Table 1 shows the main characteristics of the 35 patients. None of these 35 patients could have entered randomized studies with OACs as these agentswere contraindicated for the various reasons outlined in Table 1.

The following CHADS2 scores were calculated: 2.41 (1.53), CHA2DS2-VASc: 3.17 (1.60) and HAS-BLED13: 4.42 (1.43).

Table 2 shows the operating times, contrast volumes and time of radioscopy use, together with the measurements obtained by intraoperative TEE, angiography and CARTO-MRI or CARTO-CT. Table 2 also displays the final size of the ACP device selected and the need for a change in size, which was required in only 5 patients (a smaller device was required in 4 patients and a larger device in 1). The mean size of the device was 22.06 (3.36) mm (range: 16-28).

The success of the implantation was 97.14%; the device could not be implanted in only 1 patient. There were no cardiac complications and a vascular complication occurred in only 1 patient: a punctured artery resulting in arteriovenous fistula despite prolonged compression.

Table 3 summarizes the results of the follow-up. There were 3 noncardiac deaths in patients aged 85, 83 and 81 years, caused by obstruction and intestinal perforation, intestinal adenocarcinoma, and pneumonia, which led to hospital admission and death. There was severe bleeding in 1 patient with bleeding polyps. Clopidogrel was suspended and only acetylsalicylic acid was maintained, the patient continued treatment in the Gastrointestinal Unit and progressed well. There was 1 mild episode of epistaxis in a patient that forgot to stop the clopidogrel treatment. Thrombi were found in the device in 5 patients (14.28%). One thrombus developed in the first week (the patient who developed a fistula), and antiplatelet treatment was suspended before the vascular intervention. Afterwards, the antiplatelet and enoxaparin treatment was set for 2 weeks. The thrombus disappeared without clinical events. Two other thrombi developed during the second and third month and disappeared 2 weeks after enoxaparin was added. We found images of a 14mm thrombus in the third month in 1 patient that had undergone cardioversion for atrial flutter before discharge, but the patient did not receive enoxaparin due to a fall and facial hematoma. This was the only patient who had a typical transient ischemic stroke (amaurosis fugax) but recovered completely. This patient was admitted for treatment with intravenous heparin, and the thrombus reduced progressively. The fifth case was a laminar mural thrombus in the sixth month which disappeared after 2 weeks of enoxaparin therapy (Fig. 3). We only documented 3 minor periprosthetic leaks in the posterior-superior area, without significant parameters, and minimal shunts of small atrial septal communications in 6 patients, which disappeared during follow-up evaluations. In one patient with a double septum, where a prothrombotic smoke effect developed, we decided to close the foramen ovale with a device. The patient had this problem prior to the intervention.

Figure 3.

Three Dimensional transesophageal echocardiography (A and B) and 2-dimensional transesophageal images (C and D) with a typical mural thrombus (T) at the upper angle of the device (A and C, arrows) and disappearance of the thrombus (B and D), during follow-up following the addition of dual antiplatelet therapy for 2 weeks with a therapeutic dose of enoxaparin.

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The first publications on this technique were with the PLAATO (Percutaneous Left Atrial Appendage Transcatheter Occlusion) device, which was abandoned for a number of reasons. However, in the follow-up of patients with successful implantations, there was a lower percentage of thromboembolic complications than expected according to their CHADS210 score.

Later, the randomized PROTECT AF study, which compared warfarin with the Watchman occlusion device, showed better results for the occluder for more than 1 year, with a significant reduction in hemorrhagic stroke.11 The first ACP12 registry, which showed percentages of efficiency and complications very similar to the PROTECT AF study, was published in Europe, encouraging the continuation of this technique for this subgroup of patients. In these 2 studies of LAA closure, which are the largest published, adverse events decreased by half with greater surgeon experience. In the cohort of patients of the PROTECT AF study, which used the Watchman device (542 patients), adverse events fell from 7.7%-3.7% in the CAP registry, which was continued by some centers which previously participated in the main study but which had gained more experience. In the “Initial European Registry” series (143 patients) with the ACP device, adverse events fell from 7%-3.4% and in the “ACP Postmarket Registry” (145 patients) pericardial effusions fell from 3.5%-2% and ischemic strokes from 2.1%-0%, while the occurrence of device embolization remained at 1.4%. The ACP Italian Registry of 100 patients (G. Santoro; Communication in the congress “Progress in Clinical Pacing”; Rome, 2010) found no device embolizations or ischemic strokes and only 2 pericardial effusions.16,17 The Iberia registry includes cases from Spain and Portugal. There were 213 cases between 2009 and 2011. Of these, 197 were successful (92.5%) and the device could not be implanted in 16 (no data provided through articles and only partially in the communication).18 There were 12 major complications (5.6%) and 6 minor complications (2.81%). The major complications included 3 deaths, 4 device embolizations, 3 resolved cardiac tamponades, 1 stroke, and symptoms of ST segment elevation in the anterior side. Importantly, this registry captures the learning curves of various centers at the same time and, as the case load increased in the different hospitals, these complications clearly decreased.

A number of important studies have reported the possible advantages of new OACs over warfarin or acenocoumarol.7–9 Nevertheless, patients that are included in studies such as ours would be excluded from those studies and the PROTECT AF trial for the reasons previously outlined. In theory, this technique does not compete with the new OACs or acenocoumarol, but is a supplement for the 40% of patients who require anticoagulants but who have contraindications for these drugs.6 In our study, the age of the patients was higher than that of published randomized studies. In patients≥80 years, there is a higher percentage of bleeding (13%) compared to published studies based on a lower age group of patients (3%-4%).19 In the RE-LY (Randomized. Evaluation of Long term anticoagulant therapy) study, dabigatran was not found to be more effective than warfarin either in preventing thromboembolism or in reducing hemorrhage in patients≥75 years or in those with a low creatinine clearance, which is frequent in this age group.7 Furthermore, the discontinuation rate is higher with this subgroup of age, reaching 26% in the first year.7,8,19Table 4 shows some of the characteristics of patients in our study compared with those in the main studies. CHADS2 scores of 3 or higher identify patients that could most benefit from a reduction in thromboembolism, but at the same time could bleed more with OACs, including new OACs. Irrespective of whether warfarin or dabigatran was used, these patients had a 2%-3% annual risk for thromboembolism, almost 5% for new major bleeding and almost a 6% risk of death.20 Thus, these patients would obtain maximum benefit from closure of the appendage. It is established that a HAS-BLED score of≥3 represents a high risk of bleeding, with major hemorrhage rates of >4% per year21 and, as expected due to the patients’ characteristics, our study sample had a high HAS-BLED score (4.42 [1.43]). Figure 4 shows the clinical indications for LAA closure in our study and compares them with those in the Spanish registry. Digestive hemorrhages accounted for 43% of the indications (a figure that is slightly higher than that of the Spanish registry data, but is in line with numbers of digestive hemorrhages in patients on OACs),22 followed by patients unable to take acenocoumarol and patients with hemorrhagic stroke caused by acenocoumarol.

Figure 4.

Indications for the closure of the left atrial appendage in the national registry and in our study (HIC). Contraindications to oral anticoagulants were taken from the clinical history (Table 1). HIC, Hospital Infanta Cristina; IS, ischemic stroke; OAC, oral anticoagulants.

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Pending larger follow-up studies, the few thrombotic events which can occur in patients with the device can reasonably be expected to decrease or disappear once the device is integrated within the endothelium after 6 months, as well as the risk of hemorrhage due to dual antiplatelet therapy,22 which is limited to the first 3-6 months.

Due to our strict protocol in the search for thrombi formation in the device, we could observe their development at any time between the first day and the sixth month, but none developed after that period according to checks carried out at 12 months. Studies with less strict protocols reported lower incidence rates, including the absence of thrombi.23 Our protocol for thrombi detection could be considered highly exhaustive but we believe that it is appropriate, at least until the period when thrombi develop is better identified. Except for situations which require the suspension of antiplatelet therapy, monitoring for thrombi should be undertaken at 1, 3 and 6 months. The identification of thrombi is highly important and they respond very well to enoxaparin, probably because they are in an early stage of development during re-endothelialization.24 Although the smoke effect and the size of the left atrium could have influenced our study, there were no clear predictors upon analysis of these aspects.

Finally, satisfactory selection of the size of the device is important. The measurements obtained with intraoperative TEE were slightly lower than angiographic measurements, and the latter were slightly lower than those of the SI axis obtained by CARTO–CT/MRI, the measurement of the short axis being the smallest of the 4 measurements (Table 2). The use of a third measuring technique with MRI or CT could have influenced the finding that the need to change the occlusion device in our study was acceptably low (14.28%), compared with the average in other studies (17%-24%).12,25Figure 5 shows a rate of change in the Iberian Registry of 20%, usually, although not always, changing from a smaller to larger size. In our study, however, it was more frequent to change from a larger to a smaller size, possibly influenced by the decisive weight given to the major axis (SI) of the ostium in the CARTO-CT. This choice was very effective in general (the measurement of the SI axis in the CARTO-CT was accurate in the selection of the correct size in 76.6%, angiography in 66.6%, TEE in 46.6% and the short axis or the anteroposterior view of the CARTO-CT in 26.6%) but in some cases we had to change to a larger device, particularly when there were large ostium measurements (in these cases, angiography was more reliable). The use of these techniques as the ‘gold standard’ has been suggested in some interesting studies, comparing them with other techniques such as 3D echocardiography. However, in these studies, these techniques were not followed by implantation of the device in their patients, which is a limitation.26–30 This third technique is not necessary in most patients, and more in-depth research is required, although it could be used when a device cannot be inserted at the first attempt. Our group observed that a subtype of appendages with low exits and closer to the vestibule of the mitral valve were more complex and could require a more delicate strategy.31

Figure 5.

The use of more than one device. A: The relationship between the implants and the number of devices. Approximately 20% of patients required a change of device. B: Most devices were substituted for a larger device.

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