Atrial fibrillation is associated with increased risk of lethal ventricular arrhythmias

Prognosis of patients with nonspecific electrocardiogram findings in a Tanzanian emergency department

BACKGROUND

Nonspecific electrocardiogram (ECG) findings are associated with increased morbidity and mortality in high-income settings. ECGs are increasingly available in emergency departments (EDs) in low- and middle-income countries (LMICs), however the prognostic value of nonspecific ECG findings in resource-limited settings, particularly in sub-Saharan Africa, remains unclear.

OBJECTIVE

To assess the association between nonspecific ECG findings and 30-day mortality among patients presenting with chest pain and shortness of breath to a Tanzanian ED.

METHODS

Patient demographics and initial ECGs were collected from patients presenting with chest pain or shortness of breath to an ED in Moshi, Tanzania from January 2019 through January 2023. Two independent adjudicators interpreted ECGs using standardized criteria. Unadjusted and adjusted (adjusting for age and gender) odds ratios were calculated, and Pearson's chi-squared test was used to assess the association of each ECG finding with 30-day mortality.

RESULTS

Among 1,111 participants, 231 (20.8%) died within 30 days of ED presentation. T-wave inversions (aOR 1.60, 95% CI 1.19-2.15, P = .002), resting tachycardia (aOR 1.57, 95% CI 1.16-2.13, P = .003), non-sinus rhythms (aOR 1.93, 95% CI 1.26-2.96, P = .003), and ST depressions (aOR 1.73, 95% CI 1.17-2.56, P = .006) were significantly associated with increased mortality. There was no significant association between 30-day mortality and left ventricular hypertrophy, bundle branch blocks, or Q waves. Patients with any abnormal ECG finding had higher mortality compared to those with normal ECGs (OR 1.53, 95% CI, 1.08-2.21, P = .019).

CONCLUSION

Certain nonspecific ECG findings are associated with increased risk of 30-day mortality. Locally tailored risk stratification tools and increased attention to nonspecific ECG changes may enhance ED care in LMICs.

Causes of death in patients with atrial fibrillation in the UK: a nationwide electronic health record study

Aims

Causes of death remain largely unexplored in the atrial fibrillation (AF) population. We aimed to (i) thoroughly assess causes of death in patients with AF, especially those associated with sudden cardiac death (SCD) and (ii) evaluate the potential association between AF and SCD.

Methods and results

Linked primary and secondary care United Kingdom Clinical Practice Research Datalink dataset comprising 6 529 382 individuals aged ≥18. We identified 214 222 patients with newly diagnosed AF, and an equivalent number of non-AF patients matched for age, sex and primary care practice. The underlying primary cause of death for each patient was assessed in the form of International Classification of Diseases Tenth Revision (ICD-10) codes and also as part of broader disease categories (i.e. ICD-10 chapters).

Findings

Over a median follow-up of 2.7 (interquartile range: 0.7-6.0) years, 124 781 (58.25%) patients with AF died. Sudden cardiac death occurred in 13 923 patients with AF [6.50% patients with AF vs. 2.01% non-AF patients; odds ratio (OR) = 3.38, 95% confidence interval (CI): 3.27-3.50, P < 0.0001], contributing to 11.05% of all AF mortality. Diseases of the circulatory system, neoplasms and respiratory diseases explained 45% of AF mortality. Sudden cardiac death occurred more frequently in males (OR = 1.87, 95% CI: 1.80-1.93, P < 0.0001), and females with AF died more often of diseases of the circulatory, respiratory, digestive, and genitourinary system and less often of neoplastic disorders.

Interpretation

Conditions of the circulatory system are the main driver of mortality in the AF population. Females with AF experience higher cardiovascular and respiratory mortality but die less frequently of neoplasms. The risk of SCD is higher in the AF population, occurring more frequently in males.

Identification and Functional Investigation of SOX4 as a Novel Gene Underpinning Familial Atrial Fibrillation

Background: Atrial fibrillation (AF) signifies the most prevalent supraventricular arrhythmia in humans and may lead to cerebral stroke, cardiac failure, and even premature demise. Aggregating strong evidence points to genetic components as a cornerstone in the etiopathogenesis of familial AF. However, the genetic determinants for AF in most patients remain elusive. Methods: A 4-generation pedigree with idiopathic AF and another cohort of 196 unrelated patients with idiopathic AF as well as 278 unrelated healthy volunteers were recruited from the Chinese population of Han ethnicity. A family-based whole-exome sequencing examination followed by a Sanger sequencing assay in all research subjects was implemented. The functional impacts of the identified SOX4 mutations were explored via a dual-reporter assay. Results: Two new heterozygous SOX4 mutations, NM_003107.3: c.211C>T; p.(Gln71*) and NM_003107.3: c.290G>A; p.(Trp97*), were observed in the family and 1 of 196 patients with idiopathic AF, respectively. The two mutations were absent in the 278 control individuals. The biochemical measurements revealed that both Gln71*- and Trp97*-mutant SOX4 failed to transactivate GJA1 (Cx43). Moreover, the two mutations nullified the synergistic activation of SCN5A by SOX4 and TBX5. Conclusions: The findings first indicate SOX4 as a gene predisposing to AF, providing a novel target for antenatal genetic screening, individualized prophylaxis, and precision treatment of AF.

Atrial fibrillation and risk of sudden cardiac arrest in young adults

AIMS

Evidence of an association between atrial fibrillation (AF) and sudden cardiac arrest (SCA) in young adults is limited. In this study, we aim to evaluate this association in a general population aged between 20 and 39 years.

METHODS AND RESULTS

Young adults who underwent health check-ups between 2009 and 2012 were screened from a nationwide healthcare database in South Korea. A history of AF diagnosis before the health check-ups was identified based on the relevant International Classification of Diseases, 10th edition codes reported in the database. Associations between an established diagnosis of AF and the risk of SCA during follow-up were examined. A total of 6 345 162 young people were analysed with a mean follow-up duration of 9.4 years. The mean age was 30.9 ± 5.0 years, and 5875 (0.09%) individuals were diagnosed with AF. During follow-up, SCA occurred in 5352 (0.08%) individuals, and the crude incidence was 0.56 and 0.09 events per 1000 person-years for participants with and without AF, respectively. Individuals with AF had a 3.0-fold higher risk in a multivariate model adjusted for age, sex, lifestyle, anthropometric data, and medical comorbidities (adjusted hazard ratio 2.96, 95% confidence interval 1.99-4.41, P < 0.001). Both incident and prevalent AFs were associated with an increased risk of SCA, with no significant differences between the two groups.

CONCLUSION

Atrial fibrillation was associated with a significantly higher risk of SCA developing in healthy young adults. Whether the rate or rhythm control influences the risk of SCA in young patients with AF remains to be examined.

Ventricular Tachycardia in Patients With Peripartum Cardiomyopathy: Prevalence, Predictors, and Associated In-Hospital Adverse Events

Introduction  The purpose of this study was to determine the prevalence of ventricular tachycardia (VT) among patients admitted with peripartum cardiomyopathy (PPCM) as well as to analyze the independent association of VT with in-hospital outcomes among PPCM patients. Methods Data were obtained from the National Inpatient Sample from January 2016 to December 2019. We assessed predictors of VT in patients admitted with PPCM. We also assessed the independent association of VT with clinical outcomes among patients admitted with PPCM. Results From 2016 to 2019, 4730 patients with PPCM were reported to the national inpatient sample database, 309 of which developed VT (6.5%). Using multivariate analysis, we found predictors of VT to include patient characteristics and factors such as age (adjusted OR (aOR)=1.020, p=0.023), chronic kidney disease (aOR=1.440, p=0.048), coagulopathy (aOR=1.964, p=0.006), and atrial fibrillation (aOR=3.965, p<0.001). Conversely, pre-eclampsia was significantly associated with a decreased risk of VT in PPCM patients (aOR=0.218, p=0.001).  Conclusion  In a large cohort of patients admitted with peripartum cardiomyopathy, we found the prevalence of VT to be 6.5%. Risk factors for VT in this patient population included conditions such as coagulopathy and atrial fibrillation.

A Real-World Data Driven Pharmacovigilance Investigation on Drug-Induced Arrhythmia Using KAERS DB, a Korean Nationwide Adverse Drug Reporting System

This study aims to investigate the prevalence and seriousness of drug-induced arrhythmia and to identify predictors associated with the seriousness of arrhythmia. Drug-induced arrhythmia cases reported to the Korean Adverse Event Reporting System Database (KAERS DB) from January 2012 to December 2021 were investigated. A disproportionality test was performed to detect the association of the etiologic medication classes and types, along with patient demographic information, with the seriousness of drug-induced arrhythmia. Logistic regression was performed to investigate the predictors that increase the risk of serious arrhythmia. The most common etiologic agent for drug-induced arrhythmia was sevoflurane, whereas serious arrhythmia was most prevalent with narcotics. Antibiotics (reporting odds ratio (ROR) 4.125; 95% CI 1.438-11.835), chemotherapy (ROR 6.994; 95% CI 2.239-21.542), and iodinated contrast media (ROR 8.273; 95% CI 3.062-22.352) had a strong association with the seriousness of drug-induced arrhythmia. Among numerous etiologic agents, ioversol (ROR 16.490; 95% CI 3.589-75.772) and lidocaine (ROR 12.347; 95% CI 2.996-50.884) were more likely to be reported with serious arrhythmia. Aging and comorbidity, primarily cancer, are the most contributing predictors associated with serious arrhythmia. Further studies on the clinical significance of patient-specific predictors for the increased risk of serious drug-induced arrhythmia are warranted to promote drug safety.

Discovery of TBX20 as a Novel Gene Underlying Atrial Fibrillation

Atrial fibrillation (AF), the most prevalent type of sustained cardiac dysrhythmia globally, confers strikingly enhanced risks for cognitive dysfunction, stroke, chronic cardiac failure, and sudden cardiovascular demise. Aggregating studies underscore the crucial roles of inherited determinants in the occurrence and perpetuation of AF. However, due to conspicuous genetic heterogeneity, the inherited defects accounting for AF remain largely indefinite. Here, via whole-genome genotyping with genetic markers and a linkage assay in a family suffering from AF, a new AF-causative locus was located at human chromosome 7p14.2-p14.3, a ~4.89 cM (~4.43-Mb) interval between the markers D7S526 and D7S2250. An exome-wide sequencing assay unveiled that, at the defined locus, the mutation in the TBX20 gene, NM_001077653.2: c.695A>G; p.(His232Arg), was solely co-segregated with AF in the family. Additionally, a Sanger sequencing assay of TBX20 in another family suffering from AF uncovered a novel mutation, NM_001077653.2: c.862G>C; p.(Asp288His). Neither of the two mutations were observed in 600 unrelated control individuals. Functional investigations demonstrated that the two mutations both significantly reduced the transactivation of the target gene KCNH2 (a well-established AF-causing gene) and the ability to bind the promoter of KCNH2, while they had no effect on the nuclear distribution of TBX20. Conclusively, these findings reveal a new AF-causative locus at human chromosome 7p14.2-p14.3 and strongly indicate TBX20 as a novel AF-predisposing gene, shedding light on the mechanism underlying AF and suggesting clinical significance for the allele-specific treatment of AF patients.

COVID-19 HEART unveiling as atrial fibrillation: pathophysiology, management and future directions for research

BACKGROUND

COVID-19 infections are known to cause numerous systemic complications including cardiovascular disorders. In this regard, clinicians recently noticed that patients recovering from COVID-19 infections presented with diverse set of cardiovascular disorders in addition to those admitted to ICU (intensive care unit). COVID-19 heart has multifaceted presentation ranging from dysrhythmias, myocarditis, stroke, coronary artery disease, thromboembolism to heart failure. Atrial fibrillation is the most common cardiac arrhythmia among COVID-19 patients. In the background section, we briefly discussed epidemiology and spectrum of cardiac arrhythmias in COVID-19 patients.

MAIN BODY

In this state-of-the-art review we present here, we present the information regarding COVID-19-induced A-fib in sections, namely mechanism of action, clinical presentation, diagnosis and treatment. Unfortunately, its occurrence significantly increases the mortality and morbidity with a potential risk of complications such as cardiac arrest and sudden death. We included separate sections on complications including thromboembolism and ventricular arrhythmias. Since its mechanism is currently a gray area, we included a separate section on basic science research studies that are warranted in the future to comprehend its underlying pathogenic mechanisms.

CONCLUSIONS

Taken together, this review builds upon the current literature of COVID-19-induced A-fib, including pathophysiology, clinical presentation, treatment and complications. Furthermore, it provides recommendations for future research moving forward that can open avenues for developing novel remedies that can prevent as well as hasten clinical recovery of atrial fibrillation in COVID-19 patients.

Atrial Fibrillation and the Risk of Ventricular Arrhythmias and Cardiac Arrest: A Nationwide Population-Based Study

BACKGROUND

Atrial fibrillation (AF) has been linked to an increased risk of ventricular arrhythmias (VAs) and sudden death. We investigated this association in hospitalised patients in France.

METHODS

All hospitalised patients from 2013 were identified from the French National database and included if they had at least 5 years of follow-up data.

RESULTS

Overall, 3,381,472 patients were identified. After excluding 35,834 with a history of VAs and cardiac arrest, 3,345,638 patients were categorised into two groups: no AF (n = 3,033,412; mean age 57.2 ± 21.4; 54.3% female) and AF (n = 312,226; 78.1 ± 10.6; 44.0% female). Over a median follow-up period of 5.4 years (interquartile range (IQR) 5.0-5.8 years), the incidence (2.23%/year vs. 0.56%/year) and risk (hazard ratio (HR) 3.657 (95% confidence interval (CI) 3.604-3.711)) of VAs and cardiac arrest were significantly higher in AF patients compared to non-AF patients. This was still significant after adjusting for confounders, with a HR of 1.167 (95% CI 1.111-1.226) and in the 1:1 propensity score-matched analysis (n = 289,332 per group), with a HR of 1.339 (95% CI 1.313-1.366). In the mediation analysis, the odds of cardiac arrest were significantly mediated by AF-associated VAs, with an OR of 1.041 (95% CI 1.040-1.042).

CONCLUSION

In hospitalised French patients, AF was associated with an increased risk of VAs and sudden death.