Intraoperative prophylactic right ventricular assist device in prevention of postcardiotomy failure.

OBJECTIVES: In patients at risk of developing right ventricular failure after cardiac surgery, right ventricular support with a ventricular assist device may be a promising strategy to reduce mortality. We present our experience with intraoperative right ventricular assist device implantation as a prevention strategy of right ventricular failure after cardiac surgery. METHODS: Between 2016 and 2022, we implanted four right ventricular assist devices prophylactically in a series of patients with surgical indication for valvular heart disease and high risk of postoperative right ventricular failure. Indications for the right ventricular assist device were suprasystemic pulmonary hypertension or severe right ventricular dysfunction. RESULTS: Externalization of the device cannulas through intercostal spaces was performed in three patients, allowing early mobilization and withdrawal without resternotomy. Removal of the device ocurred on the eighth postoperative day. ICU and hospital length of stay was 12 (±1.6) and 23 days (±4.2) respectively. Hospital mortality was null. No patient died during follow-up, mean follow-up was 32.5 months [1-72]. Patients improved their NYHA functional class up to grade II during follow-up. CONCLUSIONS: Acute right ventricular failure after cardiac surgery remains a significant cause of morbidity and mortality. Prophylactic strategies to prevent postoperative right ventricular dysfunction may decrease the incidence of refractory postoperative right ventricular failure. We propose a novel approach to prevent right failure after cardiac surgery with prophylactic intraoperative ventricular assist device implantation.

Ovarian hormones do not mediate protection against pulmonary hypertension and right ventricular remodeling in female mice exposed to chronic, inhaled nicotine.

Electronic cigarette use has increased globally prompting calls for improved understanding of nicotine's cardiovascular health effects. Our group has previously demonstrated that chronic, inhaled nicotine induces pulmonary hypertension and right ventricular (RV) remodeling in male mice, but not female mice, suggesting sex differences in nicotine-related pathology. Clinically, biological females develop pulmonary hypertension more often but have less severe disease than biological males, likely because of the cardiopulmonary protective effects of estrogen. Nicotine is also metabolized more rapidly in biological females because of differences in cytochrome-P450 activity, which are thought to be mediated by female sex hormones. These findings led us to hypothesize that female mice are protected against nicotine-induced pulmonary hypertension by an ovarian hormone-dependent mechanism. In this study, intact and ovariectomized (OVX) female mice were exposed to chronic, inhaled nicotine or room air for 12 h/day for 10-12 wk. We report no differences in serum cotinine levels between intact and OVX mice. In addition, we found no structural (RV or left ventricular dimensions and Fulton index) or functional (RV systolic pressure, pulmonary vascular resistance, cardiac output, ejection fraction, and fractional shortening) evidence of cardiopulmonary dysfunction in intact or OVX mice. We conclude that ovarian hormones do not mediate cardiopulmonary protection against nicotine-induced pulmonary hypertension. Due to profound sex differences in clinical pulmonary hypertension pathogenesis and nicotine metabolism, further studies are necessary to elucidate mechanisms underlying protection from nicotine-induced pathology in female mice.NEW & NOTEWORTHY The emergence of electronic cigarettes poses a threat to cardiovascular and pulmonary health, but the direct contribution of nicotine to these disease processes is largely unknown. Our laboratory has previously shown that chronic, inhaled nicotine induces pulmonary hypertension and right ventricular remodeling in male mice, but not female mice. This study using a bilateral ovariectomy model suggests that the cardiopulmonary protection observed in nicotine-exposed female mice may be independent of ovarian hormones.

Can Right Ventricular Branch Bypass Alleviate Right Ventricular Dysfunction?

BACKGROUND: Right ventricle (RV) dysfunction after a coronary artery bypass grafting procedure is a challenge that adversely affects RV filling pressure and contraction. This study sought to determine whether additional bypass of an RV branch would lessen RV dysfunction. METHODS: Patients with severe right coronary artery (RCA) stenosis were divided into 2 groups. Group 1 patients (n = 50) had a single distal bypass on the RCA. Group 2 patients (n = 50) had both distal RCA and additional bypass on the RV branch of the RCA. Right ventricular function was examined by echocardiogram by measuring transannular plane systolic excursion, fractional area change, tissue Doppler S-wave velocity, and inferior vena cava diameter. RESULTS: Transannular plane systolic excursion and fractional area change measurements rapidly decreased below the cutoff in both groups, but group 2 patient values reached normal limits at 90 days. Tissue Doppler S-wave velocity reached the normal limit in 7 days. Inotropic agents were required in 11 patients in group 1 and 2 patients in group 2 (P = .013). The mean (SD) intensive care unit stay was 2.11 (1.12) days and 1.45 (0.71) days (P = .033), and the hospital stay was 7.32 (1.44) days and 6.22 (0.45) days in groups 1 and 2, respectively (P = .027). CONCLUSION: The data in this study suggest that an additional graft on the RV branch of the RCA (eg, conus, marginal, any good runoff vessels on the RV) prevents severe RV dysfunction and allows for rapid recovery of RV dysfunction after off-pump coronary surgery.

Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling.

BACKGROUND: Malignant ventricular arrhythmia (VA) is a major contributor to sudden cardiac death (SCD) in patients with pulmonary arterial hypertension (PAH)-induced right heart failure (RHF). Recently, dapagliflozin (DAPA), a sodium/glucose cotransporter-2 inhibitor (SGLT2i), has been found to exhibit cardioprotective effects in patients with left ventricular systolic dysfunction. In this study, we examined the effects of DAPA on VA vulnerability in a rat model of PAH-induced RHF. METHODS: Rats randomly received monocrotaline (MCT, 60 mg/kg) or vehicle via a single intraperitoneal injection. A day later, MCT-injected rats were randomly treated with placebo, low-dose DAPA (1 mg/kg/day), or high-dose (3 mg/kg/day) DAPA orally for 35 days. Echocardiographic analysis, haemodynamic experiments, and histological assessments were subsequently performed to confirm the presence of PAH-induced RHF. Right ventricle (RV) expression of calcium (Ca2+) handling proteins were detected via Western blotting. RV expression of connexin 43 (Cx43) was determined via immunohistochemical staining. An optical mapping study was performed to assess the electrophysiological characteristics in isolated hearts. Cellular Ca2+ imaging from RV cardiomyocytes (RVCMs) was recorded using Fura-2 AM or Fluo-4 AM. RESULTS: High-dose DAPA treatment attenuated RV structural remodelling, improved RV function, alleviated Cx43 remodelling, increased the conduction velocity, restored the expression of key Ca2+ handling proteins, increased the threshold for Ca2+ and action potential duration (APD) alternans, decreased susceptibility to spatially discordant APD alternans and spontaneous Ca2+ events, promoted cellular Ca2+ handling, and reduced VA vulnerability in PAH-induced RHF rats. Low-dose DAPA treatment also showed antiarrhythmic effects in hearts with PAH-induced RHF, although with a lower level of efficacy. CONCLUSION: DAPA administration reduced VA vulnerability in rats with PAH-induced RHF by improving RVCM Ca2+ handling.

Repair with a pulmonary neovalve in tetralogy of Fallot: does this avoid ventricular dysfunction?

OBJECTIVES: Given the anatomical variations of tetralogy of Fallot (TOF), different surgical techniques can be used to achieve correction. Transannular patches (TAPs) are the most commonly used technique; they are associated with right ventricular dysfunction, the incidence of which can be reduced through pulmonary valve preservation. METHODS: Between January 2010 and July 2019, we performed 274 surgical corrections of tetralogy of Fallot at Fundación Cardioinfantil; 63 patients (23%) underwent repair with a TAP in addition to a pulmonary neovalve (Group I), 66 patients (24.1%) received a TAP without a pulmonary valve (Group II) and 145 patients (52.9%) had a repair with valve preservation (Group III). We analysed patient's characteristics before, during and after surgery at a 30-day follow-up. RESULTS: We found that patients in Group III were older (P = 0.04). Group II had the lowest level of O2 saturation before surgery (82%, P = 0.001). Cardiopulmonary bypass and aortic cross-clamp times were longer in Group I (P < 0.001). Right ventricular dysfunction was less frequent in Group III (15.9%, P = 0.011). Severe residual pulmonary regurgitation was more common in Group II (21.9%, P = 0.001). CONCLUSIONS: Preservation of the pulmonary valve is an important factor for immediate postoperative management of tetralogy of Fallot. Patients who were repaired with a TAP with or without a pulmonary neovalve had a higher incidence of right ventricular dysfunction than those with pulmonary valve preservation.

Patient characteristics and surgical variables associated with intraoperative reduced right ventricular function.

OBJECTIVE: Perioperative right ventricular function is a significant predictor of patient outcomes after cardiac surgery. This prospective study aimed to identify perioperative factors associated with reduced intraoperative right ventricular function. METHODS: Right ventricular function was assessed at the beginning and end of surgery by standardized transesophageal echocardiographic measurements, including tricuspid annular plane systolic excursion, peak systolic longitudinal right ventricular strain, and fractional area change, in 109 adult patients undergoing cardiac surgery at Cleveland Clinic. Associations between right ventricular function and 33 patient characteristics and perioperative factors were analyzed by random forest machine learning. The relative importance of each variable in predicting right ventricular function at the end of surgery was determined. RESULTS: Longer aortic clamp duration and lower baseline right ventricular function were highly important variables for predicting worse right ventricular function measured by tricuspid annular plane systolic excursion, right ventricular strain, and fractional area change at the end of surgery. For example, right ventricular function after longer aortic clamp times of 100-120 minutes was worse (median [Q1, Q3] tricuspid annular plane systolic excursion 1.0 [0.9, 1.1] cm) compared with right ventricular function after shorter aortic clamp times of 50 to 70 minutes (tricuspid annular plane systolic excursion 1.5 [1.3, 1.7]; P = .001). Right ventricular strain at the end of surgery was reduced in patients with worse baseline right ventricular function compared with those with higher baseline right ventricular function (end of surgery right ventricular strain in lowest quartile -13.7 [-16.6, -12.4]% vs highest quartile -17.7 [-18.6, -15.3]% of baseline right ventricular function; P = .043). CONCLUSIONS: Intraoperative decline in right ventricular function is associated with longer aortic clamp time and worse baseline right ventricular function. Efforts to optimize these factors, including better myocardial protection strategies, may improve perioperative right ventricular function.

Neuregulin-1 enhances cell-cycle activity, delays cardiac fibrosis, and improves cardiac performance in rat pups with right ventricular pressure load.

OBJECTIVES: Right ventricular (RV) failure is a leading cause of death in patients with congenital heart disease. RV failure is kept at bay during childhood. Limited proliferation of cardiomyocytes is present in the postnatal heart. We propose that cardiomyocyte proliferation improves RV adaptation to pressure load (PL). We studied adaptation in response to increased RV PL and the role of increased cardiomyocyte cell cycle activity (CCA) in rat pups growing into adulthood. METHODS: We induced RV PL at day of weaning in rats (3 weeks; 30-40 g) by pulmonary artery banding and followed rats into adulthood (300 g). We performed histological analyses and RNA sequencing analysis. To study the effects of increased cardiomyocyte cell cycle activity, we administered neuregulin-1 (NRG1), a growth factor involved in cardiac development. RESULTS: PL induced an increase in CCA, with subsequent decline of CCA (sham/PL at 4 weeks: 0.14%/0.83%; P = .04 and 8 weeks: 0.00%/0.00%; P = .484) and cardiac function (cardiac index: control/PL 4 weeks: 4.41/3.29; P = .468 and 8 weeks: 3.57/1.44; P = .024). RNA sequencing analysis revealed delayed maturation and increased CCA pathways. NRG1 stimulated CCA (PL vehicle/NRG1 at 2 weeks: 0.62%/2.28%; P = .003), improved cardiac function (cardiac index control vs vehicle/NRG1 at 2 weeks: 4.21 vs 3.07/4.17; P = .009/.705) and postponed fibrosis (control vs vehicle/NRG1 at 4 weeks: 1.66 vs 4.82%/2.97%; P = .009/.078) in RV PL rats during childhood. CONCLUSIONS: RV PL during growth induces a transient CCA increase. Further CCA stimulation improves cardiac function and delays fibrosis. This proof-of-concept study shows that stimulation of CCA can improve RV adaptation to PL in the postnatal developing heart and might provide a new approach to preserve RV function in patients with congenital heart disease.

Impact of tricuspid regurgitation on late right ventricular failure in left ventricular assist device patients ~can prophylactic tricuspid annuloplasty prevent late right ventricular failure? ~.

BACKGROUND: In this study, we evaluated the prevalence of tricuspid regurgitation (TR) worsening in patients with left ventricular assist devices (LVADs) and its impact on late right ventricular (RV) failure. METHODS: We enrolled 147 patients of the 184 patients who underwent continuous-flow LVAD implantations from 2005 to March 2018. The prevalence of postoperative TR worsening and late RV failure were retrospectively evaluated. RESULTS: Concomitant tricuspid annuloplasty (TAP) was performed in 28 of 41 patients (68%) with preoperative TR greater than or equal to moderate (TR group) and in 23 of 106 patients (22%) with preoperative TR less than or equal to mild (non-TR group). Regarding the TR-free rates, despite receiving or not receiving concomitant TAP, there was no significant difference between the 2 groups (TR group: p = 0.37; non-TR group: p = 0.42). Of the 9 patients with postoperative TR greater than or equal to moderate, late RV failure developed in 3 patients, with TR worsening after RV failure in each case. During follow-up, 16 patients (11%) had late RV failure. As for the late RV failure-free rates, despite receiving or not receiving concomitant TAP, there was no significant difference between the 2 groups (TR group: p = 0.37; non-TR group: p = 0.96). CONCLUSIONS: TR prognosis was preferable regardless of a patient receiving concomitant TAP; however, the presence of postoperative TR seemed to unrelated to late RV failure. Prophylactic TAP might not be necessary to prevent late RV failure.

The inflammation-resolution promoting molecule resolvin-D1 prevents atrial proarrhythmic remodelling in experimental right heart disease.

AIMS: Inflammation plays a role in atrial fibrillation (AF), but classical anti-inflammatory molecules are ineffective. Recent evidence suggests that failure of inflammation-resolution causes persistent inflammatory signalling and that a novel drug-family called resolvins promotes inflammation-resolution. Right heart disease (RHD) is associated with AF; experimental RHD shows signs of atrial inflammatory-pathway activation. Here, we evaluated resolvin-therapy effects on atrial arrhythmogenic remodelling in experimental RHD. METHODS AND RESULTS: Pulmonary hypertension and RHD were induced in rats with an intraperitoneal injection of 60 mg/kg monocrotaline (MCT). An intervention group received daily resolvin-D1 (RvD1), starting 1 day before MCT administration. Right atrial (RA) conduction and gene-expression were analysed respectively by optical mapping and qPCR/gene-microarray. RvD1 had no or minimal effects on MCT-induced pulmonary artery or right ventricular remodelling. Nevertheless, in vivo transoesophageal pacing induced atrial tachyarrhythmias in no CTRL rats vs. 100% MCT-only rats, and only 33% RvD1-treated MCT rats (P < 0.001 vs. MCT-only). Conduction velocity was significantly decreased by MCT, an effect prevented by RvD1. RHD caused RA dilation and fibrosis. RvD1 strongly attenuated RA fibrosis but had no effect on RA dilation. MCT increased RA expression of inflammation- and fibrosis-related gene-expression pathways on gene-microarray transcriptomic analysis, effects significantly attenuated by RvD1 (334 pathways enriched in MCT-rats vs. control; only 177 dysregulated by MCT with RvD1 treatment). MCT significantly increased RA content of type 1 (proinflammatory) CD68-positive M1 macrophages without affecting type 2 (anti-inflammatory) M2 macrophages. RvD1-treated MCT-rat RA showed significant reductions in proinflammatory M1 macrophages and increases in anti-inflammatory M2 macrophages vs. MCT-only. MCT caused statistically significant increases in protein-expression (western blot) of COL3A1, ASC, CASP1, CASP8, IL1ß, TGFß3, CXCL1, and CXCL2, and decreases in MMP2, vs. control. RvD1-treatment suppressed all these MCT-induced protein-expression changes. CONCLUSION: The inflammation-resolution enhancing molecule RvD1 prevents AF-promoting RA remodelling, while suppressing inflammatory changes and fibrotic/electrical remodelling, in RHD. Resolvins show potential promise in combating atrial arrhythmogenic remodelling by suppressing ongoing inflammatory signalling.

Risk Stratification and Optimization to Prevent Right Heart Failure During Left Ventricular Assist Device Implantation.

Left ventricular assist device (LVAD) implantation results in superior survival rates compared with optimal medical therapy in patients with end-stage heart failure. However, a potential complication of LVAD implantation is right heart failure (RHF), which can be devastating. Therefore, identifying preoperative risk factors for RHF and optimal management for these patients are critical for ensuring favorable postoperative outcomes. This review focuses on methods of assessing the risk factors for RHF before surgery, including evaluation of biomarkers, echocardiography, hemodynamics, risk-scoring systems, and existing conditions of right heart dysfunction. In addition, the review also explores the perioperative strategic approaches to reducing the likelihood of RHF.

Estrogen receptor-α prevents right ventricular diastolic dysfunction and fibrosis in female rats.

Although women are more susceptible to pulmonary arterial hypertension (PAH) than men, their right ventricular (RV) function is better preserved. Estrogen receptor-α (ERα) has been identified as a likely mediator for estrogen protection in the RV. However, the role of ERα in preserving RV function and remodeling during pressure overload remains poorly understood. We hypothesized that loss of functional ERα removes female protection from adverse remodeling and is permissive for the development of a maladapted RV phenotype. Male and female rats with a loss-of-function mutation in ERα (ERαMut) and wild-type (WT) littermates underwent RV pressure overload by pulmonary artery banding (PAB). At 10 wk post-PAB, WT and ERαMut demonstrated RV hypertrophy. Analysis of RV pressure waveforms demonstrated RV-pulmonary vascular uncoupling and diastolic dysfunction in female, but not male, ERαMut PAB rats. Similarly, female, but not male, ERαMut exhibited increased RV fibrosis, comprised primarily of thick collagen fibers. There was an increased protein expression ratio of TIMP metallopeptidase inhibitor 1 (Timp1) to matrix metalloproteinase 9 (Mmp9) in female ERαMut compared with WT PAB rats, suggesting less collagen degradation. RNA-sequencing in female WT and ERαMut RV revealed kallikrein-related peptidase 10 (Klk10) and Jun Proto-Oncogene (Jun) as possible mediators of female RV protection during PAB. In summary, ERα in females is protective against RV-pulmonary vascular uncoupling, diastolic dysfunction, and fibrosis in response to pressure overload. ERα appears to be dispensable for RV adaptation in males. ERα may be a mediator of superior RV adaptation in female patients with PAH.NEW & NOTEWORTHY Using a novel loss-of-function mutation in estrogen receptor-α (ERα), we demonstrate that female, but not male, ERα mutant rats display right ventricular (RV)-vascular uncoupling, diastolic dysfunction, and fibrosis following pressure overload, indicating a sex-dependent role of ERα in protecting against adverse RV remodeling. TIMP metallopeptidase inhibitor 1 (Timp1), matrix metalloproteinase 9 (Mmp9), kallikrein-related peptidase 10 (Klk10), and Jun Proto-Oncogene (Jun) were identified as potential mediators in ERα-regulated pathways in RV pressure overload.

Angiotensin Receptor-Neprilysin Inhibition Attenuates Right Ventricular Remodeling in Pulmonary Hypertension.

BackgroundPulmonary hypertension (PH) results in increased right ventricular (RV) afterload and ventricular remodeling. Sacubitril/valsartan (sac/val) is a dual acting drug, composed of the neprilysin inhibitor sacubitril and the angiotensin receptor blocker valsartan, that has shown promising outcomes in reducing the risk of death and hospitalization for chronic systolic left ventricular heart failure. In this study, we aimed to examine if angiotensin receptor-neprilysin inhibition using sac/val attenuates RV remodeling in PH.Methods and ResultsRV pressure overload was induced in Sprague-Dawley rats via banding the main pulmonary artery. Three different cohorts of controls, placebo-treated PH, and sac/val-treated PH were studied in a 21-day treatment window. Terminal invasive hemodynamic measurements, quantitative histological analysis, biaxial mechanical testing, and constitutive modeling were employed to conduct a multiscale analysis on the effects of sac/val on RV remodeling in PH. Sac/val treatment decreased RV maximum pressures (29% improvement, P=0.002), improved RV contractile (30%, P=0.012) and relaxation (29%, P=0.043) functions, reduced RV afterload (35% improvement, P=0.016), and prevented RV-pulmonary artery uncoupling. Furthermore, sac/val attenuated RV hypertrophy (16% improvement, P=0.006) and prevented transmural reorientation of RV collagen and myofibers (P=0.011). The combined natriuresis and vasodilation resulting from sac/val led to improved RV biomechanical properties and prevented increased myofiber stiffness in PH (61% improvement, P=0.032).ConclusionsSac/val may prevent maladaptive RV remodeling in a pressure overload model via amelioration of RV pressure rise, hypertrophy, collagen, and myofiber reorientation as well as tissue stiffening both at the tissue and myofiber level.

PBI-4050 reduces pulmonary hypertension, lung fibrosis, and right ventricular dysfunction in heart failure.

AIMS: Heart failure with reduced ejection fraction (HFrEF) causes lung remodelling with myofibroblasts proliferation and fibrosis leading to a restrictive lung syndrome with pulmonary hypertension (PH) and right ventricular (RV) dysfunction. PBI-4050 is a first-in-class anti-fibrotic, anti-inflammatory, and anti-proliferative compound. The present study evaluated the therapeutic impact of PBI-4050 on PH in an HFrEF model. METHODS AND RESULTS: HFrEF was induced after myocardial infarction (MI) in rats. Two weeks later, sham-operated and MI groups received PBI-4050 (200 mg/kg/day by gavage) or saline for 3 weeks. Animals were analysed according to infarct size as large (≥30% left ventricle) or medium MI (<30%). Large MI caused PH and RV hypertrophy (RVH) with a restrictive lung syndrome. PBI-4050 did not adversely affect left ventricular (LV) function but markedly reduced PH and RVH and improved RV dysfunction. PBI-4050 reduced lung remodelling and improved respiratory compliance with decreased lung fibrosis, alveolar wall cellular proliferation and α-smooth muscle actin expression. The increased expression of endothelin-1 (ET-1), transforming growth factor beta (TGF-ß), interleukin-6 (IL-6) and of tissue inhibitor of metalloprotease-1 in the lungs from HFrEF were reduced with PBI-4050 therapy. Activation of isolated human lung fibroblasts (HLFs) to a myofibroblastic pro-fibrogenic phenotype was markedly reduced by PBI-4050. The fatty acid receptor GPR84 was increased in HFrEF lungs and in activated HLFs, and reduced by PBI-4050. GPR84 agonists activated fibrogenesis in HLFs and finally, PBI-4050 reduced ERK1/2 phosphorylation. CONCLUSIONS: PBI-4050 reduces PH and RVH in HFrEF by decreasing lung fibrosis and remodelling. This novel agent decreases the associated restrictive lung syndrome and recovers RV function. A contributing mechanism involves reducing the activation of lung fibroblasts by IL-6, TGF-ß, and ET-1 by antagonism of GPR84 and reduced ERK1/2 phosphorylation. PBI-4050 is a novel promising therapy for targeting lung remodelling in group II PH.

Treatment of Pulmonary Hypertension With Angiotensin II Receptor Blocker and Neprilysin Inhibitor Sacubitril/Valsartan.

BACKGROUND: Angiotensin II has been implicated in maladaptive right ventricular (RV) hypertrophy and fibrosis associated with pulmonary hypertension (PH). Natriuretic peptides decrease RV afterload by promoting pulmonary vasodilation and inhibiting vascular remodeling but are degraded by neprilysin. We hypothesized that angiotensin receptor blocker and neprilysin inhibitor, sacubitril/valsartan (Sac/Val, LCZ696), will attenuate PH and improve RV function by targeting both pulmonary vascular and RV remodeling. METHODS: PH was induced in rats using the SU5416/hypoxia model (Su/Hx), followed by 6-week treatment with placebo, Sac/Val, or Val alone. There were 4 groups: CON-normoxic animals with placebo (n=18); PH-Su/Hx rats+placebo (n=34); PH+Sac/Val (N=24); and PH+Val (n=16). RESULTS: In animals with PH, treatment with Sac/Val but not Val resulted in significant reduction in RV pressure (mm Hg: PH: 62±4, PH+Sac/Val: 46±5), hypertrophy (RV/LV+S: PH: 0.74±0.06, PH+Sac/Val: 0.46±0.06), collagen content (µg/50 µg protein: PH: 8.2±0.3, PH+Sac/Val: 6.4±0.4), pressures and improvement in RVs (mm/s: PH: 31.2±1.8, PH+Sac/Val: 43.1±3.6) compared with placebo. This was associated with reduced pulmonary vascular wall thickness, increased lung levels of ANP (atrial natriuretic peptide), BNP (brain-type natriuretic peptide), and cGMP, and decreased plasma endothelin-1 compared with PH alone. Also, PH+Sac/Val animals had altered expression of PKC isozymes in RV tissue compared with PH alone. CONCLUSIONS: Sac/Val reduces pulmonary pressures, vascular remodeling, as well as RV hypertrophy in a rat model of PH and may be appropriate for treatment of pulmonary hypertension and RV dysfunction.

Less invasive left ventricular assist device implantation may reduce right ventricular failure.

OBJECTIVES: Right ventricular (RV) failure after left ventricular assist device (LVAD) implantation continues to be a morbid complication. In this study, we hypothesized that a less invasive approach to implantation would preserve RV function relative to a conventional sternotomy (CS) approach. METHODS: All patients (2013-2017) who underwent LVAD implantation were reviewed. Patients were stratified by surgical approach: less invasive left thoracotomy with hemi-sternotomy (LTHS) and CS. The primary outcome was severe RV failure. RESULTS: Eighty-three patients (LTHS: 37, CS: 46) were identified. The median Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) score was significantly worse in the LTHS compared to the CS cohort, and there was a trend towards higher RV failure scores and HeartMate II mortality scores. Preoperative RV dysfunction, in pulmonary artery pulsatility index and RV stroke work index were similar between the 2 groups. Though operative time did not significantly differ between the 2 groups, cardiopulmonary bypass time was significantly shorter in the LTHS group (61 vs 95 min, P < 0.001). The incidence of postoperative severe RV failure was significantly reduced in the LTHS group (16% vs 39%, P = 0.030), along with the need for temporary right ventricular assist device (3% vs 26%, P = 0.005). Improvement in RV function, along with a change in pulmonary artery pulsatility index, was significantly greater in the LTHS cohort. There was a trend towards improved Kaplan-Meier 1-year survival in the LTHS cohort (91% vs 56%, P = 0.056). CONCLUSIONS: In this cohort, less invasive LVAD implantation appears to be associated with reduced postoperative RV failure, and equivalent or improved survival compared to conventional LVAD implantation.

Planned right ventricular support for combined heart-liver transplantation.

Right ventricular dysfunction post heart transplantation (HTx) is a common problem and its likelihood to occur after combined heart-liver transplantation is even higher. The placement of an extracorporeal planned right ventricular assist device following the HTx during liver transplantation may assist in preventing this complication.

Effect of iloprost inhalation on postoperative outcome in high-risk cardiac surgical patients: a prospective randomized-controlled multicentre trial (ILOCARD).

PURPOSE: Perioperative right ventricular (RV) failure due to pressure overload from pulmonary hypertension (PH) worsens postoperative outcomes after cardiac surgery. Inhaled iloprost is a potent pulmonary vasodilator improving RV performance, ameliorating myocardial and pulmonary ischemia-reperfusion injury and attenuating inflammation. We hypothesized that the prophylactic inhalation of iloprost would reduce postoperative ventilation times after cardiac surgery. METHODS: In this phase III, multicentre, randomized, double-blind, placebo-controlled trial, we randomly assigned 253 cardiac surgical patients at high risk of perioperative RV failure to the prophylactic inhalation of 20 µg iloprost or placebo before and during weaning from extracorporeal circulation. The primary endpoint was the duration of postoperative ventilation. Secondary endpoints included perioperative hemodynamics, intensive care unit and hospital length of stay, and 90-day mortality. Safety was assessed by the incidence of adverse events. RESULTS: Iloprost had no significant effect on the median [interquartile range] duration of postoperative ventilation compared with placebo (720 [470-1170] min vs 778 [541-1219] min, respectively; median decrease, 65 min; 95% confidence interval [CI], - 77 to 210; P = 0.37). While the nebulization of iloprost decreased RV afterload and improved cardiac index, major secondary endpoints were not significantly affected. Ninety-day mortality occurred in 14% of the iloprost patients compared with 14% of the placebo patients (hazard ratio, 0.97; 95% CI, 0.50 to 1.89; P = 0.93). The incidence of adverse events was comparable in both groups. CONCLUSIONS: The prophylactic inhalation of iloprost did not meaningfully improve the outcome in high-risk cardiac surgical patients. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT00927654); registered 25 June, 2009.

RéSUMé: OBJECTIF: L'insuffisance cardiaque droite périopératoire due à une surcharge de pression provoquée par l'hypertension pulmonaire (HP) a un impact négatif sur le pronostic postopératoire après une chirurgie cardiaque. L'iloprost administré par inhalation est un vasodilatateur pulmonaire puissant qui améliore la performance du ventricule droit (VD), réduisant ainsi la lésion d'ischémie-reperfusion myocardique et pulmonaire et atténuant l'inflammation. Nous avons émis l'hypothèse qu'une inhalation prophylactique d'iloprost réduirait les temps de ventilation postopératoire après une chirurgie cardiaque. MéTHODE: Dans cette étude multicentrique de phase III, contrôlée par placebo, à double insu et randomisée, nous avons distribué aléatoirement 253 patients chirurgicaux courant un risque élevé d'insuffisance cardiaque droite périopératoire à une prophylaxie de 20 µg d'iloprost ou d'un placebo par inhalation avant et pendant le sevrage de la circulation extracorporelle. Le critère d'évaluation principal était la durée de ventilation postopératoire. Les critères d'évaluation secondaires étaient les données hémodynamiques périopératoires, la durée de séjour à l'unité de soins intensifs et à l'hôpital, et la mortalité à 90 jours. L'innocuité a été évaluée en fonction de l'incidence d'événements indésirables. RéSULTATS: L'iloprost n'a pas eu d'effet significatif sur la durée médiane [écart interquartile] de ventilation postopératoire par rapport au placebo (720 [470­1170] min vs 778 [541­1219] min, respectivement; réduction médiane, 65 min; intervalle de confiance [IC] 95 %, − 77 à 210; P = 0,37). Bien que la nébulisation d'iloprost ait réduit la post-charge du VD et amélioré l'index cardiaque, cette manœuvre n'a pas eu d'impact significatif sur les critères d'évaluation secondaires majeurs. Une mortalité à 90 jours a été observée chez 14 % des patients ayant reçu de l'iloprost, comparativement à 14 % des patients ayant reçu un placebo (rapport de risque, 0,97; IC 95 %, 0,50 à 1,89; P = 0,93). L'incidence d'événements indésirables était comparable dans les deux groupes. CONCLUSION: L'inhalation prophylactique d'iloprost n'a pas amélioré le pronostic des patients de chirurgie cardiaque à haut risque. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT00927654); enregistrée le 25 juin 2009.

Autologous endothelial progenitor cell therapy improves right ventricular function in a model of chronic thromboembolic pulmonary hypertension.

BACKGROUND: Right ventricular (RV) failure is the main prognostic factor in pulmonary hypertension, and ventricular capillary density (CD) has been reported to be a marker of RV maladaptive remodeling and failure. Our aim was to determine whether right intracoronary endothelial progenitor cell (EPC) infusion can improve RV function and CD in a piglet model of chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: We compared 3 groups: sham (n = 5), CTEPH (n = 6), and CTEPH with EPC infusion (CTEPH+EPC; n = 5). After EPC isolation from CTEPH+EPC piglet peripheral blood samples at 3 weeks, the CTEPH and sham groups underwent right intracoronary infusion of saline, and the CTEPH+EPC group received EPCs at 6 weeks. RV function, pulmonary hemodynamics, and myocardial morphometry were investigated in the animals at 10 weeks. RESULTS: After EPC administration, the RV fractional area change increased from 32.75% (interquartile range [IQR], 29.5%-36.5%) to 39% (IQR, 37.25%-46.50%; P = .030). The CTEPH+EPC piglets had reduced cardiomyocyte surface areas (from 298.3 µm2 [IQR, 277.4-335.3 µm2] to 234.6 µm2 (IQR, 211.1-264.7 µm2; P = .017), and increased CD31 expression (from 3.12 [IQR, 1.27-5.09] to 7.14 [IQR, 5.56-8.41; P = .017). EPCs were found in the RV free wall at 4 and 24 hours after injection but not 4 weeks later. CONCLUSIONS: Intracoronary infusion of EPC improved RV function and CD in a piglet model of CTEPH. This novel cell-based therapy might represent a promising RV-targeted treatment in patients with pulmonary hypertension.

Extracorporeal membrane oxygenation for right ventricular failure following pericardiectomy.

We report the case of a 61-year-old gentleman who underwent pericardiectomy for constrictive pericarditis. Constrictive pericarditis was diagnosed through echocardiogram, computed tomography chest and cardiac magnetic resonance imaging. An elective decision was made for commencing venoarterial extracorporeal membrane oxygenation (ECMO) immediately postoperatively to prevent significant right ventricular failure (RVF). Postoperatively, the patient remained on ECMO for 4 days in a stable condition, showing no further signs of RVF. Venoarterial ECMO may be of use as an elective adjunct in cases at high risk of RVF following pericardiectomy.

17ß-estradiol preserves right ventricular function in rats with pulmonary arterial hypertension: an echocardiographic and histochemical study.

Pulmonary arterial hypertension (PAH) is more prevalent in females. Paradoxically, female patients have better right ventricular (RV) function and higher survival rates than males. However, the effects of 17ß-estradiol (E2) on RV function in PAH has not been studied. Twenty-four male rats were exposed to monocrotaline (MCT) to induce experimental PAH, while treated with E2 or vehicle respectively. Together with eight control rats, thirty-two rats were examined by echocardiography 4 weeks after drug administration. Echocardiographic measurement of RV function included: tricuspid annular plane systolic excursion (TAPSE), RV index of myocardial performance (RIMP), RV fractional area change (RVFAC) and tricuspid annular systolic velocity (s'). RV free wall longitudinal strain (RVLSFW) and RV longitudinal shortening fraction (RVLSF) were also used to quantify RV function. RV morphology was determined by echocardiographic and histological analysis. TAPSE, RVFAC and s' were reduced, and RIMP was elevated in the MCT-treated group and vehicle-treated group, when compared with control group (P < 0.01). TAPSE, RVFAC and s' in the E2 group were higher, while RIMP was lower than those in the MCT-treated group and vehicle-treated group (P < 0.01). Myocardial functional parameters (RVLSFW and RVLSF) were also higher in the E2 group. Enhanced serum E2 levels were closely correlated with the improvement in RV functional parameters and enhancement of serum BNP levels (P < 0.01 for all groups). RV function decreased significantly in male rats with MCT-induced PAH, while E2 exhibited a protective effect on RV function, suggesting that E2 is a critical modulator of sex differences in PAH.