A new electrophysiological triad for atrial flutter critical isthmus identification and localization

Funding Acknowledgements

Type of funding sources: None.

Introduction

In a previous retrospective study it was demonstrated that an electrophysiological triad was able to identify critical isthmus in atrial flutter (AFL) patients.  This triad is based in the Carto® electroanatomical mapping (EAM) version 7, which displays a histogram of the local activation times (LAT) of the tachycardia cycle length (TCL), in addition to the activation and voltage maps. This study aimed to prospectively assess the ability of an electrophysiological triad to identify and localize the AFL’s critical isthmus.

Methods

Prospective analysis of a unicentric registry of individuals who underwent left AFL ablation with Carto® EAM. All patients with non-left AFL, lack of high-density EAM, less than 2000 collected points or lack of mapping in any of the left atrium walls or structures were excluded. Ablation sites of arrhythmia termination were compared to an electrophysiological triad constituted by: areas of low-voltage (0.05 to 0.3mV), sites of deep histogram valleys (LAT-Valleys) with less than 20% density points relative to the highest density zone and a prolonged LAT-Valley duration that included 10% or more of the TCL. The longest LAT-Valley was designated as the primary valley, while additional valleys were named as secondary.

Results

A total of 12 patients (9 men, median age 72 IQR 67-75 years) were included. All patients presented with left AFL and 67% had a previous atrial fibrillation and/or flutter ablation. The median TCL and number collected points were 250 (230─290) milliseconds and 3150 (IQR 2340─3870) points, respectively. All AFL presented with at least 1 LAT-Valley in the analysed histograms, which corresponded to heterogeneous low-voltage areas (0.05 to 0.3mV) and encompassed more than 10% of TCL. Eleven of the 12 patients presented with at least 1 secondary LAT-Valley. All arrhythmias were effectively terminated after undergoing radiofrequency ablation in the primary or the secondary LAT-Valley location.

Conclusion

In a prospective analysis, an electrophysiological triad was able to identify the AFL critical isthmus in all patients. Further studies are needed to assess the usefulness of this algorithm to improve catheter ablation outcomes.

Neuropsychiatric manifestations of SARS-CoV-2 infection

Introduction

Starting in December 2019, the coronavirus SARS-CoV-2 emerged and soon acquired a pandemic dimension. The evidence that 1 in 3 patients presented neuropsychiatric symptoms highlighted SARS-CoV-2 neurotropic properties. The involvement of the Central Nervous System (CNS) seems to be associated with poor prognosis, and it can occur independently of the respiratory system.

Objectives

To assess neuropsychiatric symptoms in SARS-CoV-2 patients and possible mechanisms of CNS invasion; to reflect on what changes should be made in order to avoid short and long-term complications.

Methods

A non-systematic literature review was performed, including publications between January and August 2020.

Results

The most frequent CNS presentations included fatigue (38-75%), headache (6,5-34%), nausea or vomiting (1-13,7%). Regarding PNS involvement, three kinds of hypoesthesia (hyposmia, hypogeusia, and hypopsia) were commonly present. Additionally, cases of neurological syndromes associated with SARS-CoV2 were reported, being related to a poor prognosis in cases such as brainstem infiltration. Another major concern regarding CNS involvement is the possibility of permanent neurological disabilities. Importantly there are reports of patients who tested positive for SARS-CoV-2 in CFS, without samples from nasopharyngeal swabs. Different hypothesis are postulated to explain possible mechanisms through which SARS-CoV-2 affects CNS, including: direct invasion through the olfactory nerve, hematogenous route through ACE-2 (angiotensin-converting enzyme) receptor expressed in blood-brain-barrier; or indirect mechanisms.

Conclusions

Here we discuss the neuropsychiatric manifestations of SARS-CoV-2 infection and the potential mechanisms by which they occur at an early stage. Awareness, prevention and early treatment of potential neuropsychiatric symptoms of COVID-19 should not be overlooked, especially because they seem to predict a worse prognosis.

Disclosure

No significant relationships.

Alcohol-related dementia – an overlooked entity?

Introduction

The relationship between alcohol use and dementia is complex. There is a J-shaped relationship between alcohol use and cognitive impairment and evidence shows that one-quarter of the dementia population have alcohol related problems. It is estimated that alcohol-related dementia (ARD) contributes for about 10% of all cases of dementia, especially early-onset dementia, but is largely overlooked or seen as a comorbid factor.

Objectives

To clarify the relationship between alcohol use, alcohol-related brain damage and dementia; to review the clinical features, neuropathology, nosology and neuropsychology of ARD and alcohol-induced persisting amnestic syndrome (Wernicke-Korsakoff syndrome- WKS).

Methods

We performed a review of systematic reviews from the last 10 years. A total of 28 systematic reviews were identified.

Results

Heavy alcohol use has been shown to be a contributory factor and necessary factor in the development of multiple brain diseases. It may cause brain damage in multiple ways: direct neurotoxic effect of acetaldehyde; thiamine deficiency. It is also a risk factor for other conditions, such as hepatic encephalopathy, epilepsy and head injury.

Conclusions

Clinical observation favors the diagnosis of ADR as a distinct entity, but broader evidence reflects significant commonality between ARD and WKS, tough neuropsychological studies have largely attempted to differentiate these syndromes. Repeated episodes of WKS may cause cognitive deterioration. In contrast to other common causes of dementia, the decline in cognitive functioning in ARD is relatively non-progressive if abstinence is maintained, or even partially reversible, as supported by neuroimaging evidence. Given the increase in per capita consumption, it is expected a disproportionate increase in ARD.

Alcohol consumption during COVID-19 pandemic: What have we learnt so far?

Introduction

The current SARS-CoV-2 pandemic has many implications, one of them being alcohol consumption. The impact of long-term distancing measures in terms of alcohol use and misuse is yet unknown. Any increase, would not only add to the usual disease burden associated with alcohol, but also add to the COVID-19 load, given that alcohol use may weaken the immune response.

Objectives

To characterize and compare the pattern of alcohol consumption throughout the pandemic in patients with the diagnosis of Alcohol Use Disorder; to identify factors considered as most relevant in the increase of alcohol consumption.

Methods

We conducted a observational study in an outpatient population in Centro Hospitalar Psiquiátrico de Lisboa (Portugal) with diagnosis of Alcohol Use Disorder, 6 months after the pandemic lockdown. We characterized our sample regarding social, demographic and clinical categories. We applied auto-filled questionnaires, particularly: Mental Health Inventory (MHI), Positive Mental Health Scale (PMHS) and Severity of Alcohol Dependence Questionnaire (SADQ-C).

Results

A total of 65 patients were included. More than 30% changed their drinking habits because of the pandemic. Nearly half of these increased consumption, and half decreased (16% vs 14%). The increase affected particularly men, and was related with the severity of alcohol dependence, stress-related coping strategies and psycopathology; on the other hand, a lowered level of consumption based on the decrease of alcohol accessability and affordability.

Conclusions

The current situation is unique in terms of mass physical distancing and may trigger different behaviours that should be monitored. Governments should give public health warning about excessive alcohol consumption to protect vulnerable individuals.

Disclosure

No significant relationships.

Calcium score of the aortic valve as a predictor of aortic stenosis severity

Funding Acknowledgements

Type of funding sources: None.

Background

The calcium score of the aortic valve (CaScAoV) is now recommended as a supporting tool to assist in the grading of aortic stenosis (AS) severity when echocardiographic assessment is inconclusive. However, the proposed CaScAoV cut-offs for considering severe AS "unlikely", "likely", or "very likely" have never been validated in Portuguese cohorts.

Aim

The purpose of this study was to assess the performance of the proposed CaScAoV cut-offs in identifying patients with severe aortic stenosis.

Methods

A total of 513 consecutive patients (median age 83 years [IQR 79–87], 38% males) evaluated at a single-centre TAVI-programme between Jan/2016 and Nov/2019 were retrospectively identified. Only patients with an ECG-gated cardiac computed tomography (CT) and a transthoracic echocardiography performed within a 6-month time-frame were included. Main exclusion criteria were left ventricular ejection fraction < 50%, indexed stroke volume < 35 ml/m2, previous valve surgery and

bicuspid aortic disease. CaScAoV was measured according to the Agatston method (Agatston units – AU). As previously reported, the likelihood of aortic stenosis as assessed by CT was categorized as: "very likely" (>3000 AU for men, >1600 AU for women); "likely" (>2000 AU for men, >1200 AU for women) ; or unlikely (<1600 AU for men, <800 AU for women). Diagnostic tests performance measures were calculated for each category. Separate analyses were performed for each gender.

Results

Severe AS (mean gradient ≥ 40 mmHg) was present in 422 patients (overall 82.3%: 83.1% in females and 80.8% in males), with a median transvalvular gradient of 49 mmHg (IQR 42 – 60).

Overall, the discriminative ability of the CaScAoV to distinguish severe from non-severe AS was higher in men when compared with women (c-statistic 0.86 [95%CI 0.80 – 0.93] vs. 0.72 [95%CI 0.64 – 0.80], p for comparison < 0.001). In males, the "very likely" cut-off had a sensitivity of 71% (95%CI 63 – 78%), a specificity of 81% (95%CI 65 – 92%), a positive predictive value (PPV) of 94% (95%CI 89 – 97%) and a negative predictive value (NPV) of 40% (95%CI 33 – 46%) for the diagnosis of severe AS. Conversely, in women the sensitivity was 75% (95%CI 69 – 80%), specificity was 57% (95%CI 43 – 71%), PPV was 90% (95%CI 86 – 92%) and NPV was 32% (95%CI 25 – 39%).

On the other end of the spectrum, the "unlikely" cut-off showed poor performance in dismissing severe AS, particularly in females – NPV of 43% (95%CI 25-63%) in women vs. 83% (95%CI 63-93%) in men.

Conclusion

In our population, the discriminative power of CaScAoV for identifying patients with severe AS was lower than in previously published cohorts, particularly in females. While very high CaScAoV is strongly supportive of severe AS, caution should be employed when interpreting low CaScAoV values in women, since the recommended cut-off value does not allow the safe exclusion of severe aortic stenosis.

Abstract Figure. Waterfall chart of individuals CaScAoV

Adapting the concepts of proportionate and disproportionate functional mitral regurgitation to clinical practice

Funding Acknowledgements

Type of funding sources: None.

Background

  Despite its theoretical appeal, the concept of Proportionate and Disproportionate FMR has been limited by the lack of a simple way to assess it and by the paucity of data showing its prognostic superiority over currently established ways of grading FMR.

Objectives

This study sought to evaluate the prognostic value of a new and individualized method of assessing Functional Mitral Regurgitation (FMR) Proportionality.

Methods

Patients with at least mild FMR and reduced left ventricular ejection fraction (< 50%) under optimal guideline-directed medical therapy were retrospectively identified at a single-center. To determine FMR proportionality status, we used a novel approach where two simple equations establish an individual cut-off of regurgitant volume/effective regurgitant orifice area, categorizing the study population into non-severe, proportionate and disproportionate FMR (Figure 1). The primary endpoint was all-cause mortality.

Results

A total of 572 patients (median age 70 years; 76% male) were included. Median LVEF was 35% (IQR 28-40) and LVEDV was 169 ml (IQR 132-215). Disproportionate FMR was present in 109 patients (19%) with a median EROA of 26 mm2 (IQR 22-31) and a median RegVol of 40 ml (IQR 34-48), proportionate FMR in 148 patients (26%) with a median EROA of 16mm2 (IQR 12-21) and a median RegVol of 26 ml (IQR 19-32). During a median follow-up of 3.8 years (interquartile range: 1.8 to 6.2 years) there were 254 deaths (44%). The unadjusted mortality incidence per 100 persons-year rose as the degree of FMR disproportionality worsened. On multivariable analysis, disproportionate FMR remained independently associated with all-cause mortality (adjusted hazard ratio: 1.785; 95% confidence interval [CI]: 1.249 to 2.550; P = 0.001). The FMR proportionality concept showed greater discriminative power (C-statistic 0.639; 95% CI: 0.597 to 0.680) than the American (C-statistic 0.588; 95% CI: 0.550 to 0.626; P for comparison = .001) and European guidelines (C-statistic 0.563; 95% CI: 0.534 to 0.591; P for comparison < .001). It was also able to increase the net reclassification index (0.167 [P < 0.001] and 0.084 [P = 0.001], respectively).

Conclusions

A new, simplified and individualized method of assessing FMR Proportionality showed that disproportionate FMR is independently associated with all-cause mortality. This approach seems to outperform the risk stratification of current guidelines.

Abstract Figure 1

Regurgitant volume to left ventricular end-diastolic volume ratio: another step to risk stratification in patients with secondary mitral regurgitation?

Funding Acknowledgements

Type of funding sources: None.

Background

 Quantitative evaluation of secondary mitral valve regurgitation (MR) remains an important yet challenging step in the evaluation of this entity. Its severity can be underestimated when using the proximal isovelocity surface area (PISA) method, which does not take left ventricular (LV) volume into account. Normalizing mitral regurgitant volume (Rvol) for the LV end-diastolic volume (EDV) might overcome this key limitation. This study aimed to investigate the prognostic implication of Rvol/EDV ratio in patients with secondary MR.

Methods

 Patients with at least mild secondary MR and reduced left ventricular ejection fraction (<50%) under optimal guidelines-directed medical therapy were retrospectively identified at a single-center. The cohort was divided into terciles according to the RVol/EDV ratio. The primary endpoint was all-cause mortality.

Results

 A total of 572 patients (median age 70 years; 76% male) were included. Median LVEF was 35% (IQR 28-40) and LVEDV was 169 ml (IQR 132-215). Median measures of secondary MR were EROA 14 mm2 (IQR 8-22) and RegVol 23 ml (12-34). During a median follow-up of 3.8 years (interquartile range 1.8 to 6.2 years) there were 254 deaths (44%). The unadjusted mortality incidence increases across terciles distribution. Patients at the 2nd and 3rd terciles of the RVol/EDV ratio showed significantly higher mortality when compared to those at the 1st one (baseline reference) (figure 1). After multivariable analysis, terciles of the Rvol/EDV ratio remained independently associated with increased all-cause mortality (considering the 1st tercile as the reference; adjusted HR for the 2nd tercile 1.46 [95% CI 1.05- 2.02]  p = 0.023; adjusted HR for 3rd tercile 1.56 [95% CI 1.09 – 2.22], p = 0.015).

Conclusion

 In patients with secondary MR, Rvol/EDV ratio is independently associated with all-cause mortality. However, the appropriate cut-off to determine any kind of clinical decision remains to be determined.

Abstract Figure.

External validation of the unifying concept for the quantitative assessment of secondary mitral regurgitation

Funding Acknowledgements

Type of funding sources: None.

Background

  A Unifying Concept for the Quantitative Assessment of Secondary Mitral Regurgitation (SMR) was recently proposed in order to provide a solution for the ongoing guideline controversy. However, these data were derived from a single center cohort and lacks external validation. We aimed to validate the proposed algorithm in a different patient population.

Methods

Patients with at least mild SMR and reduced left ventricular ejection fraction (< 50%) under optimal guideline-directed medical therapy were retrospectively identified at a single-center. The cohort was stratified in low-risk (effective regurgitant orifice area [EROA] < 20 mm2 and regurgitant volume [RegVol] < 30 ml), intermediate-risk (EROA 20 to 29 mm2 and RegVol 30 to 44 ml) and high-risk (EROA ≥ 30 mm2 and RegVol ≥ 45ml) according to the defined risk-based thresholds tailored to the pathophysiological concept of SMR. In the intermediate-risk group, patients were further stratified on the basis of the hemodynamic severity of SMR, into intermediate low-risk and intermediate high-risk (regurgitant fraction < 50% or ≥ 50%, respectively). The primary endpoint was all-cause mortality.

Results

A total of 572 patients (median age 70 years; 76% male) were included. Median LVEF was 35% (IQR 28-40) and LVEDV was 169 ml (IQR 132-215). Median measures of SMR severity were EROA of 14 mm2 (IQR 8-22) and RegVol of 23 ml (12-34). During a median follow-up of 3.8 years (interquartile range: 1.8 to 6.2 years) there were 254 deaths (44%). The mortality at 6-years was 38.9% for the low-risk group, 30.7% for the intermediate low-risk, 64.9% in the intermediate high-risk and 63.2% in the high-risk group. On multivariable analysis, the defined thresholds of risk for SMR severity remained independently associated with all-cause mortality (adjusted hazard ratio: 1.164; 95% confidence interval [CI]: 1.020 to 1.327; P = 0.024). The unifying concept showed similar discriminative power (C-statistic 0.588; 95% CI: 0.540 to 0.635) to the American (C-statistic 0.588; 95% CI: 0.541 to 0.635; P for comparison = 1) and European guidelines (C-statistic 0.563; 95% CI: 0.515 to 0.610; P for comparison = 0.458), but it was able to increase the net reclassification index (0.143 [P < .001] and 0.026 [P = .025], respectively).

Conclusions

In this cohort of patients with SMR and LVEF <50%, the proposed unifying concept based on combined assessment of the EROA, the RegVol, and the RegFrac proved to be associated with an increased risk of all-cause mortality and could improve risk prediction of current guidelines.

Abstract Figure.

Sorting hidden patterns in nanoparticle performance for glioblastoma using machine learning algorithms

Cationic compounds have been described to readily penetrate cell membranes. Assigning positive charge to nanosystems, e.g. lipid nanoparticles, has been identified as a key feature to promote electrostatic binding and design ligand-based constructs for tumour targeting. However, their intrinsic high cytotoxicity has hampered their biomedical application. This paper seeks to establish which cationic compounds and properties are compelling for interface modulation, in order to improve the design of tumour targeted nanoparticles against glioblastoma. How can intrinsic features (e.g. nature, structure, conformation) shape efficacy outcomes? In the quest for safer alternative cationic compounds, we evaluate the effects of two novel glycerol-based lipids, GLY1 and GLY2, on the architecture and performance of nanostructured lipid carriers (NLCs). These two molecules, composed of two alkylated chains and a glycerol backbone, differ only in their polar head and proved to be efficient in reversing the zeta potential of the nanosystems to positive values. The use of unsupervised and supervised machine learning (ML) techniques unraveled their structural similarities: in spite of their common backbone, GLY1 exhibited a better performance in increasing zeta potential and cytotoxicity, while decreasing particle size. Furthermore, NLCs containing GLY1 showed a favorable hemocompatible profile, as well as an improved uptake by tumour cells. Summing-up, GLY1 circumvents the intrinsic cytotoxicity of a common surfactant, CTAB, is effective at increasing glioblastoma uptake, and exhibits encouraging anticancer activity. Moreover, the use of ML is strongly incited for formulation design and optimization.

Perfluoro effect on the electronic excited states of para-benzoquinone revealed by experiment and theory

We report a comprehensive study on the electronic excited states of tetrafluoro-1,4-benzoquinone, through high-resolution vacuum ultraviolet photoabsorption spectroscopy and time-dependent density functional theory calculations performed within the nuclear ensemble approach. Absolute cross section values were experimentally determined in the 3.8-10.8 eV energy range. The present experimental results represent the highest resolution data yet reported for this molecule and reveal previously unresolved spectral structures. The interpretation of the results was made in close comparison with the available data for para-benzoquinone [Jones et al., J. Chem. Phys., 2017, 146, 184303]. While the dominant absorption features for both molecules arise from analogous π* ← π transitions, some remarkable differences have been identified. The perfluoro effect manifests in different ways: shifts in band positions and cross sections, appearance of features associated with excitations to σCF* orbitals, and spectrum broadening by quenching of either vibrational or Rydberg progressions. The level of agreement between experiment and theory is very satisfactory, yet that required the inclusion of nuclear quantum effects in the calculations. We have also discussed the role of temperature on the absorption spectrum, as well as the involvement of core-excited resonances in promoting dissociative electron attachment reactions in the 3-5 eV range.

Selective bond breaking of halothane induced by electron transfer in potassium collisions

We present novel experimental results of negative ion formation of halothane (C₂HBrClF₃) upon electron transfer from hyperthermal neutral potassium atoms (K°) in the collision energy range of 8-1000 eV. The experiments were performed in a crossed molecular beam setup allowing a comprehensive analysis of the time-of-flight (TOF) mass negative ions fragmentation pattern and a detailed knowledge of the collision dynamics in the energy range investigated. Such TOF mass spectra data show that the only negative ions formed are Br^-, Cl^- and F^-, with a strong energy dependence in the low-energy collision region, with the bromine anion being the most abundant and sole fragment at the lowest collision energy probed. In addition, potassium cation (K⁺) energy loss spectra in the forward scattering direction were obtained in a hemispherical energy analyser at different K° impact energies. In order to support our experimental findings, ab initio quantum chemical calculations have been performed to help interpret the role of the electronic structure of halothane. Potential energy curves were obtained along the C-X (X = Br, Cl) coordinate to lend support to the dissociation processes yielding anion formation.

Patterns of revascularization in stable ischemic heart disease in the pre-ISCHEMIA era

Introduction

New evidence on the role of myocardial revascularization in stable ischemic heart disease (SIHD), recently presented, showed that revascularization guided by the presence of moderate-to severe ischemia relieves angina more effectively than optimal medical therapy (OMT), without a significant benefit in hard clinical endpoints.

Aim

To assess the representativeness of the ISCHEMIA trial in a real-world population and compare management strategies between patients who fulfill the eligibility criteria of the trial (Group 1, G1) and those who do not (Group 2, G2).

Methods and population

Single centre retrospective analysis including all consecutive patients referred to coronary angiography (CA) for SIHD from January 2018 to December 2019. Patients were stratified in two groups (G1 and G2) according to the ISCHEMIA trial inclusion and exclusion criteria. G1 was compared with G2 and with a subset of G2 with obstructive coronary artery disease (CAD), defined as ≥70% luminal stenosis in at least one coronary artery or >50% for the left main.

Results

A total of 1020 patients underwent CA, of whom only 124 (12.2%) would have been eligible for the ISCHEMIA trial (G1). Overall, there were no significant differences in baseline characteristics between the two groups. G1 patients had more extensive and severe disease, presenting more frequently with proximal left anterior descending (LAD) involvement (26.6% vs 10.4%; p<0.001), two vessel disease without proximal LAD stenosis (23.4% vs 10.3%; p<0.001) and three vessel disease (18.5% vs 5.9%; p<0.001). These patients had higher rates of revascularization, both CABG (25.8% vs 10.8%, p<0.001) and PCI (56.5% vs 39.5%, p<0.001). However, when comparing G1 with the subset of G2 patients with obstructive CAD, G1 patients had higher rates of CABG (26.8% vs 17.8%, p=0.034) but there were no differences on the rates of PCI (58.0% vs 56.9%, p=0.916).

Conclusions

Patients included in the ISCHEMIA trial are underrepresented in a real-world population of SIHD patients referred to coronary angiography. PCI rates were similar among patients with at least one significant coronary artery stenosis, regardless of previous evidence or severity of ischemia. Our findings underline the need for further refinement in criteria for revascularization in SIHD.

Funding Acknowledgement

Type of funding source: None

Unveiling coronary inflammation by perivascular fat angio-CT: a propensity-matched score analysis

Background

Inflammation plays a pivotal role in the atherogenic process and recently has been the target of successful clinical trials. A new CT angiography method allows the identification of inflammatory pericoronary fat, which is associated with cardiovascular events. We aimed to determine whether patients with obstructive coronary artery disease (CAD) have a higher pericoronary inflammatory milieu when compared to those without CAD.

Methods

From a prospective CT angiography registry of patients with suspected obstructive CAD, those with a luminal stenosis >70% confirmed by invasive coronary angiography were screened (previous coronary artery bypass grafting was an exclusion criteria). Subsequently, we applied a 1:1 propensity score (PS) without replacement protocol to match obstructive CAD patients with those without CAD (non-CAD), using age, gender, BMI, hypertension, dyslipidemia, diabetes and smoking status as covariates. Similar to previous reports, pericoronary fat characterization by CT angiography was performed by analyzing the fat attenuation index (FAI) at the −30 to −190 HU range. Inflammatory fat was defined by a FAI >−70 HU. The proximal 50mm of the right coronary artery (RCA) was used to perform fat quantification and characterization. The perivascular fat was defined as the adipose tissue within a radial distance from the outer vessel wall equal to the diameter of the vessel.

Results

A matched cohort of 48 patients was identified (mean age 63 years; 77% males) – 24 obstructive CAD and 24 non-CAD patients. Mean FAI was numerically higher in obstructive CAD compared to the non-CAD cohort (−74±7 vs −78±7; p=0.083). Although not statistically significant, those with obstructive CAD had an increased proportion of inflammatory fat (51±10 vs 46±10%; p=0.107). After adjustment for body surface area (BSA), differences in the inflammatory fat proportion became apparent between obstructive CAD and non-CAD patients (28±6 vs 24±5%/m2; p=0.024). Furthermore, we observed a significant correlation between the inflammatory fat proportion (both absolute value and BSA adjusted) and the total number of RCA plaques (r=0.458; p=0.003; and r=0.451; p=0.003, respectively). Finally, there was 1 additional plaque observed in the RCA for each increase in 10% of proportion of inflammatory fat (p=0.018).

Conclusions

Perivascular coronary inflammation, as measured by FAI, seems significantly heightened in patients with obstructive CAD compared to a matched cohort of non-CAD patients. Further studies are needed to ascertain the mechanisms and possible implications of this association.

Funding Acknowledgement

Type of funding source: None

Risk stratification in hf with mid-range LVEF: the role of cardiopulmonary exercise testing

Background

Cardiopulmonary exercise testing (CPET) is recommended in the evaluation of selected patients with Heart Failure (HF). Notwithstanding, its prognostic significance has mainly been ascertained in those with left ventricular ejection fraction (LVEF) <40% (i.e., HFrEF). The main goal of our study was to assess the role of CPET in risk stratification of HF with mid-range (40–49%) LVEF (i.e., HFmrEF) compared to HFrEF.

Methods

We conducted a single-center retrospective study of consecutive patients with HF and LVEF <50% who underwent CPET from 2003–2018. The primary composite endpoint of death, heart transplant or HF hospitalization was assessed.

Results

Overall, 404 HF patients (mean age 57±11 years, 78.2% male, 55.4% ischemic HF) were included, of whom 321 (79.5%) had HFrEF and 83 (20.5%) HFmrEF. Compared to the former, those with HFmrEF had a significantly higher mean peak oxygen uptake (pVO2) (20.2±6.1 vs 16.1±5.0 mL/kg/min; p<0.001), lower median minute ventilation/carbon dioxide production (VE/VCO2) [35.0 (IQR: 29.1–41.2) vs 39.0 (IQR: 32.0–47.0); p=0.002) and fewer patients with exercise oscillatory ventilation (EOV) (22.0 vs 46.3%; p<0.001). Over a median follow-up of 28.7 (IQR: 13.0–92.3) months, 117 (28.9%) patients died, 53 (13.1%) underwent heart transplantation, and 134 (33.2%) had at least one HF hospitalization. In both HFmrEF and HFrEF, pVO2 <12 mL/kg/min, VE/VCO2 >35 and EOV identified patients at higher risk for events (all p<0.05). In Cox regression multivariate analysis, pVO2 was predictive of the primary endpoint in both HFmrEF and HFrEF (HR per +1 mL/kg/min: 0.81; CI: 0.72–0.92; p=0.001; and HR per +1 mL/kg/min: 0.92; CI: 0.87–0.97; p=0.004), as was EOV (HR: 4.79; CI: 1.41–16.39; p=0.012; and HR: 2.15; CI: 1.51–3.07; p<0.001). VE/VCO2, on the other hand, was predictive of events in HFrEF but not in HFmrEF (HR per unit: 1.03; CI: 1.02–1.05; p<0.001; and HR per unit: 0.99; CI: 0.95–1.03; p=0.512, respectively). ROC curve analysis demonstrated that a pVO2 >16.7 and >15.8 mL/kg/min more accurately identified patients at lower risk for the primary endpoint (NPV: 91.2 and 60.5% for HFmrEF and HFrEF, respectively; both p<0.001).

Conclusions

CPET is a useful tool in HFmrEF. Both pVO2 and EOV independently predicted the primary endpoint in HFmrEF and HFrEF, contrasting with VE/VCO2, which remained predictive only in latter group. Our findings strengthen the prognostic role of CPET in HF with either reduced or mid-range LVEF.

Funding Acknowledgement

Type of funding source: None

Who is too old for epicardial fat volume quantification?

Introduction

Epicardial adipose tissue has been implicated in the pathophysiology of atrial fibrillation (AF) and was recently shown to be an independent predictor of AF relapse rate and severity after pulmonary vein isolation (PVI). However, its impact in older patients hasn't been analyzed. The aim of this study was to assess the relative importance of pericardial fat in an older population of patients undergoing pulmonary vein isolation (PVI).

Methods

Single-center retrospective study of symptomatic drug-resistant AF patients undergoing PVI from November/2015 to June/2019. Baseline demographics, clinical and imaging data including cardiac CT and clinical outcomes were collected and analyzed. Population was dichotomized according to age above or below 70 years of age and groups were compared. Epicardial fat volume was quantified by contrast-enhanced cardiac CT using a semi-automated method. The study endpoint was symptomatic and/or documented AF recurrence after a 3-month blanking period.

Results

We assessed 575 patients (354 males, mean age 61±11 years, 449 paroxysmal AF), 145 of which were 70 or older. Compared to the younger cohort, these patients had an higher prevalence of women, lower BMI (27 kg/m2 [IQR 24–30] vs 28 kg/m2 [IQR 25–30] kg/m2, p=0.012), higher CHA2DS2-VASc score (3 [IQR 2–4] vs 1 [IQR 1–2], p<0.001) and larger indexed left atrial volumes (61mL [IQR 52–84] vs 54mL [IQR 47–66], p<0.001).

Median epicardial fat volume was 2.96 cm3/m2 [IQR 2.99–4.00] in the overall population and was higher in older patients (HR 2.21 cm3/m2 [IQR 1.44–3.17] vs HR 1.87 cm3/m2 [IQR 1.24–2.90]; p=0.016).

During follow-up, 232 patients relapsed (40%), with similar recurrence rates between younger and older patients (40% vs 42%, p=0.63) according to Kaplan-Meier survival curve analysis (HR 1.10, 95% CI 0.82–1.48; log-rank p=0.519). Epicardial fat volume remained an independent predictor of AF relapse in the older subset of patients (HR 1.06 for every 1 cm3/m2 increase in epicardial fat volume [95% CI 1.28–2.00]; p<0.001), as did the presence of non-paroxysmal AF (HR 2.78 [95% CI 1.48–5.21]; p=0.001).

Conclusion

Patients over 70 years old with drug-refractory symptomatic AF presented with higher epicardial fat volume. Epicardial fat burden showed similar predictive power for AF relapse after PVI in this subset of patients, representing a useful tool for intervention decision across this age spectrum.

Funding Acknowledgement

Type of funding source: None

External validation of a new staging system for severe aortic stenosis in a Portuguese cohort

Background

Recently, a new staging system for severe aortic stenosis (AS) based upon the extent of extra-aortic-valve cardiac damage has been developed (Genereux et al. Eur Heart J 2017). The present study aimed to: 1) determine the prevalence of the different stages of extra-aortic valvular cardiac damage and its impact on prognosis in a real-world Portuguese cohort and; 2) evaluate the distribution of aortic valve calcium score (AV-CaSc) and its prognostic value.

Methods

Consecutive patients evaluated at a single-centre TAVI-programme between Nov/2015 and Nov/2018 were retrospective selected. The extent of extra-aortic valve cardiac damage was defined by echocardiography as stage 0 (no cardiac damage), stage 1 (left ventricular damage), stage 2 (mitral valve or left atrial damage), stage 3 (tricuspid valve or pulmonary artery vasculature damage) or stage 4 (right ventricular damage). AV-CaSc was estimated routinely at CT-angiography as per TAVI-programme protocol. The primary endpoint was 1-year all-cause mortality after CT-angiography. Survival analysis (Cox-regression hazards model and Kaplan-Meier) was performed. To account for the effect of aortic valve replacement (AVR), this variable entered the Cox-regression model as a time-dependent covariate.

Results

A total of 443 patients (mean age 82±7 years, 44% men, median euroSCORE II 4% [IQR 2.4–5.8]) were identified. After Heart Team discussion, 79% (n=349) underwent AVR (TAVI=307; surgical valve repair=42); 9% (n=42) await intervention; 6% (n=25) remain under medical treatment; 4% (n=19) died during the period of evaluation; and 2% (n=8) underwent palliative aortic balloon valvuloplasty.

According to the proposed classification, the distribution of patients from stages 0 through 4 was: 0.2% (n=1), 7.5% (n=34), 67.8% (n=306), 14% (n=63), and 10.4% (n=47). Additionally, for each increasing stage of cardiac damage, the burden of AV-CaSc was higher (from stage 1 through 4: 1776 [IQR 1217–2448]; 2448 [1796–3442]; 2448 [1832–3622]; 2960 [1936–4878] units; p for trend = 0.002).

All-cause mortality at 1-year was 14% (n=63). Mortality increased alongside with increasing extent of cardiac damage (from stage 0 through 4: 0% [n=0], 6% [n=2], 12% [n=36], 20% [n=12], and 30% [n=13]) – Fig. Multivariable analysis revealed chronic renal disease (HR 1.37 per stage [1.15–1.64], p<0.001), AV-CaSc (HR 1.02 per 100 units [1.01–1.03], p=0.007), AVR (HR 0.46 [0.26–0.81], p=0.007) and stage of cardiac damage (HR 1.54 per stage [1.15–2.05], p=0.004) as independent predictors of 1-year mortality.

Conclusion

In a real-world Portuguese cohort of severe AS patients, the extent of cardiac damage was associated with 1-year mortality. AV- CaSc grants additional prognostic information to this classification. Incorporation of this staging system into patient evaluation may be useful in the risk assessment of severe AS.

Survival analysis

Funding Acknowledgement

Type of funding source: None

Epicardial fat volume outperforms classic clinical scores for predicting atrial fibrillation relapse after pulmonary vein isolation

Background

Epicardial adipose tissue has been implicated in the pathophysiology of atrial fibrillation (AF), but its relevance to clinical practice remains uncertain. The aim of this study was to compare the performance of the amount of epicardial fat with previously published clinical scores of AF-relapse risk after pulmonary vein isolation (PVI).

Methods

We assessed 575 patients (354 men, age 61±11 years, 449 paroxysmal AF) with symptomatic AF undergoing cardiac CT prior to a PVI procedure. Epicardial fat was quantified on contrast-enhanced images using a new simplified semi-automated method. The study endpoint was symptomatic and/or documented AF recurrence at 12 months. Epicardial fat was compared against the following scores: MB-LATER, APPLE, DR-FLASH, and ATLAS.

Results

Median follow-up was of 22 months (IQR 12–35), 232 patients relapsed, 130 patients (27%) within the first 12 months. After adjustment for BMI and other univariate predictors of relapse, three variables emerged independently associated with time to AF recurrence: non-paroxysmal AF (HR 2.03, 95% CI: 1.53–2.69, p<0.001), indexed left atrial (LA) volume (HR 1.02 per mL/m2, 95% CI: 1.01–1.02, p<0.001), and indexed pericardial fat volume (HR 1.55 per mL/m2, 95% CI: 1.43–1.67, p<0.001). Based on the ROC curve analysis, the epicardial fat showed greater discriminative power, with a C-statistic of 0.76 (95% CI: 0.71–0.81) against 0.67 (p=0.007 for pairwise comparison of ROC curves), 0.67 (p=0.01), 0.63 (p<0.001) and 0.57 (p<0.001) for the MBLATER, APPLE, DR-FLASH and ATLAS scores, respectively. The C-statistic for indexed LA volume and non-paroxysmal AF AUC were of 0.63 (p<0.001) and 0.61 (p<0.001), respectively.

Conclusion

Pericardial fat volume is a strong independent predictor of AF relapse after PVI, outperforming clinical scores of post-PVI AF. The underlying mechanisms of this association deserve further study.

ROC Curve Analysys

Funding Acknowledgement

Type of funding source: None

Predicting pacemaker implantation after TAVR with procedural CT

Background and aim

The need for permanent pacemaker implantation (PPMI) is a burdensome complication of transcatheter aortic valve replacement (TAVR). Calcium distribution in the aortic-valvular complex (AVC) and, more recently, membranous septum (MS) length seem to be surrogate markers for conduction abnormalities after specific last generation balloon and self-expandable expandable valves. We sough to evaluate whether such pre-procedural association remains across the entire device spectrum.

Methods

Single-centre prospective study of 239 consecutive patients (140 women, median age of 84) with severe symptomatic aortic stenosis patients who underwent ECG-gated contrast-enhanced multi-detector computed tomography (MSCT) before TAVR since Jun/2017. Exclusion criteria were those with previous PPMI, previous bioprothesis, congenital bicuspid valve, and poor imaging quality. The J-score with an 850-Hounsfield unit threshold was used to detect areas of calcium in the region of interest. AVC was characterized by leaflet sector and region, using 3mensio Valves software 7.0 TM. An independent team retrospectively measured MS length blindly by determining the thinnest part of the interventricular septum in the coronal view in the better-defined systolic phase (usually at 40% of the R-R interval, Figure). Device selection (75.8% self-expandable devices, 20.1% balloon expandable, 3.1% other) and positioning were performed according to the operator criteria. Final implant depth was assessed based on the pre-release angiogram or final aortography.

Results

Mortality at 30-days was 1.3% and PPMI occurred in 43 patients (18%). Median MS length was 9.59mm (IQR: 3.11mm). After multivariable logistic regression analysis, MS length emerged as the single significant protective predictor for PPMI (OR: 0.14; 95% 95% CI: 0.05–0.42; p<0.001), independently of the device used (p<0.001). MS length showed strong discriminatory ability for PPMI (c-statistic 0.93; 95% CI 0.88–0.99). Sensitivity/specificity decision plots yielded an MS length of 6.9 mm as the optimal cut-off point for predicting the need for PPMI with a positive and negative predictive value of 91% and 93%, respectively (Figure). There wasn't any calcium accumulation within a specific region of AVC that independently predicted the outcome.

Conclusion

In our experience, a short membranous septum was strongly and independently associated with new permanent pacemaker implantation, regardless of the device type.

Our findings suggest that this simple measure should be routinely made to help device selection and implantation technique.

Funding Acknowledgement

Type of funding source: None

Prevalence of LAA thrombus in patients undergoing percutaneous ablation of atrial fibrillation

Introduction

Computed tomography (CT) is often performed before atrial fibrillation (AF) ablation to assess the anatomy of the pulmonary veins and exclude left atrial (LA) and left atrial appendage (LAA) thrombus. With the growing use of new oral anticoagulants (NOACs), a reassessment of the need for systematic thrombus exclusion in this context seems warranted.

Objective

To evaluate the prevalence of thrombus in LA/LAA in pre-ablation CT in a contemporary cohort of patients predominantly anticoagulated with NOACs.

Methods

We evaluated 789 consecutive patients (mean age 61±12 years; 38% female; 84% with paroxysmal AF) who underwent pre-ablation CT between Oct/2015 and Oct/2019. ECG-gated CT-angiography was performed using a dual-source 64-slice CT after iodinated contrast injection. Whenever necessary, a second dedicated acquisition was made 60 seconds after the first set of images. Presence of thrombus was defined as a persistent opacification defect. For each patient, thromboembolic risk was assessed with the CHA2DS2-VASc score.

Results

The median interval between CT and AF ablation was 1 day (IQR 1 – 2 days). The median CHA2DS2-VASc was 2 points (IQR 0 – 3 points), with 590 patients (75%) having CHA2DS2-VASc ≥1. Among the 199 patients (25%) with CHA2DS2-VASc = 0, 118 (59,3%) were anticoagulated with a NOAC and 14 (7%) with a vitamin K antagonist; 67 (34%) were not anticoagulated. Conversely, amongst the 590 patients with CHA2DS2-VASc ≥1, 84% were anticoagulated with a NOAC (n=494), 11% used vitamin K antagonists (n=62), and 34 patients were not anticoagulated (23 with CHA2DS2-VASc = 1). On cardiac CT, 521 (66%) patients were in sinus rhythm. Overall, only one LAA thrombus was found (0.12% [1/789]; 95% CI: 0.0–0.7%) – in a patient with CHA2DS2-VASc = 0, anticoagulated with a NOAC. The median effective radiation dose was 3.2 mSv (IQR 2.1–4.8 mSv). There were 5 minor allergic reactions to iodinated contrast. No strokes were documented within the first 24 hours after ablation.

Conclusion

In this contemporary cohort of patients with predominantly paroxysmal AF and anticoagulated with NOAC, the prevalence of intracavitary thrombus was extremely low (0.12%). While these findings do not compromise the multipurpose role of pre-ablation CT, they should nevertheless inform future discussions on the risk/benefit and cost/benefit of performing systematic exclusion of LA/LAA thrombi prior to AF ablation.

Funding Acknowledgement

Type of funding source: None

Lung water quantification by cardiac magnetic resonance imaging: a novel prognostic tool in hf

Background

Cardiac magnetic resonance (CMR) imaging has recently been proposed to quantify lung water density (LWD, %) non-invasively. Given that pulmonary congestion plays a key role in the pathophysiology of Heart Failure (HF), we designed a study to assess the prognostic significance of a simplified LWD measure in patients with HF and reduced left ventricular ejection fraction (LVEF).

Methods

We conducted a single-center retrospective study of consecutive patients with HF and LVEF <50% who underwent CMR on a 1.5T scanner. Those with severe interstitial lung disease or chronic liver disease were excluded. All measurements were performed in a parasagittal plane at the right midclavicular line on a standard HASTE sequence, which is widely available in all CMR studies. As previously reported, LWD was determined by the lung-to-liver signal ratio multiplied by 0.7. A cohort of 102 healthy controls was used to derive the upper limit of normal (mean ± 2SD) of the LWD (21.2%). The primary endpoint was a composite of all-cause death or HF hospitalization.

Results

A total of 290 HF patients (mean age 64±12 years, 74.8% male, 56.2% of ischemic etiology) with a mean LVEF of 34±10% were included. LWD measurement took on average 35±4 seconds and showed excellent inter-observer agreement (intra-class correlation coefficient >0.90). LWD was increased in 65 (22.4%) patients. Compared to those with normal LWD, the former were more symptomatic (NYHA ≥III: 29.2% vs. 1.8%; p=0.017) and had higher median NT-proBNP [1973 (IQR: 809–3766) vs 802 (IQR: 355–2157pg/mL); p<0.001]. During a median followup of 21 months (IQR: 13–29), 20 (6.9%) patients died and 40 (13.8%) had at least one HF hospitalization. In multivariate analysis, LVEF (HR per 1%: 0.96; CI-95%: 0.93–0.99; p=0.024), creatinine (HR per 1mg/dL: 2.43; CI-95%: 1.25–4.71; p=0.009) and LWD (HR per 1%: 1.06; CI-95%: 1.01–1.12; p=0.013) were independent predictors of the primary endpoint. The findings were mainly driven by an association between LWD and HF hospitalization (HR per 1%: 1.08; CI-95%: 1.03–1.13; p=0.002).

Conclusions

A CMR-derived method for LWD quantification independently predicts an increased risk of death or HF hospitalization in HF patients with LVEF <50%. Our results support LWD measurement as a simple, reproducible and widely available method, further adding to the prognostic role of CMR in this population.

Funding Acknowledgement

Type of funding source: None

A machine-learning algorithm to predict atrial fibrillation recurrence after a pulmonary vein isolation procedure

Background

Contemporary risk models to predict the recurrence of atrial fibrillation (AF) after pulmonary vein isolation have limited predictive ability. Models with high specificity seem particularly suited for the setting of AF ablation, where they could be used as gatekeepers to withhold intervention in patients with low likelihood of success. Machine learning (ML) has the potential to identify complex nonlinear patterns within datasets, improving the predictive power of models. This study sought to determine whether ML can be used to better identify patients who will relapse within one year of an AF ablation procedure.

Methods

We assessed 484 patients (294 men, mean age 61±12 years, 76% with paroxysmal AF) who underwent radiofrequency pulmonary vein isolation (PVI) for symptomatic drug-refractory AF. Using this dataset, a machine-learning model based on Support Vector Machines (SVM) was developed to predict AF recurrence within one year of the procedure. The following variables were used to feed the model: type of AF (paroxysmal vs. non-paroxysmal), previous ablation procedure, left atrium (LA) volume, and epicardial fat volume (both derived from pre-ablation cardiac CT). The algorithm was trained in a random sample of 70% of the study population (n=339) and tested in the remainder 30% (n=145).

Results

A total of 130 patients (27%) suffered AF recurrence within one year of the procedure. The ML model predicted AF recurrence with 75% accuracy (95% CI 67–82%), yielding a sensitivity and specificity of 25% (95% CI 13–41%) and 94% (95% CI 88–98%), respectively. The corresponding positive and negative predictive values were 62% (95% CI 39–81%) and 77% (95% CI 67–82%), respectively. The relative weight of the variables in the ML model was: epicardial fat 56%, type of AF 23%, previous ablation 14%, and LA volume 7%. A high-risk subgroup representing 10.8% of patients was identified with the ML algorithm. In this subgroup, one-year recurrence was 62%, representing 24% of the total number of recurrences.

Conclusion

A machine-learning model showed high specificity in the identification of patients who relapse during the first year after AF ablation. In the future, these tools may be useful to improve patient selection.

Funding Acknowledgement

Type of funding source: None

Relationship between epicardial fat and left atrium fibrosis in patients with atrial fibrillation

Background

Epicardial adipose tissue (EAT) has recently been shown to be associated with the presence, severity, and recurrence of atrial fibrillation (AF). Although the pathophysiological mechanisms underlying this association remain to be established, several hypotheses have been put forward, including direct adipocyte infiltration, oxidative stress, and the secretion of adipokines causing inflammation and fibrosis of atrial tissue. We hypothesized that the volume of EAT and the amount of left atrium (LA) fibrosis assessed by non-invasive imaging would be significantly correlated in patients with AF, and that both would predict time to relapse after pulmonary vein isolation (PVI).

Methods

Sixty-eight patients with AF being studied for a first PVI procedure underwent both cardiac computerized tomography (CT) and cardiac magnetic resonance (CMR) within less than 48h. EAT was quantified on contrast-enhanced CT images. LA fibrosis was quantified on isotropic 1.5mm 3D delayed enhancement CMR for image intensity ratio values >1.20. Radiofrequency PVI was performed using an irrigated contact force-sensing ablation catheter, guided by electroanatomical mapping. After PVI, patients were followed for AF recurrence, defined as symptomatic or documented AF after a 3-month blanking period. Pearson's correlation coefficient was used for gauging the correlation between EATLM volume and LA fibrosis. The relationship between these two variables and time to AF recurrence was assessed by Cox regression.

Results

Most of the 68 patients (46 men, mean age 61±12 years) had paroxysmal AF (71%, n=48). The mean body mass index (BMI) was 28.0±4.0 kg/m2. Patients had a median EATLM volume of 2.4 cm3/m2 [interquartile range (IQR) 1.6–3.2 cm3/m2], and a median estimated amount of LA fibrosis of 8.9 g (IQR 5–15 g), corresponding to 8% (IQR 5–11%) of the total LA wall mass. The correlation between EATLM and LA fibrosis was statistically significant but weak (Pearson's R = 0.38, P=0.001) – Figure 1. During a median follow-up of 22 months (IQR 12–31), 31 patients (46%) suffered AF recurrence. Four predictors of relapse were identified in univariate Cox regression: EATLM (HR 2.19, 95% CI 1.65–2.91, P<0.001), LA fibrosis (HR 1.05, 95% CI 1.01–1.09, P=0.033), non-paroxysmal AF (HR 3.36, 95% CI 1.64–6.87, P=0.001), and LA volume (HR 1.03, 95% CI 1.01–1.06, P=0.006). Multivariate analysis yielded two independent predictors of time to AF relapse: EATLM (HR 2.05, 95% CI 1.51–2.79, P<0.001), and non-paroxysmal AF (HR 2.36, 95% CI 1.08–5.16, P=0.031).

Conclusion

The weak correlation between EAT and LA suggests that LA fibrosis is not the main mechanism by which EAT and AF are linked. EAT was more strongly associated with AF recurrence than LA fibrosis, which supports the existence of other, more important mediators between EAT and this arrhythmia.

Correlation between EAT and LA

Funding Acknowledgement

Type of funding source: None

Downstream testing after an halted coronary CT angiography due to high coronary artery calcium score

Background and aim

In many centers, coronary artery calcium score (CACS) is performed immediately before coronary CT angiography (CCTA) in order to exclude heavy calcification that could hamper test performance. When high CACS values are found, CCTA is usually aborted and other tests suggested. However, there are no recommendations on which test to pursue, and little data on their diagnostic yield in this setting. The aim of this study was to assess the type and results of downstream testing among patients whose CCTA study was halted due to high CACS.

Methods

Single-centre retrospective study of consecutive patients undergoing CCTA for suspected obstructive coronary artery disease (CAD). A CACS threshold of >400 was generally used to cancel CCTA. Downstream testing and its results were assessed using electronic medical records. A group of consecutive patients with CACS <400 who underwent CCTA was used for comparison.

Results

Of the 795 patients who performed CCTA for suspected CAD, 86 (10.8%), had their test halted due to high CACS (57 men, mean age 71±11 years). In this subgroup, the median pre-test probability for CAD was 27% (interquartile range 25) and the median CACS was 983 (interquartile range 930). Compared to patients who underwent CCTA, those who saw their tests cancelled were older, more frequently male, and had higher prevalence of cardiovascular risk factors and higher pre-test probability for CAD.

Patient's downstream testing is illustrated in Figure. From the 86 patients enrolled, 12 are currently waiting for downstream tests and were excluded from further analysis. Overall, 35 patients ended up performing invasive coronary angiography (ICA, 47.3%) of whom 19 (54.3%) had significant CAD. Among those who underwent non-invasive testing (N=19, 25.7%), 10 (52.6%) had significant ischemia and 4 (21%) underwent additional testing with ICA. In 24 patients (32.4%), no downstream testing was pursued. Finally, 17 (22.3%) patients underwent coronary revascularization, either percutaneous (N=10, 13.5%) or surgical (N=7, 10.8%).

Conclusion

Invasive coronary angiography is the most frequently used downstream test when CCTA is halted due to high CACS values, and shows significant CAD in roughly half of the cases. Considering the high prevalence of significant CAD, direct referral for ICA (with the possibility of invasive functional testing) seems a reasonable approach.

Funding Acknowledgement

Type of funding source: None

Pre-test probability of obstructive coronary artery disease in the new guidelines: too much, too little or just enough?

Background

Previous 2013 ESC guidelines recommended the use of the Modified Diamond-Forrester method to assess the pre-test probability (PTP) of obstructive coronary artery disease (CAD). The 2019 ESC Chronic Coronary Syndrome guidelines updated this recommendation with a major downgrade in PTP. The aim of this study was to compare the performance of these two methods in patients with stable chest pain undergoing coronary computed tomography angiography (CCTA) for suspected CAD.

Methods

We performed a retrospective analysis on prospectively collected data from a cohort of consecutive patients undergoing CCTA for suspected CAD from October 2016 to 2019. Key exclusion criteria were age <30 years-old, known CAD, suspected acute coronary syndrome or symptoms other than chest pain. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. Whenever invasive coronary angiography (ICA) was subsequently performed, patients were reclassified if luminal stenosis was <50%. The two PTP prediction models were assessed for calibration and discrimination.

Results

A total of 320 patients (median age 63 years [IQR 53–70], 59% women) were included. Chest pain characteristics were: 48% atypical angina, 38% non-anginal chest pain, 14% typical angina. The observed prevalence of obstructive CAD was 16.3% (n=52). Patients with obstructive CAD were more often male, were significantly older and had a higher prevalence of typical angina and cardiovascular risk factors (except for family history of CAD). On average, individual PTP was 22.1% lower in the new guidelines. The 2013 prediction model significantly overestimated the likelihood of obstructive CAD (mean PTP 37.3% vs 16.3%; relative overestimation of 130%, p-value for miscalibration 0.005). The updated 2019 method showed good calibration for predicting the likelihood of obstructive CAD (mean PTP 15.2% vs 16.3%; relative underestimation of 6.5%, p-value for miscalibration 0.712). The two approaches showed similar discriminative power, with a C-statistics of 0.730 and 0.735 for the 2013 and 2019 methods, respectively (p-value for comparison 0.933). Stratification by gender produced similar results.

Conclusions

In patients with stable chest pain undergoing CCTA, the updated 2019 prediction model allows for a more precise estimation of pre-test probabilities of obstructive CAD than the previous model. Adoption of this new score may improve disease prediction and change the downstream diagnostic pathway in a significant proportion of cases.

Graph 1

Funding Acknowledgement

Type of funding source: None

Combined endocardial and epicardial ventricular tachycardia ablation for ischemic and nonischemic dilated cardiomyopathy

Background

Patients with ischemic (IHD) and nonischemic (NICM) dilated heart disease and reduced left ventricular ejection fraction are at increased risk of ventricular tachycardias (VTs) or sudden cardiac death. VT catheter ablation is an invasive treatment modality for antiarrhythmic drugs-resistant VT that reduces arrhythmic episodes, improves quality of life and improves survival in patients with electrical storm. Direct comparison of the outcomes from combined and non-combined endoepicardial ablations is limited by patient characteristics, follow-up durations, protocols heterogeneity and scarcity of randomized trials. We aim to investigate the long-term clinical outcomes of these 2 strategies in the IHD and NICM populations.

Methods

Multicentric observational registry including 316 consecutive patients who underwent combined (C-ABL) and non-combined (NC-ABL) endoepicardial ventricular tachycardia (VT) ablation for drug-resistant VT between January 2008 and July 2019. Chagas' disease patients were excluded. Primary and secondary efficacy endpoints were defined as VT-free survival and all-cause death after ablation. Safety outcomes were defined by 30-days mortality and procedure-related complications.

Results

Most of the patients were male (85%), with IHD (67%) and a mean age of 63±13 years. During a mean follow-up of 3±2 years, 117 (37%) patients had VT recurrence and 73 (23%) died. Multivariate survival analysis identified storm (ES) at presentation (HR=2.17; 95% CI 1.44–3.25), IHD (HR=0.53, 95% CI 0.36–0.78), left ventricular ejection fraction (LEVF) (HR=0.97, 95% CI 0.95–0.99), New York Heart Association (NYHA) functional class III or IV (HR=1.79, 95% CI 1.13–2.85) and C-ABL (HR=0.49, 95% CI 0.27–0.92) as independent predictors of VT recurrence. In 135 patients undergoing two or more ablation procedures only C-ABL (HR=0.36, 95% CI 0.17–0.80) and ES at presentation (HR=2.42, 95% CI 1.24–4.70) were independent predictors of arrhythmia recurrence. The independent predictors of all-cause mortality were ES (HR=2.17, 95% CI 1.33–3.54), LVEF (HR=0.95, 95% CI 0.92–0.98), age (HR=1.03, 95% CI 1.01–1.05), NYHA functional class III or IV (HR=2.04, 95% CI 1.12–3.73), and C-ABL (HR=0.22, 95% CI 0.05–0.91). The survival benefit was only seen in patients with a previous ablation (P for interaction=0.04) – Figure 1. Mortality at 30-days was similar between NC-ABL and C-ABL (4% vs. 2%, respectively, P=0.777), as was the complication rate (10.3% vs. 15.1% respectively, P=0.336).

Conclusion

A combined endo-epicardial approach appears to be associated with greater VT-free survival and overall survival in ischemic and nonischemic patients undergoing repeated VT catheter ablations. Both strategies seem equally safe.

Survival analysis for C-ABL vs NC-ABL

Funding Acknowledgement

Type of funding source: None