Prognostic implications of cardiac 82-rubidium positron emission tomography in angina patients with no perfusion defects

Background

Myocardial perfusion imaging with 82-Rubidium positron emission tomography (82Rb-PET) is increasingly used in the assessment of stable coronary artery disease (CAD). Among other variables, it provides quantitative measures of myocardial blood flow (MBF) which has shown the prognostic significance of coronary microvascular dysfunction (CMD), also in patients without perfusion defects. However, other 82Rb-PET variables may also be of prognostic significance in these patients.

Purpose

The purpose of this study was to evaluate the prognostic value of 82Rb-PET in patients with symptoms suggestive of CAD but no perfusion defects.

Methods

A study was conducted with 3726 consecutive patients who underwent 82Rb-PET on the suspicion of stable CAD between January 2018 and August 2020. After exclusion of patients with regional perfusion defects, we examined the association of 82Rb-PET derived parameters with a composite endpoint: all-cause mortality, hospitalization for unstable angina pectoris, acute myocardial infarction, heart failure or ischemic stroke in 2175 patients. CMD was defined as myocardial blood flow reserve (MBFR) <2. Analyses were further stratified to assess differences across gender.

Results

Resting and stress MBF were higher in women, while MBFR was lower and CMD more prevalent (30.5% among women versus 25.3% among men, p=0.008). Over a median follow-up of 1.7 years (IQR 1.1–2.5 years) a total of 148 events were observed. In unadjusted analyses, MBF during stress, MBFR, left ventricular ejection fraction (LVEF), LVEF-reserve, heart rate reserve and Ca-score were associated with adverse outcomes in both genders (Figure 1). A joint multivariable Cox model, for both genders, adjusted for patient characteristics, cardiovascular risk factors and 82Rb-PET variables showed reduced MBFR <2 (HR 1.75, 95% CI 1.24–2.48), resting LVEF (HR 1.38 per 10% decrease, 95% CI 1.24–1.54) and LVEF-reserve (HR 1.19 per 5% decrease, 95% CI 1.07–1.31) to be significant predictors of outcomes (Figure 2). Results were consistent in subgroups defined by gender, previous history of ischemic heart disease (IHD), reduced LVEF and atrial fibrillation.

Conclusion

MBFR, LVEF and LVEF-reserve derived from 82Rb-PET are predictors of adverse outcome and provide prognostic information in patients with no perfusion defects. This may aid in identifying patients at risk and provide opportunity of prevention.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Department of Cardiology, Bispebjerg Frederiksberg Hospital, Copenhagen

Translation and linguistic validation of the Composite Autonomic Symptom Score COMPASS 31 in Danish

INTRODUCTION

The Composite Autonomic Symptom Score (COMPASS 31) is a validated self-assessment questionnaire quantifying the severity and distribution of autonomic symptoms across six domains (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder and pupillomotor functions) by scoring 31 clinically selected questions. The aim of this study was to translate into Danish and validate the Danish version of COMPASS 31.

METHODS

The original (US) English version of the COMPASS 31 questionnaire was translated into Danish via forward/backward translation and validated in accordance with a protocol set forth by the Autonomic Group at the Mayo Clinic. Ten healthy controls and 20 patients with disorders associated with a variable degree of autonomic dysfunction were enrolled - all bilingual (Danish mother tongue, proficiency in English).

RESULTS

A total of 20 patients (16 women, aged 48 + 17 years) and ten healthy controls (six women, aged 40 + 19 years) were included. Test-retest reliability was high with no consistent bias, and the Danish version of the COMPASS 31 significantly correlated with the English version of the COMPASS 31 in both total score and all sub-scores. Patients scored significantly higher on the COMPASS 31 questionnaire than healthy controls (34.0 (26.5-49.2) versus 2.3 (1.6-24.3) (median (interquartile ranges); p = 0.01).

CONCLUSIONS

We present a Danish version of the COMPASS 31 - a validated self-reported questionnaire allowing for the quantification of autonomic dysfunction. We hope this Danish version will be implemented in both clinical practice and research settings in Denmark.

FUNDING

none.

TRIAL REGISTRATION

not relevant.

Complex syndromes of chronic pain, fatigue and cognitive impairment linked to autoimmune dysautonomia and small fiber neuropathy

Chronic fatigue syndrome, postural orthostatic tachycardia syndrome, complex regional pain syndrome and silicone implant incompatibility syndrome are a subject of debate among clinicians and researchers. Both the pathogenesis and treatment of these disorders require further study. In this paper we summarize the evidence regarding the role of autoimmunity in these four syndromes with respect to immunogenetics, autoimmune co-morbidities, alteration in immune cell subsets, production of autoantibodies and presentation in animal models. These syndromes could be incorporated in a new concept of autoimmune neurosensory dysautonomia with the common denominators of autoantibodies against G-protein coupled receptors and small fiber neuropathy. Sjogren's syndrome, which is a classical autoimmune disease, could serve as a disease model, illustrating the concept. Development of this concept aims to identify an apparently autoimmune subgroup of the disputable disorders, addressed in the review, which may most benefit from the immunotherapy.

Autonomic dysfunction and HPV immunization: an overview

This article reviews the case series reported from several countries describing patients with suspected severe side effects to the HPV vaccines. The described symptom clusters are remarkably similar and include disabling fatigue, headache, widespread pain, fainting, gastrointestinal dysmotility, limb weakness, memory impairment episodes of altered awareness, and abnormal movements. This constellation of symptoms and signs has been labeled with different diagnoses such as complex regional pain syndrome (CRPS), postural orthostatic tachycardia syndrome (POTS), small fiber neuropathy (SFN), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), or fibromyalgia. It is known that autoimmunity and autoantibodies are present in a subset of patients with CRPS, POTS, SFN, ME/CFS, and fibromyalgia. This article proposes that vaccine-triggered, immune-mediated autonomic dysfunction could lead to the development of de novo post-HPV vaccination syndrome possibly in genetically susceptible individuals. Being cognizant that a temporal relationship between vaccination and symptom onset does not necessarily equate to causality, mounting evidence of case series calls for well-designed case-control studies to determine the prevalence and possible causation between these symptom clusters and HPV vaccines. Since personalized medicine is gaining momentum, the use of adversomics and pharmacogenetics may eventually help identify individuals who are predisposed to HPV vaccine adverse events.

[Myalgic encephalomyelitis or chronic fatigue syndrome]

In this review, we discuss the myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), which is characterised by extreme mental and physical fatigue with associated symptoms of pain, disturbed sleep, cognitive and autonomic dysfunction, as well as post-exertional malaise. This con-dition is often preceded by an infection, severe physiological and/or psychological strain. Over the last decades, research has demonstrated mitochondrial, neuroendocrine, immuno-logical, and metabolic perturbations in patients with ME/CFS, giving hope for the development of new biomarkers and new treatment modalities.

Correction to: Autonomic dysfunction and HPV immunization: an overview

In the recently published paper, "Autonomic dysfunction and HPV immunization: an overview", the last name of the lead author is listed incorrectly. The author's name is Svetlana Blitshteyn.

Semen Quality as a Predictor of Subsequent Morbidity: A Danish Cohort Study of 4,712 Men With Long-Term Follow-up

Semen quality has been suggested to be a biological marker of long-term morbidity and mortality; however, few studies have been conducted on this subject. We identified 5,370 men seen for infertility at Frederiksberg Hospital, Denmark, during 1977-2010, and 4,712 of these men were followed in the Danish National Patient Registry until first hospitalization, death, or the end of the study. We classified patients according to hospitalizations and the presence of cardiovascular disease, diabetes, testicular cancer, or prostate cancer. We found a clear association between sperm concentration below 15 million/mL and all-cause hospitalizations (hazard ratio = 1.5, 95% confidence interval: 1.4, 1.6) and cardiovascular disease (hazard ratio = 1.4, 95% confidence interval: 1.2, 1.6), compared with men with a concentration above 40 million/mL. The probabilities for hospitalizations were also higher with a low total sperm count and low motility. Men with a sperm concentration of 195-200 million/mL were, on average, hospitalized for the first time 7 years later than were men with a sperm concentration of 0-5 million/mL. Semen quality was associated with long-term morbidity, and a significantly higher risk of hospitalization was found, in particular for cardiovascular diseases and diabetes mellitus. Our study supports the suggestion that semen quality is a strong biomarker of general health.

Cohort description: The Danish study of Functional Disorders

The Danish study of Functional Disorders (DanFunD) cohort was initiated to outline the epidemiology of functional somatic syndromes (FSS) and is the first larger coordinated epidemiological study focusing exclusively on FSS. FSS are prevalent in all medical settings and can be defined as syndromes that, after appropriate medical assessment, cannot be explained in terms of a conventional medical or surgical disease. FSS are frequent and the clinical importance varies from vague symptoms to extreme disability. No well-described medical explanations exist for FSS, and how to delimit FSS remains a controversial topic. The specific aims with the cohort were to test delimitations of FSS, estimate prevalence and incidence rates, identify risk factors, delimitate the pathogenic pathways, and explore the consequences of FSS. The study population comprises a random sample of 9,656 men and women aged 18–76 years from the general population examined from 2011 to 2015. The survey comprises screening questionnaires for five types of FSS, ie, fibromyalgia, whiplash-associated disorder, multiple chemical sensitivity, irritable bowel syndrome, and chronic fatigue syndrome, and for the unifying diagnostic category of bodily distress syndrome. Additional data included a telephone-based diagnostic interview assessment for FSS, questionnaires on physical and mental health, personality traits, lifestyle, use of health care services and social factors, and a physical examination with measures of cardiorespiratory and morphological fitness, metabolic fitness, neck mobility, heart rate variability, and pain sensitivity. A biobank including serum, plasma, urine, DNA, and microbiome has been established, and central registry data from both responders and nonresponders are similarly available on morbidity, mortality, reimbursement of medicine, heath care use, and social factors. A complete 5-year follow-up is scheduled to take place from year 2017 to 2020, and further reexaminations will be planned. Several projects using the DanFunD data are ongoing, and findings will be published in the coming years.

Decreased heart rate variability responses during early postoperative mobilization--an observational study

BACKGROUND

Intact orthostatic blood pressure regulation is essential for early mobilization after surgery. However, postoperative orthostatic hypotension and intolerance (OI) may delay early ambulation. The mechanisms of postoperative OI include impaired vasopressor responses relating to postoperative autonomic dysfunction. Thus, based on a previous study on haemodynamic responses during mobilization before and after elective total hip arthroplasty (THA), we performed secondary analyses of heart rate variability (HRV) and aimed to identify possible abnormal postoperative autonomic responses in relation to postural change.

METHODS

A standardized mobilization protocol before, 6 and 24 h after surgery was performed in 23 patients scheduled for elective THA. Beat-to-beat arterial blood pressure was measured by photoplethysmography and HRV was derived from pulse wave interbeat intervals and analysed in the time and frequency domain as well as by non-linear analysis using sample entropy

RESULTS

Before surgery, arterial pressures and HR increased upon standing, while HRV low (LF) and high frequency (HF) components remained unchanged. At 6 and 24 h after surgery, resting total HRV power, sample entropy and postural responses in arterial pressures decreased compared to preoperative conditions. During standing HF variation increased by 16.7 (95 % CI 8.0-25.0) normalized units (nu) at 6 h and 10.7 (2.0-19.4) nu at 24 h compared to the preoperative evaluation. At 24 h the LF/HF ratio decreased from 1.8 (1.2-2.6) nu when supine to 1.2 (0.8-1.8) nu when standing.

CONCLUSIONS

This study observed postoperative autonomic cardiovascular dysregulation that may contribute to limited HRV responses during early postoperative mobilization.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01089946.

[Postural orthostatic tachycardia syndrome]

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous condition of dysautonomia and suspected autoimmunity characterized by abnormal increments in heart rate upon assumption of the upright posture accompanied by symptoms of cerebral hypoperfusion and sympathoexcitation. An increase in heart rate equal to or greater than 30 bpm or to levels higher than 120 bpm during a head-up tilt test is the main diagnostic criterion. Management includes both non-pharmacological and pharmacological treatment focusing on stress management, volume expansion and heart rate control.

Suspected side effects to the quadrivalent human papilloma vaccine

INTRODUCTION

The quadrivalent vaccine that protects against human papilloma virus types 6, 11, 16 and 18 (Q-HPV vaccine, Gardasil) was included into the Danish childhood vaccination programme in 2009. During the past years, a collection of symptoms primarily consistent with sympathetic nervous system dysfunction have been described as suspected side effects to the Q-HPV vaccine.

METHODS

We present a description of suspected side effects to the Q-HPV vaccine in 53 patients referred to our Syncope Unit for tilt table test and evaluation of autonomic nervous system function.

RESULTS

All patients had symptoms consistent with pronounced autonomic dysfunction including different degrees of orthostatic intolerance, severe non-migraine-like headache, excessive fatigue, cognitive dysfunction, gastrointestinal discomfort and widespread pain of a neuropathic character.

CONCLUSION

We found consistency in the reported symptoms as well as between our findings and those described by others. Our findings neither confirm nor dismiss a causal link to the Q-HPV vaccine, but they suggest that further research is urgently warranted to clarify the pathophysiology behind the symptoms experienced in these patients and to evaluate the possibility and the nature of any causal link and hopefully establish targeted treatment options.

FUNDING

not relevant.

TRIAL REGISTRATION

not relevant.

Blunted autonomic response in cluster headache patients

Background

Cluster headache (CH) is a disabling headache disorder with chronobiological features. The posterior hypothalamus is involved in CH pathophysiology and is a hub for autonomic control. We studied autonomic response to the head-up tilt table test (HUT) including heart rate variability (HRV) in CH patients and compared results to healthy controls.

Methods and materials

Twenty-seven episodic and chronic CH patients and an equal number of age-, sex- and BMI-matched controls were included. We analyzed responses to HUT in the time and frequency domain and by non-linear analysis.

Results

CH patients have normal cardiovascular responses compared to controls but increased blood pressure. In the frequency analysis CH patients had a smaller change in the normalized low- (LF) (2.89 vs. 13.38, p < 0.05) and high-frequency (HF) (–2.86 vs. –13.38, p < 0.05) components as well as the LF/HF ratio (0.81 vs. 2.62, p < 0.05) in response to tilt. In the Poincaré plot, the change in ratio between long- and short-term variation was lower in patients (SD1/SD2, –0.05 vs. –0.17, p < 0.05).

Conclusions

CH patients show decreased autonomic response to HUT compared to healthy controls. This can be interpreted as dysregulation in the posterior hypothalamus and supports a theory of central autonomic mechanisms involvement in CH.

[Postural orthostatic tachycardia syndrome]

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous condition of dysautonomia and suspected autoimmunity characterized by abnormal increments in heart rate upon assumption of the upright posture accompanied by symptoms of cerebral hypoperfusion and sympathoexcitation. An increase in heart rate equal to or greater than 30 bpm or to levels higher than 120 bpm during a head-up tilt test is the main diagnostic criterion. Management includes both non-pharmacological and pharmacological treatment focusing on stress management, volume expansion and heart rate control.

Limited value of novel pulmonary embolism biomarkers in patients with coronary atherosclerosis

BACKGROUND

Recent research supports the efficacy of various plasma biomarkers in diagnosing pulmonary embolism (PE) including E-selectin, MMP-9, MPO, sVCAM-1, sICAM-1, adiponectin, hs-CRP and tPAI-1.

OBJECTIVE

We hypothesized that these biomarkers, which are affected in both venous and arterial thromboembolic diseases, have a limited potential of diagnosing PE in patients with concomitant coronary atherosclerosis, as assessed from a low-dose CT scan of the thorax, compared to patients without atherosclerosis.

METHODS

Consecutive patients suspected of PE were referred. All patients had a ventilation/perfusion single photon emission tomography (V/Q-SPECT), low-dose pulmonary CT, pulmonary multidetector computer tomography angiography, blood samples and ECG-gated cardiac CT performed the same day.

RESULTS

A total of 69 patients were included, of which 28 (41%) had PE. In patients without coronary calcium, MMP-9 and tPAI-1 were significantly elevated (P<0·042 and P<0·049) in patients diagnosed with PE. From the receiver operating curves, we chose a cut-off value for MMP-9 at 164·4 ng l(-1) , which yielded sensitivity, specificity, positive and negative predictive values of 63%, 78%, 71% and 70%, respectively. With a chosen cut-off value for tPAI-1 at 56·3 ng l(-1) , the sensitivity, specificity, positive and negative predictive values were 88%, 89%, 88% and 89%, respectively. In patients with coronary calcium, none of the biomarkers could discriminate between PE and no PE.

CONCLUSION

Plasma levels of tPAI-1 and MMP-9 are potentially useful in patients suspected of PE, however, not in the presence of the coronary atherosclerosis.