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1.
Nature ; 616(7958): 755-763, 2023 04.
Article in English | MEDLINE | ID: mdl-37046083

ABSTRACT

Mutations in a diverse set of driver genes increase the fitness of haematopoietic stem cells (HSCs), leading to clonal haematopoiesis1. These lesions are precursors for blood cancers2-6, but the basis of their fitness advantage remains largely unknown, partly owing to a paucity of large cohorts in which the clonal expansion rate has been assessed by longitudinal sampling. Here, to circumvent this limitation, we developed a method to infer the expansion rate from data from a single time point. We applied this method to 5,071 people with clonal haematopoiesis. A genome-wide association study revealed that a common inherited polymorphism in the TCL1A promoter was associated with a slower expansion rate in clonal haematopoiesis overall, but the effect varied by driver gene. Those carrying this protective allele exhibited markedly reduced growth rates or prevalence of clones with driver mutations in TET2, ASXL1, SF3B1 and SRSF2, but this effect was not seen in clones with driver mutations in DNMT3A. TCL1A was not expressed in normal or DNMT3A-mutated HSCs, but the introduction of mutations in TET2 or ASXL1 led to the expression of TCL1A protein and the expansion of HSCs in vitro. The protective allele restricted TCL1A expression and expansion of mutant HSCs, as did experimental knockdown of TCL1A expression. Forced expression of TCL1A promoted the expansion of human HSCs in vitro and mouse HSCs in vivo. Our results indicate that the fitness advantage of several commonly mutated driver genes in clonal haematopoiesis may be mediated by TCL1A activation.


Subject(s)
Clonal Hematopoiesis , Hematopoietic Stem Cells , Animals , Humans , Mice , Alleles , Clonal Hematopoiesis/genetics , Genome-Wide Association Study , Hematopoiesis/genetics , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/metabolism , Mutation , Promoter Regions, Genetic
2.
Ann Neurol ; 93(3): 479-488, 2023 03.
Article in English | MEDLINE | ID: mdl-36373166

ABSTRACT

OBJECTIVE: Approximately 20% of strokes are embolic strokes of undetermined source (ESUS). Undetected atrial fibrillation (AF) remains an important cause. Yet, oral anticoagulation in unselected ESUS patients failed in secondary stroke prevention. Guidance on effective AF detection is lacking. Here, we introduce a novel, non-invasive AF risk assessment after ESUS. METHODS: Catch-Up ESUS is an investigator-initiated, observational cohort study conducted between 2018 and 2019 at the Munich University Hospital. Besides clinical characteristics, patients received ≥72 h digital electrocardiogram recordings to generate the rhythm irregularity burden. Uni- and multivariable regression models predicted the primary endpoint of incident AF, ascertained by standardized follow-up including implantable cardiac monitors. Predictors included the novel rhythm irregularity burden constructed from digital electrocardiogram recordings. We independently validated our model in ESUS patients from the University Hospital Tübingen, Germany. RESULTS: A total of 297 ESUS patients were followed for 15.6 ± 7.6 months. Incident AF (46 patients, 15.4%) occurred after a median of 105 days (25th to 75th percentile 31-33 days). Secondary outcomes were recurrent stroke in 7.7% and death in 6.1%. Multivariable-adjusted analyses identified the rhythm irregularity burden as the strongest AF-predictor (hazard ratio 3.12, 95% confidence interval 1.62-5.80, p < 0001) while accounting for the known risk factors age, CHA2 DS2 -VASc-Score, and NT-proBNP. Independent validation confirmed the rhythm irregularity burden as the most significant AF-predictor (hazard ratio 2.20, 95% confidence interval 1.45-3.33, p < 0001). INTERPRETATION: The novel, non-invasive, electrocardiogram-based rhythm irregularity burden may help adjudicating AF risk after ESUS, and subsequently guide AF-detection after ESUS. Clinical trials need to clarify if high-AF risk patients benefit from tailored secondary stroke prevention. ANN NEUROL 2023;93:479-488.


Subject(s)
Atrial Fibrillation , Embolic Stroke , Intracranial Embolism , Stroke , Humans , Atrial Fibrillation/complications , Embolic Stroke/complications , Risk Assessment , Risk Factors , Intracranial Embolism/etiology
3.
Europace ; 25(9)2023 08 02.
Article in English | MEDLINE | ID: mdl-37470430

ABSTRACT

AIMS: Sudden cardiac death (SCD) is challenging to predict. Electrocardiogram (ECG)-derived heart rate-corrected QT-interval (QTc) is used for SCD-risk assessment. QTc is preferably determined manually, but vendor-provided automatic results from ECG recorders are convenient. Agreement between manual and automatic assessments is unclear for populations with aberrant QTc. We aimed to systematically assess pairwise agreement of automatic and manual QT-intervals and QTc. METHODS AND RESULTS: A multi-centre cohort enriching aberrant QTc comprised ECGs of healthy controls and long-QT syndrome (LQTS) patients. Manual QT-intervals and QTc were determined by the tangent and threshold methods and compared to automatically generated, vendor-provided values. We assessed agreement globally by intra-class correlation coefficients and pairwise by Bland-Altman analyses and 95% limits of agreement (LoA). Further, manual results were compared to a novel automatic QT-interval algorithm. ECGs of 1263 participants (720 LQTS patients; 543 controls) were available [median age 34 (inter-quartile range 35) years, 55% women]. Comparing cohort means, automatic and manual QT-intervals and QTc were similar. However, pairwise Bland-Altman-based agreement was highly discrepant. For QT-interval, LoAs spanned 95 (tangent) and 92 ms (threshold), respectively. For QTc, the spread was 108 and 105 ms, respectively. LQTS patients exhibited more pronounced differences. For automatic QTc results from 440-540 ms (tangent) and 430-530 ms (threshold), misassessment risk was highest. Novel automatic QT-interval algorithms may narrow this range. CONCLUSION: Pairwise vendor-provided automatic and manual QT-interval and QTc results can be highly discrepant. Novel automatic algorithms may improve agreement. Within the above ranges, automatic QT-interval and QTc results require manual confirmation, particularly if T-wave morphology is challenging.


Subject(s)
Electrocardiography , Long QT Syndrome , Humans , Female , Adult , Male , Long QT Syndrome/diagnosis , Death, Sudden, Cardiac/etiology , Death, Sudden, Cardiac/prevention & control , Arrhythmias, Cardiac , Risk Assessment
4.
Europace ; 26(1)2023 12 28.
Article in English | MEDLINE | ID: mdl-38102318

ABSTRACT

AIMS: In-hospital complications of catheter ablation for atrial fibrillation (AF), atrial flutter (AFL), and ventricular tachycardia (VT) may be overestimated by analyses of administrative data. METHODS AND RESULTS: We determined the incidences of in-hospital mortality, major bleeding, and stroke around AF, AFL, and VT ablations in four German tertiary centres between 2005 and 2020. All cases were coded by the G-DRG- and OPS-systems. Uniform code search terms were applied defining both the types of ablations for AF, AFL, and VT and the occurrence of major adverse events including femoral vascular complications, iatrogenic tamponade, stroke, and in-hospital death. Importantly, all complications were individually reviewed based on patient-level source records. Overall, 43 031 ablations were analysed (30 361 AF; 9364 AFL; 3306 VT). The number of ablations/year more than doubled from 2005 (n = 1569) to 2020 (n = 3317) with 3 times and 2.5 times more AF and VT ablations in 2020 (n = 2404 and n = 301, respectively) as compared to 2005 (n = 817 and n = 120, respectively), but a rather stable number of AFL ablations (n = 554 vs. n = 612). Major peri-procedural complications occurred in 594 (1.4%) patients. Complication rates were 1.1% (n = 325) for AF, 1.0% (n = 95) for AFL, and 5.3% (n = 175) for VT. With an increase in complex AF/VT procedures, the overall complication rate significantly increased (0.76% in 2005 vs. 1.81% in 2020; P = 0.004); but remained low over time. Following patient-adjudication, all in-hospital cardiac tamponades (0.7%) and strokes (0.2%) were related to ablation. Major femoral vascular complications requiring surgical intervention occurred in 0.4% of all patients. The in-hospital mortality rate adjudicated to be ablation-related was lower than the coded mortality rate: AF: 0.03% vs. 0.04%; AFL: 0.04% vs. 0.14%; VT: 0.42% vs. 1.48%. CONCLUSION: Major adverse events are low and comparable after catheter ablation for AFL and AF (∼1.0%), whereas they are five times higher for VT ablations. In the presence of an increase in complex ablation procedures, a moderate but significant increase in overall complications from 2005-20 was observed. Individual case analysis demonstrated a lower than coded ablation-related in-hospital mortality. This highlights the importance of individual case adjudication when analysing administrative data.


Subject(s)
Atrial Fibrillation , Atrial Flutter , Catheter Ablation , Stroke , Tachycardia, Ventricular , Humans , Hospital Mortality , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Atrial Fibrillation/epidemiology , Atrial Flutter/diagnosis , Atrial Flutter/surgery , Atrial Flutter/etiology , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/epidemiology , Tachycardia, Ventricular/surgery , Hospitals , Stroke/epidemiology , Catheter Ablation/adverse effects , Catheter Ablation/methods , Treatment Outcome
5.
Stroke ; 53(4): e130-e135, 2022 04.
Article in English | MEDLINE | ID: mdl-34911345

ABSTRACT

BACKGROUND: Observational studies suggest an association of stroke with cardiac traits beyond atrial fibrillation, the leading source of cardioembolism. However, controversy remains regarding a causal role of these traits in stroke pathogenesis. Here, we leveraged genetic data to systematically assess associations between cardiac traits and stroke risk using a Mendelian Randomization framework. METHODS: We studied 66 cardiac traits including cardiovascular diseases, magnetic resonance imaging-derived cardiac imaging, echocardiographic imaging, and electrocardiographic measures, as well as blood biomarkers in a 2-sample Mendelian Randomization approach. Genetic predisposition to each trait was explored for associations with risk of stroke and stroke subtypes in data from the MEGASTROKE consortium (40 585 cases/406 111 controls). Using multivariable Mendelian Randomization, we adjusted for potential pleiotropic or mediating effects relating to atrial fibrillation, coronary artery disease, and systolic blood pressure. RESULTS: As expected, we observed strong independent associations between genetic predisposition to atrial fibrillation and cardioembolic stroke and between genetic predisposition to coronary artery disease as a proxy for atherosclerosis and large-artery stroke. Our data-driven analyses further indicated associations of genetic predisposition to both heart failure and lower resting heart rate with stroke. However, these associations were explained by atrial fibrillation, coronary artery disease, and systolic blood pressure in multivariable analyses. Genetically predicted P-wave terminal force in V1, an electrocardiographic marker for atrial cardiopathy, was inversely associated with large-artery stroke. CONCLUSIONS: Available genetic data do not support substantial effects of cardiac traits on the risk of stroke beyond known clinical risk factors. Our findings highlight the need to carefully control for confounding and other potential biases in studies examining candidate cardiac risk factors for stroke.


Subject(s)
Atrial Fibrillation , Coronary Artery Disease , Stroke , Atrial Fibrillation/epidemiology , Atrial Fibrillation/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Mendelian Randomization Analysis , Polymorphism, Single Nucleotide , Risk Factors , Stroke/epidemiology , Stroke/genetics
6.
Circulation ; 141(13): 1057-1067, 2020 03 31.
Article in English | MEDLINE | ID: mdl-32000514

ABSTRACT

BACKGROUND: Catheter ablation for ventricular tachycardia (VT) reduces the recurrence of VT in patients with implantable cardioverter-defibrillators (ICDs). The appropriate timing of VT ablation and its effects on mortality and heart failure progression remain a matter of debate. In patients with life-threatening arrhythmias necessitating ICD implantation, we compared outcomes of preventive VT ablation (undertaken before ICD implantation to prevent ICD shocks for VT) and deferred ablation after 3 ICD shocks for VT. METHODS: The BERLIN VT study (Preventive Ablation of Ventricular Tachycardia in Patients With Myocardial Infarction) was a prospective, open, parallel, randomized trial performed at 26 centers. Patients with stable ischemic cardiomyopathy, a left ventricular ejection fraction between 30% and 50%, and documented VT were randomly assigned 1:1 to a preventive or deferred ablation strategy. The primary outcome was a composite of all-cause death and unplanned hospitalization for either symptomatic ventricular arrhythmia or worsening heart failure. Secondary outcomes included sustained ventricular tachyarrhythmia and appropriate ICD therapy. We hypothesized that preventive ablation strategy would be superior to deferred ablation strategy in the intention-to-treat population. RESULTS: During a mean follow-up of 396±284 days, the primary end point occurred in 25 (32.9%) of 76 patients in the preventive ablation group and 23 (27.7%) of 83 patients in the deferred ablation group (hazard ratio, 1.09 [95% CI, 0.62-1.92]; P=0.77). On the basis of prespecified criteria for interim analyses, the study was terminated early for futility. In the preventive versus deferred ablation group, 6 versus 2 patients died (7.9% versus 2.4%; P=0.18), 8 versus 2 patients were admitted for worsening heart failure (10.4% versus 2.3%; P=0.062), and 15 versus 21 patients were hospitalized for symptomatic ventricular arrhythmia (19.5% versus 25.3%; P=0.27). Among secondary outcomes, the proportions of patients with sustained ventricular tachyarrhythmia (39.7% versus 48.2%; P=0.050) and appropriate ICD therapy (34.2% versus 47.0%; P=0.020) were numerically reduced in the preventive ablation group. CONCLUSIONS: Preventive VT ablation before ICD implantation did not reduce mortality or hospitalization for arrhythmia or worsening heart failure during 1 year of follow-up compared with the deferred ablation strategy. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02501005.


Subject(s)
Cardiomyopathies/complications , Catheter Ablation/methods , Defibrillators, Implantable/standards , Tachycardia, Ventricular/therapy , Aged , Cardiomyopathies/surgery , Female , Humans , Male , Prospective Studies
7.
Cardiovasc Diabetol ; 20(1): 111, 2021 05 20.
Article in English | MEDLINE | ID: mdl-34016094

ABSTRACT

BACKGROUND: The metabolic syndrome (MetS), defined by the simultaneous clustering of cardio-metabolic risk factors, is a significant worldwide public health burden with an estimated 25% prevalence worldwide. The pathogenesis of MetS is not entirely clear and the use of molecular level data could help uncover common pathogenic pathways behind the observed clustering. METHODS: Using a highly multiplexed aptamer-based affinity proteomics platform, we examined associations between plasma proteins and prevalent and incident MetS in the KORA cohort (n = 998) and replicated our results for prevalent MetS in the HUNT3 study (n = 923). We applied logistic regression models adjusted for age, sex, smoking status, and physical activity. We used the bootstrap ranking algorithm of least absolute shrinkage and selection operator (LASSO) to select a predictive model from the incident MetS associated proteins and used area under the curve (AUC) to assess its performance. Finally, we investigated the causal effect of the replicated proteins on MetS using two-sample Mendelian randomization. RESULTS: Prevalent MetS was associated with 116 proteins, of which 53 replicated in HUNT. These included previously reported proteins like leptin, and new proteins like NTR domain-containing protein 2 and endoplasmic reticulum protein 29. Incident MetS was associated with 14 proteins in KORA, of which 13 overlap the prevalent MetS associated proteins with soluble advanced glycosylation end product-specific receptor (sRAGE) being unique to incident MetS. The LASSO selected an eight-protein predictive model with an (AUC = 0.75; 95% CI = 0.71-0.79) in KORA. Mendelian randomization suggested causal effects of three proteins on MetS, namely apolipoprotein E2 (APOE2) (Wald-Ratio = - 0.12, Wald-p = 3.63e-13), apolipoprotein B (APOB) (Wald-Ratio = - 0.09, Wald-p = 2.54e-04) and proto-oncogene tyrosine-protein kinase receptor (RET) (Wald-Ratio = 0.10, Wald-p = 5.40e-04). CONCLUSIONS: Our findings offer new insights into the plasma proteome underlying MetS and identify new protein associations. We reveal possible casual effects of APOE2, APOB and RET on MetS. Our results highlight protein candidates that could potentially serve as targets for prevention and therapy.


Subject(s)
Blood Proteins/analysis , Metabolic Syndrome/blood , Proteome , Proteomics , Adult , Aged , Aged, 80 and over , Apolipoprotein B-100/blood , Apolipoprotein B-100/genetics , Apolipoprotein E2/blood , Apolipoprotein E2/genetics , Biomarkers/blood , Blood Proteins/genetics , Cardiometabolic Risk Factors , Cross-Sectional Studies , Female , Germany/epidemiology , Humans , Incidence , Male , Mendelian Randomization Analysis , Metabolic Syndrome/diagnosis , Metabolic Syndrome/epidemiology , Metabolic Syndrome/genetics , Middle Aged , Norway/epidemiology , Predictive Value of Tests , Prevalence , Prospective Studies , Proto-Oncogene Mas , Proto-Oncogene Proteins c-ret/blood , Proto-Oncogene Proteins c-ret/genetics , Risk Assessment
8.
Europace ; 23(3): 329-344, 2021 03 08.
Article in English | MEDLINE | ID: mdl-33555020

ABSTRACT

AIMS: The risk of developing atrial fibrillation (AF) and its complications continues to increase, despite good progress in preventing AF-related strokes. METHODS AND RESULTS: This article summarizes the outcomes of the 7th Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA) held in Lisbon in March 2019. Sixty-five international AF specialists met to present new data and find consensus on pressing issues in AF prevention, management and future research to improve care for patients with AF and prevent AF-related complications. This article is the main outcome of an interactive, iterative discussion between breakout specialist groups and the meeting plenary. AF patients have dynamic risk profiles requiring repeated assessment and risk-based therapy stratification to optimize quality of care. Interrogation of deeply phenotyped datasets with outcomes will lead to a better understanding of the cardiac and systemic effects of AF, interacting with comorbidities and predisposing factors, enabling stratified therapy. New proposals include an algorithm for the acute management of patients with AF and heart failure, a call for a refined, data-driven assessment of stroke risk, suggestions for anticoagulation use in special populations, and a call for rhythm control therapy selection based on risk of AF recurrence. CONCLUSION: The remaining morbidity and mortality in patients with AF needs better characterization. Likely drivers of the remaining AF-related problems are AF burden, potentially treatable by rhythm control therapy, and concomitant conditions, potentially treatable by treating these conditions. Identifying the drivers of AF-related complications holds promise for stratified therapy.


Subject(s)
Atrial Fibrillation , Stroke , Anticoagulants/adverse effects , Atrial Fibrillation/diagnosis , Atrial Fibrillation/epidemiology , Atrial Fibrillation/therapy , Consensus , Humans , Risk Assessment , Risk Factors , Stroke/diagnosis , Stroke/epidemiology , Stroke/prevention & control , Treatment Outcome
9.
RNA Biol ; 18(sup1): 409-415, 2021 10 15.
Article in English | MEDLINE | ID: mdl-34313541

ABSTRACT

lncRNAs are at the core of many regulatory processes and have also been recognized to be involved in various complex diseases. They affect gene regulation through direct interactions with RNA, DNA or proteins. Accordingly, lncRNA structure is likely to be essential for their regulatory function. Point mutations, which manifest as SNPs (single nucleotide polymorphisms) in genome screens, can substantially alter their function and, subsequently, the expression of their downstream regulated genes. To test the effect of SNPs on structure, we investigated lncRNAs associated with dilated cardiomyopathy. Among 322 human candidate lncRNAs, we demonstrate first the significant association of an SNP located in lncRNA H19 using data from 1084 diseased and 751 control patients. H19 is generally highly expressed in the heart, with a complex expression pattern during heart development. Next, we used MFE (minimum free energy) folding to demonstrate a significant refolding in the secondary structure of this 861 nt long lncRNA. Since MFE folding may overlook the importance of sub-optimal structures, we showed that this refolding also manifests in the overall Boltzmann structure ensemble. There, the composition of structures is tremendously affected in their thermodynamic probabilities through the genetic variant. Finally, we confirmed these results experimentally, using SHAPE-Seq, corroborating that SNPs affecting such structures may explain hidden genetic variance not accounted for through genome wide association studies. Our results suggest that structural changes in lncRNAs, and lncRNA H19 in particular, affect regulatory processes and represent optimal targets for further in-depth studies probing their molecular interactions.


Subject(s)
Cardiomyopathy, Dilated/pathology , Genetic Predisposition to Disease , Nucleic Acid Conformation , Polymorphism, Single Nucleotide , RNA, Long Noncoding/chemistry , RNA, Long Noncoding/genetics , Adult , Aged , Aged, 80 and over , Base Pairing , Base Sequence , Cardiomyopathy, Dilated/genetics , Case-Control Studies , Female , Genotype , Humans , Male , Middle Aged , Young Adult
10.
Circulation ; 140(22): 1834-1850, 2019 11 26.
Article in English | MEDLINE | ID: mdl-31765261

ABSTRACT

Cardiac thromboembolism attributed to atrial fibrillation (AF) is responsible for up to one-third of ischemic strokes. Stroke may be the first manifestation of previously undetected AF. Given the efficacy of oral anticoagulants in preventing AF-related ischemic strokes, strategies of searching for AF after a stroke using ECG monitoring followed by oral anticoagulation (OAC) treatment have been proposed to prevent recurrent cardioembolic strokes. This white paper by experts from the AF-SCREEN International Collaboration summarizes existing evidence and knowledge gaps on searching for AF after a stroke by using ECG monitoring. New AF can be detected by routine plus intensive ECG monitoring in approximately one-quarter of patients with ischemic stroke. It may be causal, a bystander, or neurogenically induced by the stroke. AF after a stroke is a risk factor for thromboembolism and a strong marker for atrial myopathy. After acute ischemic stroke, patients should undergo 72 hours of electrocardiographic monitoring to detect AF. The diagnosis requires an ECG of sufficient quality for confirmation by a health professional with ECG rhythm expertise. AF detection rate is a function of monitoring duration and quality of analysis, AF episode definition, interval from stroke to monitoring commencement, and patient characteristics including old age, certain ECG alterations, and stroke type. Markers of atrial myopathy (eg, imaging, atrial ectopy, natriuretic peptides) may increase AF yield from monitoring and could be used to guide patient selection for more intensive/prolonged poststroke ECG monitoring. Atrial myopathy without detected AF is not currently sufficient to initiate OAC. The concept of embolic stroke of unknown source is not proven to identify patients who have had a stroke benefitting from empiric OAC treatment. However, some embolic stroke of unknown source subgroups (eg, advanced age, atrial enlargement) might benefit more from non-vitamin K-dependent OAC therapy than aspirin. Fulfilling embolic stroke of unknown source criteria is an indication neither for empiric non-vitamin K-dependent OAC treatment nor for withholding prolonged ECG monitoring for AF. Clinically diagnosed AF after a stroke or a transient ischemic attack is associated with significantly increased risk of recurrent stroke or systemic embolism, in particular, with additional stroke risk factors, and requires OAC rather than antiplatelet therapy. The minimum subclinical AF duration required on ECG monitoring poststroke/transient ischemic attack to recommend OAC therapy is debated.


Subject(s)
Atrial Fibrillation , Brain Ischemia , Electrocardiography , Stroke , Thromboembolism , Aged , Atrial Fibrillation/diagnosis , Atrial Fibrillation/etiology , Atrial Fibrillation/physiopathology , Brain Ischemia/complications , Brain Ischemia/diagnosis , Brain Ischemia/physiopathology , Female , Humans , Male , Stroke/complications , Stroke/diagnosis , Stroke/physiopathology , Thromboembolism/diagnosis , Thromboembolism/physiopathology
11.
Circulation ; 138(21): 2345-2358, 2018 11 20.
Article in English | MEDLINE | ID: mdl-30571576

ABSTRACT

BACKGROUND: Long QT syndrome (LQTS) is associated with potentially fatal arrhythmias. Treatment is very effective, but its diagnosis may be challenging. Importantly, different methods are used to assess the QT interval, which makes its recognition difficult. QT experts advocate manual measurements with the tangent or threshold method. However, differences between these methods and their performance in LQTS diagnosis have not been established. We aimed to assess similarities and differences between these 2 methods for QT interval analysis to aid in accurate QT assessment for LQTS. METHODS: Patients with a confirmed pathogenic variant in KCNQ1(LQT1), KCNH2(LQT2), or SCN5A(LQT3) genes and their family members were included. Genotype-positive patients were identified as LQTS cases and genotype-negative family members as controls. ECGs were analyzed with both methods, providing inter- and intrareader validity and diagnostic accuracy. Cutoff values based on control population's 95th and 99th percentiles, and LQTS-patients' 1st and 5th percentiles were established based on the method to correct for heart rate, age, and sex. RESULTS: We included 1484 individuals from 265 families, aged 33±21 years and 55% females. In the total cohort, QTTangent was 10.4 ms shorter compared with QTThreshold (95% limits of agreement±20.5 ms, P<0.0001). For all genotypes, QTTangent was shorter than QTThreshold ( P<0.0001), but this was less pronounced in LQT2. Both methods yielded a high inter- and intrareader validity (intraclass correlation coefficient >0.96), and a high diagnostic accuracy (area under the curve >0.84). Using the current guideline cutoff (QTc interval 480 ms), both methods had similar specificity but yielded a different sensitivity. QTc interval cutoff values of QTTangent were lower compared with QTThreshold and different depending on the correction for heart rate, age, and sex. CONCLUSION: The QT interval varies depending on the method used for its assessment, yet both methods have a high validity and can both be used in diagnosing LQTS. However, for diagnostic purposes current guideline cutoff values yield different results for these 2 methods and could result in inappropriate reassurance or treatment. Adjusted cutoff values are therefore specified for method, correction formula, age, and sex. In addition, a freely accessible online probability calculator for LQTS ( www.QTcalculator.org ) has been made available as an aid in the interpretation of the QT interval.


Subject(s)
Electrocardiography , Long QT Syndrome/diagnosis , Adolescent , Adult , Age Factors , Case-Control Studies , Child , Databases, Factual , ERG1 Potassium Channel/genetics , Female , Genotype , Humans , KCNQ1 Potassium Channel/genetics , Long QT Syndrome/pathology , Male , Middle Aged , NAV1.5 Voltage-Gated Sodium Channel/genetics , Retrospective Studies , Sex Factors , Young Adult
13.
BMC Cardiovasc Disord ; 19(1): 120, 2019 05 21.
Article in English | MEDLINE | ID: mdl-31113362

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) is caused by different mechanisms but current treatment strategies do not target these mechanisms. Stratified therapy based on mechanistic drivers and biomarkers of AF have the potential to improve AF prevention and management outcomes. We will integrate mechanistic insights with known pathophysiological drivers of AF in models predicting recurrent AF and prevalent AF to test hypotheses related to AF mechanisms and response to rhythm control therapy. METHODS: We will harmonise and combine baseline and outcome data from 12 studies collected by six centres from the United Kingdom, Germany, France, Spain, and the Netherlands which assess prevalent AF or recurrent AF. A Delphi process and statistical selection will be used to identify candidate clinical predictors. Prediction models will be developed in patients with AF for AF recurrence and AF-related outcomes, and in patients with or without AF at baseline for prevalent AF. Models will be used to test mechanistic hypotheses and investigate the predictive value of plasma biomarkers. DISCUSSION: This retrospective, harmonised, individual patient data analysis will use information from 12 datasets collected in five European countries. It is envisioned that the outcome of this analysis would provide a greater understanding of the factors associated with recurrent and prevalent AF, potentially allowing development of stratified approaches to prevention and therapy management.


Subject(s)
Atrial Fibrillation/therapy , Decision Support Techniques , Heart Rate , Adolescent , Adult , Aged , Aged, 80 and over , Atrial Fibrillation/diagnosis , Atrial Fibrillation/epidemiology , Atrial Fibrillation/physiopathology , Data Mining , Databases, Factual , Delphi Technique , Europe/epidemiology , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prevalence , Prognosis , Recurrence , Reproducibility of Results , Research Design , Retrospective Studies , Risk Assessment , Risk Factors , Young Adult
15.
Eur Heart J ; 39(45): 4020-4029, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30085086

ABSTRACT

Aims: Risks of catheter ablation for atrial fibrillation and flutter assessed in retrospective studies, registries, and controlled trials may underestimate 'real world' conditions. Methods and results: To assess complications in a nationwide approach, we included all cases undergoing catheter ablation for atrial fibrillation and atrial flutter in Germany in 2014, using ICD-10-GM-based German Diagnosis Related Group (G-DRG) codes and the well differentiated German Operation and Procedure Classification (OPS) analysing 33 353 in-hospital cases. For left atrial ablations (19 514 cases), the overall complication rate ranged from a mean of 11.7% to 13.8% depending on type and site of applied energy, including major complications ranging from 3.8% to 7.2%. Whereas overall complication rates were lower for atrial flutter ablations (13 871 cases, 10.5%; P < 0.001), interestingly, major complications occurred more frequently (7.4%; P < 0.001). Particularly, in-hospital death was four-times more common following right than following left atrial ablations (47 vs. 18 cases, 0.34% vs. 0.09%; P < 0.001). Stratified by centre ablation volume, significantly fewer overall complications occurred in centres performing >100 vs. ≤100 left atrial ablations annually (12.7% vs. 16.4%; P < 0.002). Conclusion: Administrative data of all atrial fibrillation ablations in Germany in 2014 revealed higher overall and major complication rates than previously reported. Few patients were treated in low volume centres, but were exposed to a higher overall complication risk. Atrial flutter ablations were associated with surprisingly high rates of life-threatening complications. Advanced age combined with highly prevalent cardiac, pulmonary and, vascular comorbidities likely play a major role. In addition, individual-level clinical studies need to address the safety and benefits of catheter ablation in an elderly, diseased population.


Subject(s)
Atrial Fibrillation/surgery , Atrial Flutter/surgery , Catheter Ablation/adverse effects , Postoperative Complications/epidemiology , Aged , Aged, 80 and over , Databases, Factual , Female , Germany/epidemiology , Humans , Incidence , Male , Middle Aged
16.
Eur Heart J ; 38(27): 2100-2106, 2017 Jul 14.
Article in English | MEDLINE | ID: mdl-28449090

ABSTRACT

AIMS: Alcohol is a risk factor for cardiac arrhythmias. Retrospective analyses suggest supraventricular arrhythmias consecutive to acute alcohol consumption, but prospective data are limited. We intended to prospectively associate acute alcohol consumption with cardiac arrhythmias. METHODS AND RESULTS: At the 2015 Munich Octoberfest, we enrolled 3028 voluntary participants who received a smartphone-based ECG and breath alcohol concentration (BAC) measurements. ECGs were analysed for cardiac arrhythmias (sinus tachycardia, sinus arrhythmia, premature atrial/ventricular complexes, atrial fibrillation/flutter) and respiratory sinus arrhythmia. By multivariable adjusted logistic regression we associated BACs with cardiac arrhythmias. Similarly, we analysed 4131 participants of the community-based KORA S4 Study (Co-operative Health Research in the Region of Augsburg) and associated cardiac arrhythmias with chronic alcohol consumption. In our acute alcohol cohort (mean age 34.4 ± 13.3 years, 29% women), mean BAC was 0.85 ± 0.54 g/kg. Cardiac arrhythmias occurred in 30.5% (sinus tachycardia 25.9%; other arrhythmia subtypes 5.4%). Breath alcohol concentration was significantly associated with cardiac arrhythmias overall (odds ratio (OR) per 1-unit change 1.75, 95% confidence interval (CI) 1.50-2.05; P < 0.001) and sinus tachycardia in particular (OR 1.96, 95%CI 1.66-2.31; P < 0.001). Respiratory sinus arrhythmia measuring autonomic tone was significantly reduced under the influence of alcohol. In KORA S4, chronic alcohol consumption was associated with sinus tachycardia (OR 1.03, 95%CI 1.01-1.06; P = 0.006). CONCLUSIONS: Acute alcohol consumption is associated with cardiac arrhythmias and sinus tachycardia in particular. This partly reflects autonomic imbalance as assessed by significantly reduced respiratory sinus arrhythmia. Such imbalance might lead to sympathetically triggered atrial fibrillation resembling the holiday heart syndrome. CLINICALTRIALS.ORG ACCESSION NUMBER: NCT02550340.


Subject(s)
Alcohol Drinking/adverse effects , Arrhythmias, Cardiac/etiology , Adult , Alcohol Drinking/epidemiology , Arrhythmias, Cardiac/epidemiology , Breath Tests , Electrocardiography/instrumentation , Female , Germany/epidemiology , Humans , Male , Prevalence , Prospective Studies , Smartphone , Tachycardia, Sinus/epidemiology , Tachycardia, Sinus/etiology
17.
Value Health ; 20(6): 769-776, 2017 06.
Article in English | MEDLINE | ID: mdl-28577694

ABSTRACT

OBJECTIVES: To compare complication rates, length of hospital stay, and resulting costs between the use of manual compression and a vascular closing device (VCD) in both diagnostic and interventional catheterization in a German university hospital setting. METHODS: A stratified analysis according to risk profiles was used to compare the risk of complications in a retrospective cross-sectional single-center study. Differences in costs and length of hospital stay were calculated using the recycled predictions method, based on regression coefficients from generalized linear models with gamma distribution. All models were adjusted for propensity score and possible confounders, such as age, sex, and comorbidities. The analysis was performed separately for diagnostic and interventional catheterization. RESULTS: The unadjusted relative risk (RR) of complications was not significantly different in diagnostic catheterization when a VCD was used (RR = 0.70; 95% confidence interval [CI] 0.22-2.16) but significantly lower in interventional catheterization (RR = 0.44; 95% CI 0.21-0.93). Costs were on average €275 lower in the diagnostic group (95% CI -€478.0 to -€64.9; P = 0.006) and around €373 lower in the interventional group (95% CI -€630.0 to -€104.2; P = 0.014) when a VCD was used. The adjusted estimated average length of stay did not differ significantly between the use of a VCD and manual compression in both types of catheterization. CONCLUSIONS: In interventional catheterization, VCDs significantly reduced unadjusted complication rates, as well as costs. A significant reduction in costs also supports their usage in diagnostic catheterization on a larger scale.


Subject(s)
Cardiac Catheterization/methods , Length of Stay/statistics & numerical data , Percutaneous Coronary Intervention/methods , Vascular Closure Devices , Aged , Cardiac Catheterization/adverse effects , Cardiac Catheterization/economics , Cross-Sectional Studies , Female , Femoral Artery , Germany , Hospital Costs , Hospitalization/economics , Hospitalization/statistics & numerical data , Hospitals, University , Humans , Length of Stay/economics , Male , Middle Aged , Percutaneous Coronary Intervention/economics , Retrospective Studies
18.
Europace ; 18(5): 718-25, 2016 May.
Article in English | MEDLINE | ID: mdl-26759124

ABSTRACT

AIMS: Idiopathic ventricular fibrillation (iVF) accounts for up to 14% of VF incidence. Data regarding long-term outcome and clinical risk markers of arrhythmia recurrence are scarce. The objective of our study was to describe a long-term follow-up (FU) of a cohort of iVF survivors in our centre during the past 20 years, and to investigate the influence of clinical parameters, e.g. presence of an early repolarization pattern (ERP), on recurrence rate of arrhythmias. METHODS AND RESULTS: Thirty-five iVF survivors were identified and retrospectively analysed regarding recurrent implantable cardioverter-defibrillator (ICD) interventions and covariates potentially influencing arrhythmia recurrence. Appropriate ICD interventions occurred in 15 patients (43%) after a median of 6.6 years during a median FU period of 8.8 years. Two patients (13%) received the first appropriate therapy after an assumed average ICD battery longevity of 7 years, while in all other patients, the first therapy occurred within the first ICD period. Appropriate interventions were observed more often and earlier in patients with ERP (HR 3.9; 1.4-11.0; P = 0.01), whereas all other covariates failed to predict subsequent events. A high incidence of inappropriate ICD therapies (67 interventions in 14 patients) could be attributed to the occurrence of atrial fibrillation (66% of all inappropriate therapies). CONCLUSION: The recurrence rate of ventricular arrhythmias in iVF survivors is high and recurrence might occur delayed (>7 years after the initial event). ERP seems to be highly predictive with respect to early arrhythmia recurrence. Our results highlight that better pathophysiologic understanding of ERP might facilitate a better risk stratification before and an optimal treatment after an iVF event. The high rate of AF and ERP in iVF survivors might indicate an underlying heart disease or myocardial electrical disorder not apparent at the index event.


Subject(s)
Death, Sudden, Cardiac/epidemiology , Defibrillators, Implantable/adverse effects , Ventricular Fibrillation/diagnostic imaging , Ventricular Fibrillation/therapy , Adult , Aged , Death, Sudden, Cardiac/etiology , Echocardiography , Electrocardiography , Female , Follow-Up Studies , Germany , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Recurrence , Retrospective Studies , Risk Factors
19.
Europace ; 18(8): 1170-8, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26759125

ABSTRACT

AIMS: Pulmonary vein isolation (PVI) is an established therapy for atrial fibrillation (AF). However, PVI remains a time-consuming procedure. A novel multipolar irrigated radiofrequency (RF) ablation catheter (nMARQ™) is aiming to improve PVI. We investigated the influence on procedural parameters and assessed clinical outcomes after PVI using this novel catheter. METHODS AND RESULTS: Fifty-eight consecutive patients with paroxysmal AF were equally allocated (n = 29/group) to PVI treatment with (i) the novel multipolar ablation catheter (nMARQ™) and (ii) a standard single-tip ablation catheter (SAC). Study endpoints included procedure time, fluoroscopy time, radiation dose, RF time, number of energy applications, and clinical outcome defined as freedom from AF after a single procedure. Successful PVI was confirmed by a separate circular, multipolar mapping catheter in all patients treated with the nMARQ™. Pulmonary vein isolation was achieved in 100% in the SAC group. In the nMARQ™ group, PVI was suggested in all patients. However, confirmatory mapping revealed persistent pulmonary vein (PV) conduction in 19 out of 29 nMARQ™ patients. These patients underwent further ablation, which still failed to achieve PVI in 5 of the 29 nMARQ™ patients, mainly due to significant temperature rise in the oesophagus and device-related limitations reaching the right inferior PV. Mean fluoroscopy time (31 ± 12 vs. 23 ± 10 min, P < 0.05) and (132 ± 37 vs. 109 ± 30 min, P < 0.05) were longer in nMARQ™ vs. SAC patients. Radiofrequency time was shorter in nMARQ™ vs. SAC group (21 ± 9 vs. 35 ± 12 min, P < 0.001). Radiation dose and the number of energy applications did not differ between both groups. Clinical outcome analysis revealed no significant differences (nMARQ™: 72 vs. SAC: 72%) after a mean follow-up of 373 ± 278 days. CONCLUSION: The use of the nMARQ™ catheter is associated with important device-related limitations to achieve successful PVI. However, clinical outcomes were equivalent in nMARQ™- and SAC-treated patients.


Subject(s)
Atrial Fibrillation/therapy , Catheter Ablation/instrumentation , Adenosine/blood , Aged , Anticoagulants/therapeutic use , Catheter Ablation/adverse effects , Equipment Design , Equipment Failure Analysis , Female , Fluoroscopy , Follow-Up Studies , Humans , Male , Middle Aged , Operative Time , Prospective Studies , Pulmonary Veins/surgery , Treatment Outcome
20.
Circulation ; 130(15): 1225-35, 2014 Oct 07.
Article in English | MEDLINE | ID: mdl-25124494

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) affects >30 million individuals worldwide and is associated with an increased risk of stroke, heart failure, and death. AF is highly heritable, yet the genetic basis for the arrhythmia remains incompletely understood. METHODS AND RESULTS: To identify new AF-related genes, we used a multifaceted approach, combining large-scale genotyping in 2 ethnically distinct populations, cis-eQTL (expression quantitative trait loci) mapping, and functional validation. Four novel loci were identified in individuals of European descent near the genes NEURL (rs12415501; relative risk [RR]=1.18; 95% confidence interval [CI], 1.13-1.23; P=6.5×10(-16)), GJA1 (rs13216675; RR=1.10; 95% CI, 1.06-1.14; P=2.2×10(-8)), TBX5 (rs10507248; RR=1.12; 95% CI, 1.08-1.16; P=5.7×10(-11)), and CAND2 (rs4642101; RR=1.10; 95% CI, 1.06-1.14; P=9.8×10(-9)). In Japanese, novel loci were identified near NEURL (rs6584555; RR=1.32; 95% CI, 1.26-1.39; P=2.0×10(-25)) and CUX2 (rs6490029; RR=1.12; 95% CI, 1.08-1.16; P=3.9×10(-9)). The top single-nucleotide polymorphisms or their proxies were identified as cis-eQTLs for the genes CAND2 (P=2.6×10(-19)), GJA1 (P=2.66×10(-6)), and TBX5 (P=1.36×10(-5)). Knockdown of the zebrafish orthologs of NEURL and CAND2 resulted in prolongation of the atrial action potential duration (17% and 45%, respectively). CONCLUSIONS: We have identified 5 novel loci for AF. Our results expand the diversity of genetic pathways implicated in AF and provide novel molecular targets for future biological and pharmacological investigation.


Subject(s)
Atrial Fibrillation/genetics , Connexin 43/genetics , Homeodomain Proteins/genetics , Nuclear Proteins/genetics , Repressor Proteins/genetics , T-Box Domain Proteins/genetics , Ubiquitin-Protein Ligases/genetics , Aged , Animals , Atrial Fibrillation/ethnology , Atrial Fibrillation/physiopathology , Chromosome Mapping , Connexin 43/physiology , Europe , Female , Gene Knockdown Techniques , Genetic Loci/physiology , Genetic Predisposition to Disease/ethnology , Genotype , Homeodomain Proteins/physiology , Humans , Japan , Male , Middle Aged , Muscle Proteins , Nuclear Proteins/physiology , Quantitative Trait Loci , Repressor Proteins/physiology , T-Box Domain Proteins/physiology , Transcription Factors/genetics , Transcription Factors/physiology , Ubiquitin-Protein Ligases/physiology , Zebrafish , Zebrafish Proteins/genetics , Zebrafish Proteins/physiology , Homeobox Protein PITX2
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