Aims: The European PLAATO (Percutaneous Left Atrial Appendage Transcatheter Occlusion) study was performed to determine the safety and efficacy of left atrial appendage occlusion by catheter technique. Embolic stroke due to atrial fibrillation is a common observation, especially in the elderly. Most thrombi in atrial fibrillation form in the left atrial appendage (LAA), its occlusion may therefore reduce the incidence of stroke in these patients.
Methods and results: One hundred and eighty patients with non-rheumatic atrial fibrillation and contraindication to warfarin therapy were enrolled in the PLAATO study. Patients were eligible if they had a?history of transient ischaemic attack (TIA) or stroke or at least two independent risk factors for stroke such as age > or =75 years, hypertension, congestive heart failure or diabetes. The primary endpoint was LAA closure as determined by transesophageal echocardiography (TEE) two months after the procedure and stroke rate at 150 patient years. Left atrial appendage occlusion was successful in 162/180 patients (90%, 95% CI 83.1% to 92.9%). Two patients died within 24 hours of the procedure (1.1%, 95% CI 0.3% to 4%). Six cardiac tamponades were observed (3.3%, 95% CI 1.5% to 7.1%). In two cases, surgical drainage of the tamponade was necessary (1.1%, 95% CI 0.3% to 4%). In one patient, the device that was chosen was too small and embolised into the aorta after its release (0.6%, 95% CI 0.1% to 3.1%). It was snared and replaced without further complications. Successful occlusion of the LAA was achieved in 126/ 140 (90%, 95% CI 83.5% to 94.2%) of patients as noted by TEE at the two months follow-up. In a follow-up time of 129 documented patient years, three strokes occurred (2.3% per year). The expected incidence of stroke according to the CHADS2-Score was 6.6% per year. The trial was halted prematurely during the follow-up phase for financial considerations.
Conclusions: Left atrial appendage closure is relatively safe and effective. However, severe complications can occur. It might become an alternative for atrial fibrillation patients who are ineligible for long-term anticoagulation therapy.