Conduction system pacing (CSP) modalities, including His-bundle pacing (HBP) and left bundle branch pacing (LBBP), are increasingly used as alternatives to biventricular (BiV) pacing in heart failure (HF) patients scheduled for pace and ablate strategy. The aim of the study was to compare clinical outcomes of HF patients with refractory AF who received either BiV pacing or CSP in conjunction with atrio-ventricular node ablation (AVNA). Fifty consecutive patients (male 48%, age 70 years (IQR 9), left ventricular ejection fraction (LVEF) 39% (IQR 12)) were retrospectively analysed. Thirteen patients (26%) received BiV pacing, 27 patients (54%) HBP and 10 patients (20%) LBBP. All groups had similar baseline characteristics and acute success rate. While New York Heart. Association (NYHA) class improved in both HBP (p < 0.001) and LBBP (p = 0.008), it did not improve in BiV group (p = 0.096). At follow-up, LVEF increased in HBP (form 39% (IQR 15) to 49% (IQR 16), p < 0.001) and LBBP (from 28% (IQR 13) to 40% (IQR 13), p = 0.041), but did not change in BiV group (p = 0.916). Conduction system pacing modalities showed superior symptomatic and echocardiographic improvement compared to BiV pacing after AVNA. With more stable pacing parameters, LBBP could present a more feasible pacing option compared to HBP.

Background: There are limited prospective randomized studies comparing left bundle branch area pacing (LBBAP) and biventricular (BiV) pacing for cardiac resynchronization therapy (CRT). Aim: The study tested whether LBBAP is noninferior to BiV pacing in patients with Class I indication for CRT. Methods: The CSP-SYNC study is an investigator-initiated, randomized, single-center study. Sixty-two patients were randomized 1:1 to LBBAP or BiV. The primary study endpoint was change in left ventricular ejection fraction (LVEF) at 6 months. Secondary endpoints included changes in echo and clinical parameters after 6 months and 12 months. Results: Thirty-one patients were randomized to each arm. Most patients were males (71%), and 32 % had ischemic cardiomyopathy. At 6 months, similar improvement of LVEF was observed in the LBBAP group compared to the BiV group (14.0% (95% CI: 11.2-16.8) in LBBAP vs. 8.5% (95% CI: 5.6-11.2) in BiV) with mean intergroup difference of 5.6% (95% CI: 1.6-9.5; P<0.001 for noninferiority). Both groups showed comparable decrease in LVESV (-64 ml (95% CI: -78 to -50) vs -40 ml (95% CI: -54 to -25) respectively, mean difference -24 ml (CI 95%: -44 to -4); P<0.001 for noninferiority), changes in 6-minute walk test (P<0.001 for noninferiority) and NYHA class (P=0.011 for noninferiority). Temporal trends of LV remodelling and heart failure hospitalization rates were also comparable. Conclusions: In patients with a Class I indication for CRT, LBBAP was noninferior to BiV pacing in improving LVEF and provided similar structural and electrical remodelling.

Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome’s components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12–0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs. Preventive ablation of coronary total occlusion-related substrate at the time of primary prevention defibrillator implantation is associated with a reduced risk of appropriate defibrillator therapy or unplanned hospitalization due to ventricular arrhythmias.

Background: Severe first‐degree atrioventricular (AV) block may produce symptoms similar to heart failure due to AV dyssynchrony, a syndrome termed AV dromotropathy. According to guidelines, it should be considered for permanent pacemaker implantation, yet evidence supporting this treatment is scarce.Objectives: This study aimed to determine the impact of AV‐optimized conduction system pacing (CSP) in patients with symptomatic severe first‐degree AV block and echocardiographic signs of AV dyssynchrony.Methods: Patients with symptomatic first‐degree AV block (PR > 250 ms), preserved left ventricular ejection fraction, narrow QRS, and AV dyssynchrony were included in the study. In a single‐blind cross‐over design, patients were randomized to AV sequential CSP or backup VVI pacing with a base rate of 40 bpm. We compared exercise capacity, echocardiographic parameters, and symptom occurrence at the end of 3 months of each period.Results: Fourteen patients completed the study. During the AV‐optimized CSP compared to the backup pacing period, patients achieved a higher workload on exercise test (147.2 ± 50.9 vs. 140.7 ± 55.8 W; p = .032), with a trend towards higher peak VO2 (23.3 ± 7.1 vs. 22.8 ± 7.1 mL/min/kg; p = .224), and higher left ventricular stroke volume (LVSV 74.5 ± 13.8 vs. 66.4 ± 12.5 mL; p < .001). Symptomatic improvement was recorded, with fewer patients reporting general tiredness and 71% of patients preferring the AV‐optimized CSP (p = .008).Conclusions: AV‐optimized CSP could improve symptoms, exercise capacity and LVSV in patients with severe first‐degree AV block.

Coronary sinus reducer (CSR) implantation is a new treatment option for patients with refractory angina pectoris. However, there is no evidence from a randomized trial that would show an improvement in exercise capacity after this treatment. The aim of this study was to evaluate the influence of CSR treatment on maximal oxygen consumption and compare it to a sham procedure. Twenty-five patients with refractory angina pectoris (Canadian Cardiovascular Society (CCS) class II–IV) were randomized to a CSR implantation (n = 13) or a sham procedure (n = 12). At baseline and after 6 months of follow-up, the patients underwent symptom-limited cardiopulmonary exercise testing with an adjusted ramp protocol and assessment of angina pectoris using the CCS scale and Seattle angina pectoris questionnaire (SAQ). In the CSR group, maximal oxygen consumption increased from 15.56 ± 4.05 to 18.4 ± 5.2 mL/kg/min (p = 0.03) but did not change in the sham group (p = 0.53); p for intergroup comparison was 0.03. In contrast, there was no difference in the improvement of the CCS class or SAQ domains. To conclude, in patients with refractory angina and optimized medical therapy, CSR implantation may improve oxygen consumption beyond that of optimal medical therapy.