Chronotropic Incompetence in Parkinson's Disease: A Possible Marker of Severe Disease Phenotype?

Autonomic dysfunction is a prevalent feature of Parkinson's disease (PD), mediated by disease involvement of the autonomic nervous system. Chronotropic incompetence (CI) refers to inadequate increase of heart rate in response to elevated metabolic demand, partly dependent on postganglionic sympathetic tone. In a retrospective study, PD patients with/without CI were identified. We show that PD with CI was associated with a higher levodopa equivalent daily dose and Hoehn and Yahr stage, 5±2 years after motor onset. Our data support a putative role of CI as a clinical marker of a more severe disease phenotype, possibly reflecting more widespread alpha-synuclein pathology.

Acyl ghrelin increases cardiac output while preserving right ventricular-pulmonary arterial coupling in heart failure.

AIM: Acyl ghrelin increases cardiac output (CO) in heart failure with reduced ejection fraction (HFrEF). This could impair the right ventricular-pulmonary arterial coupling (RVPAC), both through an increased venous return and right ventricular afterload. We aim to investigate if acyl ghrelin increases CO with or without worsening the right-sided haemodynamics in HFrEF assessed by RVPAC. METHODS AND RESULTS: The Karolinska Acyl ghrelin Trial was a randomized double-blind placebo-controlled trial of acyl ghrelin versus placebo (120-min intravenous infusion) in HFrEF. RVPAC was assessed echocardiographically at baseline and 120 min. ANOVA was used for difference in change between acyl ghrelin versus placebo, adjusted for baseline values. Of the 30 randomized patients, 22 had available RVPAC (acyl ghrelin n = 12, placebo n = 10). Despite a 15% increase in CO in the acyl ghrelin group (from 4.0 (3.5-4.6) to 4.6 (3.9-6.1) L/min, P = 0.003), RVPAC remained unchanged; 5.9 (5.3-7.6) to 6.3 (4.8-7.5) mm·(m/s)-1 , P = 0.372, while RVPAC was reduced in the placebo group, 5.2 (4.3-6.4) to 4.8 (4.2-5.8) mm·(m/s)-1 , P = 0.035. Comparing change between groups, CO increased in the acyl ghrelin group versus placebo (P = 0.036) while RVPAC and the right ventricular pressure gradient remained unchanged. CONCLUSION: Treatment with acyl ghrelin increases CO while preserving or even improving RVPAC in HFrEF, possibly due to increased contractility, reduced PVR and/or reduced left sided filling pressures. These potential effects strengthen the role of acyl ghrelin therapy in HFrEF with right ventricular failure.

Cardiovascular dysautonomia in postacute sequelae of SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) has led to a worldwide pandemic that continues to transform but will not go away. Cardiovascular dysautonomia in postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection has led to persistent symptoms in a large number of patients. Here, we define the condition and its associated symptoms as well as potential mechanisms responsible. We provide a careful and complete overview of the topic addressing novel studies and a generalized approach to the management of individuals with this complex and potentially debilitating problem. We also discuss future research directions and the important knowledge gaps to be addressed in ongoing and planned studies.

Dysregulations in hemostasis, metabolism, immune response, and angiogenesis in post-acute COVID-19 syndrome with and without postural orthostatic tachycardia syndrome: a multi-omic profiling study.

Post-acute COVID-19 (PACS) are associated with cardiovascular dysfunction, especially postural orthostatic tachycardia syndrome (POTS). Patients with PACS, both in the absence or presence of POTS, exhibit a wide range of persisting symptoms long after the acute infection. Some of these symptoms may stem from alterations in cardiovascular homeostasis, but the exact mechanisms are poorly understood. The aim of this study was to provide a broad molecular characterization of patients with PACS with (PACS + POTS) and without (PACS-POTS) POTS compared to healthy subjects, including a broad proteomic characterization with a focus on plasma cardiometabolic proteins, quantification of cytokines/chemokines and determination of plasma sphingolipid levels. Twenty-one healthy subjects without a prior COVID-19 infection (mean age 43 years, 95% females), 20 non-hospitalized patients with PACS + POTS (mean age 39 years, 95% females) and 22 non-hospitalized patients with PACS-POTS (mean age 44 years, 100% females) were studied. PACS patients were non-hospitalized and recruited ≈18 months after the acute infection. Cardiometabolic proteomic analyses revealed a dysregulation of ≈200 out of 700 analyzed proteins in both PACS groups vs. healthy subjects with the majority (> 90%) being upregulated. There was a large overlap (> 90%) with no major differences between the PACS groups. Gene ontology enrichment analysis revealed alterations in hemostasis/coagulation, metabolism, immune responses, and angiogenesis in PACS vs. healthy controls. Furthermore, 11 out of 33 cytokines/chemokines were significantly upregulated both in PACS + POTS and PACS-POTS vs. healthy controls and none of the cytokines were downregulated. There were no differences in between the PACS groups in the cytokine levels. Lastly, 16 and 19 out of 88 sphingolipids were significantly dysregulated in PACS + POTS and PACS-POTS, respectively, compared to controls with no differences between the groups. Collectively, these observations suggest a clear and distinct dysregulation in the proteome, cytokines/chemokines, and sphingolipid levels in PACS patients compared to healthy subjects without any clear signature associated with POTS. This enhances our understanding and might pave the way for future experimental and clinical investigations to elucidate and/or target resolution of inflammation and micro-clots and restore the hemostasis and immunity in PACS.

Acyl ghrelin improves cardiac function in heart failure and increases fractional shortening in cardiomyocytes without calcium mobilization.

BACKGROUND AND AIMS: Ghrelin is an endogenous appetite-stimulating peptide hormone with potential cardiovascular benefits. Effects of acylated (activated) ghrelin were assessed in patients with heart failure and reduced ejection fraction (HFrEF) and in ex vivo mouse cardiomyocytes. METHODS AND RESULTS: In a randomized placebo-controlled double-blind trial, 31 patients with chronic HFrEF were randomized to synthetic human acyl ghrelin (0.1 µg/kg/min) or placebo intravenously over 120 min. The primary outcome was change in cardiac output (CO). Isolated mouse cardiomyocytes were treated with acyl ghrelin and fractional shortening and calcium transients were assessed. Acyl ghrelin but not placebo increased cardiac output (acyl ghrelin: 4.08 ± 1.15 to 5.23 ± 1.98 L/min; placebo: 4.26 ± 1.23 to 4.11 ± 1.99 L/min, P < 0.001). Acyl ghrelin caused a significant increase in stroke volume and nominal increases in left ventricular ejection fraction and segmental longitudinal strain and tricuspid annular plane systolic excursion. There were no effects on blood pressure, arrhythmias, or ischaemia. Heart rate decreased nominally (acyl ghrelin: 71 ± 11 to 67 ± 11 b.p.m.; placebo 69 ± 8 to 68 ± 10 b.p.m.). In cardiomyocytes, acyl ghrelin increased fractional shortening, did not affect cellular Ca2+ transients, and reduced troponin I phosphorylation. The increase in fractional shortening and reduction in troponin I phosphorylation was blocked by the acyl ghrelin antagonist D-Lys 3. CONCLUSION: In patients with HFrEF, acyl ghrelin increased cardiac output without causing hypotension, tachycardia, arrhythmia, or ischaemia. In isolated cardiomyocytes, acyl ghrelin increased contractility independently of preload and afterload and without Ca2+ mobilization, which may explain the lack of clinical side effects. Ghrelin treatment should be explored in additional randomized trials. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05277415.

Tests for the identification of reflex syncope mechanism.

INTRODUCTION: Treatment efficacy of reflex syncope is mainly related to the mechanism underlying syncope rather than its etiology or clinical presentation. The predominant mechanism underlying reflex syncope can be assigned to hypotensive or to bradycardic phenotypes. AREAS COVERED: Methodology and diagnostic criteria of the most useful tests for the identification of hypotensive and bradycardic phenotypes are discussed. Diagnostic tests for the hypotensive phenotype include office blood pressure measurement with active standing test, home, and wearable blood pressure monitoring, 24-h ambulatory blood pressure monitoring and tilt table test. Diagnostic tests for the bradycardic phenotype include carotid sinus massage, tilt table test and prolonged ECG monitoring. EXPERT OPINION: In reflex syncope, the documentation of bradycardia/asystole during a syncopal episode does not rule out the possibility that a preceding or parallel hypotensive reflex plays an important role. Similarly, even when a hypotensive mechanism is established, the possibility of an associated cardioinhibitory reflex should be investigated. Investigating the mechanism of reflex syncope is mandatory in patients with severe recurrent episodes, with the final aim to develop a personalized treatment strategy. Recent trials have demonstrated the benefits of personalized mechanism-based therapy, thus highlighting the importance of a comprehensive assessment of the mechanisms underlying syncope.

Hyperbaric oxygen therapy for long COVID (HOT-LoCO), an interim safety report from a randomised controlled trial.

BACKGROUND: With ~ 50 million individuals suffering from post-COVID condition (PCC), low health related quality of life (HRQoL) is a vast problem. Common symptoms of PCC, that persists 3 months from the onset of COVID-19 are fatigue, shortness of breath and cognitive dysfunction. No effective treatment options have been widely adopted in clinical practice. Hyperbaric oxygen (HBO2) is a candidate drug. METHODS: The objective of this interim analysis is to describe our cohort and evaluate the safety of HBO2 for post covid condition. In an ongoing randomised, placebo-controlled, double blind, clinical trial, 20 previously healthy subjects with PCC were assigned to HBO2 or placebo. Primary endpoints are physical domains in RAND-36; Physical functioning (PF) and Role Physical (RP) at 13 weeks. Secondary endpoints include objective physical tests. Safety endpoints are occurrence, frequency, and seriousness of Adverse Events (AEs). An independent data safety monitoring board (DSMB) reviewed unblinded data. The trial complies with Good Clinical Practice. Safety endpoints are evaluated descriptively. Comparisons against norm data was done using t-test. RESULTS: Twenty subjects were randomised, they had very low HRQoL compared to norm data. Mean (SD) PF 31.75 (19.55) (95% Confidence interval; 22.60-40.90) vs 83.5 (23.9) p < 0.001 in Rand-36 PF and mean 0.00 (0.00) in RP. Very low physical performance compared to norm data. 6MWT 442 (180) (95% CI 358-525) vs 662 (18) meters p < 0.001. 31 AEs occurred in 60% of subjects. In 20 AEs, there were at least a possible relationship with the study drug, most commonly cough and chest pain/discomfort. CONCLUSIONS: An (unexpectedly) high frequency of AEs was observed but the DSMB assessed HBO2 to have a favourable safety profile. Our data may help other researchers in designing trials. Trial Registration ClinicalTrials.gov: NCT04842448. Registered 13 April 2021, https://clinicaltrials.gov/ct2/show/NCT04842448 . EudraCT: 2021-000764-30. Registered 21 May 2021, https://www.clinicaltrialsregister.eu/ctr-search/trial/2021-000764-30/SE.

Enhanced External Counterpulsation for Management of Postacute Sequelae of SARS-CoV-2 Associated Microvascular Angina and Fatigue: An Interventional Pilot Study.

Background: Postacute sequelae of SARS-CoV-2 infection (PASC) are a novel clinical syndrome characterized in part by endothelial dysfunction. Enhanced external counterpulsation (EECP) produces pulsatile shear stress, which has been associated with improvements in systemic endothelial function. Objective: To explore the effects of EECP on symptom burden, physical capacity, mental health, and health-related quality of life (HRQoL) in patients with PASC-associated angina and microvascular dysfunction (MVD). Methods: An interventional pilot study was performed, including 10 patients (male = 5, mean age 50.3 years) recruited from a tertiary specialized PASC clinic. Patients with angina and MVD, defined as index of microcirculatory resistance (IMR) ≥25 and/or diagnosed through stress perfusion cardiac magnetic resonance imaging, were included. Patients underwent one modified EECP course (15 one-hour sessions over five weeks). Symptom burden, six-minute walk test, and validated generic self-reported instruments for measuring psychological distress and HRQoL were assessed before and one month after treatment. Results: At baseline, most commonly reported PASC symptoms were angina (100%), fatigue (80%), and dyspnea (80%). Other symptoms included palpitations (50%), concentration impairment (50%), muscle pain (30%), and brain fog (30%). Mean IMR was 63.6. After EECP, 6MWD increased (mean 29.5 m, median 21 m) and angina and fatigue improved. Mean depression scores showed reduced symptoms (-0.8). Mean HRQoL scores improved in seven out of eight subscales (+0.2 to 10.5). Conclusions: Patients with PASC-associated angina and evidence of MVD experienced subjective and objective benefits from EECP. The treatment was well-tolerated. These findings warrant controlled studies in a larger cohort.

Hyperbaric oxygen for treatment of long COVID-19 syndrome (HOT-LoCO): protocol for a randomised, placebo-controlled, double-blind, phase II clinical trial.

INTRODUCTION: Long COVID-19, where symptoms persist 12 weeks after the initial SARS-CoV-2-infection, is a substantial problem for individuals and society in the surge of the pandemic. Common symptoms are fatigue, postexertional malaise and cognitive dysfunction. There is currently no effective treatment and the underlying mechanisms are unknown, although several hypotheses exist, with chronic inflammation as a common denominator. In prospective studies, hyperbaric oxygen therapy (HBOT) has been suggested to be effective for the treatment of similar syndromes such as chronic fatigue syndrome and fibromyalgia. A case series has suggested positive effects of HBOT in long COVID-19. This randomised, placebo-controlled clinical trial will explore HBOT as a potential treatment for long COVID-19. The primary objective is to evaluate if HBOT improves health-related quality of life (HRQoL) for patients with long COVID-19 compared with placebo/sham. The main secondary objective is to evaluate whether HBOT improves endothelial function, objective physical performance and short-term HRQoL. METHODS AND ANALYSIS: A randomised, placebo-controlled, double-blind, phase II clinical trial in 80 previously healthy subjects debilitated due to long COVID-19, with low HRQoL. Clinical data, HRQoL questionnaires, blood samples, objective tests and activity metre data will be collected at baseline. Subjects will be randomised to a maximum of 10 treatments with hyperbaric oxygen or sham treatment over 6 weeks. Assessments for safety and efficacy will be performed at 6, 13, 26 and 52 weeks, with the primary endpoint (physical domains in RAND 36-Item Health Survey) and main secondary endpoints defined at 13 weeks after baseline. Data will be reviewed by an independent data safety monitoring board. ETHICS AND DISSEMINATION: The trial is approved by the Swedish National Institutional Review Board (2021-02634) and the Swedish Medical Products Agency (5.1-2020-36673). Positive, negative and inconclusive results will be published in peer-reviewed scientific journals with open access. TRIAL REGISTRATION NUMBER: NCT04842448.

Acute myocardial infarction in a patient with congenitally corrected transposition of the great arteries and complex coronary anatomy-a case report.

Background: Congenitally corrected transposition of the great arteries (ccTGA) is a rare congenital heart anomaly with atrioventricular and ventriculoarterial discordance that is often associated with other cardiac and coronary artery anomalies. Here, we report a case of a patient with ccTGA and non-ST elevation myocardial infarction (NSTEMI) with challenging coronary anatomy that was treated with stress-perfusion cardiac magnetic resonance imaging (spCMR) guided percutaneous coronary intervention (PCI). Case summary: A 46-year-old male smoker with ccTGA, dyslipidaemia, diabetes Type 2 managed with dietary restrictions and a family history of premature myocardial infarction, presented with typical chest pain, elevated cardiac troponin levels and ECG-changes indicative of ischaemia. The patient was diagnosed with NSTEMI and underwent initial urgent coronary angiography (CA) without apparent significant stenosis, although the right coronary artery (RCA) could not be selectively investigated. The patient had coronary anatomy 1R-2LCX according to the Leiden convention, which is the usual anatomy in patients with ccTGA. Despite this, CA was challenging due to the different anatomy compared with individuals with normally positioned great vessels. The patient remained highly symptomatic with chest pain at moderate exertion. To improve identification of the anatomic location and extent of ischaemia, we performed spCMR with adenosine. This revealed a limited septal infarction (likely embolic) in the right ventricle and reversible ischaemia in two inferior right ventricular segments. A second angiography, selectively investigating RCA demonstrated a significant stenosis in the distal RCA that was successfully treated with a drug-eluting stent. Fractional flow reserve (FFR) measurements of the left coronary arteries demonstrated hemodynamically non-significant stenosis. The patient's symptoms resolved, and he remained asymptomatic at one month follow-up. Discussion: This ccTGA patient had multiple risk factors for coronary artery disease and presented with NSTEMI. Diagnosis and treatment were challenging due to complex cardiac anatomy and associated different origins of the coronary arteries. We highlight the importance of careful evaluation of the coronary anatomy and functional testing using for example spCMR and FFR to target the culprit coronary vessel(s) in ccTGA complicated by NSTEMI.

Acute effect of spinal cord stimulation on autonomic nervous system function in patients with heart failure.

AIMS: To test the hypothesis that spinal cord stimulation (SCS) acutely improves heart rate variability (HRV) and baroreceptor sensitivity (BRS) in patients with heart failure (HF). METHODS: SCS (15 minutes) was delivered in four different settings: 90% of maximal tolerated stimulation amplitude (MTA) targeting the T1-T4 spinal cord segments (SCS90T1-4), 60% of MTA (SCS60T1-4), 90% of MTA with cranial (SCS90CR) and caudal (SCS90CA) electrode configuration. HRV and BRS were recorded continuously and stimulation was compared to device off. RESULTS: Fifteen HF patients were included. SCS90T1-4 did not change the standard deviation of intervals between normal beats (SDNN, p = 0.90), BRS (p = 0.55) or other HRV parameters. In patients with baseline SDNN <50 ms, SCS90T1-4 significantly increased SDNN (p = 0.004). CONCLUSIONS: Acute SCS at 60-90% of MTA targeting upper thoracic spinal cord segments does not improve autonomic balance or baroreceptor sensitivity in unselected patients with heart failure but may improve HRV in patients with low SDNN.

Post-Acute Sequelae of COVID-19 and Cardiovascular Autonomic Dysfunction: What Do We Know?

Post-acute sequelae of SARS-CoV-2 (PASC), or long COVID syndrome, is emerging as a major health issue in patients with previous SARS-CoV-2 infection. Symptoms commonly experienced by patients include fatigue, palpitations, chest pain, dyspnea, reduced exercise tolerance, and "brain fog". Additionally, symptoms of orthostatic intolerance and syncope suggest the involvement of the autonomic nervous system. Signs of cardiovascular autonomic dysfunction appear to be common in PASC and are similar to those observed in postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia. In this review, we report on the epidemiology of PASC, discuss current evidence and possible mechanisms underpinning the dysregulation of the autonomic nervous system, and suggest nonpharmacological and pharmacological interventions to treat and relieve symptoms of PASC-associated dysautonomia.

Post-COVID-19 Tachycardia Syndrome: A Distinct Phenotype of Post-Acute COVID-19 Syndrome.

In this paper we highlight the presence of tachycardia in post-acute COVID-19 syndrome by introducing a new label for this phenomenon-post-COVID-19 tachycardia syndrome-and argue that this constitutes a phenotype or sub-syndrome in post-acute COVID-19 syndrome. We also discuss epidemiology, putative mechanisms, treatment options, and future research directions in this novel clinical syndrome.

Long-Haul Post-COVID-19 Symptoms Presenting as a Variant of Postural Orthostatic Tachycardia Syndrome: The Swedish Experience.

Major clinical centers in Sweden have witnessed an inflow of patients with chronic symptoms following initial outpatient care for coronavirus disease-2019 (COVID-19) infection, suggestive of postural orthostatic tachycardia syndrome. This report presents the first case series of 3 Swedish patients diagnosed with postural orthostatic tachycardia syndrome more than 3 months after the primary COVID-2019 infections. (Level of Difficulty: Intermediate.).

Thromboembolism, Hypercoagulopathy, and Antiphospholipid Antibodies in Critically Ill Coronavirus Disease 2019 Patients: A Before and After Study of Enhanced Anticoagulation.

To determine the prevalence of thrombotic events, functional coagulation tests, inflammatory biomarkers, and antiphospholipid antibodies before and after enhanced anticoagulation in critically ill coronavirus disease 2019 patients. DESIGN: Retrospective. SETTING: Tertiary intensive care unit. PATIENTS: Two cross-sectional cohorts of ICU-treated coronavirus disease 2019 patients were included before (cohort 1, n = 12) and after (cohort 2, n = 14) enhanced prophylactic anticoagulation strategy. INTERVENTIONS: Before and after study of enhanced anticoagulation. MEASUREMENTS AND MAIN RESULTS: Thromboelastometry point-of-care coagulation tests were performed by thromboelastography (Tem International GmbH, Munich, Germany), standard blood tests were extracted from patient charts, and presence of antiphospholipid antibodies in plasma was measured. All patients were males on mechanical ventilation. In cohort 1 (low-molecular-weight heparin dose: 129 ± 53 U/kg/24 hr), 50% had pulmonary embolism, and thromboelastography analysis revealed hypercoagulation in a majority of patients and greater than 80% had detectable antiphospholipid antibodies. In the second cohort (enhanced low-molecular-weight heparin dose: 200 ± 82 U/kg/24 hr; p = 0.04 vs cohort 1), we found a nonsignificantly lower prevalence of pulmonary embolism (21%; p = 0.22), lower fibrinogen (6.3 ± 2.5 vs 8.7 ± 2.0; p = 0.02), reduced fibrinogen-dependent thromboelastography (p < 0.001), and lower inflammatory markers. CONCLUSIONS: In these two cross-sectional cohorts of ICU-treated coronavirus disease 2019 patients, thromboembolic complications, hypercoagulation, and antiphospholipid antibodies were common. A more aggressive anticoagulation regime was associated with a reduction in inflammatory biomarkers including plasma fibrinogen and a reduction in fibrinogen-dependent hypercoagulation, as indicated by thromboelastography analyses.

Regional protein expression changes within the left ventricle in a mouse model of dyssynchronous and resynchronized heart failure.

AIMS: The biological mechanisms conveying the salutary effects of cardiac resynchronization therapy in heart failure remain elusive. We have recently developed a mouse model of heart failure with dyssynchrony/resynchronization. The aim of this study was to characterize regional left ventricular heterogeneity in protein expression comparing early (septum) and late (lateral) activated left ventricular wall segments in synchronous (SHF), dyssynchronous (DHF), and resynchronized heart failure (RHF). METHODS AND RESULTS: Mice subjected to ischaemia/reperfusion were divided into three groups: sinus rhythm for 4 weeks (SHF), right ventricular pacing for 4 weeks (DHF), and right ventricular pacing for 2 weeks and 2 weeks of sinus rhythm (RHF). Relative concentrations of 92 proteins from septal and lateral left ventricular wall segments (n = 10 per group) were compared within each group. We also analysed the effect of DHF vs. SHF and RHF vs. DHF on protein expression pattern comparing the same left ventricular segments between the groups. Proteins with significantly differential expression between left ventricular segments were analysed for protein-protein correlations, protein-protein interactions, and biological and signalling pathways. Eight proteins were significantly down-regulated in the late activated (compared with early activated) lateral wall uniquely in RHF (P < 0.05 adjusted for a 5% false discovery rate): Erbb4, Ntf3, Pdgfb, Tnf, Notch3, Qdpr, Tpp1, and Itgb6. Protein correlation matrix showed that six of these were strongly and positively correlated and five had known protein-protein interactions. Biological pathways mainly down-regulated in late activated myocardium in RHF were MAPK signalling and hypertrophic cardiomyopathy. There were no significantly differentially expressed proteins comparing the same left ventricular segments between the DHF and SHF (range of P-values: 0.05-1.00) and RHF and DHF (range of P-values: 0.32-1.00). CONCLUSIONS: In a mouse model of heart failure with dyssynchrony and resynchronization, we observed down-regulation of several proteins in the late activated lateral wall, compared with the septum, in resynchronized mice. These proteins display significant protein-protein correlation and share biological signalling pathways, including MAPK activation and hypertrophy signalling.