Left Atrial Appendage Occlusion Study III Extended Follow Up

Study Overview
=================
Brief Summary
-----------------
LAAOS III Extension is a longer term follow-up of an international cohort study of patients who were enrolled in the Left Atrial Appendage Occlusion Study (LAAOS III) trial.

Detailed Description
-----------------
The association between atrial fibrillation and heart failure has been well established. Although the causal relationship between the two clinical entities has not been fully elucidated, atrial fibrillation is believed to cause heart failure via several mechanisms: 1) increased heart rate resulting in shorter diastolic filling time and lower cardiac output; 2) reduced atrial contraction contribution to left ventricular filling, lowering cardiac output; and 3) tachycardia-induced cardiomyopathy from myocardial ischemia, myocardial energy depletion, and abnormal calcium regulation leading to left ventricular dilatation and reduced ejection fraction. These processes occur over time. It is also established that the left atrial appendage is a source of atrial natriuretic peptide, and it has been hypothesized that removal of the appendage might impair renal clearance of salt and water, increasing the risk of heart failure. A recent non-randomized study has supported this hypothesis. In LAAOS III, we did not observe an increase in hospitalization for heart failure, either early after surgery or during the 3.8 years of follow-up. However, an adverse impact on heart failure may appear over a longer follow-up period. We need to ensure we examine this patient population for the long-term impact of left atrial appendage occlusion on heart failure hospitalization to ensure we fully appreciate the benefit-risk balance of this intervention. The extended follow-up of the LAAOS III trial aims to assess whether, in patients with a history of atrial fibrillation undergoing cardiac surgery for another indication, concomitant left atrial appendage occlusion decreases the risk of death and stroke on top of usual care including anticoagulation without increasing re-hospitalization for heart failure at a mean follow-up of 8 years.

Official Title
-----------------
Left Atrial Appendage Occlusion III Extended Follow Up

Conditions
-----------------
Heart Failure, Left Atrial Appendage Occlusion

Intervention / Treatment
-----------------
* Other: No Intervention


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Participant was enrolled in the LAAOS III trial Participant has provided written informed consent Exclusion Criteria: Participant did not undergo the index LAAOS III cardiac surgery Participant underwent heart transplant

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| LAAOS III Extended Follow-Up Cohort<br>Patients randomized into the LAAOS III trial who have consented to longer term observational follow-up. There is no intervention in this study. | Other: No Intervention<br>* Patients in the LAAOS III trial either had or did not have their left atrial appendage occluded at the time of surgery in that trial. No further intervention is required in this cohort, it is observational follow-up only.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| All cause mortality | The primary objective is to determine the impact of left atrial appendage (LAA) occlusion on all-cause mortality | Mean follow up of 8 years after LAAOS III cardiac surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Impact of LAA occlusion on the incidence of ischemic stroke or or non-cerebral systemic embolism | To examine the impact of LAA occlusion on the incidence of ischemic stroke or non-cerebral systemic embolism | Mean follow up of 8 years after LAAOS III cardiac surgery | 
| Impact of LAA occlusion on re-hospitalization for heart failure | Impact of LAA occlusion on re-hospitalization for heart failure | Mean follow up of 8 years after LAAOS III cardiac surgery |