Electrophysiological study in chagasics with syncope and conduction disorder

BACKGROUND: Investigation of syncope involves the use of electrophysiological study, particularly in patients with cardiac conduction disorder. There is conflicting evidence about the role of electrophysiological study in patients with Chagas disease. OBJECTIVE: The objective of this study was to evaluate the lectrophysiological study findings in patients with Chagas disease and bundle Branch block and/or divisional block presenting with syncope. METHODS: This is a retrospective study of patients with Chagas disease and cardiac conduction disorder who underwent electrophysiological study from 2017 to 2021 for the investigation of syncope in a tertiary hospital in São Paulo, Brazil. Those with non-interpretable ECG, known coronary artery disease, and/or other cardiomyopathies were excluded. HV interval and electrophysiological study-induced malignant ventricular arrhythmias data were analyzed. RESULTS: A total of 45 patients (60.2±11.29 years, 57.8% males) were included. The mean HV interval was 58.37 ms±10.68; 22.2% of the studied population presented an HV interval of ≥70 ms; and malignant ventricular arrhythmias were induced in 57.8% patients. The use of beta-blockers and amiodarone (p=0.002 and 0.036, respectively), NYHA functional class≥II (p=0.013), wide QRS (p=0.047), increased HV interval (p=0.02), Rassi score >6.5 (p=0.003), and reduced left ventricular ejection fraction (p=0.031) were associated with increased risk of inducible malignant ventricular arrhythmias. CONCLUSION: More than half of the patients with Chagas disease, syncope, and cardiac conduction disorder have inducible malignant ventricular arrhythmias. Prolonged HV interval was observed in only 20% of population. Wide QRS, prolonged HV, reduced ejection fraction, and higher Rassi score were associated with increased risk of malignant ventricular arrhythmias.

Relationship between ventricular repolarization parameters and the inducibility of ventricular arrhythmias during electrophysiological study in patients with coronary artery disease

OBJECTIVE: Risk stratification of sudden cardiac death in patients with coronary artery disease is of great importance. We evaluated the association between ventricular repolarization and induction of malignant ventricular arrhythmias on electrophysiological study of patients with coronary artery disease. METHODS AND RESULTS: A total of 177 patients (65±10.1 years, 83.6% male, mean left ventricular ejection fraction [LVEF] 37.5±13.6%) were analyzed. For each 10 ms increment in the QT interval, there was a 7% increase in malignant ventricular arrhythmias inducibility; QT cutoff point of 452 ms had an accuracy of 0.611 for predicting malignant ventricular arrhythmias (p=0.011). Male gender (odds ratio [OR]=4.18, p=0.012), LVEF 452 ms was associated with significantly increased risk of malignant ventricular arrhythmias (OR=5.44, p=0.0004). In those with LVEF ³35%, QT dispersion (QTd) was significantly higher in patients with inducible malignant ventricular arrhythmias. QTd >20 ms had 0.638 accuracy and 81.3% negative predictive value in predicting malignant ventricular arrhythmias. CONCLUSION: QT interval is an independent factor associated with malignant ventricular arrhythmias in patients with coronary artery disease. The combination of ventricular dysfunction and prolonged QT interval is associated with a 5.44-fold increase of malignant ventricular arrhythmias induction. Male gender, amiodarone use, and decreased left ventricular ejection fraction are also associated with increased risk of inducibility of malignant ventricular arrhythmias on the electrophysiological study.

Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial.

BACKGROUND: COVID-19 is associated with a prothrombotic state leading to adverse clinical outcomes. Whether therapeutic anticoagulation improves outcomes in patients hospitalised with COVID-19 is unknown. We aimed to compare the efficacy and safety of therapeutic versus prophylactic anticoagulation in this population. METHODS: We did a pragmatic, open-label (with blinded adjudication), multicentre, randomised, controlled trial, at 31 sites in Brazil. Patients (aged ≥18 years) hospitalised with COVID-19 and elevated D-dimer concentration, and who had COVID-19 symptoms for up to 14 days before randomisation, were randomly assigned (1:1) to receive either therapeutic or prophylactic anticoagulation. Therapeutic anticoagulation was in-hospital oral rivaroxaban (20 mg or 15 mg daily) for stable patients, or initial subcutaneous enoxaparin (1 mg/kg twice per day) or intravenous unfractionated heparin (to achieve a 0·3-0·7 IU/mL anti-Xa concentration) for clinically unstable patients, followed by rivaroxaban to day 30. Prophylactic anticoagulation was standard in-hospital enoxaparin or unfractionated heparin. The primary efficacy outcome was a hierarchical analysis of time to death, duration of hospitalisation, or duration of supplemental oxygen to day 30, analysed with the win ratio method (a ratio >1 reflects a better outcome in the therapeutic anticoagulation group) in the intention-to-treat population. The primary safety outcome was major or clinically relevant non-major bleeding through 30 days. This study is registered with ClinicalTrials.gov (NCT04394377) and is completed. FINDINGS: From June 24, 2020, to Feb 26, 2021, 3331 patients were screened and 615 were randomly allocated (311 [50%] to the therapeutic anticoagulation group and 304 [50%] to the prophylactic anticoagulation group). 576 (94%) were clinically stable and 39 (6%) clinically unstable. One patient, in the therapeutic group, was lost to follow-up because of withdrawal of consent and was not included in the primary analysis. The primary efficacy outcome was not different between patients assigned therapeutic or prophylactic anticoagulation, with 28 899 (34·8%) wins in the therapeutic group and 34 288 (41·3%) in the prophylactic group (win ratio 0·86 [95% CI 0·59-1·22], p=0·40). Consistent results were seen in clinically stable and clinically unstable patients. The primary safety outcome of major or clinically relevant non-major bleeding occurred in 26 (8%) patients assigned therapeutic anticoagulation and seven (2%) assigned prophylactic anticoagulation (relative risk 3·64 [95% CI 1·61-8·27], p=0·0010). Allergic reaction to the study medication occurred in two (1%) patients in the therapeutic anticoagulation group and three (1%) in the prophylactic anticoagulation group. INTERPRETATION: In patients hospitalised with COVID-19 and elevated D-dimer concentration, in-hospital therapeutic anticoagulation with rivaroxaban or enoxaparin followed by rivaroxaban to day 30 did not improve clinical outcomes and increased bleeding compared with prophylactic anticoagulation. Therefore, use of therapeutic-dose rivaroxaban, and other direct oral anticoagulants, should be avoided in these patients in the absence of an evidence-based indication for oral anticoagulation. FUNDING: Coalition COVID-19 Brazil, Bayer SA.

Rationale and design of the Statins Evaluation in Coronary procedUres and REvascularization: The SECURE-PCI Trial.

BACKGROUND: Previous evidence suggests that acute treatment with statins reduce atherosclerotic complications, including periprocedural myocardial infarction, but currently, there are no large, adequately powered studies to define the effects of early, high-dose statins in patients with acute coronary syndrome (ACS) and planned invasive management. OBJECTIVES: The main goal of Statins Evaluation in Coronary procedUres and REvascularization (SECURE-PCI) Trial is to determine whether the early use of a loading dose of 80 mg of atorvastatin before an intended percutaneous coronary intervention followed by an additional dose of 80 mg 24 hours after the procedure will be able to reduce the rates of major cardiovascular events at 30 days in patients with an ACS. DESIGN: The SECURE-PCI study is a pragmatic, multicenter, double-blind, placebo-controlled randomized trial planned to enroll around 4,200 patients in 58 different sites in Brazil. The primary outcome is the rate of major cardiovascular events at 30 days defined as a composite of all-cause mortality, nonfatal acute myocardial infarction, nonfatal stroke, and coronary revascularization. SUMMARY: The SECURE PCI is a large randomized trial testing a strategy of early, high-dose statin in patients with ACS and will provide important information about the acute treatment of this patient population.

Terapias anticoagulantes na doença renal crônica / Anticoagulant therapies in chronic renal disease

Os pacientes com doença renal crônica (DRC) têm tendências hemorrágicas e trombóticas e, por isso, a indicação de anticoagulantes é complexa nos indivíduos com fibrilação atrial (FA). A FA é a arritmia mais frequente na DRC, sendo o tromboembolismo e o ictus suas principais complicações. A introdução de novos anticoagulantes orais diretos (DOACs) tem se mostrado superior aos antagonistas da vitamina K, tanto na prevenção de tromboembolismos sistêmicos como no risco de sangramento. Contudo, devem ser prescritos com cautela nesse grupo de pacientes. Para os indivíduos com DRC e clearance renal entre 30 e 50 ml/min, as doses da dabigatrana e da rivaroxabana devem ser reduzidas, no caso de pacientes com elevado risco de sangramento, não havendo necessidade de reduzir as doses de apixabana e edoxabana. Em pacientes com clearance renal entre 15 e 29 ml/min o uso da dabigatrana é contraindicado, a rivaroxabana e a edoxabana não exigem ajuste terapêutico e a dose de apixabana deve ser ajustada. Nenhum dos DOACs é indicado em pacientes com clearance renal < 15 mg/min. Outro problema da terapêutica com os DOACs é o custo do medicamento, muito superior aos dos antagonistas da vitamina K, trazendo algumas implicações clínicas relevantes: suspensão terapêutica por restrições econômicas, que mesmo quando transitória, coloca o paciente em risco de eventos tromboembólicos devido à perda rápida de seus efeitos anticoagulantes e pela possibilidade de hipercoagulabilidade paradoxal. A maior parte da população é tratada em hospitais públicos e recebe os antagonistas de vitamina K. Por isso, enquanto a relação custo-efetividade dos DOACs não for esclarecida, a prevenção e o tratamento de pacientes com DRC e FA com os antagonistas de vitamina K estão consagrados e podem trazer benefícios para esse grupo de pacientes

Patients with chronic renal disease (CRD) have hemorrhagic and thrombotic tendencies, therefore the indication of anticoagulants is complex in individuals with atrial fibrillation (AF). AF is the most frequent arrhythmia in CRD, and thromboembolism and cerebral stroke are its main complications. The introduction of new oral anticoagulants (DOACs) has proven to be superior to vitamin K antagonists in preventing systemic thromboembolisms and bleeding risk. However, they should be prescribed with caution in this group of patients. For individuals with CRD and renal clearance between 30 and 50 ml/min, the doses of dabigatran and rivaroxaban should be reduced, in the case of patients with high risk of bleeding, and it is not necessary to reduce the doses of apixaban and edoxaban. In patients with renal clearance between 15 and 29 ml/min, the use of dabigatran is contraindicated, rivaroxaban and edoxaban do not require therapeutic adjustment, and the dose of apixaban should be adjusted. No DOACs is indicated in patients with renal clearance < 15 mg/min. Another problem with DOACs therapy is the cost of the medication, which is much higher than that of vitamin K antagonists, with some important clinical implications: therapeutic suspension due to economic restrictions, even if temporary, place the patient at risk of thromboembolic events due to the rapid loss of anticoagulant effects and the possibility of paradoxical hypercoagulability. Most of the population is treated in public hospitals, and receives vitamin K antagonists. Therefore, while the cost-effectiveness ratio of DOACs has not been clarified, prevention and treatment of patients with CRD and AF with vitamin K antagonists is consecrated, and can bring benefits for this group of patients

The usefulness of T-wave peak to T-wave end interval in identifying malignant arrhythmias in patients with Chagas disease.

INTRODUCTION: Abnormal ventricular repolarization has been proposed as a marker of arrhythmogenesis, and cardiovascular morbidity and mortality. However, little is known about the influence of the interval between the peak and the end of the T wave (Tp-Te) on the inducibility of sustained ventricular arrhythmias (VA) in patients with Chagas disease (CD). METHODS: Using a case-control design, chagasics undergoing electrophysiological study (EPS) in the last three years were matched by age and sex. Cases represented those with positive EPS and controls those with no inducible VA. Tp-Te>100 ms was considered abnormal. Logistic regression analysis was performed to assess the association between Tp-Te and a positive EPS, after adjusting for confounders. RESULTS: A total of 105 patients (mean age 56 years, 52.4% male) were included: 41 (39%) had a positive EPS; 85.4% with inducible VA (n=35) had non-sustained ventricular tachycardia on the Holter monitoring, compared to 62.5% with negative EPS (n=40, p<0.001). While ventricular aneurysm (adjusted OR=5.3, 95% CI: 1.11-24.96, p=0.03) and coronary artery disease (adjusted OR=8.8, 95% CI: 1.45-53.15, p=0.01) were associated with an increased risk of malignant arrhythmias, a greater ejection fraction (adjusted OR=0.96, 95% CI: 0.93-0.99, p<0.01) was associated with a lower risk of VA. Prolonged Tp-Te trended to be associated with an increased risk of induced VA (p=0.07). CONCLUSIONS: Ventricular aneurysm, coronary artery disease, and ejection fraction are associated with inducible VA. Prolonged TP-Te may have a modest role in the identification of patients with CD who are at high risk for VA. Further studies are warranted to validate our results and to correlate them with clinical outcomes.

Características do estudo eletrofisiológico na Doença de Chagas / Electrophysiological characteristics of Chagas disease

OBJETIVO: A doença de Chagas constitui importante problema de saúde pública global devido às mudanças nos padrões migratórios. O estudo eletrofisiológico é usualmente indicado na avaliação da função do nó sinusal, condução pelo nó atrioventricular e sistema His-Purkinje e mecanismos das arritmias. O objetivo deste estudo foi descrever as características do estudo eletrofisiológico em pacientes com doença de Chagas. MÉTODOS: Estudo retrospectivo e descritivo de 115 pacientes consecutivos com doença de Chagas submetidos ao estudo eletrofisiológico nos últimos 3 anos em centro terciário no Brasil. Características basais, eletrocardiográficas, ecocardiográficas e de Holter de 24 horas foram avaliadas e correlacionadas aos achados do estudo eletrofisiológico. RESULTADOS: Os tempos corrigidos de recuperação do nó sinusal e condução sinoatrial foram anormais em 6,9% e 26,1% dos pacientes, respectivamente. Apresentaram condução atrioventricular anormal 37 (32,2%) pacientes. A condução intraventricular mostrou-se alterada em 39 (33,9%) pacientes. Em aproximadamente 48%, houve indução de arritmias ventriculares sustentadas, sendo a maioria monomórfica (83,6%). A morfologia de bloqueio de ramo direito foi a mais comumente observada (52,7%). Dentre as arritmias, 51% associaram-se a sintomas/instabilidade hemodinâmica, 60% necessitaram de cardioversão elétrica e 27,3% de estimulação rápida. O sítio de origem mais comum foi a parede inferosseptal do ventrículo esquerdo (18,2%), seguido pela parede posterobasal (11%). Pacientes com fração de ejeção<40% tiveram risco 1,94 vez maior de indução de arritmias ventriculares comparados àqueles com fração de ejeção>60% (OR: 1,94; IC95%: 1,12-3,38; p=0,01). A presença de arritmias ventriculares complexas no Holter não foi preditiva de indução de arritmias ventriculares. CONCLUSÕES: Chagásicos com fração de ejeção baixa apresentam maior risco de arritmias ventriculares induzidas. Disfunção do nó sinusal e anormalidades da condução...

OBJECTIVE: Chagas disease has become a global problem due to changing migration patterns. An electrophysiological study is generally indicated for assessing sinus node function, conduction through the atrioventricular node and His-Purkinje system, in addition to evaluating the mechanisms of arrhythmia. The aim of this study was to describe the characteristics of electrophysiological study findings in patients with Chagas disease. METHODS: A retrospective descriptive study of 115 consecutive patients with Chagas disease undergoing an electrophysiological study over the last three years in a tertiary hospital in Brazil. Baseline characteristics, electrocardiogram, echocardiogram, and 24-hour Holter monitoring findings were recorded and correlated with the electrophysiological study findings. RESULTS: The corrected sinus node recovery time and sinoatrial conduction time were abnormal in 6.9% and 26.1% of patients, respectively. Thirty-seven (32.2%) had abnormal atrioventricular conduction. Intraventricular conduction was abnormal in 39 (33.9%). Approximately 48% had induced sustained ventricular arrhythmias, most of which were monomorphic (83.6%). Right bundle branch block was the most common morphology (52.7%). Fifty-one percent were associated with symptoms/hemodynamic instability, 60% required electrical cardioversion, and 27.3% needed overdrive suppression. The most common site of origin was the left ventricular inferoseptal wall (18.2%), followed by the left ventricular posterobasal wall (11%). Patients with an ejection fraction<40% had a 1.94-fold increased risk of ventricular arrhythmias compared to those with an ejection fraction>60% (OR: 1.94; 95%CI: 1.12-3.38; p=0.01). The presence of complex ventricular arrhythmias on Holter did not predict inducible ventricular arrhythmias. CONCLUSIONS: Chagas patients with a low ejection fraction have an increased risk of inducible ventricular arrhythmias. Sinus node dysfunction, and atrioventricular node...

Do omega-3 fatty acids prevent atrial fibrillation after open heart surgery? A meta-analysis of randomized controlled trials.

OBJECTIVES: N-3 polyunsaturated fatty acids have been proposed as a novel treatment for preventing postoperative atrial fibrillation due to their potential anti-inflammatory and anti-arrhythmic effects. However, randomized studies have yielded conflicting results. The objective of this study is to review randomized trials of N-3 polyunsaturated fatty acid use for postoperative atrial fibrillation. METHODS: Using the CENTRAL, PUBMED, EMBASE, and LILACS databases, a literature search was conducted to identify all of the studies in human subjects that reported the effects of N-3 polyunsaturated fatty acids on the prevention of postoperative atrial fibrillation in cardiac surgery patients. The final search was performed on January 30, 2011. There was no language restriction, and the search strategy only involved terms for N-3 polyunsaturated fatty acids (or fish oil), atrial fibrillation, and cardiac surgery. To be included, the studies had to be randomized (open or blinded), and the enrolled patients had to be ≥18 years of age. RESULTS: Four randomized studies (three double-blind, one open-label) that enrolled 538 patients were identified. The patients were predominantly male, the mean age was 62.3 years, and most of the patients exhibited a normal left atrial size and ejection fraction. N-3 polyunsaturated fatty acid use was not associated with a reduction in postoperative atrial fibrillation. Similar results were observed when the open-label study was excluded. CONCLUSIONS: There is insufficient evidence to suggest that treatment with N-3 polyunsaturated fatty acids reduces postoperative atrial fibrillation. Therefore, their routine use in patients undergoing cardiac surgery is not recommended.

Do Omega-3 fatty acids prevent atrial fibrillation after open heart surgery? A meta-analysis of randomized controlled trials

OBJECTIVES: N-3 polyunsaturated fatty acids have been proposed as a novel treatment for preventing postoperative atrial fibrillation due to their potential anti-inflammatory and anti-arrhythmic effects. However, randomized studies have yielded conflicting results. The objective of this study is to review randomized trials of N-3 polyunsaturated fatty acid use for postoperative atrial fibrillation. METHODS: Using the CENTRAL, PUBMED, EMBASE, and LILACS databases, a literature search was conducted to identify all of the studies in human subjects that reported the effects of N-3 polyunsaturated fatty acids on the prevention of postoperative atrial fibrillation in cardiac surgery patients. The final search was performed on January 30, 2011. There was no language restriction, and the search strategy only involved terms for N-3 polyunsaturated fatty acids (or fish oil), atrial fibrillation, and cardiac surgery. To be included, the studies had to be randomized (open or blinded), and the enrolled patients had to be >18 years of age. RESULTS: Four randomized studies (three double-blind, one open-label) that enrolled 538 patients were identified. The patients were predominantly male, the mean age was 62.3 years, and most of the patients exhibited a normal left atrial size and ejection fraction. N-3 polyunsaturated fatty acid use was not associated with a reduction in postoperative atrial fibrillation. Similar results were observed when the open-label study was excluded. CONCLUSIONS: There is insufficient evidence to suggest that treatment with N-3 polyunsaturated fatty acids reduces postoperative atrial fibrillation. Therefore, their routine use in patients undergoing cardiac surgery is not recommended.