The rate-pressure product as an index of myocardial oxygen consumption during exercise in patients with angina pectoris

Myocardial blood flow is the dominant factor influencing cardiac magnetic resonance adenosine stress T2

Stress imaging identifies ischemic myocardium by comparing hemodynamics during rest and hyperemic stress. Hyperemia affects multiple hemodynamic parameters in myocardium, including myocardial blood flow (MBF), myocardial blood volume (MBV), and venous blood oxygen levels (PvO2 ). Cardiac T2 is sensitive to these changes and therefore is a promising non-contrast option for stress imaging; however, the impact of individual hemodynamic factors on T2 is poorly understood, making the connection from altered T2 to changes within the tissue difficult. To better understand this interplay, we performed T2 mapping and measured various hemodynamic factors independently in healthy pigs at multiple levels of hyperemic stress, induced by different doses of adenosine (0.14-0.56 mg/kg/min). T1 mapping quantified changes in MBV. MBF was assessed with microspheres, and oxygen consumption was determined by the rate pressure product (RPP). Simulations were also run to better characterize individual contributions to T2. Myocardial T2, MBF, oxygen consumption, and MBV all changed to varying extents between each level of adenosine stress (T2 = 37.6-41.8 ms; MBF = 0.48-1.32 mL/min/g; RPP = 6507-4001 bmp*mmHg; maximum percent change in MBV = 1.31%). Multivariable analyses revealed MBF as the dominant influence on T2 during hyperemia (significant β-values >7). Myocardial oxygen consumption had almost no effect on T2 (β-values <0.002); since PvO2 is influenced by both oxygen consumption and MBF, PvO2 changes detected by T2 during adenosine stress can be attributed to MBF. Simulations varying PvO2 and MBV confirmed that PvO2 had the strongest influence on T2, but MBV became important at high PvO2 . Together, these data suggest a model where, during adenosine stress, myocardial T2 responds predominantly to changes in MBF, but at high hyperemia MBV is also influential. Thus, changes in adenosine stress T2 can now be interpreted in terms of the physiological changes that led to it, enabling T2 mapping to become a viable non-contrast option to detect ischemic myocardial tissue.

Case Series: Extracorporeal Shockwave Myocardial Revascularization Therapy Improves Ischemic Response, Functional Capacity, and Quality of Life in Indicated CABG-Stable Angina Pectoris Patients

Introduction

Extracorporeal shockwave myocardial revascularization (ESMR) is included in the guidelines only for patients with refractory angina pectoris having no option for invasive revascularization. We intend to report a case series with ESMR therapy is indicated patients with coronary artery bypass grafting-stable angina pectoris (CABG-SAP) who refuse the surgery, irrespective of angina symptoms.

Methods

We review medical records of patients with SAP admitted to ESMR therapy in Dr. Hasan Sadikin General Hospital, Bandung, Indonesia from January 2018 to December 2019. Recorded variables at baseline and after therapy extracted, namely, (1) ischemic response, double product, and (2) functional capacity measured as metabolic equivalent (MET) using treadmill test; (3) six-minute walking test distance achieved; and (4) quality of life using SF-36 Questionnaire.

Results

A total of four indicated patients with CABG-SAP from 50 to 75 years old were included in this study. At baseline, one patient is CCS class I and two patients are CCS class II with SDS ranging from 3 to 17. Ischemic response improved in all the patients. The double product improved in patient 1 9,600–14,872 mm Hg × bpm, patient 2 9,460–10,640 mm Hg × bpm, and patient 4 17,220–20,480 mm Hg × bpm. The functional capacity improved in Patient 1 8.07–8.91 METs, patient 2 1.91–4.01 METs, patient 3 3.45–6.39 METs, and patient 4 3.9–4.43 METs. The 6-min walking distance improved in patient 1 540–570 m and patient 2 345–405 m. The CCS class, bodily pain, and general health domain scores improved in all patients.

Conclusion

ESMR therapy might be beneficial for indicated patients with CABG-SAP to improve ischemic response, functional capacity, and physical component of quality of life.

Dynamic detection and reversal of myocardial ischemia using an artificially intelligent bioelectronic medicine

Myocardial ischemia is spontaneous, frequently asymptomatic, and contributes to fatal cardiovascular consequences. Importantly, myocardial sensory networks cannot reliably detect and correct myocardial ischemia on their own. Here, we demonstrate an artificially intelligent and responsive bioelectronic medicine, where an artificial neural network (ANN) supplements myocardial sensory networks, enabling reliable detection and correction of myocardial ischemia. ANNs were first trained to decode spontaneous cardiovascular stress and myocardial ischemia with an overall accuracy of ~92%. ANN-controlled vagus nerve stimulation (VNS) significantly mitigated major physiological features of myocardial ischemia, including ST depression and arrhythmias. In contrast, open-loop VNS or ANN-controlled VNS following a caudal vagotomy essentially failed to reverse cardiovascular pathophysiology. Last, variants of ANNs were used to meet clinically relevant needs, including interpretable visualizations and unsupervised detection of emerging cardiovascular stress. Overall, these preclinical results suggest that ANNs can potentially supplement deficient myocardial sensory networks via an artificially intelligent bioelectronic medicine system.

Predictive Value of Heart Rate and Blood Pressure on the Prognosis of Postural Tachycardia Syndrome in Children

BACKGROUND

To investigate the predictive value of heart rate (HR) and blood pressure (BP) on the prognosis of postural tachycardia syndrome (POTS) in children.

MATERIALS AND METHODS

53 cases of children aged 5 to 15 years who visited in the Pediatric Syncope Specialist Clinic of The Second Xiangya Hospital of Central South University for unexplained syncope or syncope precursor were diagnosed with POTS by head-up tilt test (HUTT) as the POTS group. 38 healthy children aged 5 to 16 years who underwent physical examination at the Child Health Care Clinic of the hospital in the same period were matched as controls (control group). The children with POTS were followed up after 3 months of treatment and were divided into good prognosis group (40 cases) and poor prognosis group (13 cases) according to the results of HUTT re-examination and whether the symptoms improved or not. HR and BP indicators were collected from each group at baseline and during HUTT.

RESULTS

There were 91 research subjects, of which 45 are males, with a mean age of 11.52 ± 2.13 years. (1) HR at 5 and 10 min (HR 5 and HR 10, respectively), HR difference at 5 and 10 min (HRD 5 and HRD 10, respectively), and HR and BP product at 5 and 10 min (RPP 5 and RPP 10, respectively) were greater in the POTS group than in the control group (P < 0.01). (2) HR 5, HR 10, HRD 5, HRD 10, and RPP 10 in children with POTS were smaller in the good prognosis group than the poor prognosis group (P < 0.01). (3) The area under curve was 0.925 on the four combined indicators (HR 5, HR 10, HRD 5, and HRD 10), predicting a good prognosis of POTS, sensitivity of 99.99%, and specificity of 75.00%.

CONCLUSIONS

HR 5, HR 10, HRD 5, HRD 10, and RPP 10 and the four combined indicators (HR 5, HR 10, HRD 5, and HRD 10) had predictive value for the POTS prognosis in children. The predictive value of the four combined indicators for the POTS prognosis was better than that of the single HR 5, HRD 5, and RPP 10.

Effects of Yogic practices on cardiovascular system and salivary alpha amylase on Indian healthy jail inmates

OBJECTIVES

Imprisoned people usually have a poor health status and an increase risk to suffer chronic debilitating conditions, co-infection due to their limitations in physical activity and mental disturbances. This study was carried to find out the health impacts of Yogic practice of Indian healthy jail inmates.

METHODS

It was interventional single group pre-post design study. A total no of 30, Jail inmates including 08 female were participated in this study and practiced Yoga for six months. Body Mass Index, Heart Rate, Blood Pressure, Salivary alpha amylase activity (SAA) a stress marker were assessed before, after three months and after completion of six months of Yogic practice.

RESULTS

Improvement was noted in all parameters, but significant improvement was noted in systolic blood pressure, diastolic blood pressure, mean blood pressure, double product a index of load in the heart and SAA following Yogic practice in total participants. Significant improvement was also noted in systolic blood pressure, diastolic blood pressure, mean blood pressure, double product a index of load in the heart and SAA following Yogic practice in male group. No significant effect was noted in female group.

CONCLUSIONS

The present study revealed that regular Yogic practice resulted in reduction blood pressure, load in the heart and stress in mail jail inmates, when it is practiced regularly and carefully.

F, Leicht CA. Serum and plasma brain-derived neurotrophic factor concentration are elevated by systemic but not local passive heating

Brain-derived neurotrophic factor (BDNF) plays a key role in neuronal adaptations. While previous studies suggest that whole-body heating can elevate circulating BDNF concentration, this is not known for local heating protocols. This study investigated the acute effects of whole-body versus local passive heating on serum and plasma BDNF concentration. Using a water-perfused suit, ten recreationally active males underwent three 90 min experimental protocols: heating of the legs with upper-body cooling (LBH), whole-body heating (WBH) and a control condition (CON). Blood samples were collected before, immediately after and 1 h post-heating for the determination of serum and plasma BDNF concentration, platelet count as well as the BDNF release per platelet. Rectal temperature, cardiac output and femoral artery shear rate were assessed at regular intervals. Serum and plasma BDNF concentration were elevated after WBH (serum: 19.1±5.0 to 25.9±11.3 ng/ml, plasma: 2.74±0.9 to 4.58±2.0; p<0.044), but not LBH (serum: 19.1±4.7 to 22.3±4.8 ng/ml, plasma: 3.25±1.13 to 3.39±0.90 ng/ml; p>0.126), when compared with CON (serum: 18.6±6.4 to 16.8±3.4 ng/ml, plasma: 2.49±0.69 to 2.82±0.89 ng/ml); accompanied by an increase in platelet count (p<0.001). However, there was no change in BDNF content per platelet after either condition (p = 0.392). All physiological measures were elevated to a larger extent after WBH compared with LBH (p<0.001), while shear rate and rectal temperature were higher during LBH than CON (p<0.038). In conclusion, WBH but not LBH acutely elevates circulating BDNF concentration. While these findings further support the use of passive heating to elevate BDNF concentration, a larger increase in shear rate, sympathetic activity and/or rectal temperature than found after LBH appears needed to induce an acute BDNF response by passive heating.

Personalized pacing for diastolic dysfunction and heart failure with preserved ejection fraction: Design and rationale for the myPACE randomized controlled trial

Background

Patients with pacemakers and heart failure with preserved ejection fraction (HFpEF) or isolated diastolic dysfunction (DD) may benefit from a higher backup heart rate (HR) setting compared with the standard setting of 60 bpm.

Objective

The purpose of this study was to assess the effects of a personalized backup HR setting (myPACE group) compared with 60 bpm (control group).

Methods

In this prospective, blinded, randomized controlled study, pacemaker patients with DD or HFpEF and atrial pacing with intrinsic ventricular conduction or conduction system or biventricular pacing are randomized to the myPACE group or control group for 1 year. The primary outcome is the change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores. Secondary endpoints include changes in N-terminal pro–brain natriuretic peptide levels, physical and emotional MLHFQ subscores, and pacemaker-detected atrial arrhythmia burden, patient activity levels, and thoracic impedance; hospitalization for heart failure, atrial fibrillation, cerebrovascular accident, or myocardial infarction; and loop diuretic or antiarrhythmic medication initiation or up-titration. A sample size of 118 subjects is expected to allow detection of a 5-point change in MLHFQ score in an intention-to-treat analysis and allow initial assessment of clinical outcomes and subgroup analyses.

Results

Enrollment began in July 2019. As of November 2020, 107 subjects have been enrolled. It is projected that the 1-year follow-up will be completed by December 2021.

Conclusion

Atrial pacing with intrinsic ventricular conduction or advanced ventricular pacing at a higher, personalized backup HR may be a therapeutic target for patients with isolated DD or HFpEF. The myPACE trial is designed to test this hypothesis.

Inappropriate left ventricular mass after HELLP syndrome inappropriate LVM after HELLP syndrome

OBJECTIVES

Excessive left ventricular mass (LVM) results in inefficient LV work with energy waste leading to a negative prognostic effect. We aimed at investigating the presence of inappropriate LVM and calculating the myocardial mechano-energetic efficiency index (MEEi) in former pre-eclamptic (PE) women (with or without HELLP syndrome) compared to women who experienced HELLP syndrome without PE.

STUDY DESIGN

In this cross-sectional study, women with a history of normotensive HELLP (n = 32), PE without HELLP (n = 59), and PE with HELLP (n = 101) underwent echocardiography as part of the clinical CV work-up after their complicated pregnancies from 6 months to 4 years postpartum. We excluded women with comorbidities, including chronic hypertension, hypercholesterolemia, and obesity.

MAIN OUTCOME MEASURES

LVM excess was calculated as the ratio between observed LVM and predicted LVM (by sex, stroke work and height), while MEEi was considered as the ratio between stroke work and "double product" (to approximate energy consumption), indexed to LVM.

RESULTS

LV hypertrophy was present in 8-14% and concentric remodeling in 31-42% of women, without intergroup difference. LVM was inappropriate in one-third of normotensive former HELLP and in about one-half of PE with or without HELLP, with no difference among groups. Accordingly, without nominal difference, MEEi showed a tendency towards lower values in former pre-eclamptic individuals.

CONCLUSIONS

Women with a history of HELLP syndrome, independently from the presence/absence of PE, showed inappropriate LVM in the first 4 years after delivery, which may partially explain the elevated CV risk in these women compared to the general female population.

Cannabis and Athletic Performance

Cannabis is widely used for both recreational and medicinal purposes on a global scale. There is accumulating interest in the use of cannabis and its constituents for athletic recovery, and in some instances, performance. Amidst speculation of potential beneficial applications, the effects of cannabis and its two most abundant constituents, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), remain largely un-investigated. The purpose of this review is to critically evaluate the literature describing the effects of whole cannabis, THC, and CBD, on athletic performance and recovery. While investigations of whole cannabis and THC have generally shown either null or detrimental effects on exercise performance in strength and aerobic-type activities, studies of sufficient rigor and validity to conclusively declare ergogenic or ergolytic potential in athletes are lacking. The ability of cannabis and THC to perturb cardiovascular homeostasis warrants further investigation regarding mechanisms by which performance may be affected across different exercise modalities and energetic demands. In contrast to cannabis and THC, CBD has largely been scrutinized for its potential to aid in recovery. The beneficial effects of CBD on sleep quality, pain, and mild traumatic brain injury may be of particular interest to certain athletes. However, research in each of these respective areas has yet to be thoroughly investigated in athletic populations. Elucidating the effects of whole cannabis, THC, and CBD is pertinent for both researchers and practitioners given the widespread use of these products, and their potential to interact with athletes' performance and recovery.

Hot weather and heat extremes: health risks

Hot ambient conditions and associated heat stress can increase mortality and morbidity, as well as increase adverse pregnancy outcomes and negatively affect mental health. High heat stress can also reduce physical work capacity and motor-cognitive performances, with consequences for productivity, and increase the risk of occupational health problems. Almost half of the global population and more than 1 billion workers are exposed to high heat episodes and about a third of all exposed workers have negative health effects. However, excess deaths and many heat-related health risks are preventable, with appropriate heat action plans involving behavioural strategies and biophysical solutions. Extreme heat events are becoming permanent features of summer seasons worldwide, causing many excess deaths. Heat-related morbidity and mortality are projected to increase further as climate change progresses, with greater risk associated with higher degrees of global warming. Particularly in tropical regions, increased warming might mean that physiological limits related to heat tolerance (survival) will be reached regularly and more often in coming decades. Climate change is interacting with other trends, such as population growth and ageing, urbanisation, and socioeconomic development, that can either exacerbate or ameliorate heat-related hazards. Urban temperatures are further enhanced by anthropogenic heat from vehicular transport and heat waste from buildings. Although there is some evidence of adaptation to increasing temperatures in high-income countries, projections of a hotter future suggest that without investment in research and risk management actions, heat-related morbidity and mortality are likely to increase.

Depressed myocardial mechano-energetic efficiency in subjects with dysglycemia

AIMS

Evidence indicate that 1 h post-load glucose levels (1hPG) ≥ 155 mg/dl identify amongst subjects with normal glucose tolerance (NGT) a new category of prediabetes (NGT 1 h-high). A compromised myocardial mechano-energetic efficiency (MEE) is associated with type 2 diabetes and predicts adverse cardiovascular outcomes. Herein, we explored the association between prediabetes conditions such as NGT 1 h-high, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) and a decreased MEE.

METHODS

MEE was assessed by an echocardiography-derived measure in 1467 non-diabetic individuals subdivided according to their glucose tolerance: NGT and 1-hPG < 155 mg/dl (NGT 1 h-low, n = 617), NGT 1 h-high (n = 210), isolated IFG (n = 237), and IGT (n = 403).

RESULTS

Subjects with NGT 1 h-high, isolated IFG, and IGT displayed a higher myocardial oxygen consumption, and a decreased MEE in comparison to NGT 1 h-low group. MEE was inversely related to male sex, age, body mass index, total cholesterol, triglycerides, fasting and post-load glucose and insulin, C reactive protein, and positively correlated with insulin sensitivity estimated by the Matsuda index. In a stepwise multivariate linear regression model including several cardio-metabolic risk factors, 1hPG was the major predictor of MEE.

CONCLUSIONS

Subjects with NGT 1 h-high, isolated IFG, and IGT have a raised myocardial oxygen consumption and a reduced MEE.

Influence of muscular contraction on vascular conductance during exercise above versus below critical power

We tested the hypothesis that limb vascular conductance (LVC) would increase during the immediate recovery phase of dynamic exercise above, but not below, critical power (CP) indicating a threshold for muscular contraction-induced impedance of limb blood flow (LBF). CP (115 ± 26 W) was determined in 7 men and 7 women who subsequently performed ∼5 min of near-supine cycling exercise both below and above CP. LVC demonstrated a greater increase during immediate recovery and remained significantly higher following exercise above, compared to below, CP (all p < 0.001). Power output was associated with the immediate increases in LVC following exercise above, but not below, CP (p < 0.001; r = 0.85). Additionally, variance in percent LBF impedance was significantly lower above (CV: 10.7 %), compared to below (CV: 53.2 %), CP (p < 0.01). CP appears to represent a threshold above which the characteristics of LBF impedance by muscular contraction become intensity-dependent. These data suggest a critical level of LBF impedance relative to contraction intensity exists and, once attained, may promote the progressive metabolic and neuromuscular responses known to occur above CP.

Nitrite and tempol combination promotes synergic effects and alleviates right ventricular wall stress during acute pulmonary thromboembolism

INTRODUCTION

The mechanical obstruction and pulmonary vasoconstriction are major determinants of the sudden right ventricular (RV) afterload increases observed during acute pulmonary thromboembolism (APT). Vasodilators and antioxidants agents have been shown to mitigate pulmonary hypertension. We examined whether sodium nitrite and the antioxidant tempol combination could be advantageous in an APT sheep model.

METHODS

APT was induced in anesthetized sheep by autologous blood clots (250 mg/kg) into the right atrium. Thirty minutes after APT induction, the animals received a continuous infusion of tempol (1.0 mg/kg/min), increasing sodium nitrite infusion (5, 15, and 50 μmol/kg), or a simultaneous combination of both drugs. Saline was used as a control treatment. Hemodynamic measurements were carried out every 15 min. Also, whole blood nitrite and serum 8-isoprostanes levels were measured.

RESULTS

APT induced sustained pulmonary hypertension, increased dp/dt_max, and rate pressure product (RPP). Nitrite or tempol treatments attenuated these increases (P < 0.05). When both drugs were combined, we found a robust reduction in the RV RPP compared with the treatments alone (P < 0.05). The sole nitrite infusion increased blood nitrite concentrations by 35 ± 6 μM (P < 0.05), whereas the nitrite and tempol combination produced higher blood nitrite concentrations by approximately 54 ± 7 μM. Tempol or nitrite infusions, both alone or combined, blunted the increases in 8-isoprostane concentrations observed after APT.

CONCLUSIONS

Nitrite and tempol combination protects against APT-induced RV wall stress. The association of both drugs may offer an advantage to treat RV failure during severe APT.

RBC Transfusion Induced ST Segment Variability Following the Norwood Procedure

Supplemental Digital Content is available in the text.

Objectives:

The transfusion of stored RBCs decreases nitric oxide bioavailability, which may have an adverse effect on vascular function. We assessed the effects of RBC transfusion on coronary vascular function by evaluating the relationship between myocardial oxygen delivery and demand as evidenced by ST segment variability.

Design:

Retrospective case-control study.

Setting:

Nine-hundred seventy-three–bed pediatric hospital with a 54-bed cardiovascular ICU.

Patients:

Seventy-three neonates with hypoplastic left heart syndrome following the Norwood procedure, 38 with a Blalock-Taussig shunt and 35 with a right ventricle to pulmonary artery shunt.

Interventions:

RBC transfusion.

Materials and Main Results:

High-frequency physiologic data were captured 30 minutes prior to the initiation of (baseline) and during the 120 minutes of the transfusion. A rate pressure product was calculated for each subject and used as an indicator of myocardial oxygen demand. Electrocardiogram leads (aVL, V1, II) were used to construct a 3D ST segment vector to assess ST segment variability and functioned as a surrogate indicator of myocardial ischemia. One-hundred thirty-eight transfusions occurred in the Blalock-Taussig shunt group and 139 in the right ventricle to pulmonary artery shunt group. There was no significant change in the rate pressure product for either group; however, ST segment variability progressively increased for the entire cohort during the transfusion, becoming statistically significant by the end of the transfusion. Upon subgroup analysis, this finding was noted with statistical significance in the Blalock-Taussig shunt group and trending toward significance in the right ventricle to pulmonary artery shunt group.

Conclusions:

We found a significant increase in the ST segment variability and evidence of myocardial ischemia temporally associated with RBC transfusions in neonates following the Norwood procedure, specifically among those in the Blalock-Taussig shunt group, which may impact immediate and long-term outcomes.

Diastolic dysfunction in women with ischemia and no obstructive coronary artery disease: Mechanistic insight from magnetic resonance imaging

BACKGROUND

Ischemia with no obstructive coronary artery disease (INOCA) is prevalent in women and is associated with increased risk of developing heart failure with preserved ejection fraction (HFpEF); however, the mechanism(s) contributing to this progression remains unclear. Given that diastolic dysfunction is common in women with INOCA, defining mechanisms related to diastolic dysfunction in INOCA could identify therapeutic targets to prevent HFpEF.

METHODS

Cardiac MRI was performed in 65 women with INOCA and 12 reference controls. Diastolic function was defined by left ventricular early diastolic circumferential strain rate (eCSRd). Contributors to diastolic dysfunction were chosen a priori as coronary vascular dysfunction (myocardial perfusion reserve index [MPRI]), diffuse myocardial fibrosis (extracellular volume [ECV]), and aortic stiffness (aortic pulse wave velocity [aPWV]).

RESULTS

Compared to controls, eCSRd was lower in INOCA (1.61 ± 0.33/s vs. 1.36 ± 0.31/s, P = 0.016); however, this difference was not exaggerated when the INOCA group was sub-divided by low and high MPRI (P > 0.05) nor was ECV elevated in INOCA (29.0 ± 1.9% vs. 28.0 ± 3.2%, control vs. INOCA; P = 0.38). However, aPWV was higher in INOCA vs. controls (8.1 ± 3.2 m/s vs. 6.1 ± 1.5 m/s; P = 0.045), and was associated with eCSRd (r = -0.50, P < 0.001). By multivariable linear regression analysis, aPWV was an independent predictor of decreased eCSRd (standardized β = -0.39, P = 0.003), as was having an elevated left ventricular mass index (standardized β = -0.25, P = 0.024) and lower ECV (standardized β = 0.30, P = 0.003).

CONCLUSIONS

These data provide mechanistic insight into diastolic dysfunction in women with INOCA, identifying aortic stiffness and ventricular remodeling as putative therapeutic targets.

Platelet Effects of Anti-diabetic Therapies: New Perspectives in the Management of Patients with Diabetes and Cardiovascular Disease

In type 2 diabetes, anti-thrombotic management is challenging, and current anti-platelet agents have demonstrated reduced efficacy. Old and new anti-diabetic drugs exhibited—besides lowering blood glucose levels—direct and indirect effects on platelet function and on thrombotic milieu, eventually conditioning cardiovascular outcomes. The present review summarizes existing evidence on the effects of glucose-lowering agents on platelet properties, addressing pre-clinical and clinical research, as well as drug–drug interactions with anti-platelet agents. We aimed at expanding clinicians’ understanding by highlighting new opportunities for an optimal management of patients with diabetes and cardiovascular disease. We suggest how an improvement of the thrombotic risk in this large population of patients may be achieved by a careful and tailored combination of anti-diabetic and anti-platelet therapies.

Dobutamine stress cardiac MRI is safe and feasible in pediatric patients with anomalous aortic origin of a coronary artery (AAOCA)

BACKGROUND

Risk stratification in anomalous aortic origin of a coronary artery (AAOCA) is challenged by the lack of a reliable method to detect myocardial ischemia. We prospectively studied the safety and feasibility of Dobutamine stress-cardiac magnetic resonance (DSCMR), a test with excellent performance in adults, in pediatric patients with AAOCA.

METHODS

Consecutive DSCMR from 06/2014-12/2019 in patients≤20 years old with AAOCA were included. Hemodynamic response and major/minor events were recorded. Image quality and spatial/temporal resolution were evaluated. Rest and stress first-pass perfusion and wall motion abnormalities (WMA) were assessed. Inter-observer agreement was assessed using kappa coefficient.

RESULTS

A total of 224 DSCMR were performed in 182 patients with AAOCA at a median age of 14 years (IQR 12, 16) and median weight of 58.0 kg (IQR 43.3, 73.0). Examinations were completed in 221/224 (98.9%), all studies were diagnostic. Heart rate and blood pressure increased significantly from baseline (p < 0.001). No patient had major events and 28 (12.5%) had minor events. Inducible hypoperfusion was noted in 31/221 (14%), associated with WMA in 13/31 (42%). Inter-observer agreement for inducible hypoperfusion was very good (Κ = 0.87). Asymptomatic patients with inducible hypoperfusion are considered high-risk and those with a negative test are of standard risk.

CONCLUSIONS

DSCMR is feasible in pediatric patients with AAOCA to assess for inducible hypoperfusion and WMA. It can be performed safely with low incidence of major/minor events. Thus, DSCMR is potentially a valuable test for detection of myocardial ischemia and helpful in the management of this patient population.

Pralidoxime improves the hemodynamics and survival of rats with peritonitis-induced sepsis

Several studies have suggested that sympathetic overstimulation causes deleterious effects in septic shock. A previous study suggested that pralidoxime exerted a pressor effect through a mechanism unrelated to the sympathetic nervous system; this effect was buffered by the vasodepressor action of pralidoxime mediated through sympathoinhibition. In this study, we explored the effects of pralidoxime on hemodynamics and survival in rats with peritonitis-induced sepsis. This study consisted of two sub-studies: survival and hemodynamic studies. In the survival study, 66 rats, which survived for 10 hours after cecal ligation and puncture (CLP), randomly received saline placebo, pralidoxime, or norepinephrine treatment and were monitored for up to 24 hours. In the hemodynamic study, 44 rats were randomly assigned to sham, CLP-saline placebo, CLP-pralidoxime, or CLP-norepinephrine groups, and hemodynamic measurements were performed using a conductance catheter placed in the left ventricle. In the survival study, 6 (27.2%), 15 (68.1%), and 5 (22.7%) animals survived the entire 24-hour monitoring period in the saline, pralidoxime, and norepinephrine groups, respectively (log-rank test P = 0.006). In the hemodynamic study, pralidoxime but not norepinephrine increased end-diastolic volume (P <0.001), stroke volume (P = 0.002), cardiac output (P = 0.003), mean arterial pressure (P = 0.041), and stroke work (P <0.001). The pressor effect of norepinephrine was short-lived, such that by 60 minutes after the initiation of norepinephrine infusion, it no longer had any significant effect on mean arterial pressure. In addition, norepinephrine significantly increased heart rate (P <0.001) and the ratio of arterial elastance to ventricular end-systolic elastance (P = 0.010), but pralidoxime did not. In conclusion, pralidoxime improved the hemodynamics and 24-hour survival rate in rats with peritonitis-induced sepsis, but norepinephrine did not.

Dynamic FDG PET Imaging to Probe for Cardiac Metabolic Remodeling in Adults Born Premature

Individuals born very premature have an increased cardiometabolic and heart failure risk. While the structural differences of the preterm heart are now well-described, metabolic insights into the physiologic mechanisms underpinning this risk are needed. Here, we used dynamic fluorodeoxyglucose (FDG) positron emission tomography/magnetic resonance imaging (PET-MRI) in young adults born term and preterm during normoxic (N = 28 preterm; 18 term) and hypoxic exposure (12% O2; N = 26 preterm; 17 term) to measure the myocardial metabolic rate of glucose (MMRglc) in young adults born term (N = 18) and preterm (N = 32), hypothesizing that young adults born preterm would have higher rates of MMRglc under normoxic conditions and a reduced ability to augment glucose metabolism under hypoxic conditions. MMRglc was calculated from the myocardial and blood pool time-activity curves by fitting the measured activities to the 3-compartment model of FDG kinetics. MMRglc was similar at rest between term and preterm subjects, and decreased during hypoxia exposure in both groups (p = 0.02 for MMRglc hypoxia effect). There were no differences observed between groups in the metabolic response to hypoxia, either globally (serum glucose and lactate measures) or within the myocardium. Thus, we did not find evidence of altered myocardial metabolism in the otherwise healthy preterm-born adult. However, whether subtle changes in myocardial metabolism may preceed or predict heart failure in this population remains to be determined.

Effects of Regular Taekwondo Intervention on Health-Related Physical Fitness, Cardiovascular Disease Risk Factors and Epicardial Adipose Tissue in Elderly Women with Hypertension

Regular exercise has been proven to prevent hypertension and to help in the management of hypertension. There is a lack of studies examining changes in these issues as a result of Taekwondo training intervention. The aim of the current trial is to identify the effects of a regular Taekwondo (TKD) training program on health-related physical fitness (HRPF), cardiovascular disease (CVD) risk factors, inflammatory factors, and epicardial adipose tissue (EAT) in elderly women with hypertension. To accomplish this, 20 participants, who were older women with hypertension, were divided into a TKD group (n = 10) and a control group (n = 10). The TKD program was conducted in program for 90 min, three times a week, for 12 weeks. Outcomes, including body composition, blood pressure (BP), HRPF, cardiovascular risk factor and EAT, were measured before and after the Taekwondo program. The 12-week TKD program improved body composition, BP, HRPF, CVD risk factor, and EAT in elderly women with hypertension relative to controls. Meanwhile, EAT and interukin-1β (r = 0.530, p < 0.05), monocyte chemotactic protein-1 (r = 0.524, p < 0.05), triglyceride (r = 0.493, p < 0.05) and sedentary behavior (r = 0.459, p < 0.05) presented a positive correlation, while EAT and lean body mass (r = -0.453, p < 0.05) showed a negative correlation. The 12-week regular TKD training intervention was found to be effective in reducing the thickness of EAT measured by multi-detector computed tomography and can also enhance health-related physical fitness and risk factors of CVD in older individuals with hypertension.

Resting Energy Expenditure: From Cellular to Whole-Body Level, a Mechanistic Historical Perspective

The basis of heat generated by the human body has been a source of speculation and research for more than 2,000 years. Basal heat production, now usually referred to as resting energy expenditure (REE), is currently recognized as deriving from biochemical reactions at subcellular and cellular levels that are expressed in the energy expended by the body's 78 organs and tissues. These organs and tissues, and the 11 systems to which they belong, influence body size and shape. Connecting these subcellular-/cellular-level reactions to organs and tissues, and then on to body size and shape, provides a comprehensive understanding of individual differences in REE, a contemporary topic of interest in obesity research and clinical practice. This review critically examines these linkages, their association with widely used statistical and physiological REE prediction formulas, and often-unappreciated aspects of measuring basal heat production in humans.

Liraglutide to Improve corONary haemodynamics during Exercise streSS (LIONESS): a double-blind randomised placebo-controlled crossover trial

BACKGROUND

Glucagon-like peptide-1 receptor (GLP-1R) activation may improve myocardial performance in the context of ischaemia, independent of glycaemic control, in individuals with and without type 2 diabetes mellitus.

METHODS

The LIONESS trial was a single-centre randomised double-blind placebo-controlled crossover study to determine whether prolonged GLP-1R activation could improve exercise haemodynamics in chronic stable angina patients. Eligibility criteria comprised angiographic evidence of obstructive coronary artery disease (CAD) and an abnormal baseline exercise tolerance test (ETT) demonstrating > 0.1 mV of planar or downsloping ST-segment depression (STD). Those randomised to active agent started with a 1-week run-in phase of 0.6 mg liraglutide daily, an established injectable GLP-1R agonist, followed by 1 week of 1.2 mg liraglutide, after which patients performed a week 2 ETT. Patients then self-administered 1.8 mg liraglutide for a week before completing a week 3 ETT. The placebo arm received visually and temporally matched daily saline injections. Participants then crossed over to a 3-week course of saline injections interspersed with a week 5 ETT and week 6 ETT and vice versa. Co-primary endpoints were rate pressure product (RPP) at 0.1 mV STD and magnitude of STD at peak exercise.

RESULTS

Twenty-two patients (21 without diabetes) were randomised. There was no significant difference between saline versus liraglutide in the co-primary endpoints of RPP achieved at 0.1 mV STD (saline vs. liraglutide 1.2 mg p = 0.097; saline vs. liraglutide 1.8 mg p = 0.48) or the degree of STD at peak exercise (saline vs. liraglutide 1.2 mg p = 0.68; saline vs. liraglutide 1.8 mg p = 0.57). Liraglutide did not cause symptomatic hypoglycaemia, renal dysfunction, acute pancreatitis or provoke early withdrawal from the trial. Liraglutide significantly reduced weight (baseline 88.75 ± 16.5 kg vs. after liraglutide 87.78 ± 16.9 kg; p = 0.0008) and improved the lipid profile (mean total cholesterol: at baseline 3.97 ± 0.88 vs. after liraglutide 3.56 ± 0.71 mmol/L; p < 0.0001).

CONCLUSION

Liraglutide did not enhance exercise tolerance or haemodynamics compared with saline placebo during serial treadmill testing in patients with established obstructive CAD. It did, however, significantly reduce weight and improve the lipid profile. Trial Registration ClinicalTrials.gov Identifier NCT02315001. Retrospectively registered on 11th December 2014.

Eccentric Left Ventricular Hypertrophy and Left and Right Cardiac Function in Chronic Heart Failure with or without Coexisting COPD: Impact on Exercise Performance

Aim

Our aim was to assess: 1) the impact of the eccentric left ventricular hypertrophy (ELVH) on exercise performance in patients diagnosed with chronic heart failure (CHF) alone and in patients with co-existing CHF and chronic obstructive pulmonary disease (COPD) and 2) the relationship between left and right cardiac function measurements obtained by doppler echocardiography, clinical characteristics and primary measures of cardiorespiratory fitness.

Methods

The current study included 46 patients (CHF:23 and CHF+COPD:23) that performed advanced pulmonary function tests, echocardiography and symptom-limited, incremental cardiopulmonary exercise testing (CPET) on a cycle ergometer.

Results

Patients with CHF+COPD demonstrated a lower work rate, peak oxygen uptake (VO₂), oxygen pulse, rate pressure product (RPP), circulatory power (CP) and ventilatory power (VP) compared to those only diagnosed with CHF. In addition, significant correlations were observed between VP and relative wall thickness (r: 0.45 p: 0.03),V_E/VCO₂ intercept and Mitral E/e' ratio (r: 0.70 p: 0.003) in the CHF group. Significant correlations were found between indexed left ventricle mass and RPP (r: -0.47; p: 0.02) and relative VO₂ and right ventricle diameter (r: -0.62; p: 0.001) in the CHF+COPD group.

Conclusion

Compared to a diagnosis of CHF alone, a combined diagnosis of CHF+COPD induced further impairments in cardiorespiratory fitness. Moreover, echocardiographic measures of cardiac function are related to cardiopulmonary exercise performance and therefore appear to be an important therapeutic target when attempting to improve exercise performance and functional capacity.

Myocardial mechano-energetic efficiency in primary aldosteronism

BACKGROUND

Available data indicate that patients with primary aldosteronism have an increased risk of cardiovascular events and cardiovascular risk seems to be, at least in part, independent of blood pressure (BP) values. Patients with primary aldosteronism have a greater prevalence of left ventricular (LV) hypertrophy and subtle alterations of ventricular function, which might contribute to the increase in cardiovascular risk. Recently, a noninvasive approach for the estimation of LV mechanical efficiency, obtained by echocardiography has been proposed.

AIM OF THE STUDY

To evaluate the determinants of myocardial mechanoenergetic efficiency index (MEEi), in a large group of patients with primary aldosteronism (n = 99) and in a control group of essential hypertensive patients (n = 99) matched for age, sex and BP values.

RESULTS

No differences between groups for age, sex, BMI, BP values, glucose, lipid profile and renal function were observed. LV mass index was greater in primary aldosteronism vs. essential hypertensive patients (46.0 ± 16.7 vs. 36.9 ± 8.6 g/m2, P < 0.001); also relative wall thickness was greater in primary aldosteronism (0.36 ± 0.1 vs. 0.32 ± 0.4, P < 0.001). Left atrial dimensions were significantly greater in primary aldosteronism. Ejection fraction was not different between groups, while endocardial and midwall fractional shortening were lower in primary aldosteronism vs. essential hypertensive patients (40 ± 7 vs. 43 ± 6, and 18 ± 3 vs. 21 ± 2, both P < 0.01). MEEi was lower in primary aldosteronism vs. essential hypertensive patients (0.44 ± 0.14 vs. 0.52 ± 0.10 ml/s per g, P < 0.01). A negative correlation was observed between MEEi and aldosterone levels (r = -0.203, P < 0.05) and aldosterone : renin ratio (P = -0.172, P < 0.05); the correlation remained significant after adjustment for possible confounders.

CONCLUSION

In patients with primary aldosteronism myocardial MEEi is lower as compared with essential hypertensive patients. A reduced MEEi may reflect an impairment of production and utilization of energy in the myocardium, which could lead to the occurrence of cardiovascular complications and therefore these findings may contribute to explain the increased risk of cardiovascular events in patients with primary aldosteronism.

Nonalcoholic fatty liver disease is associated with a decreased myocardial mechano-energetic efficiency

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is linked to a raised risk of cardiovascular diseases (CVD), although the underlying mechanisms are not completely known. A reduced myocardial mechano-energetic efficiency (MEE) has been found to be an independent predictor of CVD.

OBJECTIVE

To evaluate the association between NAFLD and a compromised MEE.

METHODS

Myocardial MEE was assessed by a validated echocardiography-derived measure in 699 nondiabetic individuals subdivided into two groups according to ultrasonography defined presence of NAFLD.

RESULTS

Subjects with NAFLD displayed higher levels of systolic (SBP) and diastolic blood pressure (DBP), triglycerides, fasting and postload glucose, high-sensitivity C-reactive protein (hsCRP), insulin resistance (IR) estimated by HOMA-IR and liver IR index, and lower values of high-density lipoprotein (HDL) in comparison with those without NAFLD. Presence of NAFLD was associated with increased levels of myocardial oxygen demand and reduced values of MEE. MEE was negatively correlated with male sex, age, BMI, waist circumference, SBP, DBP, total cholesterol, triglycerides, fasting and postload glucose, HOMA-IR and liver IR index, hsCRP and positively with HDL levels. In a multivariable regression analysis, presence of NAFLD was associated with MEE regardless of several cardio-metabolic risk factors such as age, gender, waist circumference, SBP, DBP, total and HDL cholesterol, triglycerides, glucose tolerance and hsCRP (β = -0.09, P = 0.04), but not independently of IR estimates.

CONCLUSION

Ultrasound-defined presence of NAFLD is associated with a decreased MEE, a predictor of adverse cardiovascular events. The relationship between NAFLD and a compromised MEE is dependent of IR.

Sex-Specific Associations Between Cardiac Workload, Peripheral Vascular Calcification, and Bone Mineral Density: The Gambian Bone and Muscle Aging Study

Noncommunicable diseases (NCD) are rapidly rising in Africa, with multimorbidity increasing the burden on health and social care. Osteoporosis and cardiovascular disease (CVD) share common risk factors; both often remain undiagnosed until a major life-threatening event occurs. We investigated the associations between cardiac workload, peripheral vascular calcification (PVC), and bone parameters in Gambian adults. The Gambian Bone and Muscle Aging Study (GamBAS) recruited 249 women and 239 men aged 40 to 75+ years. Body composition and areal bone mineral density (aBMD) were measured using dual-energy X-ray absorptiometry; peripheral quantitative computed tomography (pQCT) scans were performed at the radius and tibia. Supine blood pressure and heart rate were measured and used to calculate rate pressure product and pulse pressure. Presence of PVC was determined from tibia pQCT scans. Sex interactions were tested (denoted as p-int); adjustments were made for residuals of appendicular lean mass (ALM) and fat mass (FM). There were negative associations between rate pressure product and aBMD in women only, all p-int < .05; after adjustment for ALM residuals, for every 10% increase in rate pressure product, aBMD was lower at the whole body (-0.6% [-1.2, -0.1]), femoral neck (-0.9% [-1.8, -0.05]), L1 to L4 (-0.6% [-1.7, 0.5]), and radius (-1.9% [-2.8, -0.9]); there were similar associations when adjusted for FM residuals. Similar negative associations were found between pulse pressure and aBMD in women only. PVC were found in 26.6% men and 22.5% women; women but not men with calcification had poorer cardiac health and negative associations with aBMD (all sites p-int < .001). There were consistent associations with cardiac parameters and pQCT outcomes at the radius and tibia in women only. Multiple markers of cardiac health are associated with poorer bone health in Gambian women. In the context of epidemiological transition and changing NCD burden, there is a need to identify preventative strategies to slow/prevent the rising burden in CVD and osteoporosis in Sub-Saharan Africa. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Improved haemodynamic stability and cerebral tissue oxygenation after induction of anaesthesia with sufentanil compared to remifentanil: a randomised controlled trial

BACKGROUND

Balanced anaesthesia with propofol and remifentanil, compared to sufentanil, often decreases mean arterial pressure (MAP), heart rate (HR) and cardiac index (CI), raising concerns on tissue-oxygenation. This distinct haemodynamic suppression might be attenuated by atropine. This double blinded RCT, investigates if induction with propofol-sufentanil results in higher CI and tissue-oxygenation than with propofol-remifentanil and if atropine has more pronounced beneficial effects on CI and tissue-oxygenation in a remifentanil-based anaesthesia.

METHODS

In seventy patients scheduled for coronary bypass grafting (CABG), anaesthesia was induced and maintained with propofol target controlled infusion (TCI) with a target effect-site concentration (Cet) of 2.0 μg ml- 1 and either sufentanil (TCI Cet 0.48 ng ml- 1) or remifentanil (TCI Cet 8 ng ml- 1). If HR dropped below 60 bpm, methylatropine (1 mg) was administered intravenously. Relative changes (∆) in MAP, HR, stroke volume (SV), CI and cerebral (SctO2) and peripheral (SptO2) tissue-oxygenation during induction of anaesthesia and after atropine administration were analysed.

RESULTS

The sufentanil group compared to the remifentanil group showed significantly less decrease in MAP (∆ = - 23 ± 13 vs. -36 ± 13 mmHg), HR (∆ = - 5 ± 7 vs. -10 ± 10 bpm), SV (∆ = - 23 ± 18 vs. -35 ± 19 ml) and CI (∆ = - 0.8 (- 1.5 to - 0.5) vs. -1.5 (- 2.0 to - 1.1) l min- 1 m- 2), while SctO2 (∆ = 9 ± 5 vs. 6 ± 4%) showed more increase with no difference in ∆SptO2 (∆ = 8 ± 7 vs. 8 ± 8%). Atropine caused higher ∆HR (13 (9 to 19) vs. 10 ± 6 bpm) and ∆CI (0.4 ± 0.4 vs. 0.2 ± 0.3 l min- 1 m- 2) in sufentanil vs. remifentanil-based anaesthesia, with no difference in ∆MAP, ∆SV and ∆SctO2 and ∆SptO2.

CONCLUSION

Induction of anaesthesia with propofol and sufentanil results in improved haemodynamic stability and higher SctO2 compared to propofol and remifentanil in patients having CABG. Administration of atropine might be useful to counteract or prevent the haemodynamic suppression associated with these opioids.

TRIAL REGISTRATION

Clinicaltrials.gov on June 7, 2013 (trial ID: NCT01871935 ).

Impact of complex congenital heart disease on the prevalence of arterial hypertension after aortic coarctation repair

OBJECTIVES

This study was designed to evaluate the difference in the prevalence of long-term arterial hypertension among patients with corrected aortic coarctation according to the existence of associated cardiac congenital lesions.

METHODS

We identified 235 patients who had undergone surgery for aortic coarctation and classified them into 2 groups: patients with isolated coarctation of the aorta (CoA) and patients with aortic coarctation associated with complex congenital heart disease. Data were retrospectively analysed.

RESULTS

There were 148 subjects with isolated CoA and 87 with complex CoA (CoA-c). Patients were defined as hypertensive if they required antihypertensive treatment and/or when blood pressure was above 95th percentile. Patients with isolated aortic coarctation were significantly younger than patients with CoA-c (P < 0.001) and a markedly higher prevalence of arterial hypertension (44% vs 24%) was documented in the isolated coarctation group. The difference in the prevalence of hypertension in the 2 groups was still significant after correcting for differences in age (P < 0.001), confirming that the prevalence of arterial hypertension in patients with CoA-c was half of that of patients with isolated CoA.

CONCLUSIONS

We conclude that complex congenital heart disease in patients who have undergone surgical correction for aortic coarctation results in a significantly lower prevalence of late-onset hypertension. Reduced systemic flow and pressure before surgery in patients with CoA-c might be associated with a lower rate of arterial hypertension.

The Vicious Circle of Left Ventricular Dysfunction and Diabetes: From Pathophysiology to Emerging Treatments

CONTEXT

Diabetes and heart failure (HF) are 2 deadly and strictly related epidemic disorders. The aim of this review is to present an updated discussion of the epidemiology, pathophysiology, clinical presentation and treatment options for HF in diabetes.

EVIDENCE ACQUISITION

Relevant references published up to February 2020 were identified through searches in PubMed. Quality was graded using the Newcastle-Ottawa score in observational studies and the Cochrane Collaboration tool in randomized studies.

EVIDENCE SYNTHESIS

Metabolic and neurohumoral derangements, oxidative stress, inflammation, micro- and macroangiopathy all contribute through complex molecular and cellular mechanisms to cardiac dysfunction in diabetes, which in turn, results as one the most frequent underlying conditions affecting up to 42% of patients with HF and causing a 34% increased risk of cardiovascular death. On top of traditional guideline-based HF medical and device therapies, equally effective in patients with and without diabetes, a new class of glucose-lowering agents acting through the sodium-glucose cotransporter 2 (SGLT2) inhibition showed impressive results in reducing HF outcomes in individuals with diabetes and represents an active area of investigation.

CONCLUSIONS

Diabetes and HF are strictly linked in a bidirectional and deadly vicious circle difficult to break. Therefore, preventive strategies and a timely diagnosis are crucial to improve outcomes in such patients. SGLT2 inhibitors represent a major breakthrough with remarkably consistent findings. However, it is still not clear whether their benefits may be definitely extended to patients with HF with preserved ejection fraction, to those without diabetes and in the acute setting.

Rate Pressure Products Affect the Relationship between the Fractional Flow Reserve and Instantaneous Wave-Free Ratio

The rate pressure product (RPP) is an index of myocardial metabolism that correlates closely with myocardial hemodynamics. The relationship between the RPP and the fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) is not known. In this study, we investigated the effects of the RPP on the FFR and iFR. We retrospectively enrolled 195 patients (259 lesions) who had undergone invasive coronary angiography and both the iFR and FFR examinations between 2012 and 2017. The RPP was defined as systolic blood pressure multiplied by the heart rate, measured prior to the iFR evaluation. The study population was divided into the low-RPP (n = 129, mean RPP: 6981 ± 1149) and high-RPP (n = 130, mean RPP: 10391 ± 1603) groups according to the median RPP. Correlations and biases between the iFR and FFR were compared. The diagnostic performance of the iFR in the groups was calculated, using FFR as the gold standard. The correlation between the iFR and FFR was higher in the high-RPP group than in the low-RPP group. The bias between the iFR and FFR in the high-RPP group was smaller than that in the low-RPP group. The best cutoff value of the iFR for predicting an FFR of 0.8 was 0.90 for all lesions, 0.93 for the low-RPP group, and 0.82 for the high-RPP group. The iFR and RPP showed a weak but a statistically significant negative correlation (R = 0.14; p = 0.029). This was not observed for the relationship between the FFR and RPP. In conclusion, the RPP affects the relationship between the FFR and iFR. With FFR as the gold standard, the iFR may underestimate and overestimate the functionality of ischemia in the low- and high-RPP groups, respectively.

Comparison of Orotracheal versus Nasotracheal Fiberoptic Intubation Using Hemodynamic Parameters in Patients with Anticipated Difficult Airway

Background:

Both nasal and oral routes can be used for fiberoptic intubation. Often it leads to hemodynamic disturbances, which may have a significant effect in patients with limited cardiopulmonary reserve as well as with cerebrovascular diseases.

Aims:

The aim of the study was to evaluate whether there is a clinically relevant difference between the circulatory responses to oral and nasal fiberoptic intubation.

Settings and Design:

This was a prospective, randomized, and comparative study.

Materials and Methods:

In this study, a total of 90 patients with the American Society of Anesthesiologist physical status I and II of either sex in the age group of 18–60 years and having anticipated difficult airway (DA) posted for elective surgery under general anesthesia were randomly allocated into two groups. Patients underwent fiberoptic intubation via either oral or nasal route under sevoflurane anesthesia with bispectral index guidance. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), time taken to intubation, and need of maneuver were measured.

Statistical Analysis Used:

All the analyses were carried out on SPSS 16.0 version (Inc., Chicago, USA). Mean and standard deviation were calculated. The test of analysis between two groups was done by unpaired t-test.

Results:

Demographic and DA characteristics were similar in both the groups. Significantly (P < 0.01) lesser alteration in HR, SBP, DBP, and MAP was seen in oral fiberoptic intubation when compared to nasal fiberoptic intubation in the early phase of postintubation. Time taken to intubation was also significantly (P < 0.01) lesser in the oral route compared to the nasal route.

Conclusions:

Oral fiberoptic intubation causes less hemodynamic alteration and takes less time in comparison to nasal fiberoptic intubation.

The Pharmacodynamic Effects of a Dopamine-Somatostatin Chimera Agonist on the Cardiovascular System

The quantification of the effect of pharmacological treatment on the cardiovascular system is complicated because of the high level of interindividual and circadian variability. Recently, a dopamine-somatostatin chimera, BIM23B065, was under investigation to concurrently target the somatostatin and dopamine D2 receptors for the treatment of neuroendocrine tumors. However, both dopamine and somatostatin interact with different components of the cardiovascular system. This study established the response of the heart rate and the systolic blood pressure after administration of BIM23B065 in healthy male volunteers by analysis of the rate-pressure product (RPP), in a model-informed analysis. The RPP in the supine position of placebo-treated subjects showed a clear circadian component, best described by 2 cosine functions. The pharmacokinetics of BIM23B065 and its metabolite were best described using 2-compartment models with different forms of elimination kinetics. The administration of BIM23B065 gave a statistically significant reduction in the RPP, after which the effect diminished because of the tolerance to the cardiovascular effects after prolonged exposure to BIM23B065. This model provided insight in the circadian rhythm of the RPP in the supine position and the level of interindividual variability in healthy male volunteers. The developed population pharmacokinetic/pharmacodynamic model quantified the interaction between BIM23B065 and the RPP, informing on the clinical pharmacological properties of BIM23B065.

Frailty as Tested by Gait Speed Is a Risk Factor for Liver Transplant Respiratory Complications

OBJECTIVES

Frailty and sarcopenia are known risk factors for adverse liver transplant outcomes and mortality. We hypothesized that frailty or sarcopenia could identify the risk for common serious transplant-related adverse respiratory events.

METHODS

For 107 patients (74 men, 33 women) transplanted over 1 year, we measured frailty with gait speed, chair stands, and Karnofsky Performance Scale (KPS) and sarcopenia with Skeletal Muscle Index on computed tomography at L3. We recorded the stress-tested cardiac double product as an index of cardiac work capacity. Outcomes included days of intubation, aspiration, clinical pneumonia, reintubation/tracheostomy, days to discharge, and survival. We modeled the outcomes using unadjusted regression and multivariable analyses controlled for (i) age, sex, and either Model for End-Stage Liver Disease-Na (MELDNa) or Child-Turcotte-Pugh scores, (ii) hepatocellular carcinoma status, and (iii) chronic obstructive pulmonary disease and smoking history. Subgroup analysis was performed for living donor liver transplant and deceased donor liver transplant recipients.

RESULTS

Gait speed was negatively associated with aspiration and pulmonary infection, both in unadjusted and MELDNa-adjusted models (adjusted odds ratio for aspiration 0.10 [95% confidence interval [CI] 0.02-0.67] and adjusted odds ratio for pulmonary infection 0.12 [95% CI 0.02-0.75]). Unadjusted and MELDNa-adjusted models for gait speed (coefficient -1.47, 95% CI -2.39 to -0.56) and KPS (coefficient -3.17, 95% CI -5.02 to -1.32) were significantly associated with shorter intubation times. No test was associated with length of stay or need for either reintubation or tracheostomy.

DISCUSSION

Slow gait speed, an index of general frailty, indicates significant risk for post-transplant respiratory complications. Intervention to arrest or reverse frailty merits exploration as a potentially modifiable risk factor for improving transplant respiratory outcomes.

Compound Danshen Dripping Pill Promotes Adaptation to Acute High-Altitude Exposure

Li, Zongbin, Jun Guo, Chunwei Liu, Yajun Shi, Yang Li, Jinli Wang, Dandan Li, Jing Wang, and Yundai Chen. Compound Danshen Dripping Pill promotes adaptation to acute high-altitude exposure. High Alt Med Biol. 21:258-264, 2020. Background: In this study, we aimed to investigate whether the traditional Chinese medicine, Compound Danshen Dripping Pill (CDDP), can prevent acute mountain sickness (AMS). We allocated CDDP and matching placebos to 160 volunteers before they ascended to a high altitude. Treadmill exercise tests, echocardiography, blood routine examinations, biochemical analysis, and blood gas analysis were performed upon arrival at high altitude. The primary outcome included incidence of AMS, exercise times, and metabolic equivalents (METs) of treadmill exercise tests. Second endpoints included the heart rates and rate-pressure product (RPP) before and after treadmill exercise tests. Results: After high-altitude exposure, the incidence of AMS in the CDDP group was lower than that in the placebo group (48.6% vs. 67.6%, p = 0.022). The exercise time of the treadmill exercise test was significantly longer (507 ± 77.9 seconds vs. 457 ± 90.8 seconds, p = 0.004), the heart rate was lower (pre-exercise: 91.8 ± 11.7 beats/min vs. 97.2 ± 12.7 beats/min, p = 0.016; postexercise: 114 ± 22.2 beats/min vs. 121 ± 22.6 beats/min, p = 0.019), the pre-exercise and postexercise RPP were lower (pre-exercise: 1.13 × 10⁴ ± 1.68 × 10³ mmHg·beats/min vs. 1.23 × 10⁴ ± 1.84 × 10³ mmHg·beats/min, p = 0.027; postexercise: 1.19 × 10⁴ ± 1.75 × 10³ mmHg·beats/min vs. 1.31 × 10⁴ ± 2.00 × 10³ mmHg·beats/min, p = 0.002), and the MET value of the treadmill exercise test was significantly higher (9.93 ± 1.18 METs vs. 9.31 ± 1.52 METs, p = 0.037) in the CDDP group. Discussion: CDDP decreases the incidence of AMS and enhances exercise tolerance greater than placebo after high-altitude exposure. CDDP decreases the heart rate and myocardial oxygen consumption, increases the levels of hemoglobin, hematocrit, and antioxidant factors, and decreases the levels of inflammatory factors, which may explain the roles of CDDP in improving the adaptation to high-altitude exposure.

Chronic mirabegron treatment increases human brown fat, HDL cholesterol, and insulin sensitivity

BACKGROUNDMirabegron is a β3-adrenergic receptor (β3-AR) agonist approved only for the treatment of overactive bladder. Encouraging preclinical results suggest that β3-AR agonists could also improve obesity-related metabolic disease by increasing brown adipose tissue (BAT) thermogenesis, white adipose tissue (WAT) lipolysis, and insulin sensitivity.METHODSWe treated 14 healthy women of diverse ethnicities (27.5 ± 1.1 years of age, BMI of 25.4 ± 1.2 kg/m2) with 100 mg mirabegron (Myrbetriq extended-release tablet, Astellas Pharma) for 4 weeks in an open-label study. The primary endpoint was the change in BAT metabolic activity as measured by [18F]-2-fluoro-d-2-deoxy-d-glucose (18F-FDG) PET/CT. Secondary endpoints included resting energy expenditure (REE), plasma metabolites, and glucose and insulin metabolism as assessed by a frequently sampled intravenous glucose tolerance test.RESULTSChronic mirabegron therapy increased BAT metabolic activity. Whole-body REE was higher, without changes in body weight or composition. Additionally, there were elevations in plasma levels of the beneficial lipoprotein biomarkers HDL and ApoA1, as well as total bile acids. Adiponectin, a WAT-derived hormone that has antidiabetic and antiinflammatory capabilities, increased with acute treatment and was 35% higher upon completion of the study. Finally, an intravenous glucose tolerance test revealed higher insulin sensitivity, glucose effectiveness, and insulin secretion.CONCLUSIONThese findings indicate that human BAT metabolic activity can be increased after chronic pharmacological stimulation with mirabegron and support the investigation of β3-AR agonists as a treatment for metabolic disease.TRIAL REGISTRATIONClinicaltrials.gov NCT03049462.FUNDINGThis work was supported by grants from the Intramural Research Program of the NIDDK, NIH (DK075112, DK075116, DK071013, and DK071014).

Exercise-based cardiac rehabilitation for postcoronary artery bypass grafting and its effect on hemodynamic responses and functional capacity evaluated using the Incremental Shuttle Walking Test: A retrospective pilot analysis

BACKGROUND

Coronary artery bypass grafting (CABG) is a common surgical procedure for the restoration of blood flow into stenotic or blocked coronary arteries. Cardiac rehabilitation has been implemented to some extent worldwide for the management of postoperative CABG. However, studies about the effect of exercise training on hemodynamic responses of the heart using the Incremental Shuttle Walking (ISWT) test are limited in Saudi Arabia.

OBJECTIVES

To investigate the effect of exercise-based cardiac rehabilitation (Phase 3, hospital-based) on some hemodynamic responses including blood pressure, heart rate (HR) and heart rate recovery (HRR), and rate pressure product (RPP) using ISWT on post-CABG patients.

METHODS

Fifteen CABG (51.4 ± 6.4 years, 14 male, 1 female) patients without altering their medication were enrolled in a hospital-based cardiac rehabilitation program (Phase 3) between 2011 and 2012 for supervised individual exercise training sessions (three times per week for 8 weeks; 60-minute session at a moderate intensity). Patients performed two tests (ISWT1 and ISWT2) and one before exercise training program and one after, during which resting systolic blood pressure (SBP) and diastolic blood pressure (DBP), post-ISWT SBP and DBP, resting HR, peak HR, HRR (which was defined as the absolute change from peak HR to 1-minute post peak HR), and RPP at rest and at the end of the ISWT were measured. Exercise training sessions included both aerobic and resistance exercises, which were preceded by a cooling down period and followed by a recovery period.

RESULTS

Paired t-test showed a significant reduction in both resting SBP (p = 0.04) and DBP (p = 0.03), and a significant increase in post-ISWT2 SBP (p = 0.004), peak HR (p = 0.003), HRR (p = 0.03), and RPP at maximum (p = 0.002) after 8 weeks of supervised exercise training. In addition, there was a significant increase in the speed and distance achieved on ISWT2 (p < 0.001) after the training program.

CONCLUSION

Supervised exercise training (cardiac rehabilitation) for 8 weeks was effective in improving hemodynamic responses and functional exercise capacity in CABG patients. Cardiac rehabilitation should be implemented more frequently and health-care providers should be aware of its importance. Further research is needed in this area to confirm these findings in the region.

Relationship of stroke volume to different patterns of Cheyne-Stokes respiration in heart failure

STUDY OBJECTIVES

In patients with heart failure (HF) and reduced left ventricular ejection fraction (HFrEF), stroke volume (SV) falls during hyperpnea of Cheyne-Stokes respiration with central sleep apnea (CSR-CSA). We have identified two distinct patterns of hyperpnea: positive, in which end-expiratory lung volume (EELV) remains at or above functional residual capacity (FRC), and negative, in which EELV falls below FRC. The increase in expiratory intrathoracic pressure generated by the latter should have effects on the heart analogous to external chest compression. To test the hypotheses that in HFrEF patients, CSR-CSA with the negative pattern has an auto-resuscitation effect such that compared with the positive pattern, it is associated with a smaller fall in SV and a smaller increase in cardiac workload (product of heart rate and systolic blood pressure).

METHODS

In 15 consecutive HFrEF patients with CSR-CSA during polysomnography, hemodynamic data derived from digital photoplethysmography during positive and negative hyperpneas were compared.

RESULTS

Compared to the positive, negative hyperpneas were accompanied by reductions in the maximum and mean relative fall in SV of 30% (p = 0.002) and 10% (p = 0.031), respectively, and by reductions in the degree of increases in heart rate and rate pressure product during hyperpnea of 46% (p < 0.001) and 13% (p = 0.007), respectively.

CONCLUSIONS

Our findings suggest the novel concept that the negative pattern of CSR-CSA may constitute a form of auto-resuscitation that acts as a compensatory mechanism to maintain SV in patients with severe HF.

Comparison between ticagrelor and clopidogrel on myocardial blood flow in patients with acute coronary syndrome, using 13 N-ammonia positron emission tomography

BACKGROUND

The PLEIO (comParison of ticagreLor and clopidogrEl on mIcrocirculation in patients with acute cOronary syndrome) study showed that 6 months of ticagrelor therapy significantly improved microvascular dysfunction in acute coronary syndrome (ACS) patients with stent implantation compared to clopidogrel. Improved microvascular function may affect myocardial blood flow (MBF). We compared the effects of ticagrelor and clopidogrel on MBF over a 6-month follow-up period among patients diagnosed with ACS treated with percutaneous coronary intervention (PCI).

METHODS

In the PLEIO trial, 120 participants were randomized to receive ticagrelor 90 mg twice daily or clopidogrel 75 mg once daily after at least 6 months. 13 N-ammonia positron emission tomography (PET) imaging was performed in 94 patients to measure MBF at the 6-month follow-up visit.

RESULTS

On a per-patient level, MBF (1.88 ± 0.52 versus 1.67 ± 0.64 mL/min per gram, P = .01) was significantly higher with ticagrelor compared with clopidogrel in the hyperemic state, but not under resting state (0.75 ± 0.24 versus 0.75 ± 0.19 mL/min per gram, P = .84). On a culprit-vessel analysis, the resting MBF was similar (0.69 ± 0.20 versus 0.70 ± 0.21, P = .89) between the two groups. However, the hyperemic MBF and myocardial flow reserve in the ticagrelor group were significantly higher compared with clopidogrel (1.75 ± 0.46 versus 1.52 ± 0.59, P = .03 and 2.71 ± 0.89 versus 2.20 ± 0.81, P = .02, respectively). These differences were not observed in non-culprit vessels.

CONCLUSIONS

Maintenance treatment of ticagrelor increased the hyperemic MBF and myocardial flow reserve compared with clopidogrel.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02618733.

Evaluation of a risk index for predicting short-term and long-term outcomes in patients with ST-elevation myocardial infarction

OBJECTIVE

This study aimed to evaluate the usefulness of the admission risk index (RI) to predict short-term and long-term outcomes in a broad population with ST-elevation myocardial infarction (STEMI) using data from the Chinese Acute Myocardial Infarction Registry.

BACKGROUND

The RI was developed as a simple tool to predict risk of death in STEMI patients. The performance in predicting short-term and long-term risk of death in Chinese patients receiving percutaneous coronary intervention and conservative treatment for STEMI remains unclear.

METHODS

Age, heart rate (HR), and systolic blood pressure (SBP) were used to calculate RI using (HR×[age/10]² )/SBP. We used the prediction tool to predict mortality over 12 months.

RESULTS

The C-index of the admission RI for predicting in-hospital, 1-, 6-, and 12-months mortality were 0.78, 0.78, 0.78, and 0.77, respectively, compared with 0.75 of the Global Registry in Acute Coronary Events score. Based on the receiver operating characteristic curve analysis, the RI was categorized into quintiles for convenient clinical use, and it revealed a nearly 15-fold gradient of increasing mortality from 2.29 to 32.5% (p < .0001) while RI >34 had the highest mortality. By categorizing into five different risk groups, the short-term and long-term mortality of patients receiving different treatments could be distinguished.

CONCLUSIONS

RI based on three routine variables and easily calculated by any medical practitioner is useful for predicting in-hospital and long-term mortality in patients with STEMI at the initial consultation with clinicians.

Thermoregulatory and cardiovasculareffects of capsaicin application on human skin during dynamic exercise to temperate and warm conditions

Thermoregulatory and cardiovascular responses during cycling in temperate and warm environments without and with application of capsaicin on the skin were investigated. We hypothesized that regardless of environmental temperature, capsaicin application would activate heat loss mechanisms attenuating exercise‐induced rectal temperature (Tre) and blood pressure increase. Eight males cycled at 55% of their maximal aerobic power so long as to reach 38.2°C Tre at 20.8 ± 1.0°C and at 30.6 ± 1.1°C ambient temperatures twice: without (NCA) and with (CA) application of capsaicin patches (12 × 18 cm, 4.8 mg). Patches were applied on pectoralis major, trapezius and vastus lateralis muscles. Thermoregulatory (Tre, proximal‐distal skin temperature gradient, sweating rate), cardiovascular variables and oxygen uptake were continuously recorded. In both ambient conditions, during the first 14 min of exercise, the local vasoconstrictive tone as a function of the relative change in Tre was lower in CA than NCA (p < .05, d = 0.84–1.15). Further, sweating rate was higher and occurred at a lower Tre increase in CA compared to NCA (p = .03, d = 0.6) resulting in extended time to reach 38.2°C Tre (p = .03, d = 0.9). Moreover, oxygen consumption was higher in CA than in NCA (p < .001, d = 0.8). Mean arterial pressure was lower during cycling in warm compared to temperate environment, but was unaffected by capsaicin. We conclude that activation of thermal sensors by capsaicin results in lower Tre rise during exercise, which is mediated through greater skin vasodilation along with higher rate and earlier onset of sweating. Nonetheless, capsaicin application has no extra effect on exercise cardiovascular responses.

A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Effectiveness of a Food Supplement Containing Creatine and D-Ribose Combined with a Physical Exercise Program in Increasing Stress Tolerance in Patients with Ischemic Heart Disease

The aim of this study is to establish whether a supplement of creatine and ribose combined with a physical exercise program can improve the total work capacity during exercise in a population of patients with known ischemic heart disease. A double-blind, six-month study was designed in which 53 patients were enrolled and randomized to take either a nutraceutical composition containing creatine, D-ribose, vitamin B₁, and vitamin B₆ (active treatment) or the placebo. Both the nutraceutical supplement and the placebo were supplied by Giellepi S.p.A. Health Science in Lissone, Italy. After six months of study, the cardiac double product at the peak of the load, the delta double product, and the chronotropic index were higher in the active treatment group than in the placebo group. We can conclude that a supplementation with creatine, D-ribose, vitamin B₁, and vitamin B₆, in addition to standard therapy and a physical exercise program, seems to be helpful in improving exercise tolerance compared to the placebo in a population with cardiovascular disease. However, this needs to be further studied, given that there is no clear evidence that the double product can be used as a surrogate measure of exercise tolerance.

Cardiovascular Responses and Cardiac Work of Selected Daily Activities in Young Healthy Indian Participants

BACKGROUND

Studies suggest that habitual daily activities may result in significant cardiovascular responses that might have implications for individuals with coronary artery disease. This study determined the cardiac work for various activities of daily living among healthy young participants.

METHODS

We evaluated cardiovascular responses in 42 young adults (21 male, 21 female) to graded activities. Subjects were divided into three groups. In each group, one light, one moderate, and one heavy activity were performed based on published METS. Cardiovascular responses were evaluated using impedance cardiography (BOMED Instruments, USA) and automated blood pressure monitor (Welch Allyn, USA). Cardiac work was computed as the double product (heart rate × systolic blood pressure) and triple product (systolic blood pressure × cardiac output [stroke volume × heart rate]). Perceived exertion was evaluated using Borg's scale.

RESULTS

There was high inter-individual variability in cardiovascular responses for each activity. There were, by and large, no gender differences across the activities. Cardiac work was significantly higher with heavy activities than light activities using both indices; however, the triple product showed greater discriminatory ability in evaluating differences in cardiac work across all categories of activities.

CONCLUSION

The data suggest a need to develop a compendium of cardiac work related to habitual activities to guide doctors and patients.

Protective Effects of Dexmedetomidine and Oxycodone in Patients Undergoing Limb Ischemia-Reperfusion

Background

Tourniquet-related complications are a common clinical problem. In the present study, we compared the effects of dexmedetomidine vs. oxycodone in patients undergoing limb ischemia-reperfusion.

Material/Methods

Fifty-four patients undergoing unilateral lower-extremity surgery under combined spinal and epidural anesthesia were randomly assigned to a control (ischemia-reperfusion, I/R) group, a dexmedetomidine (Dex) group, and an oxycodone (Oxy) group. Tourniquet-induced hemodynamic parameters changes among groups were compared. The serum concentration of malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-a (TNF-α), interleukin-6 (IL-6), fatty acid binding protein 3 (FABP3), endothelin-1 (ET-1), and brain-derived neurotrophic factor (BDNF) were measured using ELISA before anesthesia and at 30 min and at 6 h after tourniquet release.

Results

In the control group, tourniquet use caused significant increases in systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), and rate-pressure product. Compared with Oxy, Dex significantly decreased heart rate (HR). Both Dex and Oxy lowered SAP compared with the control group. No significant difference was observed in DAP between Dex and Oxy. The levels of MDA, TNF-α, IL-6, FABP3, and ET-1 were significantly higher, while the SOD and BDNF were significantly lower compared to baseline in the I/R group, but the variation range of those agents was significantly smaller in the Dex and Oxy groups, and the measured values were comparable between the 2 groups.

Conclusions

Compared with Dex, Oxy was not inferior in mitigating tourniquet-induced hyperdynamic response, ameliorating the inflammatory reaction, and protecting remote multiple organs in lower-extremity surgery patients.

Ultrathin endoscopy versus computed tomography in the detection of anastomotic leak in the early period after esophagectomy

BACKGROUND

Anastomotic leak after esophagectomy is a major postoperative complication that leads to significant mortality. The aim of this study was to evaluate the safety of early postoperative ultrathin endoscopy in detecting anastomotic leaks and compare diagnostic performance of ultrathin endoscopy and computed tomography (CT) scan in identifying anastomotic leak after esophagectomy.

MATERIALS AND METHODS

A prospective trial of 71 patients undergoing esophagectomy was conducted between January 2016 to December 2017. A contrast CT was performed prior to ultrathin endoscopy on postoperative day 5-7.

RESULTS

All 71 patients underwent ultrathin endoscopy and CT scan safely without complications. Among the 71 patients, transoral ultrathin endoscopy was performed on 51 patients and 20 patients with hypertension and coronary artery disease received transnasal ultrathin endoscopy. Overall, 14 leaks (20%) were identified. Endoscopy not only correctly identified the 2 patients of false-positive evaluations by CT, but also determined 4 leaks that were missed on CT. In addition, ultrathin endoscopy accurately identified 3 potential leaks based on pathological findings of anastomosis: ischemia and much fibrin coverings. One patient with normal postoperative CT findings showed healthy anastomosis but an ulcer on gastric conduit on endoscopy. Both sensitivity and specificity of endoscopy were 100%, while sensitivity and specificity of CT were 71.4% and 96.5%.

CONCLUSIONS

Ultrathin endoscopy after esophagectomy is safe and provides more accurate and reliable identification of anastomotic leak than CT scan. Ultrathin transnasal endoscopy may be a more appropriate diagnostic test to detect anastomosis for patients with hypertension and coronary artery disease.