Coronary calcification by computed tomography in patients with paroxysmal and persistent atrial fibrillation undergoing catheter ablation

Introduction

Cardiac computed tomography (CCT) is routinely performed for pulmonary vein isolation (PVI) planning in patients with paroxysmal or persistent atrial fibrillation (AF). This imaging method can also identify coronary artery calcium (CAC).

Purpose

To evaluate the prevalence of CAC in patients with paroxysmal and persistent AF undergoing catheter ablation.

Methods

Cross-sectional study including patients with AF/atrial flutter (AFL) undergoing CCT for ablation procedure planning from 2017 to 2019. Baseline clinical and demographic data were collected and CAC score was assessed using the Agatston method. Patients with paroxysmal and persistent AF/AFL (defined according to 2020 European Society of Cardiology guidelines for the diagnosis and management of AF) were compared.

Results

A total of 474 patients were included (441 with AF and 33 with AFL), with a mean age of 57±12 years, of which 295 (62%) were males. CHA2DS2-VASc score was ≥1 (male) or ≥2 (female) in 278 (64%) patients and most patients had a low to moderate cardiovascular risk (259, 80%). CAC was identified in 254 (54%) patients. AF/AFL was paroxysmal in 348 (75%) patients and persistent in 116 (25%). Baseline characteristics and cardiovascular risk factors were similar between groups except for diabetes mellitus (33 [10%] vs 22 [20%], p=0.012) and valvular heart disease (13 [4%] vs 18 [16%], p<0.001) that were more prevalent in patients with persistent AF/AFL. Patients with persistent AF/AFL had higher left atrial volume and left ventricle mass (36±8 vs 43±12 ml/m2, p<0.001 and 90±22 vs 96±22 g/m2, p=0.041). CAC was more frequently present in patients with persistent AF/AFL (175 [50%] vs 72 [62%], p=0.028), especially CAC score >100 (58 [17%] vs 35 [30%], p=0.002). After multivariate analysis, CAC score>100 remained an independent predictor of persistent AF/AFL (OR 2.12, 95% CI 1.18–3.82, p=0.013) along with higher left atrial volume (OR 1.06, 95% CI 1.03–1.08, p<0.001).

Conclusion

In this study, coronary artery calcium was present in more than half of AF/FLA patients undergoing catheter ablation. Patients with persistent AF/AFL showed higher calcium scores and this could derive from chronic, more advanced disease. Especially in those patients, opportunistic CV risk screening and CAC-guided clinical management might be clinically useful.

Funding Acknowledgement

Type of funding sources: None.

Coronary artery calcium in patients with atrial fibrillation undergoing catheter ablation – an opportunity to personalize cardiovascular and thromboembolic risk management

Introduction

There is a well-established association between atrial fibrillation (AF) and coronary artery disease (CAD). Coronary artery calcium score (CACS) is a helpful tool to refine cardiovascular risk stratification and guide strategies of cardiovascular (CV) primary prevention.

Purpose

To evaluate the prevalence and clinical implications of CACS in terms of CV and thromboembolic risk stratification and preventive therapies, in patients with AF and atrial flutter (AFL) undergoing catheter ablation.

Methods

Cross-sectional study including patients with AF/AFL undergoing multidetector computed tomography (MDCT) for ablation procedure planning from 2017 to 2019. Baseline clinical and demographical data were collected. CV and thromboembolic risks were evaluated based on the SCORE (Systematic Coronary Risk Evaluation) system and CHA2DS2-VASc score. CACS was assessed in patients without history of coronary artery disease using the Agatston method.

Results

A total of 474 patients were included (441 with AF and 33 with AFL, mean age of 58±10 years, 62% male). Excluding those over 70 years of age (n=50, 11%), most patients had low (n=69, 22%) or moderate (n=188, 60%) CV risk and 277 (64%) patients had a CHA2DS2-VASc score ≥1 (male) or ≥2 (female). Overall, 265 patients (65%) were under chronic anticoagulation and 157 (39%) were under statin therapy. CAC was present in 254 (54%) patients and showed a multivessel distribution in 62% of the cases. The left main stem was affected in 81 (17%) patients and the left anterior descending artery in 211 (45%). Incorporating CACS>100 as a variable in CHA2DS2-VASc score (vascular disease parameter in patients without history of vascular disease) would have resulted in a significant score reclassification (n=87, 20%) and identification of new potential candidates for anticoagulation (n=12, 3%). Additional, anticoagulation would be indicated as a class IA recommendation in more 26 (6%) patients. Twenty three percent of patients with zero calcium were taking statins, and only 7% of patients with a CACS >300 were on high-intensity statin therapy. According to the recommendations and based on their CACS and current therapy, 103 (25%) patients would be candidates for statin therapy and 69 (17%) patients would be candidates for changes in the current statin therapy intensity (Table 1).

Conclusion

In our study, more than half of the patients undergoing MDCT before AF/AFL catheter ablation had coronary calcium above zero. Our findings suggest that an opportunistic evaluation of CACS can be clinically valuable in thromboembolic risk stratification and management of preventive pharmacological strategies such as anticoagulation and statins.

Funding Acknowledgement

Type of funding sources: None.

Is coronary computed tomography angiography a good choice for elders and high probability cases?

Introduction

Coronary computed tomography angiography (cCTA) is widely considered the optimal non-invasive test to rule out coronary artery disease (CAD) and the gatekeeper for invasive coronary angiography (ICA). However, its diagnostic utility in elderly patients (pts) and in cases of high pre-test probability (PTP) is still questioned.

Aim

To determine whether older age and high PTP are correlated with non-diagnostic cCTA scans in pts with suspected chronic coronary syndrome (CCS).

Methods

Single-centre retrospective study of 302 pts with suspected CAD assigned to two groups: (A) 207 pts aged ≥70 years (y); (B) 95 aged <70y. Younger pts were randomly selected from our database. We excluded pts with known history of CAD and suspected acute coronary syndrome. A 192x2 dual-source CT equipment was used. Baseline demographic and clinical characteristics were collected as well as scan features and findings. We defined high PTP according to clinical Morise score. Our endpoint was the obtention of diagnostic scan (all segments evaluable). Multivariate analysis was performed to assess the determinants of non-diagnostic scans. We used SPSS Statistics 22 for statistical analysis.

Results

Overall, mean age was 68±9y and 53% were male. Elderly pts presented more co-morbidities (hypertension: 78.3 vs 54.7%, p<0.01; hyperlipidaemia: 69.1 vs 52.6%, p<0.01; pulmonary disease: 13.0 vs 4.2%, p=0.02) and high PTP more frequently (16.9 vs 6.3%, p<0.01). Total coronary calcium score (CaS) was higher in elderly pts (382.7±658.7 vs 243.5±490.8, p=0.04); per-vessel, both left anterior descending (156.7±254.2 vs 92.2±187.8, p=0.01) and left circumflex (LCX) arteries (65.5±131.3 vs 26.8±67.6, p<0.01) showed higher CaS in the elderly. Multiple calcified plaques (≥5) were also more common in this group (60.4 vs 45.3%, p=0.01). However, the proportion of pts with CaS considered prohibitive for angiography (13.5 vs 7.4%; p=0.12) and calcium blooming artefacts impairing interpretation (14.5 vs 12.5%; p=0.65) did not differ. A diagnostic study was more frequently obtained in younger pts but without reaching statistical significance (69.1 vs 76.8%; p=0.17). Obstructive CAD was equally identified (30.3 vs 30.4%; p=0.92) with a respective per-patient accuracy of 68.4% (13/19) and 57.1% (8/14) comparing with ICA when performed. Multivariate analysis showed that LCX CaS ≥75th percentile and multiple calcified plaques (≥5) were associated with non-diagnostic cCTA scan (Figure 1). High PTP (p=0.83) and age ≥70y (p=0.61) were not associated with the endpoint.

Conclusion

In this comparison study of elderly and young pts undergoing cCTA for suspected CCS, age ≥70y and high PTP were not associated with non-diagnostic tests while multiple calcified lesions and severe LCX calcification predicted inconclusive studies. Our results cast hope on the applicability of cCTA to elderly pts and cases with high PTP, although larger studies are required.

Funding Acknowledgement

Type of funding source: None

Frailty Syndrome: Visceral Adipose Tissue and Frailty in Patients with Symptomatic Severe Aortic Stenosis

BACKGROUND/OBJECTIVES

In patients with severe aortic stenosis (AS), frailty is a clinically relevant measure of increased vulnerability that should be included in the preoperative risk assessment. Bioelectrical impedance analysis (BIA) derived phase angle (PA) reflects cell membrane integrity and function. Few studies are available on the relative contribution of adiposity distribution on frailty, and about the influences of frailty and visceral obesity in PA value. Therefore, we aimed to evaluate associations among frailty, visceral fat depots and PA in patients with symptomatic severe AS.

METHODS

In a cohort of patients with symptomatic severe AS and preserved ejection fraction, we examined the associations between frailty, visceral fat depots and bioelectrical impedance analysis (BIA) derived phase angle (PA); and between visceral fat and PA. Frailty was defined according the Fried et al. scale criteria and the body fat distribution was determined by multidetector computed tomography and by BIA.

RESULTS

Of the fifty-five included patients, 26 were frail (47%). Adjusting for age and gender, frailty was associated with indexed epicardial adipose tissue volume (EATVi) (the odds of frailty increased 4.1-fold per additional 100 cm3/m2 of EAT [95% confidence interval (CI) of 1.03 to 16.40, p=0.04] and with PA (OR of 0.50, 95% CI, 0.26 to 0.97, p=0.04), but not with body mass index (BMI), waist circumference (WC), indexed total, visceral and subcutaneous abdominal fat areas (TAFAi, VAFAi and SAFAi) nor with indexed mediastinal adipose tissue volume (MATVi). In an age and gender adjusted linear model, PA was inversely correlated with EATVi (β=-0.008, 95% CI, -0.016 to -0.001, p=0.03), but not with BMI, WC, nor with MATVi, VAFAi, SAFAi and TAFAi.

CONCLUSIONS

In patients with symptomatic severe AS, EATVi is associated with frailty, independently of age and gender, but not with MAFVi or VAFAi. Moreover, frailty and EATVi are associated with impaired cell membrane integrity and function assessed by PA.

Rapid ecological assessment of benthic indicators of water quality: a successful capacity-building experience for Brazilian postgraduate students in ecology

Rapid Ecological Assessment protocols are important tools for the training of postgraduate students, as well as the collection of data on poorly-known and protected areas with the potential for the preservation of water supplies for urban areas. The objective of this study was to perform a survey of water quality and diversity of benthic macroinvertebrates in two sub-basins at the Mata do Junco Wildlife Refuge in the Brazilian state of Sergipe. The collection of data in the field, laboratory processing, and the interpretation and discussion of data were conducted in groups by students from two postgraduate programmes in Ecology and Conservation (UFMG and UFS), personnel of the state environment agency (SEMARH), school teachers from the local town of Capela, and members of the reserve's voluntary fire brigade. The results of the assessment were organised, analysed, and presented at the reserve headquarters in the form of posters, for the development of environmental education activities with pupils from local schools, as well as contributing to a SEMARH seminar. Samples were characterised by distinct taxonomic compositions and diversity, as confirmed by MDS and additive partitioning of diversity analyses. The gravel substrate presented the lower mean taxonomic richness in each sampling unit (a1 = 28%), while the average difference among samples (b1 diversity) was elevated for both substrates (39% for leaf litter, 41% for gravel), reflecting the pronounced variation among samples, even adjacent ones within the same stream. Diversity between streams was lower in the case of leaf litter in comparison with gravel (b2 = 21 and 31%, respectively). A total of 57 fish specimens were collected with a predominance of individuals of the orders Characiformes (62%) and Perciformes (21%). This rapid ecological assessment confirmed the importance of the conservation unit and emphasised the need for its continuation, given its importance for the maintenance of water quality and its other ecological services, such as the conservation of the region's aquatic biodiversity and providing the local town of Capela (circa 20,000 inhabitants) with its water supply, the Mata do Junco being its only source.

Hyperalgesia and edema responses induced by rat peripheral blood mononuclear cells incubated with carrageenin

The aim of this study was to verify the role played by mononuclear cells in an acute (nonimmune) inflammatory reaction. Mononuclear cells purified from rat peripheral blood were incubated for 1, 2, or 24 h with 100 or 250 microg/ml carrageenin (Cg). The resultant donor supernatant was injected into recipient rats to test its ability to induce hyperalgesia (reduction in threshold for paw pressure) and edema (increase in paw volume). Mononuclear cell supernatants (MnS) induced a significant time- and dose-dependent hyperalgesia and edema in rat paws, which reached a maximal effect at 3 h, lasted for 6 h, and returned to basal levels at 24 h of injection. Prostaglandins and cytokines (interleukin 1, 2, 6, 8, and tumor necrosis factor alpha) accounted for the hyperalgesia induced by MnS, as it was reduced (40 to 90%) by synthesis inhibitors such as indomethacin, dexamethasone, rolipram, and cyclosporin added to the cultures at a microgram dose-range. Edema was dependent on serotonin release in rat paws. These results indicate that mononuclear cells may be important contributors to acute inflammatory reactions, especially under those conditions where pain is an important component.

Glutamatergic postsynaptic block by Pamphobeteus spider venoms in crayfish

The effects of toxins from venom glands of two south american spiders (Pamphobeteus platyomma and P. soracabae) on glutamatergic excitatory synaptic transmission were studied in the neuromuscular junction of the opener muscle of crayfish. The toxins selectively and reversibly blocked both excitatory postsynaptic currents and potentials in a dose-dependent manner. They also reversibly abolished glutamate-induced postsynaptic membrane depolarization. They had no effect on resting postsynaptic membrane conductance nor on postsynaptic voltage-gated currents. The synaptic facilitation and the frequency of miniature postsynaptic potentials were unaffected by the toxins, indicating that presynaptic events were not modified. Picrotoxin, a selective antagonist of the gamma-aminobutyric acid (GABA)A receptor, did not modify toxin effects. We conclude that both toxins specifically block the postsynaptic glutamate receptor-channel complex.

Aortic valve replacement in preteenage children

During the last 15 years, 26 children who ranged from 4 to 12 years old underwent subcoronary aortic valve replacement (AVR) at the Texas Heart Institute. The valve lesions resulted from congenital heart disease in 20 patients, 15 of whom had had a previous operation including 13 aortic valve procedures. Cystic medial necrosis necessitated AVR in 5 patients, all of whom had physical findings of Marfan's syndrome. One patient had rheumatic heart disease and required double-valve (aortic and mitral) replacement. Six different types of prosthesis were used: the Smeloff-Cutter, Starr-Edwards, Cooley-Cutter, Hancock porcine, Ionescu-Shiley, and Bjork-Shiley. The first patient in the series was the only early death (3.8%). Log-term follow-up data ranging from 1 month to 10 years were available on 20 patients. Three late deaths occurred (11.5%). All survivors are doing well and have good exercise tolerance. These data suggest that AVR performed in childhood is a safe, durable, and well-tolerated form of therapy. Later replacement, if necessary, can be accomplished with larger-sized prostheses. Our present choice is the Ionescu-Shiley bovine xenograft because of its superior hemodynamic characteristics and low incidence of embolic complications.

Origin and progress of the 1968-69 Hong Kong influenza epidemic

The Hong Kong strain of influenza virus A2 may have originated in the mainland of China but this is not certain. It caused a very large epidemic in Hong Kong and spread rapidly to countries as far as India and the Northern Territory of Australia-as happened in the 1957 epidemic. Later its progress slowed down but epidemics occurred in many countries in the northern hemisphere in the winter of 1968-69. In all these countries except the United States of America the disease was mild and not associated with a large increase of deaths. In the United States of America, however, the number of "excess deaths" was similar to the number in 1957-58.In the southern hemisphere epidemics began in May-June 1969; they have been clinically mild and the reported incidence of disease has been only moderately high.In many countries the infection has spread slowly and smouldered instead of bursting into the usual sharp epidemics.The smouldering spread and the contrast in the behaviour of the disease in the USA compared with the rest of the world are the outstanding features of the Hong Kong strain of virus. Satisfactory explanations of these observations might lead to the development of more effective means of control of influenza.

WHO respiratory disease survey in children: a serological study

This paper is a report on the first (serological) phase of a study organized by WHO in collaboration with the WHO International Reference Centre for Respiratory Virus Diseases other than Influenza in Bethesda, Md., USA, to define the viral etiology of severe respiratory infections in children, particularly in tropical areas. Paired sera from 528 children up to 5 years old admitted to hospital with severe respiratory illness of probable viral etiology were collected in 10 countries and sent frozen to the International Reference Centre, where standard complement-fixation tests were made for the following agents: parainfluenza virus types 1, 2 and 3, influenza virus types A and B, adenoviruses, respiratory syncytial virus, Mycoplasma pneumoniae, Coxiella burneti and psittacosis-ornithosis.Some 41% of paired sera showed rising antibody titres for one or more of these agents, multiple infections being observed in 8%. In most of the countries the pattern of infection was similar. RS virus was the most important respiratory tract pathogen of early life, particularly in the first year of life and in cases of bronchiolitis and pneumonia; the parainfluenza viruses were next in importance, particularly in cases of croup, but, in contra-distinction to RS virus infections, they were commoner in older children. Influenza, adenoviruses, and M. pneumoniae were of moderate importance, and C. burneti and the psittacosis-ornithosis agents were relatively rare. This pattern is similar to that which has been observed in temperate climates.

WHO collaborative study on the sero-epidemiology of rubella

Under the auspices of WHO an investigation was made by 9 laboratories in different parts of the world on the distribution of rubella antibodies in girls and women of child-bearing age. In the first part of the study the objective was to determine the reliability and reproducibility of the tests employed. It was found that there were no significant differences in the variability of the titres obtained in different laboratories when the results were compared with those obtained by repeatedly testing the same sera in one laboratory.In the second part of the study sera were obtained from girls in schools and women attending clinics and health centres. They were not taken from random samples of the populations. In most of the studies the pattern of development of antibody was similar. About half the persons had antibody at 6-8 years of age and 80%-87% at 17-22 years of age, the percentage remaining relatively constant thereafter. The island populations of Trinidad and Jamaica and a rural area of Japan were, however, found to have significantly fewer women with antibodies than urban areas in Europe or the Americas.