Clot composition and recanalization outcomes in mechanical thrombectomy

BACKGROUND

Mechanical thrombectomy (MT) has become standard for large vessel occlusions, but rates of complete recanalization are suboptimal. Previous reports correlated radiographic signs with clot composition and a better response to specific techniques. Therefore, understanding clot composition may allow improved outcomes.

METHODS

Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin-eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of first-pass effect (FPE, modified Thrombolysis in Cerebral Infarction 2c/3) and the number of passes.

RESULTS

A total of 1430 patients of mean±SD age 68.4±13.5 years (median (IQR) baseline National Institutes of Health Stroke Scale score 17.2 (10.5-23), IV-tPA use 36%, stent-retrievers (SR) 27%, contact aspiration (CA) 27%, combined SR+CA 43%) were included. The median (IQR) number of passes was 1 (1-2). FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for red blood cell (RBC)-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes than RBC-rich and mixed clots (median 2 and 1.5 vs 1, respectively; P=0.02). CA showed a trend towards a higher number of passes with fibrin-rich clots (2 vs 1; P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots.

CONCLUSIONS

Despite the lack of correlation between clot histology and FPE, our study adds to the growing evidence supporting the notion that clot composition influences recanalization treatment strategy outcomes.

30 years of the ABFO study: Reproduction in a Brazilian sample

The ABFO study on third molar development is a benchmark in the scientific literature of dental age estimation. In its 30th anniversary, the study has been reproduced in the present external validation. Standardized comparative outcomes were obtained and discussed across studies. The sample consisted of 1.087 panoramic radiographs of Brazilian females (n=542, 49.87%) and males (n=545, 50.13%) between 14 and 22.9 years. All available third molars were classified into developmental stages following Mincer's adaptation of Demirjian's system (8 sequential stages, from A to H). The mean chronological age of individuals within each stage was assessed. The probability of an individual being ≥ 18 years was calculated for each third molar, sex and stage. Maxillary and mandibular third molars showed a similar development with an agreement between stages of about 90%. In general, males developed 0.5 years (6 months) earlier than females. The probability of being an adult increased considerably when at least one third molar is in stage G. Maxillary third molars had higher coefficients of determination (right: 0.704; left: 0.702), showing that statistical models with these teeth could explain better the age estimation outcomes. The reproducibility of the ABFO study on third molar development led to reference tables and probability measures for the studied Brazilian population.

Abstract 99: Clot Composition And Reperfusion Outcomes In 1430 Mechanical Thrombectomy Patients: Analysis Of The Stroke Thromboembolism Registry Of Imaging And Pathology

Background: Understanding clot composition may allow for better technical planning and improved outcomes in mechanical thrombectomy (MT). We sought to correlate clot composition with reperfusion outcomes in MT.

Methods: Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin and eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of First-Pass Effect (mTICI2c/3, FPE) and the number of device passes.

Results: A total of 1430 patients (mean age, 68.4±13.5years; median [IQR] baseline NIHSS,17.2 [10.5-23]; IV-tPA use, 36%; Stent-Retrievers [SR], 27%; Contact Aspiration [CA], 27%; Combined SR + CA, 43%) were included. The median [IQR] number of passes was 1 [1-2]. FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for RBC-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes compared to RBC-rich and mixed clots (median, 2 and 1.5 vs.1, respectively, P=0.02). CA displayed a trend towards a higher number of passes with fibrin-rich clots (2 vs.1, P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots.

Conclusion: Despite the lack of correlation between clot histology and FPE in the overall population, our study adds to the growing body of evidence supporting the notion that clot composition influences reperfusion treatment strategy outcomes. Additional studies are needed.

Direct to Angiosuite Versus Conventional Imaging in Suspected Large Vessel Occlusion: A Systemic Review and Meta-Analysis

BACKGROUND

There is growing evidence to suggest that the direct transfer to angiography suite (DTAS) approach for patients with suspected large vessel occlusion stroke potentially requiring mechanical thrombectomy shortens treatment times and improves outcomes compared with the direct transfer to conventional imaging (DTCI) model. Therefore, we conducted this meta-analysis to compare both approaches to build more concrete evidence to support this innovative treatment concept.

METHODS

All potentially relevant studies published in 4 electronic databases/search engines (PubMed, Web of Science, Cochrane Library, and Scopus) from inception to November 2021 were reviewed. Eligible studies were included if they enrolled ≥10 patients in both groups, were published in English, and reported baseline and procedural characteristics and outcomes. Relevant data were then extracted and analyzed.

RESULTS

Among 4514 searched studies, 7 qualified for the analysis with 1971 patients (DTAS=675, DTCI=1296). Times from door to puncture (mean difference, -30.76 minutes [95% CI, -43.70 to -17.82]; P<0.001) as well as door-to-reperfusion (mean difference=-33.24 minutes [95% CI, -51.82 to -14.66]; P<0.001) were significantly shorter and the rates of functional independence (modified Rankin Scale score, 0-2: risk ratio [RR], 1.25 [95% CI, 1.02-1.53]; P=0.03) at 90 days were higher in the DTAS versus the DTCI approach. There was no difference across the DTAS and DTCI groups in terms of the rates of successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2B-3: RR, 1.03 [95% CI, 0.95-1.12]; P=0.42), near-complete/full reperfusion (modified Thrombolysis in Cerebral Infarction 2C-3: RR, 0.89 [95% CI, 0.74-1.08]; P=0.23), symptomatic intracranial hemorrhage (RR, 0.81 [95% CI, 0.56-1.17]; P=0.26), or fair outcomes (modified Rankin Scale score, 0-3: RR, 1.14 [95% CI, 0.88-1.47]; P=0.32) or mortality (RR, 0.98 [95% CI, 0.67-1.44]; P=0.93) at 90 days. Subgroup analysis showed no significant difference in 90-day functional independence across approaches in transfer patients (RR, 1.20 [95% CI, 0.96-1.51]; P=0.11).

CONCLUSIONS

Our meta-analysis showed that the DTAS approach seems to be associated with improved time metrics and functional outcomes with comparable safety to the DTCI approach. Ongoing multicenter randomized clinical trials will hopefully provide more definite data about this promising approach.

Specialty-related asymmetries in treatment and outcomes of younger patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) is the most common arrhythmia and one of the most frequent motives for presentation in the emergency department (ED). However, there are still significant inequalities concerning its treatment.

Purpose

We aimed to assess if management and outcomes of patients with AF differed according to the specialty to which they were referred at hospital discharge.

Methods

We conducted a retrospective single-centre analysis including adult patients admitted to the ED in 2016 with the International Classification of Diseases codes correspondent to AF. Patients older than 75 years and those whose electronic medical file was not accessible were excluded. Patient referral at discharge was not based on any pre-specified criteria but rather performed at the discretion of the physician in the ED.

We divided our sample into 3 groups according to whom the patients were referred at hospital discharge: A) patients referred to an electrophysiologist; B) patients referred to a general cardiologist; and C) those referred to a non-cardiologist (general practitioner or internist).

We assessed patient characteristics, delay to first appointment, treatment strategies as well as stroke and all-cause mortality at 3 years of follow-up.

Results

Of the 372 patients initially screened, 184 were excluded due to age over 75 and 85 patients due to inaccessible medical records, resulting in a final sample of 103 patients with a median age of 65 (58-71) years and median CHA2DS2-VASc of 2 (1-3).

At discharge from the index admission, one third of patients were referred to an electrophysiologist (group A), 41% to a general cardiologist (group B) and the remaining 26% to a non-cardiologist (group C). There were no significant differences in baseline characteristics or type of AF between the groups.

The delay from index hospital admission to the first appointment was superior in groups A and B compared with C (3 and 2 vs 0 months, p=0.050).

Patients referred to an electrophysiologist were more frequently started on a rhythm-control strategy compared with those referred to other physicians (71% vs 38% and 26%, p=0.004). Similarly, significantly more patients in group A underwent catheter ablation (47% vs 12% and 4%, p&lt;0.001), around 2 years after the diagnosis (tendentially earlier than those in group B).

At 3 years follow-up, mortality was higher in group C compared with the other groups (15% vs 0 in group A and 2% in group B, p=0.019). Stroke rates did not differ between groups.

Conclusion

In this group of AF patients, referral to an electrophysiologist at discharge was associated with a higher rate of a rhythm-control strategy, including catheter ablation. In the long-term, those patients showed better survival. These results suggest that, in patients under 75 years, an earlier referral to an electrophysiologist might be beneficial.

Impact of sleep apnea treatment with CPAP on recurrence of atrial fibrillation after catheter ablation

Funding Acknowledgements

Type of funding sources: None. Main funding source(s): None

Background

Sleep apnea, as well as other risk factors such as obesity and high blood pressure, increase the risk of recurrence of atrial fibrillation after catheter ablation. But the true impact of sleep apnea treatment on recurrence of atrial fibrillation is less well defined.

Purpose

Assess the impact of untreated sleep apnea and treatment with CPAP (continuous positive airway pressure) on the risk of atrial fibrillation recurrence in patients undergoing catheter ablation.

Methods

We performed a retrospective analysis of 160 patients undergoing catheter ablation of paroxysmal or persistent atrial fibrillation in our institution, in a period between November of 2015 and November of 2021. We compared two groups: with atrial fibrillation recurrence and without atrial fibrillation recurrence, in a follow-up period of eighteen months. We analysed the clinical characteristics, diagnosis of sleep apnea, treatment with CPAP, echocardiographic findings (indexed volume of left atrium and left ventricular ejection fraction), cardiovascular risk factors and other comorbidities (table 1). Survival analysis of atrial fibrillation recurrence was performed using a Cox Regression analysis (figure 1).

Results

During a mean follow-up time of 22,8 ± 19,9 months, 46 patients (28,8%) had atrial fibrillation recurrence and none died. The recurrence was associated with hypertension, alcohol habits and untreated sleep apnea. Untreated sleep apnea was associated with a 4-fold increased risk of atrial fibrillation recurrence (HR 3,74; 95% CI 1,89-7,42; p &lt;0,001). In patients with sleep apnea (n = 41), CPAP treatment was associated with a 74% decreased risk of recurrence (HR 0,26; 95% CI 0,10-0,72; p = 0,009).

Conclusions

Treatment with CPAP was associated with lower risk of recurrence of atrial fibrillation after catheter ablation in patients with sleep apnea.

Benefit of sleep study in all patients with atrial fibrillation and BMI&gt; 28,0 Kg/m2 before catheter ablation

Funding Acknowledgements

Type of funding sources: None. Main funding source(s): None

Background

Sleep apnea is a known risk factor for atrial fibrillation recurrence after catheter ablation. Despite this, in recent atrial fibrillation guidelines, it is unclear in which patients to test sleep apnea before catheter ablation.

Purpose

Evaluate if body mass index (BMI) has a good discriminative power to predict sleep apnea in patients with atrial fibrillation proposed to catheter ablation.

Methods

We retrospectively studied 160 consecutive patients undergoing catheter ablation of paroxysmal or persistent atrial fibrillation in our institution. We evaluated recurrence of atrial fibrillation after catheter ablation and analysed diagnosis of sleep apnea, body mass index, treatment with CPAP, echocardiographic findings (indexed volume of left atrium and left ventricular ejection fraction), cardiovascular risk factors and other comorbidities and clinical characteristics. Receiver operator characteristics (ROC) curve and area under the curve (AUC) were obtained to determine the discriminative power of body mass index as predictor of sleep apnea. Optimal cut-point value was obtained (Youden index) and patients were divided according to this value.

Results

During a mean follow-up time of 22,8 ± 19,9 months, 46 patients (28,8%) had atrial fibrillation recurrence and none died. The recurrence was associated with hypertension, alcohol habits and untreated sleep apnea (HR 3,74; 95% CI 1,89-7,42; p &lt;0,001). Optimal cut-point value for predicting sleep apnea in patients with atrial fibrillation proposed to catheter ablation was BMI of 28,0 Kg/m2 (AUC 0,733, p = 0,001, 95% CI 0,640-0,827). The group of patients with BMI of 28,0 Kg/m2 had a 4-fold increased risk of sleep apnea (OR 3,95, 95% CI 1,85-8,42, p =0,001) and 2-fold risk of atrial fibrillation recurrence (HR 1,96; 95% CI 1,10-3,51; p = 0,023).

Conclusions

In this group of patients undergoing catheter ablation of atrial fibrillation, a BMI ≥ 28,0 Kg/m2 was independent predictor of sleep apnea and recurrence of atrial fibrillation after catheter ablation. In patients with atrial fibrillation proposed to catheter ablation and BMI ≥ 28,0 Kg/m2 is reasonable to do a sleep study before catheter ablation.

STEMI with mid-range ejection fraction: a group of intermediate risk not to be forgotten

Background

Reduced left ventricular ejection fraction (LVEF) &lt;40% is an important negative prognostic factor in the setting of ST-elevation acute myocardial infarction (STEMI). On the other hand, data concerning mid-range LVEF (mrEF) post-STEMI are scarce. Consequently, recommendations regarding reassessment of LVEF or administration of neurohormonal medication in this group of patients (pts) are also lacking.

Purpose

To assess the current treatment and prognosis of STEMI with mrEF.

Methods

Retrospective study including all consecutive pts hospitalized for STEMI and submitted to primary percutaneous coronary intervention in a Cardiology centre in 2018. Pts were divided into 3 groups according to LVEF assessed before hospital discharge: preserved EF (pEF: LVEF ≥50%), mid-range EF (mrEF: LVEF 40–49%) and reduced EF (rEF: LVEF &lt;40%). We analysed clinical characteristics, treatment, evolution of LVEF post-STEMI and clinical outcomes - death, myocardial infarction (MI) and hospitalization for heart failure (HF) – of the mrEF group and compared it with pEF.

Results

188 pts with a mean age of 61 years were admitted for STEMI in 2018. The majority (58%, n=109) had pEF; 29% (n=55) had mrEF and 13% (n=24) were in the rEF group. Pts in the mrEF group had similar baseline characteristics to the others. However, compared with pEF, culprit-lesion was more often located in left main or left anterior descending arteries (80% vs 35%, p&lt;0.001) and NT-proBNP levels were higher in mrEF pts (2270 vs 881 pg/mL, p&lt;0.001).

At discharge, all mrEF patients were medicated with a renin-angiotensin-aldosterone blocker and 91% with a beta-blocker.

After a median of 8 months, LVEF improved a mean of 4% (± 9%) in the mrEF group. However, in 12.5% LVEF worsened to &lt;40% (vs 0 in the pEF group, p=0.006).

At a median follow-up of 2.6 years, there was an increase in mortality according to the EF group (pEF 4% vs mrEF 13% vs rEF 48%, log-rank: p&lt;0.001 – fig. 1) with a hazard ratio (adjusted for age) of 3.75 (95% CI 1.1–12.8, p=0.035) for mrEF vs pEF. There was also a non-significant tendency to higher rates of the composite endpoint of MI and hospitalization for HF in the mrEF group vs pEF (8.2% vs 2.9%, p=0.213).

Conclusions

This study confirms previous reports of the worse prognosis of STEMI with mrEF and suggests the existence of a continuum of risk of adverse clinical outcomes according to LVEF. Therefore, this group of intermediate risk might also benefit from neurohormonal medication, which is only specifically recommended for rEF in current STEMI guidelines. It also highlights the importance of a closer follow-up (with reassessment of LVEF) of mrEF pts since a non negligeable proportion ultimately progress to rEF and may require additional medical treatment or even an implantable cardioverter defibrillator. Further research with larger samples is required to identify predictors of worsening LVEF and assess the impact of neurohormonal modulation in this population.

Funding Acknowledgement

Type of funding sources: None. Kaplan-Meier Survival Analysis

Aortic plaques in patients with atrial fibrillation: an often-forgotten risk factor for thromboembolism

Background

CHA2DS2-VASc risk score is the main determinant for maintaining anticoagulation after atrial fibrillation (AF) ablation, irrespective of the procedure outcome. The presence of aortic plaques is included in the score, but isn't regularly assessed previously to AF ablation. This way, risk factors for coronary artery disease (CAD) other than arterial hypertension and diabetes mellitus may influence stroke risk in patients with AF, albeit not being included in the CHA2DS2-VASc score.

Purpose

We sought to evaluate the prevalence of aortic plaques diagnosed during transesophageal echocardiography (TOE) in patients submitted to AF ablation and to assess its determinants and clinical impact on the CHA2DS2-VASc score.

Methods

Retrospective study of patients submitted to AF ablation that performed TOE prior to the procedure, with assessment of aortic plaques. CHA2DS2-VASc risk score was evaluated in the pre-ablation patient evaluation and reassessed after TOE. Demographic, clinical and echocardiographic data, including cardiovascular risk factors, were analyzed. We assessed AF recurrence rate, cerebrovascular events and death during follow-up.

Results

120 patients were submitted to TOE prior to AF ablation from November 2015 to December 2020, mean age 66.6 (±9.55) years, 48% male. In 30 (25%) patients aortic plaques were identified in TOE. Mean CHA2DS2-VASc was 2.2 (±1.47) in pre-ablation evaluation and 2.5 (±1.69) post-TOE, increasing in all patients with aortic plaques and prompting beginning of oral anticoagulation in 5 patients. AF was paroxysmal in 74% and persistent in 26% of patients, mean duration of 6.28 (±3.76) years. Arterial hypertension was present in 79 (66%) of patients, type 2 diabetes mellitus in 24 (20%) and dyslipidemia in 67 (56%). 17 (14%) patients had a prior stroke. During a mean follow-up of 30 (±18.3) months, 32 (27%) patients had AF recurrence and 10 (8%) were submitted to redo procedures. 107 (89%) patients remained under oral anticoagulation, stroke occurred in 1 patient and 2 patients died.

In univariate analysis, age, type 2 diabetes mellitus and dyslipidemia predicted an increase in CHA2DS2-VASc score after TOE (respectively, OR 1.113, 95% CI 1.041–1.190, p-value 0.002; OR 2.907, 95% CI 1.145–7.379, p-value 0.025; and OR 2.442, 95% CI 1.016–5.868, p-value 0.046).

In multivariate analysis, age is the only independent predictor of increased CHA2DS2-VASc score after TOE (OR 1.095, 95% CI 1.013–1.185, p-value 0.023). No risk factor for CAD was independently associated with the presence of aortic plaques (Table 1).

Conclusion

In this population, single CAD risk factors were not independent predictors of aortic plaques. If TOE had not been performed prior to AF ablation, 25% of patients would have had an underestimated CHA2DS2-VASc score and would be off anticoagulation after the procedure, unprotected from thromboembolic events.

Funding Acknowledgement

Type of funding sources: None. Table 1

Left atrial stiffness measured by echocardiography is a stronger predictor of atrial fibrillation recurrence after radiofrequency catheter ablation than left atrial volume

Introduction

Left atrial volume (LAV) is an accepted predictor of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation, stronger than AF duration.

Objective

The aim of this study was to assess the value of left atrial stiffness (LAS) index as a new parameter evaluated by echocardiography to the prediction of AF recurrence after radiofrequency catheter ablation.

Methods

We retrospectively studied consecutive patients with paroxysmal or persistent AF submitted to radiofrequency catheter ablation at our institution between 2017 and 2019. We used transthoracic echocardiography to measure the LAV indexed to body surface area and the LAS index, defined as the ratio between the mitral E/e' (obtained with pulsed Doppler at the tip of the mitral leaflets – E, and tissue Doppler imaging at the mitral annulus – e') and the left atrial strain during the reservoir phase (obtained by speckle tracking echocardiography) [LAS index = (E/e') / LA reservoir strain]. The left ventricular ejection fraction (LVEF) was also evaluated. Patients with poor quality echocardiographic images were excluded. We compared 2 groups of patients, according to the recurrence of AF after the blanking period. We analysed the clinical characteristics and echocardiographic findings. The effect of clinical and echocardiography parameters on AF recurrence was evaluated by univariate and multivariate Cox Regression analysis.

Results

We studied 33 patients, 27 with paroxysmal AF and 6 with persistent AF. Baseline patients' characteristics are presented in Table 1. During a mean follow-up time of 17.9±10.4 months, 7 patients (21%) had AF recurrence, and none died. Patients with AF recurrence had a higher LAS index. After adjusting for confounding variables, only LAS index and LAV were independently associated with AF recurrence (Table 2). Every one unit increase in LAS index was associated with an 11-fold increased risk of AF recurrence (HR 10.86, 95% CI 1.38–85.56; p=0.024), while every one unit increase in LAV index was only associated with a 6% increased risk of AF recurrence (HR 1.06, 95% CI 1.01–1.11, p=0.010).

Conclusion

LAS index evaluated by echocardiography was a much stronger predictor of AF recurrence after radiofrequency catheter ablation than left atrial volume.

Funding Acknowledgement

Type of funding sources: None.

Patients with reflex syncope have a higher prevalence of atrial fibrillation than general population which is predicted by the type of the tilt table test response

Introduction

Reflex syncope is the result of an imbalance between the sympathetic and parasympathetic nervous system. The autonomic nervous system has been associated to some forms of atrial fibrillation (AF).

Objective

The aim of this study was to assess the prevalence of AF in patients with reflex syncope and a positive tilt table test and to identify the type of tilt test response in patients with AF in comparison to patients without AF.

Methods

We retrospectively studied consecutive patients that underwent a tilt table test at our institution between 2016 and 2019. We selected those patients with a positive test. Patients with an implanted pacemaker at the time of the tilt test and patients followed in a different institution were excluded. Previous diagnoses of AF episodes were assessed. We analysed the clinical characteristics and the tilt table test results according to previous history of AF.

Results

We studied 49 patients with a positive tilt test. Seven (14.3%) patients had previously diagnosed paroxysmal AF at the time of the tilt table test. Patients with AF were older, had more frequently hypertension, and the tilt test response was more frequently a vasodepressor than mixed or cardioinhibitory response (71.4% vs. 28.6%) (Table). In univariate analysis, age and hypertension were associated with AF, respectively, OR 1.08 (95% CI 1.01–1.17), p=0.034 and OR 10.80 (95% CI 1.19–98.36), p=0.035. A vasodepressor response was also associated with AF (OR 6.25, 95% CI 1.06–36.74, p=0.043).

Conclusions

Patients with reflex syncope and a positive tilt table test had a higher prevalence of AF than the general population. A vasodepressor response was associated with AF as were age and hypertension, demonstrating the possible impact of the autonomic nervous system and the multifactorial nature of AF.

Funding Acknowledgement

Type of funding sources: None.

Rapid atrial fibrillation increases cardiac biomarkers: decision to perform coronary angiography based on novel high-sensitivity Troponin I peak

Funding Acknowledgements

Type of funding sources: None.

Background

Since January 2018 the availability of high sensitivity Troponin I (hsTnI) has improved ischemia diagnosis. In patients with rapid atrial fibrillation (AF), the decision to undergo coronary angiography is usually due to elevated cardiac biomarkers. However, evidence to support the rentability of this approach is sparse.

Purpose

Evaluate if hsTnI in patients with rapid AF and elevated cardiac biomarkers has a good discriminative power to predict a positive coronary angiography.

Methods

We retrospectively studied consecutive patients admitted to the emergency department (ED) between January 2018 and December 2019 with rapid AF that underwent coronary angiography and had multiple hsTnI values obtained. We analysed risk factors, initial and peak hsTnI, time from ED admission to peak hsTnI and ST-T segment abnormalities (ST depression and/or T wave inversion). We evaluated the presence of significant coronary artery stenosis with the need of revascularization at coronary angiography. Univariable and multivariable analysis was performed to obtain the Odds Ratio (OR, 95% CI, p-value) for significant coronary artery disease (CAD).

Receiver operator characteristics (ROC) curve and area under the curve (AUC) were obtained to determine the discriminative power of peak hsTnI as predictor of a positive coronary angiography. Optimal cut-point value was obtained (Youden index) and patients were divided according to this value.

Results

From 1407 patients admitted to the ED with rapid AF, 30 patients, 60% male, median age 74 (IQR 61.25-80.75) years, were submitted to coronary angiography. Significant coronary artery stenosis was present in 17 (57%) patients.

Age, ST-T segment abnormalities and peak hsTnI were predictors of significant CAD, respectively 1.203, 1.064-1.361, 0.003; 25.00, 3.522-177.477, 0.001; and 1.000, 1.000-1.001, 0.015.

Optimal cut-point value for predicting the presence of significant coronary artery stenosis at coronary angiography was a peak hsTnI of 359 pg/mL (AUC 0.869, p-value 0.001, 95% CI 0.742-0.995). The two groups with hsTnI &lt; 359 and hsTnI &gt;359 differed in age and ST-T segment abnormalities (see Table).

After adjustment, peak hsTnI &gt;359 pg/mL was the only independent predictor of significant CAD (23.894, 1.310-435.669, 0.032).

Conclusion

In this group of patients with rapid AF, peak hsTnI &gt;359 pg/mL was the only independent predictor of significant coronary artery disease. Therefore, those patients should undergo coronary angiography. Abstract Figure.

Optimal percentage of biventricular pacing to obtain CRT response: how high is high enough

Funding Acknowledgements

Type of funding sources: None.

Background

The greatest benefit with cardiac resynchronization therapy (CRT) is achieved when biventricular pacing (BivP) percentage (%) is close to 100%. However, in some patients that goal can be challenging to obtain.

Purpose

Determine whether a lower BivP% could lead to similar CRT response and events, as compared with patients with BivP% &gt;98%.

Methods

Patients with CRT followed up in a remote-monitoring network were retrospectively analyzed. BivP% was assessed and response to CRT was defined as an absolute increase in left ventricle ejection fraction (LVEF) &gt;5% or a relative increase in LVEF &gt;15%.

Low BivP% was defined as &lt;98%. Clinical, echocardiographic data and all-cause death during follow-up were evaluated. ROC curve and AUC were obtained to determine the discriminative power of BivP% as predictor of CRT response. Optimal cut-point value was obtained and patients were divided according to this value. Kaplan-Meyer survival function was used to compare survival in the different groups and the Log-rank test was used for comparison between the groups.

Results

88 patients, 76% male, median age 73.5 (IQR 65.75-79.25) years were included. A CRT-D was implanted in 69%. Etiology was ischemic in 44%. 93% were under beta-blockers. Median LVEF before CRT was 27% (IQR 20.25-32). 

44 patients (50%) had low BivP% (median 91%, IQR 96-99), 55% due to atrial fibrillation and 52% due to frequent premature ventricular complexes. After optimization of medical therapy, device programming and/or interventional procedures, we obtained a BivP &gt;98% in 26 out of the 44 patients (59%). However, in 18 patients (20%) BivP% was &lt;98% (median 95, IQR 92.25-96). 66% patients were CRT responders. Median follow-up was 36 (IQR 23.75-84) months. During follow-up, all-cause mortality was 27% (24 patients).

Optimal cut-point value for predicting CRT response was 91% BivP% (AUC 0.644, p-value 0.047, 95% CI 0.496-0.792). The characteristics of the two groups didn’t differ significantly (Table).

Survival was significantly higher in patients with BivP% &gt;91% (Log-rank 3.667, p-value 0.050) – Figure.

Conclusion

In this population, BivP% &gt;91% was sufficient to achieve CRT-response and was associated with a better survival. BivP% &lt;91%(n = 4)BivP% &gt;91%(n = 84)p-valueAge in years, median (IQR)72.50 (70.50-73.75)74.00 (65.00-80.00)0.666CRT-D, n (%)3 (75.0)58 (69.0)0.999Ischemic cardiopathy, n (%)3 (75.0)35 (41.7)0.311LVEF before CRT, median (IQR)27 (19-39)27 (20-32)0.795Beta-blockers, n (%)4 (100.0)78 (95.1)0.999Abstract Figure.

Clinical impact of transoesophageal echocardiography in acute brain ischaemia: who should we select?

Funding Acknowledgements

Type of funding sources: None.

Background

Stroke is a prevalent disease and is still the leading cause of death in Portugal. Transoesophageal echocardiography (TOE) is a sensitive test often performed to detect embolic sources. However, since its most common findings such as patent foramen ovale (PFO) and atheroma plaques do not necessarily mandate a change in treatment, there is still debate over its clinical impact in the context of brain ischaemia (BI) and which patients (pts) should be submitted to it. 

Purpose

To assess the clinical impact of TOE following BI and to identify clinical and diagnostic testing results that could help predict which pts benefit from it.

Methods

A retrospective study was conducted including all pts submitted to TOE in our hospital after acute BI in 2018 and 2019. Clinical and testing data (brain, vascular and cardiac imaging and 24h-Holter monitoring) was analysed and compared between 2 groups: the pts who had findings in TOE compatible with a source of embolism which resulted in a change in treatment ("relevant TOE" group) vs all other pts who had no such findings or whose findings did not result in change in treatment ("others"). Predictors of relevant TOE were also analysed.

Results

 Of the 87 pts (mean age of 57 and maximum of 83) included in the study, 51 (59%) had findings compatible with a potential source of embolism in TOE, PFO being the most common (n = 42). In only half of them did these findings result in a change in treatment (the relevant TOE group: n = 25; 29% of the overall population).

Age and other baseline characteristics did not significantly differ between groups. Pts with a relevant TOE presented more often with visual-field defects (32% vs 10%, p = 0.020) and were more likely to have visible acute lesions on brain imaging (96% vs 76%, p = 0.032) compared with the others. There was also a borderline significant association between the presence of infarct in the territory of the superior cerebellar artery and a relevant TOE (p = 0.054). On the contrary, the presence of significant lesions in extracranial arteries was negatively associated with a relevant TOE (p = 0.016).

Considering the whole population, there were no transthoracic echocardiography (TTE) predictors of a relevant TOE but when analysing only younger patients (age &lt; 50), the presence of any abnormality in TTE became associated with a relevant TOE (OR 8.5, CI 1.1-63.9; p = 0.044). We found no predictors of relevant TOE in 24h-Holter results.

Conclusions

TOE commonly identified potential sources of brain embolism, which proved relevant in half the cases. In the impossibility of submitting all BI patients to TOE, this study suggests that brain and vascular imaging rather than age or other baseline characteristics may be useful in predicting a relevant result. Moreover, TTE does not seem to be an adequate screening method to select patients for TOE, except possibly in younger patients. Studies with larger samples are needed to confirm these results.

Acute coronary syndrome in COVID-19 times: could it be business as usual?

Funding Acknowledgements

Type of funding sources: None.

Background

In an attempt to cope with the COVID-19 pandemic, several measures of social distancing and reorganization of health care systems have been adopted. In Portugal, these included suspending elective clinical activity and a temporary national lockdown. Data from multiple centres, including central hospitals in Portugal, has shown a reduction in hospital admissions for acute coronary syndrome (ACS) during the COVID-19 outbreak. Fear of going to the hospital and physical inactivity have been pointed as possible explanations.

Purpose

to assess the impact of this pandemic and the measures taken against it on the pattern of admissions and treatment of patients with ACS in a district hospital. 

Methods

A single-centre retrospective study was conducted in the Cardiology Department of a Portuguese district hospital, capable of performing 24h percutaneous coronary intervention. We analyzed the admissions for ACS during the peak of the first COVID-19 outbreak in Portugal (16th of March to 3rd of May 2020, coinciding with the suspension of elective activity) and compared it with two control periods: one immediately preceding the study period (27th of January to 15th of March - 2020 control) and one exactly one year before (16th of March to 3rd of May 2019 - 2019 control).

Results

During the 7 weeks of the first COVID-19 outbreak, 46 patients were hospitalized for ACS in our department, while 54 had been admitted during the 2020 control period and 40 in the 2019 control period, with a mean of 7 admissions/week (vs 8 and 6, respectively; p > 0.05). There were no significant differences between the study group and both controls regarding basal characteristics. Their presentation did not differ: the majority of patients (57%) was admitted for ST-elevation myocardial infarction and median time from symptom onset to admission to the emergency room was 3 hours, with 4% of patients presenting in Killip class ≥III (p > 0.05 for all). We also found no significant differences in the treatment administered nor in the outcomes (96% submitted to coronary angiography, median length of hospitalization of 4 days and in-hospital mortality rate of 2%, p > 0.05 for all). 

Conclusions

Our study suggests that the reduction in admissions for ACS during the COVID-19 outbreak is not universal. Additionally, severity at presentation, treatment administered and outcomes did not seem to differ. The relatively low prevalence of COVID-19 in our hospital"s region might be the cause, since people might fear and refrain less from going to the hospital. Larger studies with other centres in low-prevalence regions are needed to confirm this hypothesis.

Left atrial mechanics improvement after initiation of sacubitril-valsartan

Introduction

Heart failure with reduced ejection fraction (HFrEF) is associated with significant morbidity and mortality. Recently, in the PARADIGM-HF, sacubitrilvalsartan was superior to enalapril in reducing death and hospitalization for heart failure, and there is a growing interest in determining the structural changes besides reverse left ventricular remodelling.

Purpose

To determine if, in patients treated with sacubitril-valsartan, there was a change in left atrial (LA) mechanics quantified by two-dimensional strain echocardiography (2D-STE).

Methods

A total of 38 consecutive patients with HFrEF, followed in an outpatient heart failure clinic, were recruited. Population characteristics are summarized in Table 1. 2D-STE was used to measure left atrial strain in the reservoir phase (LASr) (Figure 1) and strain rate (LA-SR) before and 3 months after initiation of sacubitril-valsartan.

Results

There was a significant improvement in LASr (11.3±6.5% vs 14.2±7.4%, p=0.006) and LA-SR (0.55±0.25 s-1 vs 0.69±0.31 s-1, p=0.008) after initiation of sacubitril-valsartan. There was also a significant reduction in N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels (1443.5 pg/ml (Interquartile range [IQR], 772–2912) vs 1112.0 pg/ml (IQR, 510–1455), p=0.016) and a tendency towards reduction in left atrial volume index (LAVI) (54.6±17.0 ml/m2 vs 51.4±18.8 ml/m2, p=0.053). The change in LASr and LA-SR was not related with the dose of sacubitril-valsartan (p=0.089).

Conclusion

In this population of HFrEF patients LA mechanics, as determined by 2D-STE, as well as NT-proBNP levels, significantly improved after treatment with sacubitril-valsartan.

Figure 1. Left atrial strain

Funding Acknowledgement

Type of funding source: None

Predictors of relapse after improved ejection fraction in patients with heart failure

Background

Patients with systolic dysfunction with improvement in left ventricular ejection fraction (LVEF) present a more favorable clinical profile when compared to those that maintain dysfunction. However, little is known about the characteristics of patients who “relapse” after LVEF improvement.

Purpose

Evaluate prevalence, clinical characteristics and outcomes of patients in whom ejection fraction declined after previous improvement.

Methods

We retrospectively studied patients followed at a heart failure (HF) clinic with LVEF improvement after an initial diagnosis of HF with reduced ejection fraction (EF), which was defined as having an LVEF &gt;40% on follow-up. We then evaluated the presence of LVEF “relapse” in these patients – a decline in LVEF to &lt;50% or &lt;40%, in cases where it recovered to preserved EF or to mid-range EF, respectively. We analysed patient demographics, clinical parameters and outcomes and used logistic regression to assess the predictors of LVEF “relapse”.

Results

98 patients were studied, 70 (71%) male, median age 69 (58–76) years.

Fifty-four (55%) patients had recovered EF (&gt;50%) and in 44 (45%) it had improved to mid-range values. In 36 (37%) occurred LVEF “relapse”: in 10 (10%) patients to an EF 40–50% and in 88 (90%) to an EF&lt;40%.

Ischemic cardiomyopathy and non-ischemic dilated cardiomyopathy were the main HF aetiologies (38% and 35%, respectively).

During a median follow-up of 7 years, 39 (40%) patients had at least one HF hospitalization. Global mortality was 30%, with no significant statistical difference between the two groups.

In univariate analysis, HF duration, type 2 diabetes mellitus (T2DM), left main or left anterior descending coronary (LAD) disease, valvular heart disease (VHD) and chronic kidney disease (CKD) predicted LVEF “relapse”.

In multivariate analysis, T2DM, left main or LAD disease and VHD were the only predictors of LVEF “relapse” (Table).

Conclusion

In this group of patients, LVEF “relapse” after it had initially improved was frequent and was predicted by the presence of T2DM, left main or LAD disease and VHD. Despite improved systolic function, these patients remain at high risk, thus the need to maintain treatment.

Funding Acknowledgement

Type of funding source: None

235Anatomic guided ablation of the right ganglionated plexus is enough for cardiac autonomic denervation in patients with significant bradyarrhythmias

Background

In patients with significant bradyarrhytmias, cardiac denervation is an alternative therapeutic approach. Previous reports proposed different methods (as high frequency ednocardial stimulation of ganglionated plexus and specific atrial electrogram identification) and targets (right and left atrial ganglionated plexus) for adequate denervation. There is no consensus on the best way to perform these procedures, in spite the right atrial ganglia plexus (GP) ablation seeming to be the most contributive to its success.

Purpose

To assess the results of a purely anatomic approach for ablation of just the right atrial plexus in patients with severe vagal bradyarrhytmias.

Methods

We enrolled patients referred for ablation of cardiac parasympathetic ganglia, with or without atrial fibrillation ablation.  We performed eletroanatomic mapping of the right and left atria and used an irrigated tip catheter for ablation, aiming at the anterior right GP at the right pulmonary veins antrum along with ablation at the superior vena cava junction and the inferior right GP at the posterior aspect of the right inferior pulmonary vein along with ablation of the right aspect of the interatrial septum, between the posterior wall and coronary sinus ostium (Figure 1). We assessed the PW and Wenckenback cycle lengths (CL) pre and post procedure in patients with sinus arrest or AV block, respectively, and the patients had new 24h holter readings at least 30 days from the index procedure.

Results

We enrolled 12 patients: 9 males (75%), median age of 49,5 years (IQR 36-61,75). All patients had structurally normal hearts. 7 patients had only ablation of the parasympathetic ganglia and 5 patients had simultaneous pulmonary vein isolation for previously documented atrial fibrillation. 7 patients (58,3%) had sinus bradycardia (2 patients had sinus arrest with pauses of 8 and 13 seconds), 2 patients with cardioinhibitory syncope (with pauses of 23 and 28 seconds) and 3 patients had transient high degree AV block. The ablation procedure led to a median sinus rate acceleration of 15 bpm (IQR 3-29), a median decrease of 320 ms in PW (IQR 23,75-609,5) in patients with sinus arrest and a decrease of 80 ms in wenckenback CL (IQR 60-200) in patients with AV block. With a median follow up of 133,50 days (IQR 36-61,75), no patient had recurrence of symptoms or conduction disturbances.

Conclusions

In selected patients with severe functional paroxysmal bradyarrhytmias, cardiac denervation using an ablation strategy purely based on anatomic aspects and targeting only the right GP, seems to be an effective therapeutic approach.

Abstract Figure 1: Abl of right ganglionated plex

P1506Prolonged and recurrent hospital admissions predict risk of cardiac implantable electronic device infections in hospitalized patients with bacteriaemia

Background

As the use of Cardiac Implantable Electronic Devices (CIED) is expanding, the burden of device-related infections, particularly infectious endocarditis, is also increasing. Furthermore, with the increase in life expectancy, these devices are being implanted in patients who are older, with more serious co-morbidities and who are frequently hospitalized.

Purpose

To assess incidence and predisposing factors for infective endocarditis (IE) in hospitalized patients with CIED and nosocomial bacteraemia.

Methods

We performed a retrospective analysis of all hospitalized patients with CIED and positive blood cultures admitted to the Cardiology department between January 2012 and February 2019. Endocarditis was defined according to modified Duke criteria. We analyzed clinical parameters, device- and procedure-related characteristics, length of hospital stay and hospitalizations in the previous year.

Results

25 patients had positive blood cultures, 4 patients (16.0%) were diagnosed with infective endocarditis (median age 59.25 years, 75.0% male).

Patients characteristics are displayed in the Table.

In univariable analysis, the number and presence of hospitalizations in the previous year and the length of hospital stay was significantly associated with the possibility of endocarditis (respectively, OR 3.411, 95% CI 1.164-9.998, p-value 0.025; OR 18.000, 95% CI 1.375-235.686, p-value 0.028; and OR 1.047, 95% IC 1.001-1.096, p-value 0.046).

Conclusion

In this group of patients with positive blood cultures during hospitalization, the possibility of CIED infection was predicted by the length of hospital stay and the presence and number of hospitalizations in the previous year.

With CIED-IE Without CIED-IE p-value Age in years, median (IQR) 63 (16) 76 (16) 0.002 Heart failure, n (%) 4 (100%) 10 (47.6%) 0.105 LVEF in %, median (IQR) 21 (9) 51 (30) 0.008 LV dilation, n (%) 4 (100%) 8 (38.1%) 0.039 Device revision/upgrade/substitution, n (%) 2 (50.0%) 6 (28.57%) 0.570 LOS in days, median (IQR) 58.5 (83) 20 (15) 0.004 Hospital admissions in the previous year, n (%) 3 (75.0%) 3 (14.3%) 0.031 No. of hospital admissions in the previous year, mean (standard deviation) 1.67 (1.528) 0.29 (0.784) 0.005 Use of central venous access, n (%) 4 (100%) 4 (19.05%) 0.008 LOS – Length of Stay; LV – Left Ventricle; LVEF – Left Ventricle Ejection Fraction

P3563The influence of circadian patterand obstructive sleep apnean of blood pressure in nocturnal arrhythmias in hypertensive patients

Introduction

There is growing evidence suggesting hypertension is related to the occurrence of arrhythmias. When occurring predominantly during the night, two potential entities commonly present in hypertensive patients could be related with increased arrhythmogenesis: (1) the lack of normal nocturnal dipping of blood pressure (BP) (non-dipping pattern of hypertension) or (2) obstructive sleep apnea (OSA). Thus, nocturnal arrhythmias (NAs) can identify hypertensive patients with OSA and/or non-dipping pattern, both related with adverse outcomes.

Aims

To determine if NAs are related with non-dipping hypertension, OSA or both.

Methods

We studied hypertensive patients who performed ambulatory blood pressure monitoring (ABPM) and also polysomnography and 24-hour Holter monitoring. Non-dipping pattern was considered when nocturnal BP reduction was inferior to 10%. Based on Holter monitoring, NAs were present when atrial fibrillation, frequent premature atrial contractions (PACs) (>30 PACs/hour), runs of >4 consecutive PACs, frequent premature ventricular contractions (PVCs) (>30PVCs/hour) or runs of >4 consecutive PVCs were present predominantly during sleeping hours. During polyssonography, apnoea/hypopnoea index (AHI) and oxygen saturation (SaO2) were analysed. Moderate to severe OSA was considered when AHI >15.

Results

We studied 104 patients [median age 62 (54–70) years, 65% male): 42 (40%) had moderate to severe OSA (median AHI=11 (6–26), mean SaO2=94% (92–95)] and 64 (61%) were non-dippers. NAs occurred in 18 patients (17%) and they were independently associated with AHI (Odds Ratio (OR) for a one unit increase 1.04, 95% confidence interval (CI) 1.01–1.07, p=0.03) but not with SaO2 (OR 0.96, CI 0.78–1.19, p=0.73) nor non-dipping pattern (OR 1.23, CI 0.38–3.98, p=0.72). No interaction was found between OSA and non-dipping hypertension (p=0.35). In patients with dipping pattern (n=40), AHI was higher in NAs patients comparing with no NAs patients (median AHI 29 versus 10, p=0.04), while in those with non-dipping pattern (n=64), AHI was not statistically different between patients with and without NAs (21 versus 11, p=0.12) (figure).

Figure 1

Conclusion

In this population of hypertensive patients, the presence of NAs was associated with OSA severity (i.e AHI), but not with the non-dipping pattern of hypertension. The importance of obstructive events in arrhythmogenesis seemed to be more pronounced in dipping patients, suggesting the abnormal high blood pressure during the night may also have some impact on NAs in non-dipping patients. Overall, our results suggest that OSA screening should be considered when nocturnal arrhythmias are detected in hypertensive patients, but ABPM should not be forgotten since multiple mechanisms can be involved in nocturnal arrhythmogenesis.

P6560Delayed ablation of atrioventricular nodal reentry tachycardia as a risk factor for future atrial fibrillation

Introduction

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common type of supraventricular tachycardia. Most of the patients experience recurrent symptoms for years before electrocardiographic documentation and AVNRT ablation. The effects of these ongoing episodes of AVNRT on atrial structure and function, and their influence on new-onset atrial fibrillation (AF) in patients with delayed AVNRT ablation are unknown.

Purpose

To assess if delayed ablation of AVNRT was associated with the development of AF.

Methods

We retrospectively evaluated patients subjected to AVNRT ablation between 2009 and 2016. Patients with history of AF previous to ablation were excluded. We evaluated age at the time of AVNRT ablation, the presence of cardiovascular risk factors, left atrial (LA) dilatation and the presence of frequent premature atrial contractions (PACs) (by 24-hour holter monitoring, defined as >30/h). During follow-up we assessed the occurrence of sustained AF episodes and age at the time of the first AF episode.

Results

We studied 130 patients that underwent AVNRT ablation. Mean follow-up time was 75±27 months and seventeen patients (13%) had new-onset AF during follow-up. Patients who developed AF were more often males (35% vs. 22%, p=0,015), older at the time of AVNRT ablation (60±16 vs. 50±15, p=0,01), had a higher prevalence of hypertension (64% vs. 35%, p=0,03), diabetes mellitus (35% vs. 6%, p=0,02), LA dilation (41% vs. 7%, p=0,01) and frequent PACs (24% vs. 2%, p=0,03). In Univariable Cox regression analysis all these available variables were associated with AF occurrence during follow-up. However, in Multivariable Cox regression analysis, only age at the time of the ablation procedure was independently associated with AF occurrence (Table 1).

Multivariable Analysis HR 95% CI P value Age at ablation 8.762 3.308–23.20 <0.001 Age at the time of the first AF episode 0.113 0.043–0.302 <0.001 LA dilation 0.408 0.113–1.472 0.171 Frequent PACs 1.016 0.156–6.611 0.987

Conclusion

In this group of patients the occurrence of new-onset AF during follow-up was independently associated with delayed AVNRT ablation. These findings suggest that longer atrial exposure to AVNRT episodes before ablation may be associated with LA structural and functional changes leading to higher occurrence of AF.

P3795Should we also screen for obstructive sleep apnea in patients presenting with excessive supraventricular ectopic activity?

Background

It is recommended to consider obstructive sleep apnoea (OSA) screening in atrial fibrillation (AF) patients with risk factors, due to the strong evidence of an association between these two entities. Excessive supraventricular ectopic activity (ESVEA) has been proposed to be a risk factor for AF. However, strong evidence between ESVEA and OSA has not been established.

Objective

We aimed to determine if ESVEA is associated with moderate to severe OSA since its treatment may prevent AF.

Methods

We studied patients who performed polysomnography and 24-hour Holter monitoring. Patients with atrial fibrillation were excluded. ESVEA was defined as more than 30 PACs per hour (frequent PACs) or runs of >4 consecutive PACs. The circadian pattern of PACs was also evaluated. Sleeping hours were used to define “nocturnal”. Moderate to severe OSA was defined when polyssonography demonstrated a apnoea/hypopnoea index (AHI) >15. We examined the association between ESVEA and moderate to severe OSA during wakefulness and sleep.

Results

We studied 290 patients [median age 65 (55–72) years, 62% males, body mass index (BMI) 30 (27–34)]. 112 (38%) had moderate to severe OSA. Median AHI was 11 (5–24) and mean oxygen saturation was 94% (92–95). Median PACs was 35 (9–117) and 29 patients (10%) had frequent PACs. Runs of >4PACs occurred in 114 patients (39%). Forty-three patients (15%) had predominant nocturnal PACs and 42 (14%) had nocturnal runs of PACs. Multivariate logistic regression analysis demonstrated only nocturnal PACs were associated with moderate to severe OSA (p=0.027) (table 1).

Multivariate logistic regression Odds Ratio 95% Confidence Interval p-value Male gender 4.49 2.48–8.17 <0.001 Body mass index (kg/m2) 1.09 1.03–1.15 0.002 Nocturnal PACs 4.12 1.17–14.46 0.027 Variables not included in the model: age, number of PACs/h, frequent PACs (>30 PAcs/hour), runs of PACs (>4 consecutive PACs), nocturnal frequent PACs and nocturnal runs of PACs.

Conclusion

OSA screening in patients presenting with nocturnal PACs should be routinely considered, especially in male and obese. Treating moderate to severe OSA patients with CPAP has a potential benefit in preventing ESVEA and consequently AF.

Abstract P3-06-11: Withdrawn

This abstract was withdrawn by the authors.

Biological network-driven gene selection identifies a stromal immune module as a key determinant of triple-negative breast carcinoma prognosis

Triple-negative breast cancer (TNBC) is a heterogeneous group of aggressive breast cancers for which no targeted treatment is available. Robust tools for TNBC classification are required, to improve the prediction of prognosis and to develop novel therapeutic interventions. We analyzed 3,247 primary human breast cancer samples from 21 publicly available datasets, using a five-step method: (1) selection of TNBC samples by bimodal filtering on ER-HER2 and PR, (2) normalization of the selected TNBC samples, (3) selection of the most variant genes, (4) identification of gene clusters and biological gene selection within gene clusters on the basis of String© database connections and gene-expression correlations, (5) summarization of each gene cluster in a metagene. We then assessed the ability of these metagenes to predict prognosis, on an external public dataset (METABRIC). Our analysis of gene expression (GE) in 557 TNBCs from 21 public datasets identified a six-metagene signature (167 genes) in which the metagenes were enriched in different gene ontologies. The gene clusters were named as follows: Immunity1, Immunity2, Proliferation/DNA damage, AR-like, Matrix/Invasion1 and Matrix2 clusters respectively. This signature was particularly robust for the identification of TNBC subtypes across many datasets (n = 1,125 samples), despite technology differences (Affymetrix© A, Plus2 and Illumina©). Weak Immunity two metagene expression was associated with a poor prognosis (disease-specific survival; HR = 2.68 [1.59-4.52], p = 0.0002). The six-metagene signature (167 genes) was validated over 1,125 TNBC samples. The Immunity two metagene had strong prognostic value. These findings open up interesting possibilities for the development of new therapeutic interventions.

Gluttonous predators: how to estimate prey size when there are too many prey

Prey size is an important factor in food consumption. In studies of feeding ecology, prey items are usually measured individually using calipers or ocular micrometers. Among amphibians and reptiles, there are species that feed on large numbers of small prey items (e.g. ants, termites). This high intake makes it difficult to estimate prey size consumed by these animals. We addressed this problem by developing and evaluating a procedure for subsampling the stomach contents of such predators in order to estimate prey size. Specifically, we developed a protocol based on a bootstrap procedure to obtain a subsample with a precision error of at the most 5%, with a confidence level of at least 95%. This guideline should reduce the sampling effort and facilitate future studies on the feeding habits of amphibians and reptiles, and also provide a means of obtaining precise estimates of prey size.

ISER: selection of differentially expressed genes from DNA array data by non-linear data transformations and local fitting

SUMMARY

This report describes an algorithm (intensity-dependent selection of expression ratios or ISER) developed to analyse DNA array data by optimizing the selection of genes with the most significant variations in expression amongst two RNA samples. The algorithm is designed for use when little or no replication of array hybridizations is available.

Dental and oral lesions in HIV infected patients: a study in Brazil

AIM

To determine the prevalence of dental and oral lesions, as well as treatment need, in a group of HIV sero-positive Brazilians. In addition, to test the association between oral manifestation of HIV infection and age, sex, mode of transmission and drug therapy.

METHOD

All HIV seropositive patients attending a dedicated dental clinic in Recife were invited to participate in the study. They were all examined by one trained and calibrated examiner and interviewed by one trained interviewer.

RESULTS

161 of 204 patients (78.9%) agreed to participate in this study. Most of the participants were male (76%), had acquired HIV sexually (74.5%), and were taking some form of antiretroviral therapy (70.8%). 33.5% had one or more oral manifestation of HIV. Candidiasis was the most common (28.6%), followed by hairy leukoplakia (9.3%), Kaposi sarcoma (2.5%), ulceration (2.5%), herpes simplex (1.2%), papiloma (0.6%), and 4.4% had periodontal disease. Only 1.2% reported xerostomia. There were no differences in the prevalence of oral manifestations of HIV infection between age groups, sexes, modes of transmission and types of drug therapy (P>0.05). The mean DMF-T score was 19 (SD 8) and 78.9% needed some form of dental treatment.

CONCLUSIONS

While the prevalence of oral manifestations of HIV/AIDS was low in this sample of HIV seropositive Brazilians, dental status was poor and need for dental treatment was high.

Pregnancy weight gain and its correlation to birth weight

This study was done to determine whether a relationship existed between maternal weight gain during pregnancy and the birth weight and if such a relationship did exist, to establish the minimum weight gain required for a normal birth weight baby. This was a retrospective study involving an audit of all antenatal records at a rural hospital and health centre. The records reviewed belonged to a period between '86-'99. About 2000 antenatal records were scanned and cases with complications and multiple pregnancy were excluded. The records reviewed pertained only to mothers who had delivered at this rural hospital. The final sample size was 935 mothers. The study revealed that a greater weight gain in second trimester resulted in a better birth weight (P < 0.05). Other factors that influenced the birth weight were: age (P < 0.001), regular antenatal check up (P < 0.05) and parity (P < 0.05).

Optical imaging in vitro provides evidence for the minicolumnar nature of cortical response

The response of rat neocortical slices to electrical stimulation at the layer VI/white matter border was recorded using intrinsic signal optical imaging. The optical response of the slice is column-shaped, extends from layer VI to the pial surface, and is strongly correlated with the amplitude of simultaneously recorded evoked potentials. Spectral analysis revealed radially oriented spatial variations in the intensity of the optical signal with a period of 30-60 microm/cycle. Nissl-stained sections of slices also exhibited a radially oriented periodicity in optical density with the same period. We conclude that the periodic variations in the intrinsic optical signal correspond to stimulus-activated minicolumns.

[Chronic eosinophilic pneumonia]

Various types of pulmonary eosinophilia have been known for several years. Chronic eosinophilic pneumonia (original word for Christoforidis and Molnar 1960) is a rare entity whose diagnosis is possible through clinical, laboratory and radiological data. Other non sophisticated data-CAT, bronchoalveolar lavage, transbronchial biopsy, transthoracic biopsy and even thoracotomy can be used. Seriousness can be very high, demanding an urgent diagnosis and treatment.