinical condition over the anatomical SYNTAX-1-score.

Low cardiac output syndrome in cardiac surgery

Low cardiac output syndrome is one of the most common and serious complications in cardiac surgery and is associated with increased morbidity and mortality. Several prognostic features have been recognized, including preoperative, intraoperative risk factors and laboratory predictors. The pathophysiologic mechanisms of low cardiac output syndrome are not limited by ventricular systolic dysfunction only, diastolic dysfunction and valvular abnormalities also contribute to low cardiac output syndrome development. There is a broad spectrum of monitoring techniques during cardiac surgery, all of them are different in their invasiveness and reliability. Goal-directed hemodynamic therapy should be based on the most informative and accurate monitoring methods and its goal is to optimize the balance between oxygen delivery and consumption. Treatment of low cardiac output syndrome is intended to increase tissue oxygen delivery and prevent organ dysfunction providing adequate hemodynamic support. The first line of low cardiac output syndrome therapy, to be initiated as soon as the volume status is optimized, is the use of inotropes, vasopressors and vasodilators to improve contractility, preload and afterload. In the most severe cases the need of mechanical support might take place, including intra-aortic balloon pump, ventricular assist devices and extracorporeal membrane oxygenation.

Disentangling evolutionary, environmental and morphological drivers of plant anatomical adaptations to drought and cold in Himalayan graminoids

Understanding what determine plants ability to survive drought and cold is crucial for predicting how plants may respond to ongoing climate change. Plant survival strategies are usually characterized by morphological and physiological adaptations, while their underlying anatomical settings are largely unknown. Woody angiosperms and herbaceous dicots have repeatedly evolved small water transporting conduits and large storage parenchyma tissues at colder or drier places to cope with freezing‐ and drought‐induced damages. However, whether these adaptations are also valid for graminoids remains unclear. Here we show that stem anatomical variations in grasses, sedges and rushes dominating in western Himalayan grasslands are driven by elevation and soil moisture via control over aboveground plant stature and belowground clonal growth, while phylogenetic constraints have only a weak effect. Phylogenetic comparative analyses controlling for confounding factors showed that the elevation‐related cooling controls the conductive system through reduced vessel diameter and extended assimilatory and storage tissues with more chlorenchyma and less sclerenchyma around vessels. The soil moisture deficit, on the other hand, determines stabilization structures by promoting short‐rhizomatous turf graminoids with hollow stems, thicker epidermis and deep adventitious roots in dry steppes and semi‐deserts. Saline wetlands and moist alpine pastures promote long‐rhizomatous short‐stature plants with lower need for mechanical support (absence of hollow stem) and exposure to high evaporative forcing (thinner epidermis). Observed trends of decreasing vessel sizes and lignification rate with elevation supports the existing knowledge that narrower vessels and extensive parenchyma assist plants to grow in cold environments by avoiding freezing‐induced cavitation. Our results bring novel information on ecological drivers influencing the evolution of anatomical adaptations in high mountain graminoids. Distinct grassland types, covering elevations from 2650 to 6150 m, harbor unrelated species with different evolutionary histories that have converged towards similar anatomical structures.

Anatomical changes with needle length are correlated with leaf structural and physiological traits across five Pinus species.

The genus Pinus has wide geographical range and includes species that are the most economically valued among forest trees worldwide. Pine needle length varies greatly among species, but the effects of needle length on anatomy, function, and coordination and trade-offs among traits are poorly understood. We examined variation in leaf morphological, anatomical, mechanical, chemical, and physiological characteristics among five southern pine species: Pinus echinata, Pinus elliottii, Pinus palustris, Pinus taeda, and Pinus virginiana. We found that increasing needle length contributed to a trade-off between the relative fractions of support versus photosynthetic tissue (mesophyll) across species. From the shortest (7cm) to the longest (36cm) needles, mechanical tissue fraction increased by 50%, whereas needle dry density decreased by 21%, revealing multiple adjustments to a greater need for mechanical support in longer needles. We also found a fourfold increase in leaf hydraulic conductance over the range of needle length across species, associated with weaker upward trends in stomatal conductance and photosynthetic capacity. Our results suggest that the leaf size strongly influences their anatomical traits, which, in turn, are reflected in leaf mechanical support and physiological capacity.

Timing of Referral of Patients With Severe Isolated Tricuspid Valve Regurgitation to Surgeons (from a French Nationwide Database)

Series evaluating the results of isolated tricuspid valve surgery (ITVS) are rare and often limited by small sample size, selection bias, and/or long period of enrollment. Based on a mandatory administrative national database, we collected all consecutive ITVS performed in France during a 2-year period (2013 and 2014), the type of intervention, clinical profile, and in-hospital mortality and complications. During the 2-year period, 241 patients underwent an ITVS in France (84 repairs and 157 replacements). In-hospital mortality was high (10%), and most patients experienced at least 1 complication (65%) with a 19% rate of major complications (death, need for dialysis, or need for mechanical support using extracorporeal membrane oxygenation). Consequently, hospital duration was remarkably long (26 ± 40 days). Congestive heart failure at presentation was associated with mortality and major complications rates (both p = 0.01). In conclusion, in a contemporary and consecutive series, ITVS was associated with a high mortality and morbidity predicted by clinical presentation at baseline. Our results suggest that patients are often referred too late and that an earlier intervention may improve immediate and possibly midterm outcomes. With the availability of transcatheter therapies in a near future, optimal timing of intervention in this population will be of utmost importance.

BARIATRIC SURGERY IN MORBIDLY OBESE ADVANCED HEART FAILURE PATIENTS

This case study illustrates the importance of a multi-disciplinary team approach to the management of the advanced heart failure (HF) patient with multiple co-morbidities, requiring a near flawless work up process from the point of consult for advanced HF, to the need for mechanical support and