The PROTECT AF (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that left atrial appendage closure (LAAC) with the Watchman ...device (Boston Scientific, St. Paul, Minnesota) was equivalent to warfarin for preventing stroke in atrial fibrillation, but had a high rate of complications. In a second randomized trial, PREVAIL (Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy), the complication rate was low. The warfarin cohort experienced an unexpectedly low ischemic stroke rate, rendering the efficacy endpoints inconclusive. However, these outcomes were based on relatively few patients followed for a relatively short time.
The final results of the PREVAIL trial, both alone and as part of a patient-level meta-analysis with the PROTECT AF trial, are reported with patients in both trials followed for 5 years.
PREVAIL and PROTECT AF are prospective randomized clinical trials with patients randomized 2:1 to LAAC or warfarin; together, they enrolled 1,114 patients for 4,343 patient-years. Analyses are by intention-to-treat, and rates are events per 100 patient-years.
For the PREVAIL trial, the first composite coprimary endpoint of stroke, systemic embolism (SE), or cardiovascular/unexplained death did not achieve noninferiority (posterior probability for noninferiority = 88.4%), whereas the second coprimary endpoint of post-procedure ischemic stroke/SE did achieve noninferiority (posterior probability for noninferiority = 97.5%); the warfarin arm maintained an unusually low ischemic stroke rate (0.73%). In the meta-analysis, the composite endpoint was similar between groups (hazard ratio HR: 0.820; p = 0.27), as were all-stroke/SE (HR: 0.961; p = 0.87). The ischemic stroke/SE rate was numerically higher with LAAC, but this difference did not reach statistical significance (HR: 1.71; p = 0.080). However, differences in hemorrhagic stroke, disabling/fatal stroke, cardiovascular/unexplained death, all-cause death, and post-procedure bleeding favored LAAC (HR: 0.20; p = 0.0022; HR: 0.45; p = 0.03; HR: 0.59; p = 0.027; HR: 0.73; p = 0.035; HR: 0.48; p = 0.0003, respectively).
These 5-year outcomes of the PREVAIL trial, combined with the 5-year outcomes of the PROTECT AF trial, demonstrate that LAAC with Watchman provides stroke prevention in nonvalvular atrial fibrillation comparable to warfarin, with additional reductions in major bleeding, particularly hemorrhagic stroke, and mortality. (WATCHMAN Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation; NCT00129545; and Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy; NCT01182441).
BACKGROUND:In patients with atrial fibrillation, left atrial appendage closure with the Watchman device prevents thromboembolism from the left atrial appendage; however, thrombus may form on the left ...atrial face of the device, and then potentially embolize. Herein, we studied the incidence, predictors, and clinical outcome of device-related thrombus (DRT) using a large series of clinical trial cohorts of patients undergoing Watchman implantation.
METHODS:We studied the device arms of 4 prospective Food and Drug Administration trialsPROTECT-AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) (n=463); PREVAIL (Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy) (n=269); CAP (Continued Access to PROTECT AF registry) (n=566); and CAP2 (Continued Access to PREVAIL registry) (n=578). Surveillance transesophageal echocardiographs were performed at 45 days and 12 months in all patients, and also at 6 months in the randomized control trials. We assessed both the incidence of DRT during these transesophageal echocardiographs (and other unscheduled transesophageal echocardiographs), and clinical outcomes of postprocedure stroke or systemic embolism (SSE) and adjusted for CHA2DS2-VASC and HAS-BLED scores.
RESULTS:Of 1739 patients who received an implant (7159 patient-years follow-up; CHA2DS2-VASc=4.0), DRT was seen in 65 patients (3.74%). The rates of SSE with and without DRT were 7.46 and 1.78 per 100 patient-years (adjusted rate ratio, 3.55; 95% confidence interval CI, 2.18–5.79; P<0.001), and ischemic SSE rates were 6.28 and 1.65 per 100 patient-years (adjusted rate ratio, 3.22; 95% CI, 1.90–5.45, P<0.001). On multivariable modeling analysis, the predictors of DRT were as followshistory of transient ischemic attack or stroke (odds ratio OR, 2.31; 95% CI, 1.26–4.25; P=0.007), permanent atrial fibrillation (OR, 2.24; 95% CI, 1.19–4.20; P=0.012); vascular disease (OR, 2.06; 95% CI, 1.08–3.91; P=0.028); left atrial appendage diameter (OR, 1.06 per mm increase; 95% CI, 1.01–1.12; P=0.019); left ventricular ejection fraction (OR, 0.96 per 1% increase; 95% CI, 0.94–0.99; P=0.009). DRT and SSE both occurred in 17 of 65 patients (26.2%). Of the 19 SSE events in these patients with DRT, 9 of 19 (47.4%) and 12 of 19 (63.2%) occurred within 1 and 6 months of DRT detection. Conversely, after left atrial appendage closure, most SSEs (123/142, 86.62%) occurred in patients without DRT.
CONCLUSIONS:After left atrial appendage closure with Watchman, DRT (≈3.7%) is not frequent but, when present, is associated with a higher rate of stroke and systemic embolism.
This study evaluated the long-term efficacy of a standard antithrombotic strategy versus half-dose direct oral anticoagulation (DOAC) after Watchman implantation.
No consensus currently exists on the ...selection of the most effective antithrombotic strategy to prevent device-related thrombosis (DRT) in patients undergoing endocardial left atrial appendage closure.
After successful left atrial appendage closure, consecutive patients were prescribed a standard antithrombotic strategy (SAT) or long-term half-dose DOAC (hdDOAC). The primary composite endpoint was DRT and thromboembolic (TE) and bleeding events.
Overall, 555 patients (mean age 75 ± 8 years, 63% male; median CHA2DS2-VASc congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category score 4 interquartile range (IQR): 3-6; median HAS-BLED hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol score 3 IQR: 2-4) were included. Patients were categorized into 2 groups (SAT: n = 357 vs hdDOAC: n = 198). Baseline clinical characteristics were similar between groups. The median follow-up duration was 13 months (IQR: 12-15 months). DRT occurred in 12 (2.1%) patients, all in the SAT group (3.4% vs 0.0%; log-rank P = 0.009). The risk of nonprocedural major bleeding was significantly more favorable in the hdDOAC group (0.5% vs. 3.9%; log-rank P = 0.018). The rate of the primary composite endpoint of DRT and TE and major bleeding events was 9.5% in SAT patients and 1.0% in hdDOAC patients (HR: 9.8; 95% CI: 2.3-40.7; P = 0.002).
After successful Watchman implantation, long-term half-dose DOAC significantly reduced the risk of the composite endpoint of DRT and TE and major bleeding events compared with a standard, antiplatelet-based, antithrombotic therapy.
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In a randomized trial involving patients with paroxysmal atrial fibrillation, pulsed field ablation was noninferior to thermal ablation with respect to freedom from a composite of procedural and ...arrhythmia events at 1 year.
Left atrial appendage closure (LAAC) was approved by the U.S. Food and Drug Administration (FDA) as a stroke prevention alternative to warfarin for patients with nonvalvular atrial fibrillation. ...However, clinical decision-making is confounded by the fact that although LAAC attenuates the anticoagulant-related lifetime risk of bleeding, implantation is associated with upfront complications. Thus, enthusiasm for LAAC as a treatment option has been appropriately tempered, particularly as the therapy is introduced beyond the clinical trial sites into general clinical practice.
This study evaluated the acute procedural performance and complication rates for all cases performed in the United States since FDA approval.
In the absence of a formal national clinical registry since regulatory approval in March 2015, we obtained procedural data on implantation procedures. Every LAAC procedure requires the presence of a manufacturer clinical specialist and for procedural parameter and periprocedural complication data to be collected using a standardized process and forms.
In 3,822 consecutive cases, implantation was successful in 3,653 (95.6%), with a median procedure time of 50 min (range 10 to 210 min). Implanting physicians performing these procedures (n = 382) included 71% new, nonclinical trial implanters, who performed 50% of the procedures. Procedural complication rates included 39 pericardial tamponades (1.02%) (24 treated percutaneously, 12 surgically, and 3 fatal); 3 procedure-related strokes (0.078%); 9 device embolizations (0.24%) (6 requiring surgical removal); and 3 procedure-related deaths (0.078%).
Despite a large fraction of previously inexperienced operators, in the real-world post-FDA approval experience of LAAC, procedural success was high and complication rates were low.
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Transcatheter left atrial appendage (LAA) ligation may represent an alternative to oral anticoagulation for stroke prevention in atrial fibrillation.
This study sought to assess the early safety and ...efficacy of transcatheter ligation of the LAA for stroke prevention in atrial fibrillation.
This was a retrospective, multicenter study of consecutive patients undergoing LAA ligation with the Lariat device at 8 U.S. sites. The primary endpoint was procedural success, defined as device success (suture deployment and <5 mm leak by post-procedure transesophageal echocardiography), and no major complication at discharge (death, myocardial infarction, stroke, Bleeding Academic Research Consortium bleeding type 3 or greater, or cardiac surgery). Post-discharge management was per operator discretion.
A total of 154 patients were enrolled. Median CHADS2 score (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke, transient ischemic attack, or thromboembolism doubled) was 3 (interquartile range: 2 to 4). Device success was 94%, and procedural success was 86%. A major complication occurred in 15 patients (9.7%). There were 14 major bleeds (9.1%), driven by the need for transfusion (4.5%). Significant pericardial effusion occurred in 16 patients (10.4%). Follow-up was available in 134 patients at a median of 112 days (interquartile range: 50 to 270 days): Death, myocardial infarction, or stroke occurred in 4 patients (2.9%). Among 63 patients with acute closure and transesophageal echocardiography follow-up, there were 3 thrombi (4.8%) and 13 (20%) with residual leak.
In this initial multicenter experience of LAA ligation with the Lariat device, the rate of acute closure was high, but procedural success was limited by bleeding. A prospective randomized trial is required to adequately define clinical efficacy, optimal post-procedure medical therapy, and the effect of operator experience on procedural safety.
THERMOCOOL SMARTTOUCH® SF Catheter is a new contact-force (CF)-sensing catheter with 56-hole porous tip designed for improved cooling and reduced fluid delivery compared with a standard 6-hole ...open-irrigated catheter. The SMART SF study examined the periprocedural safety, acute effectiveness, and procedural efficiency of the catheter for drug-refractory symptomatic paroxysmal atrial fibrillation (PAF) ablation.
The prospective, open-label, non-randomized SMART-SF was conducted at 17 US sites. Circumferential pulmonary vein (PV) isolation was performed with confirmation of entrance block in all PVs. Stable ablation sites were identified using CARTO VISITAG™ Module. Primary adverse events (AEs; ≤1 week of index procedure), periprocedural AEs within 30 days of ablation procedure, acute effectiveness (confirmation of entrance block for targeted PVs), CF, and procedural parameters were assessed. Overall, 165 patients were enrolled (mean age, 62.7 years; male, 57.9%; white, 97%; left ventricular ejection fraction, 60.1 ± 7%; left atrium diameter, 38.8 ± 6 mm); 159 underwent radiofrequency ablation and comprised the safety cohort. Primary safety performance criteria were met: primary AE rate was 2.5% (4/159; cardiac tamponade n = 2, thrombo-embolism n = 1, transient ischaemic attack n = 1). All primary AEs resolved/improved within the 1-month follow-up period. Acute procedural effectiveness was attained in 96.2% (95% confidence interval: 92.0-98.6%) of patients. Procedure time, fluoroscopy time, and fluid delivered were observed in comparison to predecessor catheters.
In the SMART-SF trial, the predetermined safety performance goal was met, demonstrating the safety and acute effectiveness of the THERMOCOOL SMARTTOUCH® SF Catheter for PAF ablation.
There have been no studies of atrial diastolic function after catheter ablation of atrial fibrillation (AF). We encountered a few patients with symptomatic left atrial (LA) diastolic dysfunction and ...associated pulmonary hypertension (PH) that developed after catheter ablation for atrial fibrillation. Similar findings were described in patients after cardiac surgery and were referred to as the "stiff left atrial syndrome."
The purpose of this study was to prospectively quantify the incidence of patients developing PH associated with diastolic hemodynamic abnormalities of the LA after radiofrequency ablation of AF and to identify the possible predictors.
Between January 2009 and July 2010, data on 1,380 consecutive patients were prospectively collected. Before ablation and at follow-up, all patients had an echocardiogram to assess for the presence of PH. Patients with no echocardiographic evidence of PH but complaining of unexplained dyspnea with LA diastolic abnormalities were evaluated with right heart catheterization (RHC). Patients were included in the analysis if they developed new or worsening PH postablation with evidence of LA diastolic dysfunction by RHC or direct LA pressure measurement. All patients were evaluated for pulmonary vein stenosis and excluded if this condition was identified.
The mean age was 62 ± 11 (75% male), and nonparoxysmal AF was the predominant arrhythmia (71%). New or worsening PH with associated LA diastolic abnormalities was detected in 19 (1.4%) patients after ablation. The prevalence of PH did not differ between AF types (P = .612). Compared with patients who did not develop PH, LA scarring (P <.001), diabetes (P = .026), and obstructive sleep apnea (OSA; P = .006) were more frequently observed among those who developed PH. In a multivariable logistic model, preprocedure LA size ≤45 mm (odds ratio OR = 6.13; P = .033), mean LA pressure (OR 1.14; P = .025), severe LA scarring (OR = 4.4; P = .046), diabetes mellitus (OR = 9.5; P = .004), and OSA (OR = 6.2; P = .009) were independently associated with the development of PH postablation.
After radiofrequency catheter ablation of atrial fibrillation (RFCAF), PH with LA diastolic dysfunction or the so-called stiff LA syndrome is a rare but potentially significant complication of AF ablation. Severe LA scarring, LA ≤45 mm, diabetes mellitus, OSA, and high LA pressure are clinical variables that predict the development of this syndrome. The main clinical findings include dyspnea, congestive heart failure, PH, and large V waves on pulmonary capillary wedge pressure (PCWP) or LA pressure tracings in the absence of mitral regurgitation.
Percutaneous left atrial appendage (LAA) occlusion with Lariat has emerged as a viable alternative to oral anticoagulation (OAC) to prevent thromboembolic (TE) events in patients with atrial ...fibrillation.
We evaluated the long-term TE risk in post-Lariat patients.
Consecutive patients undergoing LAA ligation with the Lariat device at multiple centers with at least 1-year follow-up were included in the analysis. Transesophageal echocardiography (TEE) was performed at 4 weeks, 6 months, and 12 months to assess the completeness of LAA occlusion. OAC was discontinued if 4-week TEE revealed no device-related thrombus and complete closure of the appendage. Patients remained on 81 mg of aspirin per day after discontinuation of the blood thinner.
A total of 306 patients were included in the study (mean age 68.8 ± 11.0 years; mean CHA
DS
-VASc score 3.6 ± 1.7). Four-week TEE revealed leaks in 81 patients (26.5%); all leaks were less than 5 mm in diameter. At 6-month TEE, spontaneous closure of the leak was demonstrated in 21 patients (25.9%), 26 patients (32%) underwent a successful leak closure procedure, and the remaining 34 (42%) patients were placed on OAC. At the median follow-up period of 15.9 ± 9.2 months, 9 TE events (2.9%) were reported: 7 with persistent leak and 2 without any detectable leaks on 2-dimensional TEE (P < .001).
Complete occlusion of the LAA with the Lariat device was associated with the low rate of TE events at long-term follow-up. However, residual leaks were common after Lariat closure and the stroke rate was significantly higher in patients with incomplete occlusion, even with small leaks.
The purpose of this study was to compare the relative risk of major bleeding with left atrial appendage (LAA) closure compared with long-term warfarin therapy.
LAA closure is an alternative approach ...to chronic oral anticoagulation for the prevention of thromboembolism in patients with atrial fibrillation (AF).
We conducted a pooled, patient-level analysis of the 2 randomized clinical trials that compared WATCHMAN (Boston Scientific, Natick, Massachusetts) LAA closure with long-term warfarin therapy in AF.
A total of 1,114 patients were included, with a median follow-up of 3.1 years. The overall rate of major bleeding from randomization to the end of follow-up was similar between treatment groups (3.5 events vs. 3.6 events per 100 patient-years; rate ratio RR: 0.96; 95% confidence interval CI: 0.66 to 1.40; p = 0.84). LAA closure significantly reduced bleeding >7 days post-randomization (1.8 events vs. 3.6 events per 100 patient-years; RR: 0.49; 95% CI: 0.32 to 0.75; p = 0.001), with the difference emerging 6 months after randomization (1.0 events vs. 3.5 events per 100 patient-years; RR: 0.28; 95% CI: 0.16 to 0.49; p < 0.001), when patients assigned to LAA closure were able to discontinue adjunctive oral anticoagulation and antiplatelet therapy. The reduction in bleeding with LAA closure was directionally consistent across all patient subgroups.
There was no difference in the overall rate of major bleeding in patients assigned to LAA closure compared with extended warfarin therapy over 3 years of follow-up. However, LAA closure significantly reduced bleeding beyond the procedural period, particularly once adjunctive pharmacotherapy was discontinued. The favorable effect of LAA closure on long-term bleeding should be considered when selecting a stroke prevention strategy for patients with nonvalvular AF. (WATCHMAN Left Atrial Appendage System for Embolic PROTECTion in Patients With Atrial Fibrillation; NCT00129545; and Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy PREVAIL; NCT01182441).
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