Low haemoglobin is associated with increased risk of complications in left atrial appendage closure patients

Introduction

Left atrial appendage closure is associated with a relevant procedural complication rate. Baseline risk factors, such as pre-procedural lab results, may identify patients that develop acute complications.

Methods

We performed a retrospective analysis of the impact of baseline characteristics and preprocedural lab results on the acute procedural outcome in patients undergoing left atrial appendage closure from the Austrian Left Atrial Appendage Closure Registry between 2010 and 2019. The endpoint for procedural complications was defined as death, stroke, major bleeding, necessity for intensive care, other complications requiring invasive interventions or failure to implant the device. We also evaluated a modified endpoint with the exclusion of bleeding events. Logistic regression was performed using stepwise approach (backward method with p_out = 0.1) and forced inclusion of age, left-ventricular function and kidney function.

Results

A total of 320 consecutive patients from 9 centres with a median age of 75 years (36.6% female) were included. Seventy-eight percent had a history of bleeding and 35% had a history of stroke. Median CHA2DS2-VASc score was 5 (interquartile range, 3–5) and median HAS-BLED score was 3 (2–4). Procedural complications occurred in 15.3% of cases. Low haemoglobin and low activated partial thromboplastin time were associated with an increased complication rate. Other significant baseline factors were liver disease, absence of intracranial haemorrhage and severe aortic stenosis. In multivariate analysis, low haemoglobin remained a significant predictor, even after adjustment for age, left-ventricular function and kidney function (Table). In the modified procedural complication endpoint excluding major bleeding events (14.1%), low haemoglobin remained a significant predictor (haemoglobin 11.9±2.0 vs. 12.8±2.0 g/dL in patients with vs. without modified endpoint, p=0.013). A baseline haemoglobin lower than 12 g/dL was present in 39.4% and it increased relative risk of procedural complications by 89% (21.4 vs. 11.3% in patients with reduced vs. normal haemoglobin), and risk of complications without bleeding by 92% (19.8 vs. 10.3%).

Conclusion

Low baseline haemoglobin is independently associated with a higher complication rate after left appendage closure compared to patients with normal haemoglobin levels, even in a modified endpoint excluding bleeding and requirement for transfusion.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boston Scientific - unrestricted grant Table 1

No antiarrhythmic effect of direct oral anticoagulants versus vitamin K antagonists in paroxysmal atrial fibrillation patients undergoing catheter ablation

INTRODUCTION

Direct oral anticoagulants (DOACs) are superior to vitamin K antagonists (VKAs) for the prevention of stroke in atrial fibrillation (AF) patients with elevated stroke risk. Possible antiarrhythmic effects of DOACs have been discussed. We analyzed impact of DOAC treatment on recurrence-free survival after AF catheter ablation.

METHODS

Two-hundred and thirty-nine consecutive patients (median age 57 [IQR 48-64] years, 26.4% female) undergoing ablation for paroxysmal AF were included into this study. 68.6% of them received DOACs (DOAC group), 31.4% VKA (VKA group). The primary outcome was arrhythmia-free one-year survival.

RESULTS

DOAC patients had lower BMI, shorter history of AF, less arterial hypertension, less vascular disease, less use of antiarrhythmics and consequently lower CHA₂DS₂-VASc and HAS-BLED Scores. There was no difference in arrhythmia-free survival between DOAC and VKA groups (DOAC: 86.6%, VKA: 76.7%, p = 0.286).

CONCLUSIONS

Despite baseline characteristics favouring a better outcome of DOAC patients, arrhythmia-free survival was similar in both groups. Consequently, DOAC treatment did not have clinically relevant antiarrhythmic properties in these patients.

Indications and Outcome in Patients Undergoing Left Atrial Appendage Closure-The Austrian LAAC Registry

Background: Complete real-world data on the indications and outcomes of left atrial appendage closure (LAAC) outside of clinical trials are rare. In this study, we stratified patients undergoing LAAC by indication groups. Methods: This analysis of the national multicentre Austrian LAAC Registry comprised all patients that underwent LAAC up until 2018 at the currently active centres in Austria. The baseline characteristics, procedural details and outcomes between the following indication groups were compared: bleeding as an indication for LAAC (“bleeding” group) vs. thromboembolism despite oral anticoagulation (OAC; “thromboembolism” group) vs. an intolerance to OAC for reasons other than the above (“other” group). Results: The analysis included 186 patients, with 59.7% in the “bleeding” group, 8.1% in the “thromboembolism” group and 32.2% in the “other” group. The CHADS₂ score was the highest in the “thromboembolism” group and the HAS-BLED score was the highest in the “bleeding” group. The procedural outcomes were similar between groups (implantation success, 97.3%), with major complications occurring in 7.0% of patients. One-year survival free from stroke, bleeding or LAAC-associated hospitalisation was 83.9%, 90.0% and 81.4% in the “bleeding”, “thromboembolism” and “other” groups, respectively (p = 0.891). Conclusions: In routine clinical practice, LAAC was used in a heterogeneous patient population with atrial fibrillation (AF) and contraindication, inefficacy or intolerance to OAC. The long-term outcome was favourable in all groups.

Is there a difference in rhythm outcome between patients undergoing first line versus second line paroxysmal atrial fibrillation ablation?

BACKGROUND

Catheter ablation of atrial fibrillation (AF) is an established second line therapy for patients with symptomatic paroxysmal AF (PAF) and may be considered as a first line therapy in selected patients who are highly symptomatic, considering patient choice, benefit, and risk, according to recent guidelines. Our study investigated whether a first line vs. second line ablation approach may result in improved sinus rhythm maintenance after ablation.

METHODS

A total of 153 patients undergoing pulmonary vein isolation for PAF were included in the study (age 55±12 years, 29% female). Seventy-nine patients underwent first line AF ablation and 74 patients underwent second line AF ablation after failed antiarrhythmic drug therapy. There was no significant difference in baseline characteristics such as age, history of AF, left atrial size or LVEF between groups. Success was defined as atrial tachyarrhythmia free survival during a 12-month follow-up by means of serial ECG Holter monitoring.

RESULTS

There was no significant difference in cumulative arrhythmia-free survival between those patients who received AF ablation as a first or second line therapy. Single procedure success was 78% in the first line group vs. 81% in the second line group; multiple procedure success was 90 vs. 91%, (n.s.). Complication rate was 1.3% vs. 1.4% (n.s.).

CONCLUSION

Success of AF ablation did not differ between patients who receive ablation as first vs. second line therapy. Based on these data, a trial of AAD therapy before AF ablation may be justified in most patients with symptomatic PAF eligible for rhythm control.

Blood lactate response, oxygen consumption, and muscle activity during treadmill running with constraint

The induction of self-organization during running with a special harness may lead to reduced energy requirements. This experiment was designed to investigate the effect of practicing with a rubber tubing constraint attached between the heel and the hip for 7 wk. (18 treadmill running sessions) on oxygen consumption, caloric unit cost, blood lactate concentration, and muscle activity. 18 male recreational runners (M age = 26.3 yr.) were assigned to either an intervention or a control group. The intervention group trained with the constraint and the control group trained without it. Test 1 was conducted before the intervention, Test 2 after the intervention, and Test 3 7 wk. after Test 2 (no training between Tests 2 and 3). At Test 1, lactate and muscle activity were significantly increased during constrained running. For lactate, a significant decrease was found in the intervention group for running with the constraint; at Test 3, lactate returned to Test 1 level. No notable changes occurred in the physiological parameters. Furthermore, there was no observed transfer effect on normal running.