Left ventricular strain changes at high altitude in rats: a cardiac magnetic resonance tissue tracking imaging study.

BACKGROUND: Long-term exposure to a high altitude environment with low pressure and low oxygen could cause abnormalities in the structure and function of the heart. Myocardial strain is a sensitive indicator for assessing myocardial dysfunction, monitoring myocardial strain is of great significance for the early diagnosis and treatment of high altitude heart-related diseases. This study applies cardiac magnetic resonance tissue tracking technology (CMR-TT) to evaluate the changes in left ventricular myocardial function and structure in rats in high altitude environment. METHODS: 6-week-old male rats were randomized into plateau hypoxia rats (plateau group, n = 21) as the experimental group and plain rats (plain group, n = 10) as the control group. plateau group rats were transported from Chengdu (altitude: 360 m), a city in a plateau located in southwestern China, to the Qinghai-Tibet Plateau (altitude: 3850 m), Yushu, China, and then fed for 12 weeks there, while plain group rats were fed in Chengdu(altitude: 360 m), China. Using 7.0 T cardiac magnetic resonance (CMR) to evaluate the left ventricular ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV), as well as myocardial strain parameters including the peak global longitudinal (GLS), radial (GRS), and circumferential strain (GCS). The rats were euthanized and a myocardial biopsy was obtained after the magnetic resonance imaging scan. RESULTS: The plateau rats showed more lower left ventricular GLS and GRS (P < 0.05) than the plain rats. However, there was no statistically significant difference in left ventricular EDV, ESV, SV, EF and GCS compared to the plain rats (P > 0.05). CONCLUSIONS: After 12 weeks of exposure to high altitude low-pressure hypoxia environment, the left ventricular global strain was partially decreased and myocardium is damaged, while the whole heart ejection fraction was still preserved, the myocardial strain was more sensitive than the ejection fraction in monitoring cardiac function.

Association of left ventricular diastolic dysfunction with inflammatory activity, renal dysfunction, and liver-related mortality in patients with cirrhosis and ascites.

Left ventricular diastolic dysfunction (LVDD) is the predominant cardiac abnormality in cirrhosis. We investigated the association of LVDD with systemic inflammation and its impact on renal function, occurrence of hepatorenal syndrome (HRS) and survival in patients with cirrhosis and ascites. We prospectively enrolled 215 patients with cirrhosis and ascites. We evaluated the diagnosis and grading of LVDD by Doppler echocardiography, inflammatory markers, systemic hemodynamics, vasoactive factors, radioisotope-assessed renal function and blood flow, HRS development and liver-related mortality. LVDD was diagnosed in 142 (66%) patients [grade 2/3: n  = 61 (43%)]. Serum lipopolysaccharide-binding protein (LBP), plasma renin activity (PRA) and glomerular filtration rate (GFR) were independently associated with the presence of grade 2/3 LVDD and the severity of diastolic dysfunction. Serum tumor necrosis factor-α, cardiac output and plasma noradrenaline were also independently associated with the presence of grade 2/3 LVDD. The diastolic function marker E / e ' was strongly correlated with serum LBP ( r  = 0.731; P  < 0.001), PRA ( r  = 0.714; P  < 0.001) and GFR ( r  = -0.609; P  < 0.001) among patients with LVDD. The 5-year risk of HRS development and death was significantly higher in patients with grade 2/3 LVDD compared to those with grade 1 (35.5 vs. 14.4%; P  = 0.01 and 53.3 vs. 28.2%; P  = 0.03, respectively). The occurrence and severity of LVDD in patients with cirrhosis and ascites is closely related to inflammatory activity. Advanced LVDD is associated with baseline circulatory and renal dysfunction, favoring HRS development, and increased mortality.

Impact on carotid intima-media thickness after laparoscopic sleeve gastrectomy in patients with morbid obesity.

BACKGROUND: We aimed to investigate the impact of laparoscopic sleeve gastrectomy (LSG) on carotid intima-media thickness (CIMT) & left ventricular dysfunction (LVD) which are the independent predictors of subclinical atherosclerosis. METHODS: To assess the change in CIMT & echocardiographic parameters of left ventricular function & correlate with %EWL 6 months and 12 months after LSG, the mean CIMT of bilateral common carotid arteries were measured at 3 different places & 7 parameters were assessed for left ventricular dysfunction after 6 and 12 months of LSG & correlated with the %EWL. RESULTS: A total of 30 patients (27(90%) women & 3(10%) men) with the mean age of 38 ± 7.84 were prospectively enrolled. BMI was significantly reduced from 42.66 ± 3.79 to 37.93 ± 3.60 kg/m2 at six months to 36 ± 3.34 at 12 months after LSG. CIMT values were significantly decreased at 6 months after surgery from 0.50 ± 0.11 mm to 0.46 ± 0.09 mm (p < 0.01) to 0.39 ± 0.07 (p < 0.05) at 12 months. However, no significant change was observed in the right mean CCA values at 6 months after surgery 0.50 ± 0.11 mm vs 0.47 ± 0.09 mm (p = 0.07) as compared to decrease at 12 months after surgery to 0.40 ± 0.08 (p < 0.05). Left mean CCA values at 6 months changed from 0.50 ± 0.11 to 0.45 ± 0.09 (p < 0.01) and at 12 months after surgery to 0.39 ± 007(p < 0.05). On 2D ECHO, ejection fraction increased at 6 months from 60.80 ± 5.89 to 61.93 ± 4.47 (p < 0.5) to after 12 months at 64.30 ± 4.20 (p < 0.05). Wave deceleration time changed at 6 months from 170 ± 36.80 to 150 ± 28.82 (p < 0.05) to 12 months 139.07 ± 17.98 (p < 0.05). Peak early diastolic mitral annular velocity (e) changed at 6 months from 8.12 ± 1.66 to 7.02 ± 1.76 (p < 0.05) to 12 months 6.33 ± 0.76 (p < 0.05). Inter-ventricular septum thickness (IVSD) changed at 6 months from 0.99 ± 0.14 to 0.91 ± 0.14 (p < 0.05) to 12 months 0.82 ± 0.09 (p < 0.05). Intraventricular relaxation time (IVRT) at 6 months changed from 94.33 ± 21.71 to 84.36 ± 14.85 (p < 0.03) to 12 months after surgery 77.40 ± 10.19 (p < 0.05). Left atrial volume index (LAVI) at 6 months decreased from 38.08 ± 11.23 to 30.93 ± 7.16 (p < 0.01) to 12 months after surgery 25.43 ± 3.65 (p < 0.05). Left ventricular diastolic dysfunction [LVIDD] at 6 months changed from 4.32 ± 0.52 to 4.11 ± 0.52 (p < 0.02) to 3.94 ± 0.26 (p < 0.05) to 3.94 ± 0.26 (p < 0.05) at 12 months after surgery. PwD at 6 and 12 months changed from 1.00 ± 0.19 to 0.87 ± 0.10 (p < 0.01) to 0.82 ± 0.08 (p < 0.05) respectively. LV mass changed in 6 months from 148.37 ± 33.09 to 117 ± 29.90 (p < 0.001) to 12 months at 110.64 ± 20.79 (p < 0.05) and left ventricular mass index [LVMI] changed in 6 months from 70 ± 16.89 to 59.626 ± 15.35 (p < 0.001) reaching a value of 57.53 ± 11.18 (p < 0.05) at 12 months. The mean 10-year risk of death due to CVD calculated was significantly reduced from 5.45 ± 6.6 to 2.8 ± 1.7% at 6 months (p < 0.05). This significant decrease in CVD risk has a positive correlation with the decrease in CIMT over 6 months showing a correlation coefficient of 0.018 with statistically significant analysis (p value < 0.05). CONCLUSION: We observed a significant reduction in CIMT & improvement in 2D ECHO parameters at 6 after LSG although no statistically significant change was observed in mean right CIMT & EF at 6 months.

Assessment of left ventricular dysfunction by strain echo in primary hyperparathyroidism and its reversal after parathyroidectomy.

BACKGROUND: Strain echocardiography is a highly sensitive modality for detecting myocardial disease at an early stage. Therefore, we aim to evaluate subclinical left ventricular dysfunction in primary hyperparathyroidism (PHPT) patients with myocardial strain imaging in addition to conventional echocardiography and to look for its reversal after parathyroidectomy (PTx). METHODS: Thirty patients who underwent curative parathyroidectomy for PHPT were included. All patients were evaluated with M mode echo, 2D echo and strain imaging before and 6 months after PTx. Left ventricular ejection fraction, left ventricular diastolic dysfunction, left ventricular hypertrophy (LVH), Global Longitudinal Strain (GLS) and global circumferential strain (GCS) were recorded. RESULTS: On M mode echo, LVH was present in 15 patients and 8 of them improved completely after PTx (p < 0.038). Incidence of systolic and diastolic dysfunction on 2D echo was 10% and 13.3% respectively; while myocardial strain imaging showed impaired systolic function in 46.7% patients. Hence, compared to conventional 2D echo, strain imaging showed 36.7% high detection rate of subnormal cardiac function. There was improvement in left ventricle dysfunction (p = 0.083), GLS and GCS (p = 0.034) after PTx. Serum parathormone demonstrated a strong positive correlation with change in GLS and GCS (p = 0.013, p = 0.126) while serum calcium showed a weak correlation with change in GLS and GCS following surgery. CONCLUSION: Myocardial strain imaging should be considered for all PHPT patients as early identification of subclinical ventricle dysfunction provides an opportunity for an early intervention and thereby preventing development of irreversible LV dysfunction.

Sex-based differences in short- and longer-term diet-induced metabolic heart disease.

Sex-based differences in the development of obesity-induced cardiometabolic dysfunction are well documented, however, the specific mechanisms are not completely understood. Obesity has been linked to dysregulation of the epitranscriptome, but the role of N6-methyladenosine (m6A) RNA methylation has not been investigated in relation to the sex differences during obesity-induced cardiac dysfunction. In the current study, male and female C57BL/6J mice were subjected to short- and long-term high-fat/high-sucrose (HFHS) diet to induce obesogenic stress. Cardiac echocardiography showed males developed systolic and diastolic dysfunction after 4 mo of diet, but females maintained normal cardiac function despite both sexes being metabolically dysfunctional. Cardiac m6A machinery gene expression was differentially regulated by duration of HFHS diet in male, but not female mice, and left ventricular ejection fraction correlated with RNA machinery gene levels in a sex- and age-dependent manner. RNA-sequencing of cardiac transcriptome revealed that females, but not males may undergo protective cardiac remodeling early in the course of obesogenic stress. Taken together, our study demonstrates for the first time that cardiac RNA methylation machinery genes are regulated early during obesogenic stress in a sex-dependent manner and may play a role in the sex differences observed in cardiometabolic dysfunction.NEW & NOTEWORTHY Sex differences in obesity-associated cardiomyopathy are well documented but incompletely understood. We show for the first time that RNA methylation machinery genes may be regulated in response to obesogenic diet in a sex- and age-dependent manner and levels may correspond to cardiac systolic function. Our cardiac RNA-seq analysis suggests female, but not male mice may be protected from cardiac dysfunction by a protective cardiac remodeling response early during obesogenic stress.

Timing of Surgery for Asymptomatic Primary Mitral Regurgitation: Possible Value of Early, Serial Measurements of Left Ventricular Sphericity.

Asymptomatic primary mitral regurgitation due to myxomatous degeneration of the mitral valve leaflets may remain so for long periods, even as left ventricular function progresses to a decompensated stage. During the early compensated stage, the ventricle's initial response to the volume overload is an asymmetric increase in the diastolic short axis dimension, accomplished by a diastolic shift of the interventricular septum into the right ventricular cavity, creating a more spherical left ventricular diastolic shape, increasing diastolic filling and stroke volume. Early valve repair is recommended to reduce postoperative left ventricular dysfunction. Early serial measurements of left ventricular sphericity index [LV-Si]. during the compensated stage of mitral regurgitation might identify subtle changes in left ventricular shape and assist in determining the optimal earliest timing for surgical intervention.

Evaluating left atrial strain and left ventricular diastolic strain rate as markers for diastolic dysfunction in patients with mitral annular calcification.

BACKGROUND: Mitral annular calcification (MAC) poses many challenges to the evaluation of diastolic function using standard echocardiography. Left atrial (LA) strain and left ventricular early diastolic strain rate (DSr) measured by speckle-tracking echocardiography (STE) are emerging techniques in the noninvasive evaluation of diastolic function. We aim to evaluate the utility of LA strain and early DSr in predicting elevated left ventricular filling pressures (LVFP) in patients with MAC and compare their effectiveness to ratio of mitral inflow velocity in early and late diastole (E/A). METHODS: We included adult patients with MAC who presented between January 1 and December 31, 2014 and received a transthoracic echocardiogram (TTE) and cardiac catheterization with measurement of LVFP within a 24-h period. We used Spearman's rank correlation coefficient to assess associations of LA reservoir strain and average early DSr with LVFP. Receiver operating characteristic (ROC) curves were computed to assess the effectiveness of LA strain and DSr in discriminating elevated LVFP as a dichotomized variable and to compare their effectiveness with E/A ratio categorized according to grade of diastolic dysfunction. RESULTS: Fifty-five patients were included. LA reservoir strain demonstrated poor correlation with LVFP (Spearman's rho = 0.03, p = 0.81) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.54, 95% CI 0.38-0.69). Categorical E/A ratio alone also demonstrated poor discriminatory ability (AUC = 0.53, 95% CI 0.39-0.67), and addition of LA reservoir strain did not significantly improve effectiveness (AUC = 0.58, 95% CI 0.42-0.74, p = 0.56). Average early DSr also demonstrated poor correlation with LVFP (Spearman's rho = -0.19, p = 0.16) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.59, 95% CI 0.44-0.75). Addition of average early DSr to categorical E/A ratio failed to improve effectiveness (AUC = 0.62, 95% CI 0.46-0.77 vs. AUC = 0.54, 95% CI 0.39-0.69, p = 0.38). CONCLUSIONS: In our sample, LA reservoir strain and DSr do not accurately predict diastolic filling pressure. Further research is required before LA strain and early DSr can be routinely used in clinical practice to assess filling pressure in patients with MAC.

Scoring System for Prediction of Left Ventricular Longitudinal Myocardial Dysfunction in Preclinical Heart Failure Patients.

BACKGROUND: Detection of left ventricular (LV) abnormalities is essential for patients with preclinical heart failure (HF) to delay progression to clinical HF. Global longitudinal strain (GLS) is a sensitive marker for the early occurrence of subtle abnormalities in LV function, but not all echocardiographic instruments can measure GLS.Methods and Results: We studied 853 preclinical HF patients to devise a scoring system for predicting low GLS (<16%). The associations of medical history and echocardiographic parameters with low GLS were evaluated using Cox proportional hazards analysis. Model 1 of the system consisted of medical history; for Model 2, conventional echocardiographic parameters were added to Model 1. For Model 1, a score ≥5 points meant prediction of low GLS with 90.2% sensitivity and 62.9% specificity (male=1 point, hypertension=4 points, dyslipidemia=1 point, atrial fibrillation=2 points, history of cardiac surgery=2 points). For Model 2, a score ≥4 points denotes prediction of low GLS with 80.3% sensitivity and 76.5% specificity (male=1 point, hypertension=2 points, atrial fibrillation=2 points, LV mass index >116 g/m2[male] or >96 g/m2[female]=1 point, LV ejection fraction <59%=2 points, E/e' >14=1 point). CONCLUSIONS: Our scoring system provides an easy-to-use evaluation of LV longitudinal myocardial dysfunction, and may prove useful for risk stratification of patients with preclinical HF.

Effects of tafamidis on the left ventricular and left atrial strain in patients with wild-type transthyretin cardiac amyloidosis.

AIMS: Although tafamidis is used in patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), its specific effect on cardiac function is unclear. Thus, this study aimed to investigate the effect of tafamidis on left atrial (LA) and left ventricular function using speckle-tracking echocardiography for 1 year of treatment in patients with ATTRwt-CA. METHODS AND RESULTS: We included 23 patients (mean age, 76 years) with ATTRwt-CA confirmed via biopsy. We analysed the left ventricular and LA strain using 2D speckle-tracking echocardiography and compared these parameters before and 1 year after starting treatment with tafamidis between 16 patients with sinus rhythm (SR) and 7 patients with atrial fibrillation (AF). In ATTRwt-CA patients with SR, LA reservoir strain significantly improved by 1-year tafamidis treatment (10.5 ± 5.0% to 11.9 ± 5.3%, P = 0.0307) although global longitudinal strain (GLS) did not (-10.6 ± 3.1% to -11.3 ± 3.0%, P = 0.0608). In contrast, LA reservoir strain was not significantly changed (5.4 ± 2.9% to 4.9 ± 1.7%, P = 0.4571), and GLS deteriorated (-8.4 ± 2.3% to -6.8 ± 1.4%, P = 0.0267) in ATTRwt-CA patients with AF. CONCLUSION: LA function improved with tafamidis treatment in ATTRwt-CA patients with SR but not left ventricular function. However, these cardiac functions did not improve with tafamidis treatment in ATTRwt-CA patients with AF.

Left ventricular myocardial work improves in response to treatment and is associated with survival among patients with light chain cardiac amyloidosis.

AIMS: Complete haematologic response to treatment for light chain cardiac amyloidosis (AL-CA) may lead to improvement of myocardial function and better outcomes. We sought to evaluate the effect of response to treatment for AL-CA on echocardiographic indices of myocardial deformation and work and their prognostic significance. METHODS AND RESULTS: Sixty-one patients treated for AL were enrolled and underwent echocardiographic assessment at baseline and at 1 year. Patients were stratified according to haematologic response as complete or not complete responders. A significant reduction in median N-terminal pro-brain natriuretic peptide (NT-proBNP) (2771-1486 pg/mL; P < 0.001) and posterior wall thickness (13-12 mm; P = 0.002) and an increase in global work index (GWI) (1115-1356 mmHg%; P = 0.018) was observed at 1 year. Patients with complete response (CR) had a more pronounced decrease in intraventricular septum thickness (14.2-12.0 mm; P = 0.006), improved global longitudinal strain (GLS) (-11.6 to -13.1%; P for interaction = 0.045), increased global constructive work (1245-1436 mmHg%; P = 0.008), and GWI (926-1250 mmHg%, P = 0.002) compared with non-CR. Furthermore, deltaGLS (ρspearman = 0.35; P < 0.001) and deltaGWI (ρspearman = -0.32; P = 0.02) correlated with delta NT-proBNP. Importantly, patients with GLS and GWI response had a better prognosis (log-rank P = 0.048 and log-rank P = 0.007, respectively). After adjustment for Mayo stage, gender, and response status, deltaGLS [hazard ratio (HR) = 1.404, P = 0.046 per 1% increase] and deltaGWI (HR = 0.996, P = 0.042 per 1mmHg% increase) were independent predictors of survival. CONCLUSION: Complete haematologic response to treatment is associated with improved left ventricular myocardial work indices, and their change is associated with improved survival in AL-CA.

The Role of the Immune System on the Cardiac Complications Observed in SARS-CoV-2

Abstract An acute respiratory syndrome caused by SARS-CoV2 was declared a pandemic by the World Health Organization. Current data in the world and in Brazil show that approximately 40% of patients who died have some type of cardiac comorbidity. There are also robust reports showing an increase in IL-6 / IL-1B / TNF-alpha and the presence of lymphopenia in patients with COVID-19. Our team and others have shown that increased cytokines are the link between arrhythmias/Left ventricular dysfunction and the immune system in different diseases. In addition, it has been well demonstrated that lymphopenia can not only be a good marker, but also a factor that causes heart failure. Thus, the present review focused on the role of the immune system upon the cardiac alterations observed in the SARS-CoV2 infection. Additionally, it was well described that SARS-CoV-2 is able to infect cardiac cells. Therefore, here it will be reviewed in deep.

Correlation of serum ST2 levels with severity of diastolic dysfunction on echocardiography and findings on cardiac MRI in patients with heart failure with preserved ejection fraction.

OBJECTIVE: The aim of the present study was to find a correlation of serum Suppression of tumorigenicity 2 (ST2) levels with severity of diastolic dysfunction on echocardiography and cardiac magnetic resonance imaging (CMRI) in heart failure with preserved ejection fraction (HFpEF) patients. METHODS: Fifty patients aged ≥18 years fulfilling diagnostic criteria for HFpEF were included. ST2 levels, 2D echocardiography and CMRI were performed. Left ventricular ejection fraction, E/A, Septal E/E', left atrial volume index (LAVI), tricuspid regurgitation (TR), assessment of diastolic dysfunction, T1 mapping in milliseconds and late gadolinium enhancement (LGE) in percentage were noted. The primary outcome measure was to study correlation of ST2 levels with severity of diastolic dysfunction, whereas the secondary outcome measures were to study correlation of ST2 levels with native T1 mapping and LGE on CMRI. RESULTS: ST2 levels showed statistically significant and positive correlation with E/E' (r = 0.837), peak TR velocity (r = 0.373), LAVI (r = 0.74), E/A (r = 0.420), and T1 values in milliseconds (r = 0.619). There was no statistically significant correlation between ST2 level and LGE in % (r = 0.145). The median ST2 levels in patients with E/E' > 14 and E/E' ≤ 14 were 110.8 and 36.1 respectively (p-value < 0.05). The mean ST2 levels were significantly higher in patients who had diastolic dysfunction grade III (126.4) and New York Heart Association class IV (133.3). CONCLUSIONS: Evaluation of ST2 adds important information to support the diagnosis of left ventricular diastolic dysfunction in patients with HFpEF.

Echocardiographic study of myocardial work in patients with type 2 diabetes mellitus.

BACKGROUND: A noninvasive left ventricular (LV) pressure-strain loop (PSL) provides a new method to quantify myocardial work (MW) by combining global longitudinal strain (GLS) and LV pressure, which exerts potential advantages over traditional GLS. We studied the LV PSL and MW in patients with type 2 diabetes mellitus (T2DM). METHODS: This cross-sectional study included 201 subjects (54 healthy controls and 147 T2DM patients) who underwent complete two-dimensional echocardiography (2DE), including 2D speckle-tracking echocardiography (STE), as well as brachial artery pulse pressure measurement. The PSL was used to determine the global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) of all study participants. The association between T2DM and LV function was evaluated according to these MW indices. RESULTS: The GLS was significantly lower in the T2DM group than in the control group (P < 0.001), indicating that the LV myocardium had been damaged, although the LV ejection fraction (LVEF) was still normal. The GWI and GWE were decreased (P = 0.022) and the GWW was increased (P < 0.001) in diabetic patients compared with controls, but the GCW was comparable in the two groups (P = 0.160). In all diabetic patients, age, body mass index, systolic blood pressure, smoking history, and LVEF were correlated with GWI, GWW and GWE. CONCLUSIONS: The use of LV PSL is a novel noninvasive technique that could help to depict the relationship between LV myocardial damage and MW in patients with T2DM.

Low left ventricular ejection fraction, complication rescue, and long-term survival after coronary artery bypass grafting.

OBJECTIVES: To evaluate the association between low left ventricular ejection fraction (LVEF), complication rescue, and long-term survival after isolated coronary artery bypass grafting. METHODS: National cohort study of patients who underwent isolated coronary artery bypass grafting (2000-2016) using Veterans Affairs Surgical Quality Improvement Program data. Left ventricular ejection fraction was categorized as ≥35% (n = 55,877), 25%-34% (n = 3893), or <25% (n = 1707). Patients were also categorized as having had no complications, 1 complication, or more than 1 complication. The association between LVEF, complication rescue, and risk of death was evaluated with multivariable Cox regression. RESULTS: Among 61,477 patients, 6586 (10.7%) had a perioperative complication and 2056 (3.3%) had multiple complications. Relative to LVEF ≥35%, decreasing ejection fraction was associated with greater odds of complications (25%-34%, odds ratio, 1.30 [1.18-1.42]; <25%, odds ratio, 1.65 [1.43-1.92]). There was a dose-response relationship between decreasing LVEF and overall risk of death (≥35% [ref]; 25%-35%, hazard ratio, 1.46 [1.37-1.55]; <25%, hazard ratio, 1.68 [1.58-1.79]). Among patients who were rescued from complications, there were decreases in 10-year survival, regardless of LVEF. Among those rescued after multiple complications, LVEF was no longer associated with risk of death. CONCLUSIONS: While decreasing LVEF is associated with post-coronary artery bypass grafting complications, patients rescued from complications have worse long-term survival, regardless of left ventricular function. Prevention and timely treatment of complications should remain a focus of quality improvement initiatives, and future work is needed to mitigate their long-term detrimental impact on survival.

Trastuzumab-Induced Negative Chronotropic and Lusitropic Effects in Cynomolgus Monkeys.

ABSTRACT: Treatment with trastuzumab, an antihuman epidermal growth factor receptor type 2 humanized monoclonal antibody, has been associated with heart failure in certain patients with cancer; however, the mechanism underlying trastuzumab-induced cardiac dysfunction remains unclear. This study was conducted to clarify the cardiac effects of trastuzumab in cynomolgus monkeys, which are commonly used as cross-reactive species in preclinical safety evaluation. Monkeys were treated with trastuzumab weekly for 1 month (5 doses in total). At first and fifth doses for pressure-volume loop analysis, trastuzumab at 20 mg·kg-1·10 min-1, equivalent to the human therapeutic dose, was administered intravenously to isoflurane-anesthetized animals, followed by 60 mg·kg-1·10 min-1 at a 30-minute interval. The other doses were fixed at 80 mg·kg-1·10 min-1 under unanesthetized conditions. After the first dose, reduced heart rate, decreases in maximal rate of fall of left ventricular pressure, and prolonged time constant for isovolumic relaxation, which are predictors of drug-induced changes in lusitropy, were observed at 20 and 60 mg·kg-1. The changes after the fifth dose were comparable with those after the first dose, indicating trastuzumab did not show exacerbation of cardiac function during the 1-month trial. No significant changes in slope of preload recruitable stroke work, which is a load-independent inotropic parameter, were observed at either dose. In conclusion, trastuzumab-induced little inotropic effect but induced negative chronotropic or lusitropic effects in monkeys, which might be associated with impaired left ventricular diastolic function.

Fine-tuning the cardiac O-GlcNAcylation regulatory enzymes governs the functional and structural phenotype of the diabetic heart.

AIMS: The glucose-driven enzymatic modification of myocardial proteins by the sugar moiety, ß-N-acetylglucosamine (O-GlcNAc), is increased in pre-clinical models of diabetes, implicating protein O-GlcNAc modification in diabetes-induced heart failure. Our aim was to specifically examine cardiac manipulation of the two regulatory enzymes of this process on the cardiac phenotype, in the presence and absence of diabetes, utilising cardiac-targeted recombinant-adeno-associated viral-vector-6 (rAAV6)-mediated gene delivery. METHODS AND RESULTS: In human myocardium, total protein O-GlcNAc modification was elevated in diabetic relative to non-diabetic patients, and correlated with left ventricular (LV) dysfunction. The impact of rAAV6-delivered O-GlcNAc transferase (rAAV6-OGT, facilitating protein O-GlcNAcylation), O-GlcNAcase (rAAV6-OGA, facilitating de-O-GlcNAcylation), and empty vector (null) were determined in non-diabetic and diabetic mice. In non-diabetic mice, rAAV6-OGT was sufficient to impair LV diastolic function and induce maladaptive cardiac remodelling, including cardiac fibrosis and increased Myh-7 and Nppa pro-hypertrophic gene expression, recapitulating characteristics of diabetic cardiomyopathy. In contrast, rAAV6-OGA (but not rAAV6-OGT) rescued LV diastolic function and adverse cardiac remodelling in diabetic mice. Molecular insights implicated impaired cardiac PI3K(p110α)-Akt signalling as a potential contributing mechanism to the detrimental consequences of rAAV6-OGT in vivo. In contrast, rAAV6-OGA preserved PI3K(p110α)-Akt signalling in diabetic mouse myocardium in vivo and prevented high glucose-induced impairments in mitochondrial respiration in human cardiomyocytes in vitro. CONCLUSION: Maladaptive protein O-GlcNAc modification is evident in human diabetic myocardium, and is a critical regulator of the diabetic heart phenotype. Selective targeting of cardiac protein O-GlcNAcylation to restore physiological O-GlcNAc balance may represent a novel therapeutic approach for diabetes-induced heart failure.

Ventricular Function in Physiologically Repaired and Unrepaired Congenitally Corrected Transposition of the Great Arteries.

In patients with congenitally corrected transposition of the great arteries (ccTGA) and hemodynamically significant concomitant lesions, physiologic repair may be undertaken, in which the circulation is septated but the morphologic right ventricle (RV) remains the systemic ventricle. Patients without significant concomitant lesions may be observed without surgery, with a similar physiologic result. We compared cardiovascular magnetic resonance measures of ventricular size and function in patients with physiologically repaired and unrepaired ccTGA. Patients with ccTGA who underwent cardiovascular magnetic resonance at our center between September 2007 and July 2019 were analyzed. In 38 patients identified (12, physiologically repaired; 26, unrepaired; mean age 34.5 [18.7 to 52.0] years), there was a higher proportion of RV ejection fraction ≤45% in physiologically repaired (75% vs unrepaired 35%, p = 0.02). Physiologically repaired patients had worse left ventricle global longitudinal strain (-14.9% ± 5.0% vs unrepaired patients -18.4% ± 2.7%, p = 0.04). The difference in tricuspid regurgitant fraction between groups did not achieve statistical significance (physiologically repaired 27.4 ± 11.1% vs unrepaired patients 19.2 ± 13.0%, p = 0.08). Evaluation for late gadolinium enhancement was more commonly undertaken in physiologically repaired patients (8 of 12 vs unrepaired 7 of 26, p = 0.03) and present more frequently in the left ventricle in physiologically repaired patients in patients evaluated (6 of 8 vs unrepaired 0 of 7, p = 0.01). In conclusion, ventricular function is decreased in patients with ccTGA undergoing physiologic repair compared with those without previous surgery. These cohorts should be considered separately when using ventricular function as an outcome. RV dysfunction is concerning for long-term outcomes following physiologic repair.

Electrocardiography-Based Artificial Intelligence Algorithm Aids in Prediction of Long-term Mortality After Cardiac Surgery.

OBJECTIVE: To assess whether an electrocardiography-based artificial intelligence (AI) algorithm developed to detect severe ventricular dysfunction (left ventricular ejection fraction [LVEF] of 35% or below) independently predicts long-term mortality after cardiac surgery among patients without severe ventricular dysfunction (LVEF>35%). METHODS: Patients who underwent valve or coronary bypass surgery at Mayo Clinic (1993-2019) and had documented LVEF above 35% on baseline electrocardiography were included. We compared patients with an abnormal vs a normal AI-enhanced electrocardiogram (AI-ECG) screen for LVEF of 35% or below on preoperative electrocardiography. The primary end point was all-cause mortality. RESULTS: A total of 20,627 patients were included, of whom 17,125 (83.0%) had a normal AI-ECG screen and 3502 (17.0%) had an abnormal AI-ECG screen. Patients with an abnormal AI-ECG screen were older and had more comorbidities. Probability of survival at 5 and 10 years was 86.2% and 68.2% in patients with a normal AI-ECG screen vs 71.4% and 45.1% in those with an abnormal screen (log-rank, P<.01). In the multivariate Cox survival analysis, the abnormal AI-ECG screen was independently associated with a higher all-cause mortality overall (hazard ratio [HR], 1.31; 95% CI, 1.24 to 1.37) and in subgroups of isolated valve surgery (HR, 1.30; 95% CI, 1.18 to 1.42), isolated coronary artery bypass grafting (HR, 1.29; 95% CI, 1.20 to 1.39), and combined coronary artery bypass grafting and valve surgery (HR, 1.19; 95% CI, 1.08 to 1.32). In a subgroup analysis, the association between abnormal AI-ECG screen and mortality was consistent in patients with LVEF of 35% to 55% and among those with LVEF above 55%. CONCLUSION: A novel electrocardiography-based AI algorithm that predicts severe ventricular dysfunction can predict long-term mortality among patients with LVEF above 35% undergoing valve and/or coronary bypass surgery.

Preoperative beta-blocker in ventricular dysfunction patients: need a more granular quality metric.

BACKGROUND: The use of preoperative beta-blockers has been accepted as a quality standard for patients undergoing coronary artery bypass graft (CABG) surgery. However, conflicting results from recent studies have raised questions concerning the effectiveness of this quality metric. We sought to determine the influence of preoperative beta-blocker administration before CABG in patients with left ventricular dysfunction. METHODS: The authors analyzed all cases of isolated CABGs in patients with left ventricular ejection fraction less than 50%, performed between 2012 January and 2017 June, at 94 centres recorded in the China Heart Failure Surgery Registry database. In addition to the use of multivariate regression models, a 1-1 propensity scores matched analysis was performed. RESULTS: Of 6116 eligible patients, 61.7% received a preoperative beta-blocker. No difference in operative mortality was found between two cohorts (3.7% for the non-beta-blockers group vs. 3.0% for the beta-blocker group; adjusted odds ratio [OR] 0.82 [95% CI 0.58-1.15]). Few differences in the incidence of other postoperative clinical end points were observed as a function of preoperative beta-blockers except in stroke (0.7% for the non-beta-blocker group vs. 0.3 for the beta-blocker group; adjusted OR 0.39 [95% CI 0.16-0.96]). Results of propensity-matched analyses were broadly consistent. CONCLUSIONS: In this study, the administration of beta-blockers before CABG was not associated with improved operative mortality and complications except the incidence of postoperative stroke in patients with left ventricular dysfunction. A more granular quality metric which would guide the use of beta-blockers should be developed.