Comparison between left bundle branch area pacing and right ventricular pacing: ventricular electromechanical synchrony and risk of atrial high-rate episodes.

Background: The electromechanical dyssynchrony associated with right ventricular pacing (RVP) has been found to have adverse impact on clinical outcomes. Several studies have shown that left bundle branch area pacing (LBBAP) has superior pacing parameters compared with RVP. We aimed to assess the difference in ventricular electromechanical synchrony and investigate the risk of atrial high-rate episodes (AHREs) in patients with LBBAP and RVP. Methods: We consecutively identified 40 patients with atrioventricular block and no prior atrial fibrillation. They were divided according to the ventricular pacing sites: the LBBAP group and the RVP group (including the right ventricular apical pacing (RVA) group and the right side ventricular septal pacing (RVS) group). Evaluation of ventricular electromechanical synchrony was implemented using electrocardiogram and two-dimensional speckle tracking echocardiography (2D-STE). AHRE was defined as event with an atrial frequency of ≥176 bpm lasting for ≥6 min recorded by pacemakers during follow-up. Results: The paced QRS duration of the LBBAP group was significantly shorter than that of the other two groups: LBBAP 113.56 ± 9.66 ms vs. RVA 164.73 ± 14.49 ms, p < 0.001; LBBAP 113.56 ± 9.66 ms vs. RVS 148.23 ± 17.3 ms, p < 0.001. The LBBAP group showed shorter maximum difference (TDmax), and standard deviation (SD) of the time to peak systolic strain among the 18 left ventricular segments, and time of septal-to-posterior wall motion delay (SPWMD) compared with the RVA group (TDmax, 87.56 ± 56.01 ms vs. 189.85 ± 91.88 ms, p = 0.001; SD, 25.40 ± 14.61 ms vs. 67.13 ± 27.40 ms, p < 0.001; SPWMD, 28.75 ± 21.89 ms vs. 99.09 ± 46.56 ms, p < 0.001) and the RVS group (TDmax, 87.56 ± 56.01 ms vs. 156.46 ± 55.54 ms, p = 0.003; SD, 25.40 ± 14.61 ms vs. 49.02 ± 17.85 ms, p = 0.001; SPWMD, 28.75 ± 21.89 ms vs. 91.54 ± 26.67 ms, p < 0.001). The interventricular mechanical delay (IVMD) was shorter in the LBBAP group compared with the RVA group (-5.38 ± 9.31 ms vs. 44.82 ± 16.42 ms, p < 0.001) and the RVS group (-5.38 ± 9.31 ms vs. 25.31 ± 21.36 ms, p < 0.001). Comparing the RVA group and the RVS group, the paced QRS duration and IVMD were significantly shorter in the RVS group (QRS duration, 164.73 ± 14.49 ms vs. 148.23 ± 17.3 ms, p = 0.02; IVMD, 44.82 ± 16.42 ms vs. 25.31 ± 21.36 ms, p = 0.022). During follow-up, 2/16 (12.5%) LBBAP patients, 4/11 (36.4%) RVA patients, and 8/13 (61.5%) RVS patients had recorded novel AHREs. LBBAP was proven to be independently associated with decreased risk of AHREs than RVP (log-rank p = 0.043). Conclusion: LBBAP generates narrower paced QRS and better intro-left ventricular and biventricular contraction synchronization compared with traditional RVP. LBBAP was associated with a decreased risk of AHREs compared with RVP.

Implications of new-onset atrial fibrillation on in-hospital and long-term prognosis of patients with acute myocardial infarction: A report from the CBD bank study.

Background: An increase in the incidence of atrial fibrillation (AF) during the acute phase of myocardial infarction (AMI) has been observed. But it is still unclear whether the implications of new-onset AF on in-hospital and long-term prognosis are of similar magnitude. Methods: Using data from the CBD Bank study, 3,824 consecutive AMI patients, without prior AF, were analyzed. During the index hospitalization, all patients were monitored by continuous cardiac monitoring, twice daily performed 12- or 18-lead ECGs and timely ECG checks when cardiac symptoms occurred. Follow-up visits were routinely scheduled after discharge. Primary outcomes were all-cause death and cardiovascular death occurring during hospitalization and long-term follow-up. Secondary outcome was MACEs during hospitalization. Results: During the median hospital stay of 9.0 (7.0, 11.0) days, new-onset AF was documented in 133 (3.48%) patients; 95 (71.43%) patients had AF attacks within 3 days following AMI. Independent risk factors associated with new-onset AF were older age, larger left atrial diameter, higher level of NT-proBNP, and primary PCI. New-onset AF was found to be significantly associated with in-hospital all-cause death (OR 4.33, 95%CI: 2.37-7.89, P < 0.001), cardiovascular death (OR 4.10, 95%CI: 2.18-7.73, P < 0.001), and MACEs (OR 2.51, 95%CI: 1.46-4.33, P = 0.001). A total of 112 new-onset AF and 3,338 non-AF patients were followed up for 1,090 (365, 1,694) days after discharge. There was no significant association between new-onset AF and long-term all-cause death (HR 1.21, 95%CI: 0.77-1.92, P = 0.406) or cardiovascular death (HR 1.09, 95%CI: 0.61-1.97, P = 0.764). Conclusion: New-onset AF following AMI is strongly associated with an increased risk of adverse in-hospital prognosis, but it does not affect prognosis in those who survive until hospital discharge.

Associations of atrial fibrillation progression with clinical risk factors and clinical prognosis: A report from the Chinese Atrial Fibrillation Registry study.

BACKGROUND: An understanding of the risk factors for atrial fibrillation (AF) progression and the associated impacts on clinical prognosis are important for the future management of this common arrhythmia. We aimed to investigate the rate of progression from paroxysmal (PAF) to more sustained subtypes of AF (SAF), the associated risk factors for this progression, and its impact on adverse clinical outcomes. METHODS AND RESULTS: Using data from the Chinese trial Fibrillation Registry study, we included 8290 PAF patients. Half of them underwent initial AF ablation at enrollment. The main outcomes were ischemic stroke/systemic embolism (IS/SE), cardiovascular hospitalization, cardiovascular death, and all-cause mortality. The median follow-up duration was 1091 (704, 1634) days, and progression from PAF to SAF occurred in 881 (22.5%) nonablated patients, while 130 (3.0%) ablated patients had AF recurrence and developed SAF. The incidence rate of AF progression for the cohort was 3.87 (95% confidence interval [CI] = 3.64-4.12) per 100 patient-years, being higher in nonablated compared to ablated patients. Older age, longer AF history, heart failure, hypertension, coronary artery disease, respiratory diseases, and larger atrial diameter were associated with a higher incidence of AF progression, while antiarrhythmic drug use and AF ablation were inversely related to it. For nonablated patients, AF progression was independently associated with an increased risk of IS/SE (hazard ratio [HR] = 1.52, 95% CI = 1.15-2.01) and cardiovascular hospitalizations (HR = 1.40, 95% CI = 1.23-1.58). CONCLUSION: AF progression was common in its natural course. It was related to comorbidities and whether rhythm control strategies were used, and was associated with an increased risk of IS/SE and cardiovascular hospitalization.

The safety of discontinuation of oral anticoagulation therapy after apparently successful atrial fibrillation ablation: a report from the Chinese Atrial Fibrillation Registry study.

AIMS: We aimed to investigate the safety of discontinuing oral anticoagulation (OAC) therapy after apparently successful atrial fibrillation (AF) ablation, using data from the Chinese Atrial Fibrillation Registry study. METHODS AND RESULTS: We identified 4512 consecutive patients who underwent successful AF ablation between August 2011 and December 2017. Of them, 3149 discontinued OAC 3 months post-ablation (Off-OAC group) and 1363 continued OAC beyond this period (On-OAC group). Regular follow-up examinations were undertaken to detect AF recurrence, monitor OAC therapy, and measure clinical outcomes. Primary outcomes included thromboembolic and major bleeding (MB) events experienced beyond 3 months after ablation. Low thromboembolic and MB event rates were noted in the on-treatment analysis. The incidence rates for thromboembolism were 0.54 [95% confidence interval (CI) 0.39-0.76] and 0.86 (95% CI 0.56-1.30) per 100 patient-years, and that for MB events were 0.19 (95% CI 0.11-0.34) and 0.35 (95% CI 0.18-0.67) per 100 patient-years, for the Off-OAC and On-OAC groups over mean follow-up periods of 24.2 ± 14.7 and 23.0 ± 13.6 months, respectively. Similar results were observed in the intention-to-treat analysis. Previous history of ischaemic stroke (IS)/transient ischaemic attack (TIA)/systemic embolism (SE) [hazard ratio (HR) 3.40, 95% CI 1.92-6.02; P < 0.01] and diabetes mellitus (HR 2.06, 95% CI 1.20-3.55, P = 0.01) were independently associated with thromboembolic events, while OAC discontinuation (HR 0.71, 95% CI 0.41-1.23, P = 0.21) remained insignificant in multivariable analysis. CONCLUSIONS: This study suggests that it may be safe to discontinue OAC in post-ablation patients under diligent monitoring, in the absence of AF recurrence, history of IS/TIA/SE, and diabetes mellitus. However, further large-scale randomized trials are required to confirm this. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-OCH-13003729. URL: http://www.chictr.org.cn/showproj.aspx?proj=5831.

Safety of direct oral anticoagulants in real-world clinical practice: translating the trials to everyday clinical management.

INTRODUCTION: Direct oral anticoagulants (DOACs) may be regarded as some of the most successful innovations in recent times. These drugs which were specifically developed to overcome the challenges posed by warfarin did just that and in the process, have changed the outlook towards stroke prevention with anticoagulation. The decade of experience with these drugs that has resulted in the availability of large scale data on their safety profile has aided this. Areas covered: This review examines existing real-world studies (RWS) and their interpretation to better appreciate how they either complement or contradict findings from the hallmark trials. Specific focus has been made on the safety of DOACs, on their risks of major bleeding, intra-cranial haemorrhage (ICH), gastro-intestinal (GI) bleeding and all-cause mortality compared to warfarin and each other. DOAC use in the elderly and other sub-groups are briefly discussed. Expert opinion: Results for safety outcomes according to 'real world evidence' (RWE) are in-keeping with randomised controlled trials (RCTs) and currently, all 4 DOACs have been deemed at least as effective as warfarin, while demonstrating superiority in some aspects. While real world studies act as a complementary source of knowledge, traditional RCTs remain the gold standard for determining cause-effect relationships.