Angiotensin receptor-neprilysin inhibitor attenuates cardiac hypertrophy and improves diastolic dysfunction in a mouse model of heart failure with preserved ejection fraction.

LCZ696, an angiotensin receptor-neprilysin inhibitor, has shown promising clinical efficacy in patients with heart failure (HF) with reduced ejection fraction. However, its potential effects on heart failure with preserved ejection fraction (HFpEF) are still not fully understood. We evaluated the effect of LCZ696 on HFpEF in transverse aortic constriction mice and compared it with the effect of the angiotensin receptor blocker, valsartan. We found that LCZ696 improved cardiac diastolic function by reducing ventricular hypertrophy and fibrosis in mice with overload-induced diastolic dysfunction. In addition, there was superior inhibition of LCZ696 than stand-alone valsartan. As a potential underlying mechanism, we demonstrated that LCZ696 behaves as a potent suppressor of calcium-mediated calcineurin-nuclear factor of activated T cells (NFAT) signalling transduction pathways. Hence, we demonstrated the protective effects of LCZ696 in overload-induced HFpEF and provided a pharmaceutical therapeutic strategy for related diseases.

Influence of right ventricular pressure and volume overload on right and left ventricular diastolic function.

BACKGROUND: Ventricular interdependence may account for altered ventricular mechanics in congenital heart disease. The present study aimed to identify differences in load-dependent right ventricular (RV)-left ventricular (LV) interactions in porcine models of pulmonary stenosis (PS) and pulmonary insufficiency (PI) by invasive admittance-derived hemodynamics in conjunction with noninvasive cardiovascular magnetic resonance (CMR). METHODS: Seventeen pigs were used in the study (7 with PS, 7 with PI, and 3 controls). Progressive PS was created by tightening a Teflon tape around the pulmonary artery, and PI was created by excising 2 leaflets of the pulmonary valve. Admittance catheterization data were obtained for the RV and LV at 10 to 12 weeks after model creation, with the animal ventilated under temporary diaphragm paralysis. CMR was performed in all animals immediately prior to pressure-volume catheterization. RESULTS: In the PS group, RV contractility was increased, manifested by increased end-systolic elastance (mean difference, 1.29 mm Hg/mL; 95% confidence interval [CI], 0.57-2.00 mm Hg/mL). However, in the PI group, no significant changes were observed in RV systolic function despite significant changes in RV diastolic function. In the PS group, LV end-systolic volume was significantly lower compared with controls (mean difference, 25.1 mL; 95% CI, -40.5 to -90.7 mL), whereas in the PI group, the LV showed diastolic dysfunction, demonstrated by an elevated isovolumic relaxation constant and ventricular stiffness (mean difference, 0.03 mL-1; 95% CI, -0.02 to 0.09 mL-1). CONCLUSIONS: The LV exhibits systolic dysfunction and noncompliance with PI. PS is associated with preserved LV systolic function and evidence of some LV diastolic dysfunction. Interventricular interactions influence LV filling and likely account for differential effects of RV pressure and volume overload on LV function.

Association of Genetic Variants With Outcomes in Patients With Nonischemic Dilated Cardiomyopathy.

BACKGROUND: The clinical relevance of genetic variants in nonischemic dilated cardiomyopathy (DCM) is unsettled. OBJECTIVES: The study sought to assess the prognostic impact of disease-causing genetic variants in DCM. METHODS: Baseline and longitudinal clinical data from 1,005 genotyped DCM probands were retrospectively collected at 20 centers. A total of 372 (37%) patients had pathogenic or likely pathogenic variants (genotype positive) and 633 (63%) were genotype negative. The primary endpoint was a composite of major adverse cardiovascular events. Secondary endpoints were end-stage heart failure (ESHF), malignant ventricular arrhythmia (MVA), and left ventricular reverse remodeling (LVRR). RESULTS: After a median follow-up of 4.04 years (interquartile range: 1.70-7.50 years), the primary endpoint had occurred in 118 (31.7%) patients in the genotype-positive group and in 125 (19.8%) patients in the genotype-negative group (hazard ratio [HR]: 1.51; 95% confidence interval [CI]: 1.17-1.94; P = 0.001). ESHF occurred in 60 (16.1%) genotype-positive patients and in 55 (8.7%) genotype-negative patients (HR: 1.67; 95% CI: 1.16-2.41; P = 0.006). MVA occurred in 73 (19.6%) genotype-positive patients and in 77 (12.2%) genotype-negative patients (HR: 1.50; 95% CI: 1.09-2.07; P = 0.013). LVRR occurred in 39.6% in the genotype-positive group and in 46.2% in the genotype-negative group (P = 0.047). Among individuals with baseline left ventricular ejection fraction ≤35%, genotype-positive patients exhibited more major adverse cardiovascular events, ESHF, and MVA than their genotype-negative peers (all P < 0.02). LVRR and clinical outcomes varied depending on the underlying affected gene. CONCLUSIONS: In this study, DCM patients with pathogenic or likely pathogenic variants had worse prognosis than genotype-negative individuals. Clinical course differed depending on the underlying affected gene.

Longitudinal diastolic strain slope as an early sign for systolic dysfunction among patients with active cancer.

BACKGROUND: Diastolic dysfunction is a common finding in patients receiving cancer therapy. This study evaluated the correlation of diastolic strain slope (Dss) with routine echocardiography diastolic parameters and its role in early detection of systolic dysfunction and cardiovascular (CV) mortality within this population. METHODS: Data were collected from the Israel Cardio-Oncology Registry (ICOR), a prospective registry enrolling adult patient receiving cancer therapy. All patients performed at least three echocardiography exams (T1, T2, T3), including left ventricle Global Longitudinal Strain (LV GLS) and Dss. Systolic dysfunction was determined by either LV GLS relative reduction of ≥ 15% or LV ejection fraction reduction > 10% to < 53%. Dss was assessed as the early lengthening rate, measured by the diastolic slope (delta%/sec). RESULTS: Among 144 patients, 114 (79.2%) were female with a mean age of 57.31 ± 14.3 years. Dss was significantly correlated with e' average. Mid segment Dss change between T1 and T2 showed significant association to systolic dysfunction development (Odds Ratio (OR) = 1.04 [1.01,1.06]. p = 0.036). In multivariate prediction, Dss increase was a significant predictor for the development of systolic dysfunction (OR = 1.06 [1.03,1.1], P < 0.001).An 8% increase in Dss between T1 and T2 was associated with a trend in increased CV mortality (HR = 3.4 [0.77,15.4], p = 0.085). CONCLUSIONS: This study is the first to use the novel measurement of Dss in patients treated with cancer therapies and to show significant correlation between routine diastolic dysfunction parameters and Dss. Changes in the mid segment were found to have significant independent early predictive value for systolic dysfunction development in univariate and multivariate analyses.

Cardiotoxicidad inducida por trastuzumab en paciente con carcinoma de mama HER-2 positivo / Trastuzumab-induced cardiotoxicity in a patient with HER-2 positive breast carcinoma

Introducción: La disfunción cardíaca emerge como una de las principales causas de morbilidad y mortalidad entre los sobrevivientes de cáncer. En la actualidad, el trastuzumab se considera parte de la terapia estándar para el cáncer de mama; sin embargo, se asocia a una variada incidencia de cardiotoxicidad. Caso clínico: Paciente femenina de 52 años que recibió neoadyuvancia con antraciclinas, y luego, taxanos combinados a trastuzumab. Se le realizó una cuadrantectomía de mama izquierda por un carcinoma ducto lobulillar infiltrante, etapa IIIa, con un fenotipo: luminal B- Her2 positivo. Desarrolló una insuficiencia cardiaca congestiva, luego de dos dosis de trastuzumab posoperatorio. La fracción de eyección ventricular izquierda descendió de 65 por ciento (previo al tratamiento con antraciclinas) a 44 por ciento. Recibió tratamiento con enalapril, carvedilol, y espironolactona. Se recuperó la fracción de eyección ventricular izquierda a 57 por ciento, por lo que se reintrodujo el trastuzumab y así completar las 18 dosis planificadas, luego de cuatro meses de suspensión. Actualmente, está libre de enfermedad, en tratamiento hormonal con letrozol y sin síntomas cardiovasculares. Conclusiones: La cardiotoxicidad por trastuzumab puede ser reversible, si se trata adecuada y oportunamente, en el marco de grupos multidisciplinarios y Unidades de Cardio-Oncología(AU)

Introduction: Cardiac dysfunction emerges as one of the main causes of morbidity and mortality among cancer survivors. Currently, trastuzumab is considered part of the standard therapy for breast cancer; however, it is associated with a varied incidence of cardiotoxicity. Clinical case report: A case of a 52-year-old female patient is reported here, because she received neoadjuvant therapy with anthracyclines and later, taxanes combined with trastuzumab. She underwent a quadrantectomy of her left breast for an infiltrating lobular duct carcinoma, stage IIIa, with a phenotype: luminal B-Her2 positive. She developed congestive heart failure after two doses of postoperative trastuzumab. The left ventricular ejection fraction decreased from 65 percent (prior to anthracycline treatment) to 44 percent. She was treated with enalapril, carvedilol, and spironolactone. The left ventricular ejection fraction was recovered to 57 percent, so trastuzumab was reintroduced and thus complete the 18 planned doses, after four months of suspension. Currently, she is disease-free, on hormonal treatment with letrozole, and without cardiovascular symptoms. Conclusions: Cardiotoxicity due to trastuzumab can be reversible, if it is appropriately and timely treated, within the framework of multidisciplinary groups and Cardio-Oncology Units(AU)

Role of TSPO/VDAC1 Upregulation and Matrix Metalloproteinase-2 Localization in the Dysfunctional Myocardium of Hyperglycaemic Rats.

Clinical management of diabetic cardiomyopathy represents an unmet need owing to insufficient knowledge about the molecular mechanisms underlying the dysfunctional heart. The aim of this work is to better clarify the role of matrix metalloproteinase 2 (MMP-2) isoforms and of translocator protein (TSPO)/voltage-dependent anion-selective channel 1 (VDAC1) modulation in the development of hyperglycaemia-induced myocardial injury. Hyperglycaemia was induced in Sprague-Dawley rats through a streptozocin injection (35 mg/Kg, i.p.). After 60 days, cardiac function was analysed by echocardiography. Nicotinamide Adenine Dinucleotide Phosphate NADPH oxidase and TSPO expression was assessed by immunohistochemistry. MMP-2 activity was detected by zymography. Superoxide anion production was estimated by MitoSOX™ staining. Voltage-dependent anion-selective channel 1 (VDAC-1), B-cell lymphoma 2 (Bcl-2), and cytochrome C expression was assessed by Western blot. Hyperglycaemic rats displayed cardiac dysfunction; this response was characterized by an overexpression of NADPH oxidase, accompanied by an increase of superoxide anion production. Under hyperglycaemia, increased expression of TSPO and VDAC1 was detected. MMP-2 downregulated activity occurred under hyperglycemia and this profile of activation was accompanied by the translocation of intracellular N-terminal truncated isoform of MMP-2 (NT-MMP-2) from mitochondria-associated membrane (MAM) into mitochondria. In the onset of diabetic cardiomyopathy, mitochondrial impairment in cardiomyocytes is characterized by the dysregulation of the different MMP-2 isoforms. This can imply the generation of a "frail" myocardial tissue unable to adapt itself to stress.

Subtle cardiac dysfunction in nephropathic cystinosis: insight from tissue Doppler imaging and 2D speckle tracking echocardiography.

BACKGROUND: Nephropathic cystinosis is a rare autosomal recessive lysosomal storage disorder that initially affects the kidney progressing to multi-organ failure due to accumulation of cystine in all tissue compartments. OBJECTIVE: The main objective of this study is the evaluation of cardiac function in cystinosis patients using non-conventional echocardiographic modalities like pulsed wave tissue Doppler imaging (PW-TDI) and 2D speckle tracking echocardiography (2D-STE). METHODS: This is a case control study conducted on fifteen patients with cystinosis and 15 normal controls. Echocardiography was done for all participants and PW-TDI was performed for measurement of S', E', A' velocities and myocardial performance index (MPI) at basal parts of septal, left ventricle (LV), and right ventricle (RV) free walls. 2D-STE was done for evaluation of global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) of LV. Mitral E and A velocities and tricuspid annular plane systolic excursion (TAPSE) were also measured. RESULTS: The GLS, GRS, and S' velocity at basal septum and LV lateral wall were significantly lower in patients denoting LV systolic dysfunction (p = 0.005, p < 0.0001, p = 0.001, p = 0.006, respectively), while E/E' were significantly higher in patients group denoting LV diastolic dysfunction (p < 0.001). For RV function, TAPSE, S', and E' velocity were significantly lower in patients group (p 0.013, p < 0.01, p = 0.05, respectively) indicating RV systolic and diastolic dysfunction. The TDI-derived MPI for both LV and RV were significantly higher in patients group (p < 0.0001, p < 0.01, respectively) indicating both ventricular systolic and diastolic dysfunction. For prediction of cardiac dysfunction among patients, the receiver operating characteristic (ROC) curve showed that GRS ≤ 29% had sensitivity 93.3% and specificity 100%, GLS > - 20.1% had sensitivity 66.7% and specificity 93.3%, LV-E/E' >7.87 had sensitivity 73.3% and specificity 93.3%, and MPI-LV > 0.36 had sensitivity 100% and specificity 93.3% while MPI-RV > 0.29 had sensitivity 80% and specificity 93.3% and TAPSE ≤ 19 mm had sensitivity 80% and specificity 73.3%. CONCLUSIONS: Patients with cystinosis have significant both left and right ventricular dysfunction, which can be better evaluated using the non-conventional echocardiographic modalities like TDI and 2D-STE for early detection of subtle cardiac dysfunction.

Congenital diaphragmatic hernia-associated pulmonary hypertension.

Congenital diaphragmatic hernia (CDH) is a neonatal pathology in which intrathoracic herniation of abdominal viscera via diaphragmatic defect results in aberrant pulmonary and cardiovascular development. Despite decades of study and many advances in the diagnosis and treatment of CDH, morbidity and mortality remain high, largely due to pulmonary hypertension (PH), along with pulmonary hypoplasia and cardiac dysfunction. In patients with CDH, hypoplastic pulmonary vasculature and alterations in multiple molecular pathways lead to pathophysiologic pulmonary vasculopathy and, for severe CDH, sustained, elevated pulmonary arterial pressures. This review addresses the multiple anatomic and physiologic changes that underlie CDH-associated PH (CDH-PH), along with the multimodal treatment strategies that exist currently and future therapies currently under investigation.

Congenital diaphragmatic hernia-associated cardiac dysfunction.

There is increasing evidence that cardiac dysfunction is a key contributor to CDH pathophysiology. Dysfunction in both right and left ventricles is common in the early neonatal period, contributes to clinical disease severity, and is associated with adverse outcomes including death and ECMO use. Early and routine assessment of ventricular function and pulmonary artery pressure may guide individualized clinical decision-making, including use of pulmonary vasodilators, cardiotropes, ECMO, and timing of surgical repair. Minimizing cardiac dysfunction, whether by prenatal, postnatal or perinatal treatment strategies, may lead to improved outcome in CDH.

Decreased biventricular function following thoracic endovascular aortic repair.

OBJECTIVES: Preclinical studies have suggested acute stiffening of the aorta following experimental thoracic endovascular aortic repair (TEVAR), resulting in acute elevated pulse pressure, hypertension and possibly heart failure. The aim of this study was to evaluate cardiac remodelling following TEVAR. METHODS: From 2005 to 2018, 519 TEVAR procedures were performed at a single centre. Transthoracic echocardiography was performed pre- and post-TEVAR in 31 patients without previous replacement of the thoracic aorta. Patient characteristics, drug information, radiographic and follow-up data were evaluated. Aortic details were measured in multiplanar reconstruction. RESULTS: Transthoracic echocardiography was performed 2 ± 2 years after TEVAR. At this time, patients received significantly more antihypertensive drugs compared to the pre-TEVAR intake (beta-blocker therapy: P = 0.037; calcium channel blocker: P = 0.022). Compared to pre-TEVAR, there was a significant reduction in the left ventricular ejection fraction (P = 0.008) and tricuspid annular plane systolic excursion (P = 0.013) post-TEVAR. A significant increase in the left ventricular mass was not detected in this study (P = 0.95). The mean distance of 163 ± 66 mm of the descending aorta was covered. CONCLUSIONS: This study suggests negative cardiac remodelling with a decrease in the left and right ventricular function following TEVAR despite an increase in oral antihypertensive medication. The impact of stiffer endovascular grafts compared with the native aortic wall should be considered by endovascular specialists and manufacturers.

HOSPITAL Score, LACE Index and LACE+ Index as predictors of 30-day readmission in patients with heart failure.

This study aimed to evaluate the accuracy of the HOSPITAL Score (Haemoglobin level at discharge, Oncology at discharge, Sodium level at discharge, Procedure during hospitalization, Index admission, number of hospital admissions, Length of stay) LACE index (Length of stay, Acute/emergent admission, Charlson comorbidy index score, Emerency department visits in previous 6 months) and LACE+ index in predicting 30-day readmission in patients with diastolic dysfunction. Heart failure remains one of the most common hospital readmissions in adults, leading to significant morbidity and mortality. Different models have been used to predict 30-day hospital readmissions. All adult medical patients discharged from the SIU School of Medicine Hospitalist service from 12 June 2016 to 12 June 2018 with an International Classification of Disease, 10th Revision, Clinical Modification diagnosis of diastolic heart failure were studied retrospectively to evaluate the performance of the HOSPITAL Score, LACE index and LACE+ index readmission risk prediction tools in this patient population. Of the 730 patient discharges with a diagnosis of heart failure with preserved ejection fraction (HFpEF), 692 discharges met the inclusion criteria. Of these discharges, 189 (27%) were readmitted to the same hospital within 30 days. A receiver operating characteristic evaluation showed C-statistic values to be 0.595 (95% CI 0.549 to 0.641) for the HOSPITAL Score, 0.551 (95% CI 0.503 to 0.598) for the LACE index and 0.568 (95% CI 0.522 to 0.615) for the LACE+ index, indicating poor specificity in predicting 30-day readmission. The result of this study demonstrates that the HOSPITAL Score, LACE index and LACE+ index are not effective predictors of 30-day readmission for patients with HFpEF. Further analysis and development of new prediction models are needed to better estimate the 30-day readmission rates in this patient population.

Diastolic dysfunction - What an anesthesiologist needs to know?

Diastolic dysfunction (DD) is a common condition that is increasingly encountered in patients undergoing both cardiac and noncardiac surgery as the age profile of our patient population increases and the noninvasive diagnosis of DD becomes more accessible. There is a growing body of evidence demonstrating the significance of DD and adverse perioperative outcomes, and thus, it is becoming imperative for anesthesiologists to have an understanding of the pathophysiology, diagnosis, and management of patients with DD. Current guidelines are based on transthoracic echocardiogram (TTE) measurements in patients who are spontaneously breathing and in a euvolemic state and, consequently, not applicable to the perioperative period. In this review article, we discuss the grading of DD as well as introduce a practical approach to the diagnosis and management of patients with DD during the perioperative period.

Impact of Characteristics at Stage-2-Palliation on Outcome Following Fontan Completion.

The optimal timing of stage-2-palliation (S2P) in single left ventricle is not clear. The aim of this study was to identify S2P related factors associated with outcomes after total cavopulmonary connection (TCPC), particularly relative to the dominant systemic ventricle. A total of 405 patients who underwent both S2P and TCPC at our institute between 1997 and 2017 was included. Patients were divided into two groups, dominant right ventricle (RV type, n = 235) and dominant left ventricle (LV type, n = 170). S2P related factors associated with mortality, postoperative ventricular function, and late exercise capacity following TCPC, were analyzed. The median age at S2P was 4 [3-7] and 6 [3-11] months in RV and LV type patients, respectively (p = 0.092). Survival after TCPC was similar in RV and LV type patients (p = 0.280). In those with RV type, risk factors for mortality following TCPC were older age (p < 0.001), heavier weight (p = 0.001), higher PAP (p < 0.001), higher TPG (p = 0.010), and lower SO2 (p = 0.008) at S2P. In those with LV type, no risk factor was identified. Risk factors for postoperative impaired ventricular function were older age and higher weight at S2P in both RV and LV type patients. Older age at S2P was also identified as a risk for inferior peak oxygen uptake (VO2) years after TCPC both in RV and LV type patients. Older age at S2P was associated with higher mortality after Fontan completion only in RV type patients. However, it was associated with postoperative ventricular dysfunction and lower exercise capacity after TCPC in both RV and LV type patients.

Fibroblast growth factor-23 promotes rhythm alterations and contractile dysfunction in adult ventricular cardiomyocytes.

BACKGROUND: Cardiac dysfunction and arrhythmia are common and onerous cardiovascular events in end-stage renal disease (ESRD) patients, especially those on dialysis. Fibroblast growth factor (FGF)-23 is a phosphate-regulating hormone whose levels dramatically increase as renal function declines. Beyond its role in phosphorus homeostasis, FGF-23 may elicit a direct effect on the heart. Whether FGF-23 modulates ventricular cardiac rhythm is unknown, prompting us to study its role on excitation-contraction (EC) coupling. METHODS: We examined FGF-23 in vitro actions on EC coupling in adult rat native ventricular cardiomyocytes using patch clamp and confocal microscopy and in vivo actions on cardiac rhythm using electrocardiogram. RESULTS: Compared with vehicle treatment, FGF-23 induced a significant decrease in rat cardiomyocyte contraction, L-type Ca2+ current, systolic Ca2+ transients and sarcoplasmic reticulum (SR) load and SR Ca2+-adenosine triphosphatase 2a pump activity. FGF-23 induced pro-arrhythmogenic activity in vitro and in vivo as automatic cardiomyocyte extracontractions and premature ventricular contractions. Diastolic spontaneous Ca2+ leak (sparks and waves) was significantly increased by FGF-23 via the calmodulin kinase type II (CaMKII)-dependent pathway related to hyperphosphorylation of ryanodine receptors at the CaMKII site Ser2814. Both contraction dysfunction and spontaneous pro-arrhythmic Ca2+ events induced by FGF-23 were blocked by soluble Klotho (sKlotho). CONCLUSIONS: Our results show that FGF-23 reduces contractility and enhances arrhythmogenicity through intracellular Ca2+ mishandling. Blocking its actions on the heart by improving sKlotho bioavailability may enhance cardiac function and reduce arrhythmic events frequently observed in ESRD.

Myocardial Perfusion Is Impaired and Relates to Cardiac Dysfunction in Patients With Atrial Fibrillation Both Before and After Successful Catheter Ablation.

Background Atrial fibrillation ( AF ) is associated with myocardial infarction, and patients with AF and no obstructive coronary artery disease can present with symptoms and evidence of cardiac ischemia. We hypothesized that microvascular coronary dysfunction underlies these observations. Methods and Results Myocardial blood flow ( MBF ) at baseline and during adenosine stress and left ventricular and left atrial function were evaluated by magnetic resonance in 49 patients with AF (25 paroxysmal, 24 persistent) with no history of epicardial coronary artery disease or diabetes mellitus, before and 6 to 9 months after ablation. Findings were compared with those obtained in matched controls in sinus rhythm (n=25). Before ablation, patients with AF had impaired left atrial function and left ventricular ejection fraction and strain indices (all P<0.05 versus controls). MBF was impaired in patients both under baseline conditions (1.21±0.24 mL/min per g·[mm Hg·bpm/104]-1 versus 1.34±0.28 mL/min per g·[mm Hg·bpm/104]-1 in controls, P=0.044) and during adenosine stress (2.29±0.48 mL/min per g versus 2.73±0.37 mL/min per g in controls, P<0.001). Under baseline conditions, MBF correlated with left ventricular strain and left atrial function (all P≤0.001), so that cardiac function was most impaired in patients with the lowest MBF . Baseline and stress MBF remained unchanged postablation (both P=ns), and baseline MBF showed similar correlations with functional indices to those present preablation (all P≤0.001). Conclusions Baseline and stress MBF are significantly impaired in patients with AF but no epicardial coronary artery disease. Reduction in MBF is proportional to severity of left ventricular and left atrial dysfunction, even after successful ablation. Coronary microvascular dysfunction may be a relevant pathophysiological mechanism in patients with a history of AF .

Altered biventricular hemodynamic forces in patients with repaired tetralogy of Fallot and right ventricular volume overload because of pulmonary regurgitation.

Intracardiac hemodynamic forces have been proposed to influence remodeling and be a marker of ventricular dysfunction. We aimed to quantify the hemodynamic forces in patients with repaired tetralogy of Fallot (rToF) to further understand the pathophysiological mechanisms as this could be a potential marker for pulmonary valve replacement (PVR) in these patients. Patients with rToF and pulmonary regurgitation (PR) > 20% ( n = 18) and healthy control subjects ( n = 15) underwent MRI, including four-dimensional flow. A subset of patients ( n = 8) underwent PVR and MRI after surgery. Time-resolved hemodynamic forces were quantified using 4D-flow data and indexed to ventricular volume. Patients had higher systolic and diastolic left ventricular (LV) hemodynamic forces compared with control subjects in the lateral-septal/LV outflow tract ( P = 0.011 and P = 0.0031) and inferior-anterior ( P < 0.0001 and P < 0.0001) directions, which are forces not aligned with blood flow. Forces did not change after PVR. Patients had higher RV diastolic forces compared with control subjects in the diaphragm-right ventricular (RV) outflow tract (RVOT; P < 0.001) and apical-basal ( P = 0.0017) directions. After PVR, RV systolic forces in the diaphragm-RVOT direction decreased ( P = 0.039) to lower levels than in control subjects ( P = 0.0064). RV diastolic forces decreased in all directions ( P = 0.0078, P = 0.0078, and P = 0.039) but were still higher than in control subjects in the diaphragm-RVOT direction ( P = 0.046). In conclusion, patients with rToF and PR had LV hemodynamic forces less aligned with intraventricular blood flow compared with control subjects and higher diastolic RV forces along the regurgitant flow direction in the RVOT and that of tricuspid inflow. Remaining force differences in the LV and RV after PVR suggest that biventricular pumping does not normalize after surgery. NEW & NOTEWORTHY Biventricular hemodynamic forces in patients with repaired tetralogy of Fallot and pulmonary regurgitation were quantified for the first time. Left ventricular hemodynamic forces were less aligned to the main blood flow direction in patients compared with control subjects. Higher right ventricular forces were seen along the pulmonary regurgitant and tricuspid inflow directions. Differences in forces versus control subjects remain after pulmonary valve replacement, suggesting that altered biventricular pumping does not normalize after surgery.

The ACE 2 activator diminazene aceturate (DIZE) improves left ventricular diastolic dysfunction following myocardial infarction in rats.

Diminazene aceturate (DIZE) has been reported to enhance the catalytic efficiency of ACE-2 and presumably increases angiotensin 1-7 generation, interfering with cardiac remodeling after myocardial infarction (MI). Our aim was to investigate the chronic effects of DIZE on cardiac dysfunction post-MI. Male Wistar rats underwent myocardial infarction (MI) or SHAM surgery (SO) and were divided into groups treated with DIZE 15 mg/kg/day, s.c. or vehicle (Control). After 4 weeks, the hemodynamic variables were recorded by cardiac catheterism. Hearts were then arrested to obtain the left ventricular (LV) pressure-volume curves in situ. Cardiomyocyte hypertrophy and collagen content were determined by histology. DIZE prevented LV end-diastolic pressure increases in MI rats (MI: 26 ± 3.3 vs. MI-DIZE: 15 ± 1.6 mmHg, P < 0.001) without a significant effect on LV systolic pressure (LVSP). Moreover, DIZE improved LV contractility (+dP/dt, MI: 3014 ± 161 vs. MI-DIZE: 3884 ± 104 mmHg/s, P < 0.001) and relaxation (-dP/dt, MI: -2333 ± 91 vs. MI-DIZE: -2798 ± 120 mmHg/s, P < 0.05). Right ventricular SP was increased in the MI compared to that in the SO group (40 ± 0.6 vs. 30 ± 1.2 mmHg; P < 0.01), and DIZE partially prevented this augmentation. LV stiffness was reduced in MI-DIZE compared with that in MI (0.64 ± 0.01 vs. 0.78 ± 0.02 mmHg/mL; P < 0.01). DIZE treatment reduced the interstitial collagen content by 18% in the surviving LV myocardium. Cardiomyocyte hypertrophy remained unaffected by DIZE treatment. Our findings show that chronic DIZE treatment post-MI attenuates the morphofunctional changes induced by MI in rats. The effects on LV -dP/dt, chamber stiffness and collagen content suggest this drug can be used as a therapeutic agent to reduce interstitial fibrosis and diastolic dysfunction after MI.