Meta-analysis of clinical outcomes in cardiac resynchronisation therapy: his bundle pacing vs biventricular pacing.

INTRODUCTION AND OBJECTIVE: Cardiac resynchronization may treat severe heart failure (HF) with pharmacological optimization, left branch block, and an ejection fraction<35%. However, 30-40% of patients fail therapy. HBP could replace biventricular pacing (BiV). We compared the effectiveness of HBP versus BiV in HF patients. METHODS: We searched PubMed, Embase, and Cochrane for studies on QRS, left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) functional class, left ventricular end-systolic volume (LVESV), and 6-minute walk test. RESULTS: Six publications included 774 patients (mean [± standard deviation] age: 66.9 [14.0] years; 484 (62.5%) were males; 408 [52.71%] underwent HBP; the mean follow-up was 6-12 months. The HBP group had a higher QRS reduction in the meta-analysis (median: -17.54 [-20.46, -14.62]; I2 = 89%). LVEF showed a median of 8.48 (7.55, 9.41) and I2 of 98%, with a higher mean in HBP. The LVESV median was -18.89 (-30.03, -7.75) and I2 was 0%, and the HBP group had a lower mean. HBP had a lower NYHA functional class (median= -0.20 [-0.28, -0.12]). CONCLUSION: After implantation, HBP demonstrated bigger QRS shortening, increased LVEF, lower LVES volume, and lower NYHA class than BiV pacing.

A Narrative Review of Emerging Therapies for Hypertrophic Obstructive Cardiomyopathy.

Hypertrophic obstructive cardiomyopathy is a hereditary condition that affects myocardial contraction. In case of failure of pharmacological treatment, alternative approaches might be used that include surgical myectomy, percutaneous transluminal septal myocardial ablation, and radiofrequency ablation. In respect of long-term advantages, surgical septal myectomy remains the therapy of choice for symptomatic hypertrophic obstructive cardiomyopathy. Alcohol septal ablation has been considered an alternative to surgical myectomy, which confers the benefits of a shorter hospital stay, less discomfort, and fewer complications. However, only expert operators should perform it on carefully chosen patients. Further, radiofrequency septal ablation reduces the left ventricular outflow tract gradient and improves the NYHA functional class of patients with hypertrophic obstructive cardiomyopathy, despite complications like cardiac tamponade and atrioventricular block. Further research with a larger sample size is required to compare the radiofrequency approach with established invasive treatment methods for hypertrophic obstructive cardiomyopathy. Septal myectomy has low morbidity and mortality rates, making it the preferred procedure; however, the efficacy and morbidity remain debatable. Advances in invasive techniques, including percutaneous septal radiofrequency ablation and transcatheter myotomy, have provided alternative approaches for reducing left ventricular outflow tract (LVOT) obstruction in patients who are not candidates for traditional surgical septal myectomy. Candidates for alcohol and radiofrequency septal ablation include patients with symptomatic hypertrophic obstructive cardiomyopathy, older adults, and those with multiple comorbidities.

Efficacy and Complications of Subcutaneous versus Conventional Cardioverter Defibrillators: A Systematic Review and Meta-analysis.

BACKGROUND/OBJECTIVES: Implantable cardioverter defibrillators are used to prevent sudden cardiac death. The subcutaneous implantable cardioverter-defibrillator was newly developed to overcome the limitations of the conventional implantable cardioverter defibrillator-transvenous device. The subcutaneous implantable cardioverter defibrillator is indicated for young patients with heart disease, congenital heart defects, and poor venous access, who have an indication for implantable cardioverter defibrillator without the need for anti-bradycardic stimulation. We aimed to compare the efficacy and complications of subcutaneous with transvenous implantable cardioverter- defibrillator devices. METHODOLOGY: A systematic review was conducted using different databases. The inclusion criteria were observational and clinical randomized trials with no language limits and no publication date limit that compared subcutaneous with transvenous implantable cardioverter-defibrillators. The selected patients were aged > 18 years with complex ventricular arrhythmia. RESULTS: Five studies involving 2111 patients who underwent implantable cardioverter defibrillator implantation were included. The most frequent complication in the subcutaneous device group was infection, followed by hematoma formation and electrode migration. For the transvenous device, the most frequent complications were electrode migration and infection. Regarding efficacy, the total rates of appropriate shocks were 9.04% and 20.47% in the subcutaneous and transvenous device groups, respectively, whereas inappropriate shocks to the subcutaneous and transvenous device groups were 11,3% and 10,7%, respectively. CONCLUSION: When compared to the transvenous device, the subcutaneous device had lower complication rates owing to lead migration and less inappropriate shocks due to supraventricular tachycardia; nevertheless, infection rates and improper shocks due to T wave oversensing were comparable for both devices CRD42021251569.

Radiofrequency ablation in patients with obstructive hypertrophic cardiomyopathy: A systematic review and meta-analysis.

Study objective: Hypertrophic cardiomyopathy (HCM) is a genetic disease that can cause left ventricular outflow tract (LVOT) obstruction. This study analyzed the efficacy of radiofrequency ablation (RA) in improving clinical and hemodynamic factors in patients receiving obstructive HCM refractory treatment. This evaluation was necessary because of the small number of studies on the effectiveness of this technique for obstructive HCM in the existing literature. Design: We used the PubMed, Embase, and Science Direct databases to identify randomized clinical trials and observational studies addressing the clinical and hemodynamic outcomes before and after RA in patients with HCM. Participants: We selected six articles published between 2011 and 2022, comprising 304 patients (mean age: 45 years). Interventions: We performed a bias assessment using the ROBINS I tool, and meta-analysis processing was performed using the STATA program (v.16.0). Results: The left ventricular outflow tract (LVOT) gradient at rest and with stimulation decreased by 58.78 mmHg (p = 0.001) and 70.38 mmHg (total effect Z = 21.62; p < 0.0001), respectively. Additionally, the New York Heart Association (NYHA) functional class decreased by 0.43 (p = 0.001), indicating symptomatic and hemodynamic improvements. Furthermore, we observed a significant reduction in septal thickness (by 4 mm; p = 0.001). Conclusions: RA improved the NYHA functional class and LVOT gradient at rest and with stimulation and reduced septal thickness. These results suggest that RA is effective in patients refractory to pharmacological therapy and unsuitable for alcohol septal ablation or myectomy. However, more studies, including randomized clinical trials, should be conducted to define the role of RA in interventional therapies.

Effectiveness of multipoint cardiac resynchronizing therapy in heart failure: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Cardiac resynchronization therapy is an important validated technique for patients with dyssynchrony and heart failure. However, the response rate to conventional resynchronization is approximately 50%; therefore, new techniques and schedules have emerged. This study aimed to evaluate the different clinical and echocardiographic variables of conventional versus multipoint cardiac resynchronization therapy. RESEARCH DESIGN AND METHOD: A systematic review was conducted of randomized clinical trials in the PubMed, Cochrane, and Embase databases on cardiac resynchronization intervention with multipoint stimulation clinical and echocardiographic outcomes evaluated before and 3 months after the intervention. RESULTS: Three studies (N = 139) were ultimately selected, and 100% of patients had a New York Heart Association functional class of II-IV, QRS > 120 ms, and a left ventricular ejection fraction < 35%. Significantly greater improvement was observed in the functional class of patients who underwent multipoint versus conventional therapy. The final systolic volume and ejection fraction improved in the multipoint group, but the difference was not statistically significant. CONCLUSIONS: The literature lacks sufficient randomized controlled studies to enable conclusions regarding cardiac resynchronization therapy responses using different strategies. Moreover, the improvement in functional class in the multipoint pacing group involved few patients and had slight statistical relevance.

Catheter ablation in the treatment of electrical storm: Integrative review.

BACKGROUND: The incidence of electrical storm (ES) has been increasing with the rise of the indicated uses of implantable cardioverter defibrillators (ICDs). It is estimated that 20% of patients will evolve to have this complication. Ablative therapy stands out as the treatment for this condition when it is refractory to antiarrhythmic treatment. The objective was to define the current role of catheter ablation in the treatment of electrical storm. METHODS: An integrative literature review was performed using the PubMed and BVS databases. All identified articles were screened and verified for eligibility by the authors. RESULTS: Twenty-five out of the initial 951 articles were used in the final analysis. The categories listed for analysis included indication for ablation in ES, modality of the approach, therapeutic success, complications related to the procedure, mortality and cardiovascular follow-up and alternative therapeutic modalities by frequency of these categories in the articles researched. CONCLUSION: Catheter ablation is the initial therapy for patients with ischemic cardiomyopathy (ICM) and ES. The endocardial approach presents more relevant success rates than the other therapeutic methods presented.