A haplotype-resolved chromosome-scale genome for Quercus rubra L. provides insights into the genetics of adaptive traits for red oak species

Northern red oak (Quercus rubra L.) is an ecologically and economically important forest tree native to North America. We present a chromosome-scale genome of Q. rubra generated by the combination of PacBio sequences and chromatin conformation capture (Hi-C) scaffolding. This is the first reference genome from the red oak clade (section Lobatae). The Q. rubra assembly spans 739 Mb with 95.27% of the genome in 12 chromosomes and 33,333 protein-coding genes. Comparisons to the genomes of Quercus lobata and Quercus mongolica revealed high collinearity, with intrachromosomal structural variants present. Orthologous gene family analysis with other tree species revealed that gene families associated with defense response were expanding and contracting simultaneously across the Q. rubra genome. Quercus rubra had the most CC-NBS-LRR and TIR-NBS-LRR resistance genes out of the 9 species analyzed. Terpene synthase gene family comparisons further reveal tandem gene duplications in TPS-b subfamily, similar to Quercus robur. Phylogenetic analysis also identified 4 subfamilies of the IGT/LAZY gene family in Q. rubra important for plant structure. Single major QTL regions were identified for vegetative bud break and marcescence, which contain candidate genes for further research, including a putative ortholog of the circadian clock constituent cryptochrome (CRY2) and 8 tandemly duplicated genes for serine protease inhibitors, respectively. Genome-environment associations across natural populations identified candidate abiotic stress tolerance genes and predicted performance in a common garden. This high-quality red oak genome represents an essential resource to the oak genomic community, which will expedite comparative genomics and biological studies in Quercus species.

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.

Thirty-five years of tiger shark Galeocerdo cuvier relative abundance near Bimini, The Bahamas, and the Southeastern United States with a comparison across jurisdictional bounds

Abundances of large sharks are reported to have declined worldwide, and in response various levels of fisheries management and conservation efforts have been established. For example, marine-protected areas have been suggested as a means to protect large expanses of ocean from fishing and other industrial activities (e.g., habitat destruction), and in 2011 The Commonwealth of The Bahamas established The Bahamas Shark Sanctuary. Nonetheless, assessing the effectiveness of conservation efforts is challenging because consistent long-term data sets of shark abundances are often lacking, especially throughout the Caribbean and The Bahamas. In this study, the authors investigated the catch rates and demographics of tiger sharks Galeocerdo cuvier caught in a fishery-independent survey near Bimini, The Bahamas, from 1984 to 2019 to assess relative abundance trends following the banning of longline fishing in 1993 and the subsequent establishment of the shark sanctuary. To contextualize the relative abundance trends near Bimini, the authors compared this to the relative abundance of tiger sharks in a fishery-dependent survey from the Southeastern USA (SE USA), conducted from 1994 to 2019. The data of this study suggest that local abundance of tiger sharks has been stable near Bimini since the 1980s, including after the ban of longline fishing and the implementation of the shark sanctuary. In comparison, the abundance near the SE USA has slowly increased in the past decade, following potential declines in the decade preceding the USA Shark Management Plan. The results of this study provide some optimism that current conservation efforts in The Bahamas have been effective to maintain local tiger shark abundance within the protected area. In addition, current fisheries management in the SE USA is allowing this species to recover within those waters.

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.

Dynamic Intracranial Pressure Waveform Morphology Predicts Ventriculitis

BACKGROUND

Intracranial pressure waveform morphology reflects compliance, which can be decreased by ventriculitis. We investigated whether morphologic analysis of intracranial pressure dynamics predicts the onset of ventriculitis.

METHODS

Ventriculitis was defined as culture or Gram stain positive cerebrospinal fluid, warranting treatment. We developed a pipeline to automatically isolate segments of intracranial pressure waveforms from extraventricular catheters, extract dominant pulses, and obtain morphologically similar groupings. We used a previously validated clinician-supervised active learning paradigm to identify metaclusters of triphasic, single-peak, or artifactual peaks. Metacluster distributions were concatenated with temperature and routine blood laboratory values to create feature vectors. A L2-regularized logistic regression classifier was trained to distinguish patients with ventriculitis from matched controls, and the discriminative performance using area under receiver operating characteristic curve with bootstrapping cross-validation was reported.

RESULTS

Fifty-eight patients were included for analysis. Twenty-seven patients with ventriculitis from two centers were identified. Thirty-one patients with catheters but without ventriculitis were selected as matched controls based on age, sex, and primary diagnosis. There were 1590 h of segmented data, including 396,130 dominant pulses in patients with ventriculitis and 557,435 pulses in patients without ventriculitis. There were significant differences in metacluster distribution comparing before culture-positivity versus during culture-positivity (p < 0.001) and after culture-positivity (p < 0.001). The classifier demonstrated good discrimination with median area under receiver operating characteristic 0.70 (interquartile range 0.55-0.80). There were 1.5 true alerts (ventriculitis detected) for every false alert.

CONCLUSIONS

Intracranial pressure waveform morphology analysis can classify ventriculitis without cerebrospinal fluid sampling.

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 &gt;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 &gt;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&lt;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 &gt;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&lt;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 &gt;120 ms and PR interval were significantly associated with new onset AF (Table 1). However, after adjustment for age both, P wave duration &gt;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&lt;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