Antiarrhythmic drugs for out-of-hospital cardiac arrest with refractory ventricular fibrillation

Impact of Imaging and Pharmacological Treatment Strategies in Refractory Ventricular Tachycardia in Critically Ill Patients: A Systematic Review

Ventricular tachycardia (VT) is a life-threatening arrhythmia often leading to sudden cardiac death, particularly in critically ill patients. Refractory VT, characterized by recurrent episodes requiring intervention, poses unique challenges for management, necessitating advanced diagnostic and therapeutic strategies. This systematic review evaluates the impact of imaging and pharmacological treatments in managing refractory VT in critically ill patients. A systematic literature search was conducted using keywords such as "refractory ventricular tachycardia", "critical illness", "imaging techniques", "pharmacological treatments", "antiarrhythmic drugs", "ICD interventions", and "non-invasive therapy". Databases searched included PubMed, Google Scholar, and Cochrane Library, identifying 1590 publications. After screening, 11 studies meeting the inclusion criteria were included in this review. Oral procainamide significantly reduced VT episodes but caused severe side effects in certain patients. Noninvasive interventions such as transcutaneous magnetic stimulation (TcMS) and noninvasive electrophysiology-guided radioablation reduced VT burden and antiarrhythmic drug (AAD) use, with TcMS decreasing VT episodes in the sham group (P < 0.001). Stereotactic body radiation therapy (SBRT) and stereotactic arrhythmia radiotherapy (STAR) reduced VT episodes. Ultrasound-guided stellate ganglion blockade decreased VT episodes (P < 0.001) within 24 hours. Catheter ablation improved composite outcomes, including ICD shocks and heart failure hospitalizations, compared to AAD therapy. Quality of life significantly improved with noninvasive therapies, though SBRT presented rare complications like pneumonitis. Imaging and pharmacological interventions effectively reduce VT burden and ICD interventions while showing varying safety profiles. However, the limited sample sizes, short follow-up durations, and heterogeneity across studies highlight the need for further high-quality research to establish long-term efficacy and safety.

Meta‑analysis of the efficacy and safety of nifekalant in the conversion of atrial fibrillation

Atrial fibrillation (AF) is the most common type of supraventricular tachyarrhythmia. Nifekalant is a new class III antiarrhythmic drug approved for the treatment of ventricular tachyarrhythmias, but its effectiveness in converting AF to sinus rhythm remains unclear. The present analysis aimed to investigate the effect of nifekalant in the conversion of AF. PubMed, Cochrane Library and China National Knowledge Infrastructure databases were systematically used to search relevant studies published between 1999 (data at which the drug was first approved for marketing in Japan) and 2022. Randomized clinical trials, prospective studies and retrospective studies on the use of nifekalant for AF were screened. The study metrics included the success rate of the conversion of AF, the mean time to conversion, the success rate of 12 months after a single AF catheter ablation procedure and the incidence of adverse events. The eligible studies screened included six randomized clinical trials, three prospective studies and three retrospective studies, totalling 12 studies with 1,162 patients. The risk ratio (RR) for successful conversion in the nifekalant and control groups was 1.95 [95% confidence interval (CI), 1.23-3.08; P=0.005] and the mean difference for the mean time to conversion was -1.73 [95% CI, -2.69-(-0.77); P=0.0004]. Statistically significant differences were observed between nifekalant and control groups. Subgroup analysis revealed a statistically significant difference in the success rate of conversion following catheter ablation in the nifekalant group compared with the amiodarone group and the RR value was 1.95 (95% CI, 1.37-2.77; P=0.0002). Statistically significant difference was observed compared with the electrical cardioversion group and the RR value was 0.90 (95% CI, 0.84-0.98; P=0.01). However, the combined RR values for the two groups were 1.18 (95% CI, 0.85-1.65; P<0.0002). The RR value for adverse events was 0.85 (95% CI, 0.51-1.43; P=0.55), with no statistically significant differences between nifekalant and control groups. In conclusion, the results demonstrated that the success rate and time to conversion in the nifekalant group were improved compared with those in the control group, particularly after catheter ablation, and the conversion effect with nifekalant was significantly improved compared with that in the control group.

Pediatric Fulminant Myocarditis in Japan: A Retrospective Nationwide Database Study of Hospital Volume, Management Practices, and Mortality

OBJECTIVES

Pediatric fulminant myocarditis is a subset of pediatric acute myocarditis associated with critical illness. We aimed to compare mortality and other outcomes such as length of hospital stay between pediatric fulminant myocarditis and nonfulminant myocarditis. For the subgroup of patients with fulminant myocarditis, we also aimed to describe the current management practices and evaluate the impact of clinically relevant factors, including hospital case volume, on mortality.

DESIGN

Retrospective observational study using the Diagnosis Procedure Combination database from April 2012 to March 2018.

SETTING

Over 1,000 acute care hospitals in Japan.

PATIENTS

Patients with acute myocarditis less than 18 years old, including patients with fulminant myocarditis (i.e., those who received at least one of the following by day 7 of hospitalization: inotropes/vasopressors, mechanical circulatory support, or cardiopulmonary resuscitation).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Multivariable logistic regression analysis was conducted to investigate the association between clinically relevant factors and in-hospital mortality of patients with fulminant myocarditis. Furthermore, post hoc propensity score analyses (propensity score-adjusted, propensity score-matched, and inverse probability of treatment-weighted analyses) were performed to confirm the effect of hospital case volume on in-hospital mortality. In total, 866 pediatric patients with acute myocarditis were included, and 382 (44.1%) were categorized as fulminant myocarditis. In-hospital mortality for those with fulminant myocarditis was 24.1%. fulminant myocarditis was associated with 41.3-fold greater odds of mortality than nonfulminant myocarditis (95% CI, 14.7-115.9; p < 0.001). In the subgroup of patients with fulminant myocarditis, a higher in-hospital mortality was significantly associated with younger age (≤ 5 yr; odds ratio, 3.41; 95% CI, 1.75-6.64) and the need for either mechanical ventilation (odds ratio, 2.39; 95% CI, 1.03-5.57), cardiopulmonary resuscitation (odds ratio, 10.63; 95% CI, 5.52-20.49), or renal replacement therapy (odds ratio, 2.53; 95% CI, 1.09-5.87) by day 7. A lower in-hospital mortality rate was significantly associated with treatment at hospitals in the highest pediatric fulminant myocarditis case volume tertile (≥ 6 cases in 6 yr; odds ratio, 0.30; 95% CI, 0.13-0.68) compared with treatment at hospitals in the lowest tertile (1-2 cases in 6 yr). Post hoc propensity score analyses consistently supported the primary results.

CONCLUSIONS

In-hospital mortality of pediatric fulminant myocarditis in Japan remains high. Treatment at hospitals in the highest pediatric fulminant myocarditis case volume tertile (≥ 6 cases in 6 yr) was associated with a 70% relative reduction in odds of in-hospital mortality compared with treatment at hospitals in the lowest tertile (1-2 cases in 6 yr). The reasons for such differences need further study.

Cardiac arrhythmias in the emergency settings of acute coronary syndrome and revascularization: an European Heart Rhythm Association (EHRA) consensus document, endorsed by the European Association of Percutaneous Cardiovascular Interventions (EAPCI), and European Acute Cardiovascular Care Association (ACCA)

Despite major therapeutic advances over the last decades, complex supraventricular and ventricular arrhythmias (VAs), particularly in the emergency setting or during revascularization for acute myocardial infarction (AMI), remain an important clinical problem. Although the incidence of VAs has declined in the hospital phase of acute coronary syndromes (ACS), mainly due to prompt revascularization and optimal medical therapy, still up to 6% patients with ACS develop ventricular tachycardia and/or ventricular fibrillation within the first hours of ACS symptoms. Despite sustained VAs being perceived predictors of worse in-hospital outcomes, specific associations between the type of VAs, arrhythmia timing, applied treatment strategies and long-term prognosis in AMI are vague. Atrial fibrillation (AF) is the most common supraventricular tachyarrhythmia that may be asymptomatic and/or may be associated with rapid haemodynamic deterioration requiring immediate treatment. It is estimated that over 20% AMI patients may have a history of AF, whereas the new-onset arrhythmia may occur in 5% patients with ST elevation myocardial infarction. Importantly, patients who were treated with primary percutaneous coronary intervention for AMI and developed AF have higher rates of adverse events and mortality compared with subjects free of arrhythmia. The scope of this position document is to cover the clinical implications and pharmacological/non-pharmacological management of arrhythmias in emergency presentations and during revascularization. Current evidence for clinical relevance of specific types of VAs complicating AMI in relation to arrhythmia timing has been discussed.

Safety of Tranexamic Acid During Pediatric Trauma: A Nationwide Database Study

OBJECTIVES

The present study aimed to examine the association between tranexamic acid use and adverse effects (seizures, thromboembolism, and renal dysfunction) in a pediatric trauma population using a national inpatient database in Japan. We also assessed the association between tranexamic acid use and in-hospital mortality.

DESIGN

A nationwide, retrospective cohort study using propensity score analyses.

SETTING

Japanese Diagnosis Procedure Combination inpatient database.

PATIENTS

Pediatric patients less than or equal to 12 years old admitted in hospital with the diagnosis of trauma between July 2010 and March 2014 (n = 61,779).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Propensity score matching created 1,914 pairs of patients with and without tranexamic acid administration. Propensity-matched analysis showed that the proportion of seizures was significantly higher in the tranexamic acid group than in the nontranexamic acid group (7/1,914, 0.37% vs 0/1,914, 0%; difference, 0.37%; 95% CI, 0.10-0.64; p = 0.008). However, none of the other outcomes were significantly different between the groups.

CONCLUSIONS

Tranexamic acid use is associated with a significantly increased risk of seizures. However, no difference exists among any other outcomes between the tranexamic acid and nontranexamic acid groups.