His bundle pacing in nodal versus infranodal atrioventricular block: a mid-term follow-up study

Introduction This study evaluated the feasibility of His bundle pacing (HBP) in consecutive, unselected patients with advanced atrioventricular block (AVB) over a medium-term follow-up period, comparing procedural characteristics between nodal and infranodal sites of the conduction block.Materials and methods Seventy-five consecutive patients with second-degree or third-degree AVB in which HBP was attempted were prospectively included in this study. The clinical and procedural-related characteristics of the patients were recorded at baseline and over a mid-term follow-up.Results 72% of the patients had normal QRS duration at baseline. Intracardiac electrograms revealed nodal AVB in 46 patients (61.3%). The permanent HBP procedural success was significantly higher in nodal AVB (84.8%) vs infranodal AVB (31%). There was no statistical difference between paced QRS duration, impedance, pacing and sensing thresholds and fluoroscopy time in the two groups. Infranodal block, baseline QRS duration, left bundle branch block morphology and ejection fraction were significantly associated with HBP procedural failure. The patients were followed for a period of 627.71±160.93 days. There were no significant differences in parameters at follow-up. An increase of >1 V in the His bundle (HB) capture threshold was encountered in one patient with infranodal AVB (11.1 %) and in four patients with nodal AVB (10.25%).Conclusion Permanent HBP is a feasible pacing technique in nodal AVB with a high success rate and stable thresholds in the medium term. Most infranodal blocks are located within the HB, so there is still the possibility to capture the conduction system, although with lower success rates

The Impact of Cardiac Chamber Volumes on Permanent His Bundle Pacing Procedural Outcomes—A Single Center Experience

His bundle pacing (HBP) has several pitfalls, such as the inability to identify the His bundle and lack of capture at acceptable thresholds. The majority of data regarding HBP were obtained using a dedicated non-deflectable delivery system. This study aimed to evaluate the impact of cardiac chamber dimensions on permanent HBP procedural outcomes when using this type of fixed-curve catheter. Seventy-two patients subjected to HBP from the 1st of January to the 31st of December 2021 at our institution were retrospectively reviewed. The baseline clinical characteristics and echocardiographic measurements of all the cardiac chambers were recorded, as well as procedural outcomes (HB electrogram identification and overall procedural success). During the procedure, the HB electrogram was recorded in 59 patients (81.9%) and successful permanent HBP was achieved in 33 patients, representing 45.8% of all the studied patients. Left atrial (LA) and right atrial (RA) volumes were significantly higher in patients without HB electrogram identification. Only LA and RA volumes were statistically associated with HB electrogram localization, while there was no significant association between the echocardiographic parameters and procedural success. LA volumes above 93 mL and RA volumes above 60 mL had an 8.81 times higher chance of failure to localize the HB electrogram compared with patients with lower volumes (p < 0.001). When considering non-deflectable delivery catheters for HBP, careful preprocedural echocardiographic analysis of the atrial volumes could help in the proper selection of implanting tools, thus optimizing the procedural outcomes and costs

Zofenopril and Ramipril in Combination with Acetyl Salicylic Acid in Postmyocardial Infarction Patients with Left Ventricular Systolic Dysfunction: A Retrospective Analysis of the SMILE-4 Randomized, Double-Blind Study in Diabetic Patients

OBJECTIVE: In the SMILE-4 study, zofenopril + acetyl salicylic acid (ASA) was more effective than ramipril + ASA on 1-year prevention of major cardiovascular events (MACE) in patients with acute myocardial infarction complicated by left ventricular dysfunction. In this retrospective analysis, we evaluated drug efficacy in subgroups of patients, according to a history of diabetes mellitus. METHODS: The primary study endpoint was 1-year combined occurrence of death or hospitalization for cardiovascular causes. Diabetes was defined according to medical history (previous known diagnosis). RESULTS: A total of 562 of 693 (81.0%) patients were classified as nondiabetics and 131 (18.9%) as diabetics. The adjusted rate of MACE was lower under zofenopril than under ramipril in both nondiabetics [27.9% vs. 34.9% ramipril; odds ratio, OR and 95% confidence interval: 0.55 (0.35, 0.86)] and diabetics [30.9% vs. 41.3%; 0.56 (0.18, 1.73)], although the difference was statistically significant only for the nondiabetic group (P = 0.013). Zofenopril was superior to ramipril as regards to the primary study endpoint in the subgroup of 157 patients with uncontrolled blood glucose (≥126 mg/dL), regardless of a previous diagnosis of diabetes [0.31 (0.10, 0.90), P = 0.030]. Zofenopril significantly reduced the risk of hospitalization for cardiovascular causes in both nondiabetics [0.64 (0.43, 0.96), P = 0.030] and diabetics [0.38 (0.15, 0.95), P = 0.038], whereas it was not better than ramipril in terms of prevention of cardiovascular deaths. CONCLUSIONS: This retrospective analysis of the SMILE-4 study confirmed the good efficacy of zofenopril plus ASA in the prevention of long-term MACE also in the subgroup of patients with diabetes mellitus