Cath Lab Digest

The Miami Heart cath lab staff is continually looking for ways to improve patient care. They recently completed a study using Angiomax® (bivalirudin) and the SyvekPatch®, testing early sheath removal with this treatment combination while monitoring bleeding complications. Results were excellent, and this protocol has become standard for some clinicians in the cath lab.

Background

Recognized as a leading research institution, Miami Heart Institute is continually seeking methods to improve clinical practice, and as a very busy institution, ways to improve throughput of cases in their cath lab. For example, the staff at Miami Heart has focused on patient management post-percutaneous coronary intervention (PCI). They considered a way to remove sheaths sooner without increasing the incidence of access site bleeding. Bleeding post-PCI remains an issue. While there is evidence that major bleeding post-PCI has decreased over the years, hematomas, bleeding, oozing, and ecchymosis at the sheath site continue to be a problem that requires careful nursing management of sheath removal and first ambulation. In fact, most clinically significant bleeds associated with PCI occur at the site of femoral access. Some research shows that early sheath removal and early ambulation reduce the risk of bleeding at the access site and improve patient comfort.¹

As part of its goal of promoting the best contemporary practice, Miami Heart has introduced an alternative to heparin as a foundation anticoagulant in PCI. Angiomax, a direct thrombin inhibitor, (The Medicines Company, Cambridge, MA) has shown increased efficacy and decreased bleeding in PCI compared to heparin in clinical trials. ² Angiomax has a unique mechanism of action in that it initially inhibits thrombin completely, but is then slowly cleaved by thrombin, reversing the inhibition and allowing thrombin to resume its role in hemostasis.

In addition, Angiomax exhibits linear pharmacokinetics following intravenous (IV) administration to patients undergoing PCI. ³ A bolus dose of Angiomax rapidly achieves the therapeutic plasma level, which is then maintained at a steady state by a continuous IV infusion. Unlike heparin, Angiomax is not titrated to a specific target activated clotting time (ACT). Angiomax, with rapid plasma clearance and short 25-minute half-life, was expected to show further bleeding reductions for patients post-intervention.

The external dressing SyvekPatch® (Marine Polymer Technologies, Danvers, MA) is used frequently on PCI patients at sheath removal at Miami Heart. In order to control other factors that could influence access bleeding, the staff chose to look at one type of external device/dressing approved for vascular access site management for this study. Staff felt that the combination of the SyvekPatch with an optimal anticoagulation agent like Angiomax would be worth evaluation. With this combination, the cath lab staff reasoned sheaths could be removed in less time than the current protocols, without the risk of bleeding complications.

Current protocols for PCI patients that received heparin are to allow the ACT to decrease to 160-180 (physician-dependent) for sheath removal. As every patient reacts differently to heparin, a decision would be made dependent upon end procedure ACT, cath lab volume, and staff availability to suture sheaths and transfer patients to a critical care area or to keep the patient in the cath lab and await the ACT level to decrease for sheath removal. After the ACT reaches its designated level, sheath removal then depends on staff availability and cath lab volume. Often times, patients wait to have sheaths removed.

Study Methodology

Sixty-three patients with a combination of Syvek and Angiomax were enrolled over 8 weeks from Dec. 2001 to Jan. 2002. All patients underwent PCI, with Angiomax as the foundation anticoagulant. Twelve of the 63 patients also received ReoPro® (abciximab) (Eli Lilly and Company, Indianapolis, IN), and ^{4 patients received Integrilin® (eptifibatide) (Millennium Pharmaceuticals, Inc., South San Francisco, CA) in addition to Angiomax (21% GPIIb/IIIa inhibitor use). Patient characteristics are shown in Table 1.}

The ACT was checked prior to sheath removal, but ACT was not independently used to determine timing for sheath removal. Sheath removal decisions were based on a combination of ACT, staff availability, length of time elapsed from procedure completion, and individual physician orders; sheath removal was performed at the discretion of the holding unit nurse. SyvekPatch, an external pad applied to the sheath access site to control bleeding at sheath pull time, was used on all patients. It was applied immediately at sheath removal and manual pressure was applied for 20 minutes.

The study objective was an evaluation of early sheath pull and its effects on femoral access site complications. Patients were monitored for any bleeding, hematoma, ecchymosis, pseudoaneurysm, oozing, or other access site complications.

Results

Results are highlighted in Figure 1. The median length of time from procedure completion to sheath pull was 30 minutes. Six patients had their sheaths removed immediately upon entering the holding area, and the longest time to sheath pull was 180 minutes post-procedure for one patient. The median ACT at the time of sheath pull was 223 seconds, and 52 (82.5%) patients had the sheath pulled within one hour of the end of the procedure. In the 63-patient group, there was only one report of a small ecchymotic area in a patient who had received ReoPro and had the sheath pulled 30 minutes post-procedure. All other patients had no complications at the sheath site, and there was no other type of bleeding reported. (See Table 2.)

Discussion