This is a prospective, multi-center, single-arm cohort study. The study was performed at two centers with experience in both catheter ablation and the use of vascular access site closure devices. The study was registered at www.clinicaltrials.gov under identified NCT04904809. All subjects gave their informed consent for inclusion before they participated in the study. Only one patient who was screened for inclusion in the study declined participation; the remainder of consecutively screened patients agreed to participate in this study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Institutional Review Board of Saint Luke’s Health System. The inclusion criteria for this study were patients aged 18 years or older, who were scheduled to undergo catheter ablation procedure with planned multiple access sites in a single femoral vein, all access sites planned to be closed with Perclose™ ProGlide™ and Perclose™ ProStyle™ SMC (Abbott Cardiovascular, Plymouth, MN), and written informed consent obtained prior to the procedure. Exclusion criteria included visible thrombus on ultrasound or angiogram prior to the ablation procedure, prior ipsilateral deep vein thrombosis (DVT), INR > 3.5, pregnancy, patients unable to ambulate pre-procedure, and patients with symptoms consistent with COVID-19 infection (due to potential increased risk of a vascular thrombosis seen in these patients) and/or a positive test. Consecutive cases were included with no patients excluded due to operator preference or judgement regarding closure method. All seven operators were highly experienced in use of SMC.

The primary endpoint of this study was vascular complications detected by scheduled DUS at discharge or repeat DUS at 30 days post-discharge in patients with either asymptomatic or non-visible complications at discharge. The specific complications assessed were pseudoaneurysm, hematoma, deep venous thrombosis, arteriovenous fistula, dissection, stenosis > 50%, arterial tear/perforation with need for vascular surgery, and excessive bleeding requiring transfusion or prolonged manual pressure to achieve hemostasis. Secondary endpoints were any vascular and access site complications.

For patients on a direct oral anticoagulant, one dose of medication was held on the morning of the procedure, whereas patients on warfarin did not hold medication but were verified to have an INR between 2 and 3. All patients had vascular access using the modified Seldinger technique. The use of vascular ultrasound to guide access was routinely used. For multiple access sites in a single vessel, vascular access was obtained from caudal to cranial location with larger sheaths being placed in the cranial position. After vascular access was obtained, a pre-close technique was used to deploy the SMC for all access sites in all patients. A single SMC was used for all sheath sizes of 10Fr or less. For sheath sizes greater than 12Fr, an additional SMC was used if there was concern for additional bleeding, based upon operator experience. For patients undergoing two SMC in the same vessel, the SMC device was rotated approximately 45° to facilitate deployment of suture in orthogonal directions to facilitate large vessel closure. Once all vascular access was obtained, intravenous heparin was given for all patients undergoing an ablation in the left atrium. Heparin was given in bolus and continuous infusion to target an ACT of 280–320 s. At the conclusion of the procedure, all access sites were closed using the standard SMC technique that has been described previously [10]. The use of protamine post-procedure was used according to operator discretion. Manual pressure and/or lidocaine with epinephrine injection were routinely performed to address any superficial oozing at the access site. Patients were allowed to ambulate at 2 h post-procedure per protocol, but this duration varied at the discretion of the individual operator’s preference as well as the nursing assessment of patient’s recovery from anesthesia. Anticoagulant medication was resumed the evening of the procedure at the usual prescribed time.

All suspected complications were assessed by clinical staff and documented as related or unrelated to the procedure. All adverse events were adjudicated by a clinical events committee (CEC). Major complications were defined as those which require surgical, interventional, or pre-specified repair and/or hospitalization. All other complications were considered minor complications. DUS was scheduled at discharge in all patients. A 30-day DUS was performed in patients with vascular complications at discharge. The primary endpoints (major and minor) were adjudicated by the duplex core lab. The total duration of the study was 6 months.

The core lab recommended DUS protocols were followed at the enrolling sites. The access site veins were assessed for compressibility, flow, and the presence of deep vein thrombosis, stenosis > 50%, venous tear, or venous perforation. The corresponding arteries were examined for signs of pseudoaneurysm, AV fistula, dissection, stenosis > 50%, and arterial tear/perforation. The area surrounding soft tissue was examined for the presence of access site hematoma or other fluid collections.

Proportions are presented for binary variables. Mean and/or median with standard deviation (SD) are presented for continuous variables. Since this is an observational study with an emphasis on utility of mandatory DUS at discharge for detecting complication to supplement real-world evidence without a control group, no power calculation was performed.