Ad Hoc Percutaneous Left Atrial Appendage Closure

Abstract: Objectives. To investigate the feasibility of ad hoc left atrial appendage (LAA) closure in patients in atrial fibrillation. Background. Feasibility of ad hoc LAA closure depends, among other things, on transesophageal echocardiography (TEE) being omittable. Methods. Patients underwent ad hoc LAA closure at the same sitting as coronary angiography. TEE guidance or sedation was omitted. Left atrial access was via coexisting patent foramen ovale (PFO) or a transseptal puncture. Arriving in the left atrium, a contrast medium injection was performed, avoiding LAA intubation to exclude thrombus in the LAA. Thereafter, the 13 Fr TorqVue delivery sheath (the largest one available and compatible with all occluders) was advanced into the LAA and the diameter of the landing zone was estimated using the outer diameter of the sheath as a reference. An accordingly selected Amplatzer Cardiac Plug was deployed in the LAA. Results. Median CHA₂DS₂-VASc score of the 13 included patients (8 males; age 76 years; interquartile range [IQR], 68-84 years) was 5 (IQR, 3-5) and HAS-BLED score was 3 (IQR, 2-4). Contrast medium injection to the left atrium did not reveal a thrombus in the LAA in any patient. The LAA closure procedures were uneventful and follow-up transthoracic echocardiography before discharge confirmed correct device position. Patients were discharged on acetylsalicylic acid and clopidogrel without vitamin-K antagonists. Conclusion. Ad hoc LAA closure using local anesthesia and fluoroscopy alone appears feasible. 

J INVASIVE CARDIOL 2013;25(12):683-686

Key words: device closure, embolism, interventional closure, left atrial appendage, stroke, Amplatzer Cardiac Plug, ad hoc

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Left atrial appendage (LAA) closure joins patent foramen ovale occlusion¹ and carotid stenting² in interventional stroke prevention. The bulk of available evidence supports the concept of LAA closure³ and proves the feasibility, safety, and efficacy of the method.^4-11

Most operators use transesophageal echocardiography (TEE) before and during the procedure as an adjunct imaging modality for LAA closure⁹ to preclude mobile thrombus in the LAA and to guide the procedure. Using TEE typically warrants general anesthesia or conscious sedation (ignoring the risk of bronchial aspiration), thereby rendering the procedure more logistically intricate.

Atrial fibrillation often goes along with ischemic heart disease or the prevalence of risk factors for ischemic heart disease¹² and puts the patients at a higher risk for fatal or non-fatal myocardial infarction.¹³ Even patients in lone atrial fibrillation are at increased risk for the development of coronary artery disease.¹⁴ Therefore, in clinical practice, many patients in atrial fibrillation on oral anticoagulants are referred for coronary angiography due to suspected coronary artery disease. In case such is found, therapy with acetylsalicylic acid or stronger platelet inhibitors besides oral anticoagulation is indicated. If coronary stent implantation is performed, dual-antiplatelet therapy on top of oral anticoagulation is frequently recommended. Dual-anticoagulant therapy doubles, and triple-anticoagulant therapy (acetylsalicylic acid, clopidogrel, and warfarin) quadruples the annual incidence of bleeding complications.¹⁵ LAA closure provides an attractive alternative to oral anticoagulation in such patients. It reduces the life-long bleeding risk considerably. 

Since diagnosis of coronary artery disease is only confirmed during coronary angiography, ad hoc LAA closure at the same sitting offers a patient-friendly solution, logistically precluding, however, TEE screening and guidance and general anesthesia in most cases. Two prerequisites are: (1) fluoroscopic visualization of the LAA prior to LAA closure must be safe and reliable to exclude the presence of a protruding thrombus in the LAA; and (2) fluoroscopic guidance alone must suffice for safe transseptal puncture, device size selection, and device implantation. 

We recently showed feasibility and safety of fluoroscopic guidance for device implantation.¹⁶ 

We report our initial experience with ad hoc LAA closure in the context of coronary angiography, solely using fluoroscopy guidance for exclusion of an LAA thrombus and device implantation.

Methods

Patients. Patients referred for coronary angiography with a history of non-valvular atrial fibrillation and a CHA₂DS₂-VASc Score of ≥1, who were deemed high-risk for bleeding complications, underwent ad hoc evaluation of LAA closure. High risk for bleeding was defined as an annual bleeding risk that exceeded 3%, as reflected by a HAS-BLED Score¹⁷ of ≥3. Furthermore, blue collar workers and patients with aversion to oral anticoagulation were included. Patients with an acute coronary syndrome were not included.

Procedure and LAA closure device. Prior to performing coronary angiography, all patients were informed about the possibility of an ad hoc LAA closure in case coronary artery disease was diagnosed. The advantages and potential disadvantages of ad hoc LAA closure were explained. All patients gave written informed consent.

The procedure was done under local groin anesthesia and without TEE screening or guidance. A bolus of 5000 units of heparin was given intravenously either before or after coronary angiography. Percutaneous coronary intervention was performed after LAA closure if indicated. Femoral venous puncture was performed and a PFO was searched for using the right coronary Judkins catheter that had been used for coronary angiography or a Multipurpose diagnostic catheter. If a PFO was found, it was used for left atrial access. Otherwise, an 8 Fr transseptal kit (Mullins transseptal sheath and Brockenbrough needle; Medtronic, Inc) was introduced. Using anteroposterior and lateral views, the interatrial septum was punctured while contrast staining the septum with the needle (Figure 1).

After successful transseptal puncture, the transseptal sheath or a diagnostic catheter was directed toward the entrance of the left atrial appendage and a power contrast injection (eg, 10 mL/s for a total of 20 mL) was performed at a safe distance in a right anterior oblique (RAO) caudal (typically 40/-20°) and RAO cranial view (40/+20°) to depict the body and the lobes of the LAA (Figure 2). In case a structure suggestive of protruding thrombus at the entrance of the LAA or the landing zone of the LAA occluder device had been identified, the procedure would have been abandoned. The LAA was then cannulated with the 13 Fr delivery sheath (the largest one available accommodating all occluder sizes). A selective contrast injection was performed to better delineate the LAA and exclude mobile thrombi in its fundus.

LAA closure was performed as previously described¹⁶ using the Amplatzer Cardiac Plug and delivery system (ACP; St Jude Medical). The 13 Fr delivery sheath was introduced to the left atrium over a Backup Meier wire (Boston Scientific) and directed into the neck of the LAA. A contrast medium injection over the delivery sheath was typically performed in the aforementioned angles (RAO/caudal and RAO/cranial). With reference to the outer diameter of the 13 Fr sheath of 5.1 mm, an ACP device was chosen that was at least 20% oversized as compared to the intended landing zone (Figure 3). Then the ACP was deployed. Using contrast medium injections in a projection well separating disk and lobe to show the disk at the border of the LA and after adequate and sustained tugging at the device, the device was released (Figure 4). The arterial sheath (for coronary angiography or PCI intervention) and the venous sheath were removed at the end of the procedure.

Patients were scheduled to undergo a follow-up TEE after 4-6 months. If the device was found to seal the LAA and did not show any thrombus, antiplatelets were to be stopped unless other indications existed. 

Amplatzer Cardiac Plug. The ACP is a dedicated device for LAA closure. It consists of a lobe and disc, connected by an extensible and flexible waist. The device is filled with polyester to enhance endothelialization and prevent blood flow into the LAA. The device is made out of a Nitinol mesh, with tiny hooks at the outer side of the lobe for anchoring. Sizes range from 16-30 mm and describe the diameter of the lobe. While smaller devices theoretically fit through 9 or 10 Fr sheaths, we routinely use the universal 13 Fr sheath for all LAA closures.

Statistics. Numerical variables are presented as medians and interquartile ranges (IQRs) unless otherwise indicated.

Results

A total of 13 patients (8 males; age 76 years; IQR, 68-84 years) in atrial fibrillation (persistent in 7 and paroxysmal in 6 patients) with a median CHA₂DS₂-VASc Score of 5 (IQR, 3-5) were included. All were referred for coronary angiography due to suspected coronary artery disease (CAD). CAD was found in 12 patients, and was treated with PCI in 7 patients. Prevalence of risk factors for coronary artery disease were frequent (11 hypertension, 5 diabetes, 6 dyslipidemia, 2 smokers, 1 positive family history for CAD) and median HAS-BLED Score was 3 (IQR, 2-4). Concomitantly, a diagnostic right heart catheterization and a cardioversion were performed in 1 patient each. A PFO was present in 2 patients and was closed (using an Amplatzer PFO occluder) after LAA closure in both patients. In the 11 patients without PFO, a transseptal puncture was performed. The LAA was nicely depicted in all patients as described earlier, through the transseptal sheath or a 5 Fr diagnostic catheter. No protruding thrombus was found in any patient. The 13 Fr delivery sheath was successfully placed in the LAA in all patients for sizing and deployment of the ACP. LAA closure was successful in all patients. Procedural time from femoral venous puncture until the release of the device was 31 minutes (IQR, 27-35 minutes). The total procedural time (including coronary angiography, PCI, right heart catheterization, cardioversion, and PFO closure) was 80 minutes (IQR, 57-131 minutes). ACP sizes used were 18 mm, 22 mm, and 24 mm in 1 patient each, 26 mm in 2 patients, 28 mm in 5 patients, and 30 mm in 3 patients. 

Overall fluoroscopy time (including all procedures performed) was 23 minutes (IQR, 17-31 minutes) and contrast media amount was 329 mL (IQR, 253-408 mL).

Follow-up TTE before discharge on the same or the following day showed a correct device position in all patients. Two patients were discharged the day of admission; 9 patients were discharged on day two and 2 patients were discharged on day three.

No peri- or postprocedural complications occurred related to ad hoc LAA closure. However, acute pericardial effusion developed in 1 patient during final PFO closure and was percutaneously tapped without sequelae. This complication occurred after the 13 Fr sheath was accidentally pulled back to the right atrium after LAA closure. While trying to re-traverse the PFO with this sheath, the free atrial wall was injured.

Patients were discharged on dual-antiplatelet therapy (acetylsalicylic acid until follow-up TEE and clopidogrel for at least 1 month). 

Telephone follow-up was performed at a median of 106 days (IQR, 70-136 days). No cardiovascular events and no bleeding complications occurred. Eight patients were on dual-antiplatelet therapy and 5 were on single-antiplatelet therapy.  Oral anticoagulation had been re-initiated in zero patients.  

Discussion

We report feasibility of ad hoc LAA closure in 13 patients, solely using fluoroscopic guidance without pre- or periprocedural TEE. No complications were encountered that were directly related to this approach for LAA closure.

Our study paves the way for a larger trial investigating safety of ad hoc LAA closure as compared to staged procedures. This is to the end to make the procedure more patient friendly, less resource demanding, and maybe even safer by avoiding complications from anesthesia or TEE. 

In some centers, transseptal puncture is performed using TEE or intracardiac echocardiographic guidance. Use of adjunct imaging modalities makes the procedure more expensive and logistically more demanding, and bears a certain risk for complications (eg, risk of general anesthesia, risk of aspiration, risk of femoral arteriovenous fistula, risk of bleeding or perforation). Fluoroscopy-guided transseptal puncture bears a minimal risk, as reported in a series of 1279 fluoroscopy-guided transseptal punctures, where 1 death and systemic embolization occurred with cardiac tamponade in 1.2%.¹⁸ On the other hand, a comparable minimal risk was found for TEE, with major gastrointestinal complications occurring in about 1.2% of patients¹⁹ and complications such as laryngospasm, sustained ventricular tachycardia, and even deaths were described.^20,21 Using TEE for transseptal puncture is trading one risk for another at the price of complicating the procedure.

So far, however, our practice was to perform preprocedural TEE to preclude LAA thrombus. If ad hoc LAA closure proves to be equally safe as staged procedures in a larger trial, TEE can be entirely abandoned in cases where the decision to perform LAA closure is based on the outcome of coronary angiography. The additional procedural time of adding LAA closure was only 31 minutes.

The only complication we encountered was a tamponade after crossing the PFO with the bare 13 Fr sheath. This could have been potentially avoided if the PFO had been crossed in a standard manner and the large-bore sheath reinserted over a stiff guidewire. Whether the PFO is closed ad hoc in the same sitting for primary prevention is debatable beyond the scope of this study.

Study limitations. LAA closure is considered a complex procedure with a rather flat learning curve. In our center, >300 LAA closures have been performed over the past 10 years. The described method may be unsuitable for less experienced operators. 

Since only patients deemed “ideal for ad hoc LAA closure” (eg, patients who could understand the complexity of the procedure and the novelty of the ad hoc approach) were included, we cannot exclude a selection bias in this study. Also, the number of patients is small and there is no control group, ie, we did not have a second imaging modality to reconfirm our angiographic findings of the LAA. Further studies investigating the sensitivity of contrast injections compared to TEE in excluding LAA thrombi are therefore needed. However, it is reassuring that we did not encounter any periprocedural adverse events. Our study paves the way for a larger trial investigating the safety of ad hoc LAA closure as compared to staged procedures.

Conclusion

Ad hoc LAA closure is feasible, and clinical short-term follow-up in our cohort was uneventful. Transesophageal echocardiography can be completely omitted, thus allowing a patient-friendly procedure under local anesthesia simultaneously with coronary angiography or percutaneous coronary intervention.

References

1. Wahl A, Jüni P, Mono ML, et al. Long-term propensity score-matched comparison of percutaneous closure of patent foramen ovale with medical treatment after paradoxical embolism. Circulation. 2012;125(6):803-812.
2. Meier P, Knapp G, Tamhane U, et al. Short-term and intermediate-term comparison of endarterectomy versus stenting for carotid artery stenosis: systematic review and meta-analysis of randomised controlled clinical trials. BMJ. 2010;340:c467.
3. Blackshear JL, Odell JA. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg. 1996;61(2):755-759.
4. Sievert H, Lesh MD, Trepels T, et al. Percutaneous left atrial appendage transcatheter occlusion to prevent stroke in high-risk patients with atrial fibrillation: early clinical experience. Circulation. 2002;105(16):1887-1889.
5. Meier B, Palacios I, Windecker S, et al. Transcatheter left atrial appendage occlusion with Amplatzer devices to obviate anticoagulation in patients with atrial fibrillation. Catheter Cardiovasc Interv. 2003;60(3):417-422.
6. Ostermayer SH, Reisman M, Kramer PH, et al. Percutaneous left atrial appendage transcatheter occlusion (PLAATO system) to prevent stroke in high-risk patients with non-rheumatic atrial fibrillation: results from the international multi-center feasibility trials. J Am Coll Cardiol. 2005;46(1):9-14.
7. Bayard YL, Ostermayer SH, Hein R, et al. Percutaneous devices for stroke prevention. Cardiovasc Revasc Med. 2007;8(3):216-225
8. Holmes DR, Reddy VY, Turi ZG, et al. Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: a randomised non-inferiority trial. Lancet. 2009;374(9689):534-542.
9. Park JW, Bethencourt A, Sievert H, et al. Left atrial appendage closure with Amplatzer Cardiac Plug in atrial fibrillation: initial European experience. Catheter Cardiovasc Interv. 2011;77(5):700-706.
10. Reddy VY, Holmes D, Doshi SK, et al. Safety of percutaneous left atrial appendage closure: results from the Watchman Left Atrial Appendage System for Embolic Protection in Patients with AF (PROTECT AF) clinical trial and the Continued Access Registry. Circulation. 2011;123(4):417-424.
11. Lam YY, Yip GW, Yu CM, et al. Left atrial appendage closure with Amplatzer cardiac plug for stroke prevention in atrial fibrillation: initial Asia-Pacific experience. Catheter Cardiovasc Interv. 2012;79(5):794-800.
12. Patel MR, Mahaffey KW, Garg J, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. 2011;365(10):883-891.
13. Haywood LJ, Ford CE, Crow RS, et al. Atrial fibrillation at baseline and during follow-up in ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial). J Am Coll Cardiol. 2009;54(22):2023-2031.
14. Weijs B, de Vos CB, Tieleman RG, et al. The occurrence of cardiovascular disease during 5-year follow-up in patients with idiopathic atrial fibrillation. Europace. 2013;15(1):18-23.
15. Hansen ML, Sorensen R, Clausen MT, et al. Risk of bleeding with single, dual, or triple therapy with warfarin, aspirin, and clopidogrel in patients with atrial fibrillation. Arch Intern Med. 2010;170(16):1433-1441.
16. Nietlispach F, Gloekler S, Khattab A, et al. Percutaneous left atrial appendage closure. Eur J Geriatric Med. 2012;3:308-311.
17. Pisters R, Lane DA, Nieuwlaat R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: the Euro Heart Survey. Chest. 2010;138(5):1093-1100.
18. Roelke M, Smith AJ, Palacios IF. The technique and safety of transseptal left heart catheterization: the Massachusetts General Hospital experience with 1,279 procedures. Cathet Cardiovasc Diagn. 1994;32(4):332-339.
19. Lennon MJ, Gibbs NM, Weightman WM, et al. Transesophageal echocardiography-related gastrointestinal complications in cardiac surgical patients. J Cardiothorac Vasc Anesth. 2005;19(2):141-145.
20. Khandheria BK, Seward JB, Tajik AJ. Transesophageal echocardiography. Mayo Clin Proc. 1994;69(9):856-863.
21. Daniel WG, Erbel R, Kasper W, et al. Safety of transesophageal echocardiography. A multicenter survey of 10,419 examinations. Circulation. 1991;83(3):817-821.

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*Joint first authors.

From the Swiss Cardiovascular Center Bern, Bern University Hospital, Bern, Switzerland.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Drs Khattab, Meier, and Nietlispach report research grants and proctor fees from St Jude Medical; Dr Windecker received research grants to the institution from St Jude Medical.

Manuscript submitted June 4, 2013, provisional acceptance given July 2, 2013, final version accepted July 22, 2013.

Address for correspondence: Bernhard Meier, Professor and Head of Cardiology, Swiss Cardiovascular Center Bern, Bern University Hospital, 3010 Bern, Switzerland. Email: bernhard.meier@insel.ch