Association Between Ischemic Stroke Subtype and Stroke Severity: The Atherosclerosis Risk in Communities Study

BACKGROUND AND OBJECTIVES

Disability after stroke occurs across ischemic stroke subtypes, with a suggestion that embolic strokes are more devastating. Whether this difference is as a result of differences in comorbidities or differences in severity at the time of the stroke event is not known. The primary hypothesis was that participants with embolic stroke would have more severe stroke at the time of admission and a higher risk of mortality, compared with thrombotic stroke participants even with consideration of confounders over time, with a secondary hypothesis that this association would differ by race and sex.

METHODS

Atherosclerosis Risk in Communities (ARIC) study participants with incident adjudicated ischemic stroke, stroke severity and mortality data, and complete covariates were included. Multinomial logistic regression models determined the association between stroke subtype (embolic vs thrombotic) and admission NIH Stroke Scale (NIHSS) category (minor [≤5], mild [6-10], moderate [11-15], severe [16-20], and very severe [>20]) adjusted for covariates from visits most proximal to the stroke. Separate ordinal logistic models evaluated for interaction by race and sex. Adjusted Cox proportional hazard models estimated the association between stroke subtype and all-cause mortality (through December 31, 2019).

RESULTS

Participants (N = 940) were mean age 71 years (SD = 9) at incident stroke, 51% female, and 38% Black. Using adjusted multinomial logistic regression, the risk of having a more severe stroke (reference NIHSS ≤5) was higher among embolic stroke vs thrombotic stroke patients, with a step-wise increase for embolic stroke patients when moving from mild (odds ratio [OR] 1.95, 95% CI 1.14-3.35) to very severe strokes (OR 4.95, 95% CI 2.34-10.48). After adjusting for atrial fibrillation, there was still a higher risk of having a worse NIHSS among embolic vs thrombotic strokes but with attenuation of effect (very severe stroke OR 3.91, 95% CI 1.76-8.67). Sex modified the association between stroke subtype and severity (embolic vs thrombotic stroke, p interaction = 0.03, per severity category, females OR 2.38, 95% CI 1.55-3.66; males OR 1.75, 95% CI 1.09-2.82). The risk of death (median follow-up 5 years, interquartile range 1-12) was also increased for embolic vs thrombotic stroke patients (hazard ratio 1.66, 95% CI 1.41-1.97).

DISCUSSION

Embolic stroke was associated with greater stroke severity at the time of the event and a higher risk of death vs thrombotic stroke, even after careful adjustment for patient-level differences.

Arrhythmogenic right ventricular cardiomyopathy – evolution of electrocardiographic markers during long-term follow-up prior to ascertainment of diagnosis

Background

Depolarization and repolarization abnormalities are part of the diagnostic Task Force Criteria of 2010 (TFC2010) for arrhythmogenic right ventricular cardiomyopathy (ARVC). These abnormalities are thought to be progressive but have also been described as dynamic and sometimes reversible. Evolution of ECG abnormalities prior to clinical ARVC diagnosis is poorly studied.

Objective

To assess the evolution of ECG depolarization and repolarization characteristics in patients with ARVC prior to diagnosis and to identify markers of disease progression at a preclinical stage.

Methods

353 patients with definite ARVC from Sweden, Denmark, the Netherlands and Canada with at least one 12-lead digital ECG (65% males, 67% probands, 56% mutation carriers, median age at diagnosis 42 [IQR 29–53] years and median age at first ECG 44 [30–55] years) were included. Digital ECGs were extracted from regional ECG archives. ECGs with left bundle branch block, ventricular pacing or recorded either prior to 15 years of age or after heart transplantation were excluded. Remaining 6,871 ECGs were digitally processed and automatically analysed using the Glasgow algorithm. Median values for overall QRS duration, terminal activation delay (TAD) in lead V1 as well as amplitudes of QRS-T-components in precordial leads per patient per year were used for analyses and graphically represented using Lowess smoothing with cubic splines (Figure 1). Blue lines indicate smoothed conditional mean with 95% confidence interval (shadow). Time “0” (red line) indicates the time when TFC2010 were fulfilled for definite diagnosis.

A database of 18,564 anonymized digital ECGs (58% males, median age at latest ECG 41 years [IQR 32–52]) who were in contact with health care during 2020–2021 was processed using the same exclusion criteria and signal-processing methodology as in the ARVC group and used as a reference (black line).

Results

TAD in lead V1 and overall QRS duration demonstrated a significant increase years before ARVC diagnosis, and significant reductions were seen in QRS-T voltages measured as R wave amplitude, QRS amplitude (the absolute sum of R wave and S wave), and T wave amplitude (Table 1 and Figure 1). The changes were seen in all precordial leads, not only the right-sided, and visually diverging from the controls.

Conclusion

Development of the ARVC ECG phenotype started several years before diagnosis and continued afterwards. QRS duration and TAD increased, QRS voltages decrease, and T wave amplitude decreased eventually leading to T wave inversion. These changes might be visually assessed but also measured with available ECG software. These findings may be clinically useful in the screening and follow-up of ARVC relatives.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Governmental funding of clinical research (ALF), Region Ostergotland, Sweden.The Swedish Heart-Lung Foundation.

Longer left ventricular activation time is associated with lower mortality and risk of heart failure hospitalization in CRT recipients

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): ALF Governmental Funding within the Swedish health care system

Introduction

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure in selected patients. Longer QRS duration has been showed to correlate to clinical outcome, but measures global activation time, rather than the left ventricular dyssynchrony that CRT aims to correct. This study therefore evaluated the incremental value of using Left Ventricular Activation Time (LVAT) for prediction of outcome after CRT.

Methods

Medical records of 445 patients receiving CRT implants at a large-volume tertiary care center were retrospectively evaluated. Digital electrocardiograms (ECG) before and after CRT implantation were collected and ECG parameters were analysed in relation to a primary composite endpoint of time to heart failure hospitalisation or death from any cause. LVAT was defined as time from QRS onset to maximum positive deflection in lead V6 (Figure 1).

Results

Patients were followed for up to 6 years (median 2.7), during which 147 patients (33%) reached the primary endpoint (93 deaths and 103 heart failure hospitalisations). LVAT was measured pre-implant (median 71ms [58-88]) and post-implant (median 74ms [57-96]). There was no CRT-mediated reduction in LVAT (delta -2.3ms +/-31ms, p=0.27). When divided into quartiles, preoperative LVAT had a significant association with clinical outcome (HR 0.76 [0.64-0.90] per increasing quartile, p=0.001), also shown in a median-split Kaplan Meier curve (Figure 2, log rank p=0.001). Multivariate hazard ratio (adjusted for relevant clinical variables) was 0.83; [0.69-0.99]; p=0.047). There was an interaction between LVAT and ECG morphology (p=0.033), and when ECG groups were analysed separately, there was only a significant result for those with native left bundle branch block morphology. Post-implant LVAT, or change in LVAT, did not correlate with the primary endpoint (p=0.25 and p=0.38 respectively.

Conclusion

In CRT recipients, longer pre-implant LVAT was associated with lower risk of heart failure hospitalisation and death during a follow-up of up to 6 years. This association was mainly seen in patients with native LBBB prior to implant. No association was seen with post-CRT LVAT and clinical outcome. If confirmed in prospective trials, evaluation of preoperative LVAT may help optimise patient selection for CRT.

Clinical risk factors and P wave indices in prediction of atrial fibrillation development during long-term follow-up after acute ST-segment elevation myocardial infarction

Introduction

In patients with high thromboembolic risk detection of atrial fibrillation (AF) is crucial for implementation of proper anticoagulation therapy, which highlights the need for identification of patients at risk for AF. P wave indices reflect atrial structural abnormalities linked to AF development.

Purpose

We aimed to assess the value of clinical risk factors and P wave indices in prediction of incident AF after acute ST-segment elevation myocardial infarction (STEMI) in patients undergoing primary percutaneous intervention (PCI).

Methods

Study sample comprised of 2277 consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2010. SWEDEHEART registry was used as the source of information regarding clinical characteristics and events during index admission. Patients without known AF at discharge were included in the current study (n=1837, mean age 65±12 years, 30% females). AF in follow-up (median 9, interquartile range 25–75% (IQR) 7–10 years) was documented by linkage with the Swedish National Patient Register and Swedish Cause-of-Death Register. The closest available ECGs prior to STEMI (median 448, interquartile rate 25–75% 112–1390 days before STEMI) were extracted from the regional electronic ECG databases and automatically processed using Glasgow algorithm. P-wave duration, PR interval, P-wave frontal axis and P terminal force in lead V1 (PTF-V1) were assessed. PTF-V1 >40 mm*ms was considered abnormal.

Results

In follow-up incident AF was documented in 285 patients (15.4%). In univariate Cox regression analysis age, hypertension, history of myocardial infarction, heart failure, history of stroke, smoking status, P wave duration >120 ms, PR interval and abnormal PTF-V1 predicted the AF development during follow-up (Table). In multivariate Cox regression analysis in which significantly associated variables were included only age (hazard ratio (HR) 1.07, 95% CI 1.05–1.08, p<0.001) and abnormal PTF-V1 (HR 1.49, 95% CI 1.08–2.05, p=0.015, Figure) remained independent predictors of incident AF.

Conclusion

In patients with acute STEMI incident AF developed during long-term follow-up after discharge from hospital was strongly associated with age and atrial structural abnormalities reflected as abnormal PTF-V1 on pre-STEMI ECG which might serve as a tool in risk stratification of STEMI patients in regard to AF development.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Scholarship grant from Swedish Institute. Table 1Figure 1

ECG markers of atrial abnormalities are not associated with new onset atrial fibrillation in patients with acute ST-segment elevation myocardial infarction

Introduction

New onset AF is a known complication in patients with acute ST-segment elevation myocardial infarction (STEMI). However, whether new-onset AF is linked to atrial structural abnormalities or has different underlying mechanisms is not fully clarified.

Purpose

We aimed to assess the association of P wave indices as ECG markers of atrial structural abnormalities with new-onset AF in STEMI patients undergoing primary percutaneous intervention (PCI).

Methods

Study sample comprised of 2277 consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2010. SWEDEHEART registry was used as the source of information regarding clinical characteristics and events during index admission, including new-onset AF. The closest available ECGs prior to STEMI (median 448, interquartile rate 25–75% 112–1390 days before STEMI) were extracted from the regional electronic ECG databases and automatically processed using Glasgow algorithm. Patients with sinus rhythm ECGs were included in the current analysis (n=1481, mean age 68±12 years, 33% females). P-wave duration, PR interval, P-wave frontal axis and P terminal force in lead V1 (PTF-V1) were assessed. PTF-V1 >40 mm*ms was considered abnormal.

Results

Paroxysmal AF prior to STEMI was known in 77 patients (5.2%). Among patients without pre-existing AF (n=1404), new-onset AF during hospital admission was identified in 102 patients (6.9%). Patients with new-onset AF were older than those without AF history (74±9 vs 67±12 years, p<0.001), but did not differ in regard to other clinical characteristics. In univariate logistic regression analysis P wave duration as continuous variable, P wave duration >120 ms and PR interval were significantly associated with new onset AF (Table 1). However, after adjustment for age both, P wave duration >120 ms (odds ratio (OR) 1.20, 95% CI 0.77–1.89, p=0.418) and PR interval (OR 1.01, 95% CI 1.00–1.01, p=0.068), failed to demonstrate the significant association with new onset AF while age (OR 1.06, 95% CI 1.04–1.08, p<0.001) remained an independent risk factor for AF development.

Conclusion

In patients with acute STEMI new onset AF developed during hospital admission is common and strongly associated with age. P wave indices failed to demonstrate the significant association with new onset AF thus indicating that atrial structural abnormalities are unlikely the underlying cause of AF development in acute STEMI.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Scholarship grant from Swedish Institute. Table 1

Relationship between atrial fibrillatory rate based on analysis of a modified base-apex surface electrocardiogram analysis and the results of transvenous electrical cardioversion in horses with spontaneous atrial fibrillation

OBJECTIVES

To compare the atrial fibrillatory rate (AFR) derived from a local right atrial intracardiac recording (RA-FR) and from a single-lead surface electrocardiogram (ECG) during atrial fibrillation (AF) and to evaluate the correlation with transvenous electrical cardioversion (TVEC) threshold (in Joules), number of shocks and cardioversion success rate in horses.

ANIMALS

ECGs and clinical records of horses with AF treated by TVEC. Horses were included if a simultaneous recording of the right atrial intracardiac electrogram and a modified base-apex ECG were available.

MATERIALS AND METHODS

Clinical records of horses with AF treated by TVEC were reviewed. Three-minute long episodes of simultaneous electrograms and surface ECG during AF were selected for analysis and compared using Bland-Altman analysis. The mean RA-FR was measured from the deflections on the intracardiac electrogram, while the AFR was extracted from the surface ECG using spatiotemporal QRS and T-wave cancellation.

RESULTS

Seventy-three horses satisfied the inclusion criteria. The mean difference between RA-FR and AFR was -13 fibrillations per minute (fpm), the 95% limits of agreement were between -66 and 40 fpm, and there was a moderate (ρ = 0.65) correlation between RA-FR and AFR (p < 0.001). Neither RA-FR nor AFR appeared to influence the TVEC cardioversion threshold or the number of TVEC shocks applied.

CONCLUSIONS

The AFR may allow non-invasive long-term monitoring of AF dynamics. Neither RA-FR nor AFR could be used to predict the minimal defibrillation threshold for TVEC.

Progressive ECG changes over time in arrhythmogenic right ventricular cardiomyopathy precede diagnosis and continue – indices of disease substrate development?

Background

Depolarization and repolarization abnormalities are common in arrhythmogenic right ventricular cardiomyopathy (ARVC), and are included in the diagnostic 2010 Task Force criteria (TFC2010). However, first ARVC symptoms commonly occur before ECG abnormalities reach the diagnostic thresholds and the time course of ECG abnormalities during initial phase of the disease remains obscure. Regional digital ECG archives allow computerized signal-processing and assessment of ECG phenotype during different disease phases, including the time prior to ascertainment of ARVC diagnosis.

Purpose

We aimed to assess the natural course of ECG characteristics associated with ARVC, hypothesizing that ARVC is a progressive disease and that ECG parameters progress over time due to disease substrate development.

Methods

Definite ARVC patients with at least one digital ECG recruited in three tertiary care hospitals in Sweden and Denmark were included (n=102, 66% males, 68% probands, 52% carrying a pathogenic genetic variant, 74% ICD carriers and 25% physically active &gt;4 hours/week). Median age at diagnosis was 41 years (IQR 30–55). 12-lead digital ECGs were extracted from the regional ECG archives, containing all recordings in the hospital catchment areas since 1988. After excluding ECGs with heart rate &lt;40 or &gt;100/min, left bundle branch block or ventricular pacing, and those recorded prior to 14 years of age, the remaining 2067 ECGs were digitally processed and automatically analyzed using the Glasgow algorithm (median 3 [IQR 0–9] ECGs prior to diagnosis and 6 [IQR 2–14] ECGs during follow-up). Overall QRS duration as well as the right precordial lead indices exemplified by the lead V2 (terminal activation delay [TAD], area under the T-wave [T-wave area] and R-prime amplitude) were calculated and graphically represented using generalized additive model (GAM) with cubic splines (Figure 1). A median value for each measurement per patient per year was used for analysis. Blue line indicates smoothed conditional mean with 95% confidence interval (shadow). Time “0” (red line) indicates the time when TFC2010 criteria were fulfilled.

Results

Marked and consistent changes are seen in all studied depolarization and repolarization parameters over 10 years preceding ARVC diagnosis and continue afterwards. TAD demonstrates gradual increase, while T-wave area demonstrates consistent decrease over time before and after diagnosis indicating amplitude reduction and transition to T-wave inversion. The R-prime curve indicates that the terminal part of QRS complex demonstrate abnormalities first late in the course of the disease (Figure 1).

Conclusion

Electrocardiographic ARVC phenotype appears to become detectable long before the time of ARVC diagnosis indicating the progressive nature of ARVC and may explain arrhythmic events that may occur during the subclinical phase before ECG criteria are fulfilled.

Funding Acknowledgement

Type of funding source: None

Impact of new onset atrial fibrillation on long-term prognosis in patients with acute ST-segment elevation myocardial infarction

Introduction

New onset AF is a known complication in patients with acute ST-segment elevation myocardial infarction (STEMI). However, whether new-onset AF affects the long-term prognosis to the same extent as pre-existing AF is not fully clarified and prescription of oral anticoagulants (OAC) in patients with new-onset AF remains a matter of debates.

Purpose

We aimed to assess the impact of new-onset AF in STEMI patients undergoing primary percutaneous intervention (PCI) on outcome during long-term follow-up in comparison with pre-existing AF and to evaluate effect of OAC therapy in patients with new-onset AF on survival.

Methods

Study sample comprised of 2277 consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2010 (age 66±12 years, 70% male). AF prior to STEMI was documented by record linkage with the Swedish National Patient Register and review of ECGs obtained from the digital archive containing ECGs recorded in the hospital catchment area since 1988. SWEDEHEART registry was used as the source of information regarding clinical characteristics and events during index admission, including new-onset AF and OAC at discharge. All-cause mortality was assessed using the Swedish Cause-of-Death Register 8 years after discharge.

Results

AF prior to STEMI was documented in 177 patients (8%). Among patients without pre-existing AF (n=2100), new-onset AF was identified in 151 patients (7%). Patients with new-onset AF were older than those without AF history (74±9 vs 65±12 years, p&lt;0.001), but did not differ in regard to other clinical characteristics. Among 2149 STEMI survivors discharged alive, 523 (24%) died during 8 years of follow-up. OAC was prescribed at discharge in 45 (32%) patients with new onset AF and in 49 (31%) patients with pre-existing AF, p=0.901. In a univariate analysis, both new-onset AF (HR 2.18, 95% CI 1.70–2.81, p&lt;0.001) and pre-existing AF (HR 2.80, 95% CI 2.25–3.48, p&lt;0.001) were associated with all-cause mortality, Figure 1. After adjustment for age, gender, cardiac failure, diabetes, BMI and smoking history, new-onset AF remained an independent predictor of all-cause mortality (HR 1.40, 95% CI 1.02–1.92, p=0.037). OAC prescribed at discharge in patients with new-onset AF was not significantly associated with survival (univariate HR 0.86, 95% CI 0.50–1.50, p=0.599).

Conclusion

New-onset AF developed during hospital admission with STEMI is common and independently predicts all-cause mortality during long-term follow-up after STEMI with risk estimates similar to pre-existing AF. The effect of OAC on survival in patients with new-onset AF is inconclusive as only one third of them received OAC therapy at discharge.

Kaplan-Meier survival curve

Funding Acknowledgement

Type of funding source: None

Interatrial Block Predicts Atrial Fibrillation and Total Mortality in Patients with Cardiac Resynchronization Therapy

Background

Interatrial block (IAB) and abnormal P-wave terminal force in lead V1 (PTFV1) are electrocardiographic (ECG) abnormalities associated with new-onset atrial fibrillation (AF) and death. However, their prognostic importance has not been proven in CRT recipients with advanced heart failure (HF).

Purpose

To assess if IAB and abnormal PTFV1 are associated with new-onset AF or death in CRT recipients.

Methods

CRT recipients without AF history before CRT implantation were included (n=210, median age 67 years, 80% male, 55% ischemic heart disease, 70% NYHA Class III/IV, median LVEF 25%, 51% CRT-P). Automated analysis of P-wave duration (PWD) and morphology classified patients as having either No IAB (PWD &lt;120ms), Partial IAB (pIAB: PWD ≥120 ms, positive P waves in leads II and aVF) or Advanced IAB (aIAB: PWD ≥120 ms and biphasic or negative P wave in leads II or aVF). PTFV1 &gt;0.04 mm·s was considered abnormal. Cox regression analyses adjusted for age, NYHA Class, ischemic etiology of HF, LBBB, LVEF and CRT-P vs. CRT-D were performed to assess the impact of IAB and abnormal PTFV1 on the primary endpoint new-onset AF, death or heart transplant (HTx) and the secondary endpoint death or HTx at 5 years of follow up.

Results

IAB was found in 45% (34% pIAB and 11% aIAB) and was associated with both the primary (HR 1.9, 95% CI 1.2–2.9, p=0.004) and the secondary (HR 2.1, 95% CI 1.2–3.4, p=0.006) endpoints. Abnormal PTFV1 was not associated with outcome. See Forest plot for adjusted HRs for individual P-wave indices.

Conclusions

IAB is associated with new-onset AF and death in CRT recipients and may be helpful in risk stratification in the context of HF management. Abnormal PTFV1 did not demonstrate any prognostic value in the setting of CRT-treated patients with advanced HF.

Forest plot

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swedish Heart and Lung Foundation

Early monomorphic ventricular tachycardia is associated with increased long-term mortality in STEMI

Background

Malignant ventricular arrhythmias occurring early during ST-elevation myocardial infarction (STEMI) are known to markedly contribute to increased in-hospital mortality, but not to influence the long-term prognosis. However recent data advocate differential approach to the type of arrhythmia and indicate long-term hazard of monomorphic ventricular tachycardia (VT).

Purpose

We aimed to evaluate the prognostic value of monomorphic VT compared to non-monomorphic VT or ventricular fibrillation (VF) during the first 48 hours of STEMI in non-selected cohort of STEMI patients admitted for primary PCI.

Methods

Consecutive STEMI patients admitted to a tertiary care hospital for primary PCI during 2007–2010 were included. The Swedish national SWEDEHEART registry was used for assessment of clinical characteristics and the presence of VT/VF during index admission. The occurrence and type of VT/VF during the first 48 hours from symptom onset were verified in medical records. Information on all-cause mortality endpoint 8 years after STEMI was obtained from the Swedish Cause of Death Register.

Results

In total, 2277 patients were included (age 66±12 years, 70% male). Early monomorphic VT during index STEMI was documented in 35 (1.5%) and non-monomorphic VT or VF – in 115 (5.1%) patients. Patients with monomorphic VT had similar clinical characteristics compared to those with non-monomorphic VT/VF with a trend of higher prevalence of history of myocardial infarction by index admission among those with monomorphic VT (31% vs 21%, p=0.256). In total, 22 (63%) patients with monomorphic VT and 43 (37%) with non-monomorphic VT/VF died by 8 years of follow up (p=0.011). Monomorphic VT was associated with a higher risk of all-cause mortality compared to non-monomorphic VT/VF in a univariate analysis (HR 2.03, 95% CI 1.21–3.39, p=0.007) and after adjustment for age and history of myocardial infarction (HR 1.74, 95% CI 1.02–2.97, p=0.041) (Figure).

Conclusion

Monomorphic VT during the first 48 hours of STEMI is associated with a higher risk of all-cause mortality compared to non-monomorphic VT/VF and deserves further studies in order to refine risk stratification strategies.

Survival after STEMI by VT/VF &lt;48 hours

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Swedish Heart-Lung Foundation

Clustering of Four-Component Unitary Fermions

Ab initio nuclear physics tackles the problem of strongly interacting four-component fermions. The same setting could foreseeably be probed experimentally in ultracold atomic systems, where two- and three-component experiments have led to major breakthroughs in recent years. Both due to the problem's inherent interest and as a pathway to nuclear physics, in this Letter we study four-component fermions at unitarity via the use of quantum Monte Carlo methods. We explore novel forms of the trial wave function and find one which leads to a ground state of the eight-particle system whose energy is almost equal to that of two four-particle systems. We investigate the clustering properties involved and also extrapolate to the zero-range limit. In addition to being experimentally testable, our results impact the prospects of developing nuclear physics as a perturbation around the unitary limit.

P5683Incremental hazard associated with the degree of advanced intaratrial block in cardiac resynchronization therapy treated heart failure patients

Background

Advanced Inter Atrial Block (aIAB) reflects a disruption of the electrical signal between the atria and develops gradually. It has been predictive of atrial fibrillation and death in patients with Cardiac Resynchronization Therapy (CRT). A higher number of inferior ECG leads demonstrating biphasic P waves was proposed as a measure of aIAB severity, however its prognostic importance has not been proven.

Purpose

To assess if aIAB is associated with poor prognosis in CRT recipients and to see if there is a dose-response relationship between the aIAB severity and the outcome.

Methods

CRT recipients with sinus rhythm on digitally stored preoperative ECG were included (n=565, median age 70 years, 82% male, 55% ischemic heart failure [HF] etiology, 54% CRT-P, 70% left bundle branch block [LBBB]). Automated analysis of P-wave duration [PWD] and morphology in leads II, aVF and III assessed as positive, negative or biphasic +/− was performed and patients classified as having either No IAB (PWD <120ms), Partial IAB (pIAB, PWD ≥120 ms, positive P-waves in inferior leads), aIAB (PWD ≥120 ms and biphasic p-waves in one of the inferior leads). aIAB patients were further stratified by the presence of biphasic P waves in only one (aIAB-1) or more (aIAB-2) inferior leads. Extreme aIAB was defined as biphasic P waves in lead II and negative in leads III and aVF. Cox regression analyses adjusted for age, gender, NYHA class, ischemic HF etiology, left ventricular ejection fraction, LBBB, CRT-P versus CRT-D and PWD were performed to assess the impact of aIAB and its types on the endpoint hospitalization for HF or death at 5 years of follow up.

Results

Advanced IAB was observed in 65 patients (10 with aIAB-1, 53 with aIAB-2 and 2 with extreme aIAB) and pIAB in 151. No clinically relevant significant differences in baseline characteristics were observed between groups. Compared to the NoIAB group, aIAB-2 and extreme aIAB independently predicted the combined endpoint with adjusted HR=1.82 (95% CI 1.14–2.90, p-value 0.012) and HR=4.70 (95% CI 1.10–20.16, p-value 0.037), respectively.

Conclusion

Advanced IAB is associated with HF admissions or death from any cause in HF patients treated with CRT. Our findings indicate dose-response relationship between the severity of aIAB and the outcome.

P2661Ventricular fibrillation during acute STEMI is not associated with early repolarization pattern on ECG recorded prior to the index ischemic episode

Background

Generally considered as benign, ECG early repolarization (ER) pattern was recently claimed to be an indicator of increased susceptibility to fatal arrhythmias during acute ischemia. The victims of sudden cardiac death have been reported to have high prevalence of ER comparing with survivors of acute coronary event.

We aimed to test the association between the ER pattern on resting ECG recorded prior to ST-elevation myocardial infarction (STEMI) and the risk of ventricular fibrillation (VF) during acute phase of STEMI in non-selected population of STEMI patients.

Methods

For STEMI patients admitted to a tertiary care hospital for primary PCI during 2007–2010 (n=2286), all ECGs recorded prior to the date of admission with STEMI were extracted from a digital archive. The latest ECG recorded prior to the index STEMI was used for analysis.

After excluding ECGs with paced rhythm and intraventricular blocks with QRS duration ≥120ms, the remaining ECGs were processed using the Glasgow algorithm allowing automatic ER detection. The association between ER-pattern on historical ECG and VF during the first 48 hours of STEMI was tested using logistic regression.

Results

Historical ECGs were available for 1584 patients; 124 of them were excluded due to a paced rhythm or wide QRS, leaving 1460 patients available for analysis (age 68±12 years, 67% male). The time from historical ECG to STEMI was 16 (IQR 4–49) months. ER pattern was present on historical ECG in 272 of 1460 (18.6%) (ER+ group), among them in 90 (33%) – in inferior leads, in 116 (43%) – in lateral leads, in 66 (24%) – both in inferior and lateral leads.

ER+ patients were younger both at the time of historical ECG (64±13 vs 66±19; p=0.041) and at the time of STEMI (67±12 vs 68±12; p=0.033), and had lower heart rate on historical ECG (68±12 vs 73±15; p<0.001) than ER- patients. ER+ and ER- groups did not differ regarding clinical characteristics and conventional ECG measurements. The course of STEMI was complicated by VF in 106 patients (17 of them from ER+ group). The occurrence of VF during STEMI was not associated with ER-pattern on historical ECG (OR 0.875 95% CI 0.518–1.479; p=0.618). There was no association of ER pattern with VF before reperfusion (OR 0.54 95% CI 0.25–1.21; p=0.135) or reperfusion VF (OR 1.28 95% CI 0.55–3.01; p=0.569). No association was observed with regard to localization (inferior or lateral) of ER-pattern either.

Conclusion

In a non-selected population of STEMI patients the presence of ER-pattern on ECG recorded prior to the acute coronary event was not associated with VF during the first 48 hours of STEMI.

P5653Atrial fibrillation in arrhythmogenic right ventricular cardiomyopathy and its association with left atrial volume index

Background

Recent studies in arrhythmogenic right ventricular cardiomyopathy (ARVC) support atrial involvement in the disease progression and consider atrial fibrillation (AF) as one of the primary manifestations of ARVC. We aimed to assess clinical factors, components of 2010 Task Force criteria (TFC2010) and echocardiographic characteristics of atria associated with AF in the Scandinavian cohort of ARVC patients.

Methods

Study sample comprised of 106 definite ARVC patients by TFC2010 from three tertiary care centers participating in the Nordic ARVC Registry (33% females, median age at ARVC diagnosis 41 years [IQR 30–54 years]). No concomitant diseases were observed in 90 patients (85%) while 16 patients had one or more comorbidities: hypertension (n=6), diabetes mellitus (n=5), coronary artery disease (n=5) or congestive heart failure (n=9). AF was included in the registry protocol as a pre-specified clinical event and verified by processing of the electronic ECG databases which contains all ECG recordings from the involved hospitals catchment areas (earliest ECG from 1988). Left (LA) and right atrial (RA) dimensions were obtained by revisiting cardiac ultrasound examinations performed at the time of ARVC diagnosis. Association between AF and clinical characteristics was assessed using multivariable logistic regression analysis adjusted for age and gender.

Results

AF was diagnosed in 29 patients (27%) at a median age of 53 (IQR 38–63) years, 7 females (24%). Median time from ARVC diagnosis to AF onset was 8 (IQR 2–12) years. AF was univariately associated with right ventricular structural abnormalities meeting the definition of major imaging criterion by 2010TFC, ventricular tachycardia (VT) with superior axis (major criterion) and LA volume index. Significantly associated variables were included in a multivariate model, in which LA volume index (OR=1.07, 95% CI 1.01–1.14, p=0.021) and superior axis VT (OR=7.45, 95% CI 1.82–30.55, p=0.005) remained independently associated with AF. In receiver operating characteristic (ROC) curve analysis, LA volume index was significantly associated with AF (AUC=0.703, p=0.005) and with superior axis VT (AUC=0.703, p=0.021). AF was not associated with either RA volume index (univariate OR=1.03, 95% CI 0.99–1.06, p=0.203) or left ventricular ejection fraction (OR=0.97, 95% CI 0.92–1.03, p=0.299).

Conclusion

In patients with ARVC,AF is primarily associated with LA structural abnormalities without indication of RA involvement and is strongly associated with ventricular arrhythmias thus indicating parallel development of atrial and ventricular arrhythmic substrate.

P2247Pregnancies and childbirth in women with arrhythmogenic right ventricular cardiomyopathy are associated with low risk of ventricular arrhythmias

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a risk of ventricular arrhythmias (VA) and sudden cardiac death (SCD). Even though female patients with ARVC are considered to be at lower risk of VA, the impact of pregnancy and child birth on the arrhythmic risk and development of arrhythmic substrate in the context of ARVC remains insufficiently studied.

Objective

To assess the risk of VA in relation to childbirth in women with ARVC and the impact of multiple pregnancies on progression of arrhythmic manifestations of the disease.

Methods

The study included 186 females with definite ARVC (n=107, 70 probands) or unaffected mutation-carriers (n=79) with median age at the end of follow up of 48 (IQR 34–60) years. Seventeen women had 1, 59 had 2 and 29 had ≥3 child births by the age of 40 years. VA was defined as ventricular tachycardia, appropriate ICD therapy, aborted cardiac arrest or SCD. Proportions of patients who experienced VA by the age of 40 years were compared between nulliparous women (n=81) and those with reported child births (n=105). VA-free survival after accomplished pregnancies was assessed for women ≥40 years of age (n=119). Cumulative probability of VA for each pregnancy (n=230) was assessed from conception through 2 years after child birth and compared between those that occurred before ARVC diagnosis (Pre-Ds, n=164), after it (Post-Ds, n=11) and in unaffected mutation carriers (No-Ds, n=55).

Results

The nulliparous women had lower age at ARVC diagnosis (37 vs 44, p=0.023) and more often had VA before the age of 40 (31% vs 13%, p=0.003) while the number of child births was not related to the prevalence of VA (18% among women with 1 childbirth, 12% in those with 2 and 14% in those with 3 or more, ns). Three women suffered SCD before the age of 40. VA-free survival after 40 years did not differ between nulliparous and those who gave birth (Figure A). Only four pregnancy-related events were documented (Figure B): 1 in the Post-Ds group and three in the Pre-Ds group. No pregnancy-related events were reported in the unaffected mutation carriers.

Conclusion

In this Scandinavian cohort of women with ARVC we observed no indication of an increased VA risk either associated with pregnancies or during long-term follow up after the last child birth.

3056Orthogonal P wave morphology, traditional P wave indices, and the risk of atrial fibrillation in the general population

Background

A substantial portion of the risk of atrial fibrillation (AF) remains unexplained by the established risk markers. However, accurate assessment of AF risk would be beneficial, especially among stroke patients and subjects with symptoms attributable to arrhythmia.

Purpose

To study the associations of P-wave indices with AF risk in the general population.

Methods

Electrocardiograms, including orthogonal leads, of 7217 Finnish subjects aged over 30 years who took part in the baseline examinations of the Mini-Finland Health Survey in 1978–80, were digitized. P-wave duration, third-degree interatrial block (IAB), and P terminal force (PTF) were assessed manually. PTF was considered abnormal when the amplitude of the negative terminal part of the P wave in lead V1 was ≥0.1mV and duration ≥40ms. Third-degree IAB was defined as P-wave duration ≥120ms and the presence of ≥2 +/− biphasic P-waves in the inferior leads. Orthogonal P-wave morphology, which is related to left atrial breakthrough site and affected by atrial fibrosis (1 being considered benign, 2 borderline, and 3 shown to be associated with adverse events), was assessed with an automated algorithm, and ascertained manually. Subjects were followed 10 years for AF hospitalization and mortality. The risk of AF associated with P wave parameters was assessed using Cox proportional hazards models. Model discrimination improvement was quantified by the change in C index, integrated discrimination improvement (IDI), and continuous net reclassification improvement (cNRI).

Results

There were 5489 subjects (47.8% male, mean age 50.5 years) with a readable ECG, sinus rhythm, no missing data, and a predefined orthogonal P-wave morphology. Type 3 orthogonal P morphology (n=216, multivariate adjusted HR [maHR] 3.01, 95% confidence interval [CI] 1.66–5.45, p<0.001), P-wave duration ≥120ms (n=752, maHR 1.67, 95% CI 1.06–2.64, p=0.027), and third-degree IAB (n=103, maHR 3.18, 95% CI 1.66–6.13, p=0.001) were independently associated with the risk of AF in separate models. PTF did not independently predict AF. Subjects presenting with both Type 1 orthogonal P-wave morphology and P-wave duration <110ms (n=2074) were at low risk of AF (maHR 0.46, 95% CI 0.26–0.83, p=0.006) when compared to the rest of the subjects. The inclusion of variables combining orthogonal P-wave morphology and P-wave duration to a multivariate model including conventional AF risk factors improved C index from 0.815 to 0.832 (change 0.017, 95% CI 0.001–0.033), IDI was 0.012 (95% CI 0.006–0.051), and cNRI was 0.220 (95% CI 0.048–0.357).

Conclusions

P-wave indices and orthogonal P-wave morphology can be used to identify subjects at high and low risk for AF and possibly direct extensive AF screening protocols towards high-risk subjects in the general population in order to decrease the risk of cardioembolic stroke. However, more research is needed in this topic.

Acknowledgement/Funding

Finnish Medical Foundation, Onni and Hilja Tuovinen's Foundation, Orion Research Foundation, Paavo Nurmi's Foundation, Veritas Foundation

Predictive capacity of prodromal symptoms in first-episode psychosis of recent onset

BACKGROUND

Both the nature and number of a wide range of prodromal symptoms have been related to the severity and type of psychopathology in the psychotic phase. However, at present there is an incomplete picture focused mainly on the positive pre-psychotic dimension.

AIM

To characterize the prodromal phase retrospectively, examining the number and nature of prodromal symptoms as well as their relationship with psychopathology at the onset of first-episode psychosis.

METHODS

Retrospective study of 79 patients experiencing a first-episode psychosis of less than 1 year from the onset of full-blown psychosis. All patients were evaluated with a comprehensive battery of instruments including socio-demographic and clinical questionnaire, IRAOS interview, PANSS, stressful life events scale (PERI) and WAIS/WISC (vocabulary subtest). Bivariate associations and multiple regression analysis were performed.

RESULTS

Regression models revealed that several prodromal dimensions of IRAOS (delusions, affect, language, behaviour and non-hallucinatory disturbances of perception) predicted the onset of psychosis, with positive (22.4% of the variance) and disorganized (25.6% of the variance) dimensions being the most widely explained.

CONCLUSION

In addition to attenuated positive symptoms, other symptoms such as affective, behavioural and language disturbances should also be considered in the definitions criteria of at-high-risk people.

Interatrial block in prediction of all-cause mortality after first-ever ischemic stroke

Background

Interatrial block (IAB) is an ECG indicator of atrial fibrosis related to atrial remodeling and thrombus formation thus leading to embolic stroke and increasing mortality. We aimed to assess weather IAB predicted all-cause mortality during 10 years after ischemic stroke.

Methods

The study sample comprised 235 patients (median age 74 (interquartile range 25–75% 65–81) years, 95 female) included in the Lund Stroke Register in 2001–2002, who had sinus rhythm ECGs at stroke admission. IAB was defined as a P-wave duration ≥120 ms without = partial IAB (n = 56) or with = advanced IAB (n = 41) biphasic morphology (±) in the inferior ECG leads. All-cause mortality was assessed via linkage with the Swedish Causes of Death Register.

Results

During follow-up 126 patients died (54%). Advanced IAB, but not partial, was associated with all-cause mortality in univariate Cox regression analysis (hazard ratio (HR) 1.98, 95% CI 1.27–3.09, p = 0.003). After adjustment for age, gender, severity of stroke measured by NIHSS scale and smoking status in patients without additional comorbidities advanced IAB independently predicted all-cause mortality (HR 7.89, 95% CI 2.01–30.98, p = 0.003), while in patients with comorbidities it did not (HR 1.01 95% CI 0.59–1.72, p = 0.966).

Conclusion

Advanced IAB predicted all-cause mortality after ischemic stroke, but mostly in patients without additional cardiovascular comorbidities.

Properties of Nuclei up to A=16 using Local Chiral Interactions

We report accurate quantum Monte Carlo calculations of nuclei up to A=16 based on local chiral two- and three-nucleon interactions up to next-to-next-to-leading order. We examine the theoretical uncertainties associated with the chiral expansion and the cutoff in the theory, as well as the associated operator choices in the three-nucleon interactions. While in light nuclei the cutoff variation and systematic uncertainties are rather small, in ^{16}O these can be significant for large coordinate-space cutoffs. Overall, we show that chiral interactions constructed to reproduce properties of very light systems and nucleon-nucleon scattering give an excellent description of binding energies, charge radii, and form factors for all these nuclei, including open-shell systems in A=6 and 12.

Ground-State Properties of Unitary Bosons: From Clusters to Matter

The properties of cold Bose gases at unitarity have been extensively investigated in the last few years both theoretically and experimentally. In this Letter we use a family of interactions tuned to two-body unitarity and very weak three-body binding to demonstrate the universal properties of both clusters and matter. We determine the universal properties of finite clusters up to 60 particles and, for the first time, explicitly demonstrate the saturation of energy and density with particle number and compare with bulk properties. At saturation in the bulk we determine the energy, density, two- and three-body contacts, and the condensate fraction. We find that uniform matter is more bound than three-body clusters by nearly 2 orders of magnitude, the two-body contact is very large in absolute terms, and yet the condensate fraction is also very large, greater than 90%. Equilibrium properties of these systems may be experimentally accessible through rapid quenching of weakly interacting boson superfluids.

Detection and prevalence of Haemoproteus archilochus (Haemosporida, Haemoproteidae) in two species of California hummingbirds

Haemosporidian blood parasites are transmitted to a wide range of avian hosts via blood-sucking dipteran vectors. Microscopy has revealed an impressive diversity of avian haemosporidia with more than 250 species described. Moreover, PCR and subsequent sequence analyses have suggested a much greater diversity of haemosporidia than morphological analyses alone. Given the importance of these parasites, very few studies have focused on the charismatic hummingbirds. To date, three Haemoproteus species (Haemoproteus archilochus, Haemoproteus trochili, and Haemoproteus witti) and one Leucocytozoon species (Leucocytozoon quynzae) have been described in blood samples taken from hummingbirds (Trochilidae). Unconfirmed Plasmodium lineages have also been detected in hummingbirds. Here, we report the detection of H. archilochus in two hummingbird species (Calypte anna and Archilochus alexandri) sampled in Northern California and perform a phylogenetic analysis of mitochondrial cytochrome b (cyt b) gene lineages. A total of 261 hummingbirds (157 C. anna, 104 A. alexandri) were sampled and screened for blood parasites using PCR and microscopy techniques. Combining both methods, 4 (2.55%) haemosporidian infections were detected in C. anna and 18 (17.31%) haemosporidian infections were detected in A. alexandri. Molecular analyses revealed four distinct H. archilocus cyt b lineages, which clustered as a monophyletic clade. No species of Plasmodium or Leucocytozoon were detected in this study, raising the possibility of specific vector associations with hummingbirds. These results provide resources for future studies of haemosporidian prevalence, diversity, and pathogenicity in California hummingbird populations.

Does the social environment moderate associations of the built environment with Latinas' objectively-measured neighborhood outdoor physical activity?

Favorable perceptions of the built and social neighborhood environment may promote outdoor physical activity (PA). However, little is known about their independent and interactive effects on neighborhood-specific outdoor PA. We examined associations of perceived built and social neighborhood environment factors, and their interactions, with objectively-measured neighborhood outdoor moderate-to-vigorous physical activity (MVPA) among a sample of Latina women in San Diego, CA. Analyses included baseline data collected in 2011-2013 from 86 Latinas with ≥ 2 days of combined accelerometer and global positioning system data and complete survey measures. We examined objective neighborhood outdoor MVPA within 500-meter home buffers. Generalized linear mixed models examined associations of 3 perceived built (e.g., sidewalk maintenance) and 3 social environmental (e.g., safety from crime) factors with engaging in any daily neighborhood outdoor MVPA. Models tested interactions between the built and social environmental factors. Although the perceived neighborhood environmental factors were not significantly related to daily neighborhood outdoor MVPA, we found 2 significant interactions: perceived sidewalk maintenance x safety from crime (p = 0.05) and neighborhood aesthetics x neighborhood social cohesion (p = 0.03). Sidewalk maintenance was positively related to daily neighborhood outdoor MVPA only among Latinas that reported low levels of safety from crime. Neighborhood aesthetics was positively related to daily neighborhood outdoor MVPA only among Latinas with high neighborhood social cohesion. Findings suggest several built and social environmental factors interact to influence Latinas' neighborhood outdoor MVPA. Interventions are needed targeting both built and social neighborhood environmental factors favorable to outdoor PA in the neighborhood.

Liver Transplantation in a Patient at Psychosocial Risk

Psychosocial assessment of transplant candidates is a challenging task. Securing adequate information is made more difficult when patients present with fulminant hepatic failure. When the patient cannot be interviewed and the family is reluctant to provide vital information, a comprehensive pretransplant psychosocial evaluation is virtually impossible. However, even the most difficult cases have the potential for a positive result when a good psychosocial profile of the patient is obtained after transplantation, a team treatment plan is developed and carried out which addresses current and anticipated problems, and the patient obtains mental health treatment.

Paediatric non-progression following grandmother-to-child HIV transmission

Background

In contrast to adult HIV infection, where slow disease progression is strongly linked to immune control of HIV mediated by protective HLA class I molecules such as HLA-B*81:01, the mechanisms by which a minority of HIV-infected children maintain normal-for-age CD4 counts and remain clinically healthy appear to be HLA class I-independent and are largely unknown. To better understand these mechanisms, we here studied a HIV-infected South African female, who remained a non-progressor throughout childhood.

Results

Phylogenetic analysis of viral sequences in the HIV-infected family members, together with the history of grand-maternal breast-feeding, indicated that, unusually, the non-progressor child had been infected via grandmother-to-child transmission. Although HLA-B*81:01 was expressed by both grandmother and grand-daughter, autologous virus in each subject encoded an escape mutation L188F within the immunodominant HLA-B*81:01-restricted Gag-specific epitope TL9 (TPQDLNTML, Gag 180–188). Since the transmitted virus can influence paediatric and adult HIV disease progression, we investigated the impact of the L188F mutant on replicative capacity. When this variant was introduced into three distinct HIV clones in vitro, viral replicative capacity was abrogated altogether. However, a virus constructed using the gag sequence of the non-progressor child replicated as efficiently as wildtype virus.

Conclusion

These findings suggest alternative sequences of events: the transmission of the uncompensated low fitness L188F to both children, potentially contributing to slow progression in both, consistent with previous studies indicating that disease progression in children can be influenced by the replicative capacity of the transmitted virus; or the transmission of fully compensated virus, and slow progression here principally the result of HLA-independent host-specific factors, yet to be defined.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-016-0300-y) contains supplementary material, which is available to authorized users.

Electromagnetic Response of ^{12}C: A First-Principles Calculation

The longitudinal and transverse electromagnetic response functions of ^{12}C are computed in a "first-principles" Green's function Monte Carlo calculation, based on realistic two- and three-nucleon interactions and associated one- and two-body currents. We find excellent agreement between theory and experiment and, in particular, no evidence for the quenching of the measured versus calculated longitudinal response. This is further corroborated by a reanalysis of the Coulomb sum rule, in which the contributions from the low-lying J^{π}=2^{+}, 0_{2}^{+} (Hoyle), and 4^{+} states in ^{12}C are accounted for explicitly in evaluating the total inelastic strength.