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Higher Heparin Dose, Compression Device Use Curb Radial Artery Occlusion

By L.A. McKeown

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A 5,000 IU dose of heparin is more effective than a very low dose in minimizing the risk of radial artery occlusion after transradial coronary angiography. When occlusions do occur, a simple nonpharmacologic ulnar artery pressure device can help achieve acute recanalization of the artery, researchers report in a study published online March 25, 2011, ahead of print in the American Journal of Cardiology.

Researchers led by Olivier F. Bertrand, MD, PhD, of Quebec Heart-Lung Institute (Quebec, Canada), evaluated the incidence of radial artery occlusion with 2 different doses of heparin as well as the efficacy and safety of transient ulnar artery compression with an inflatable hemostatic device in patients undergoing coronary angiography via transradial access.

The investigators randomized 465 patients undergoing diagnostic catheterization to very-low-dose heparin (2,000 IU; n = 222) or low-dose heparin (5,000 IU; n = 243) injected gradually through the sheath side arm into the radial artery. After the procedure, the radial sheaths were removed, and the hemostatic TR Band (Terumo, Tokyo, Japan) was applied at the access site. The device was inflated with 15 mL of air then promptly partially deflated for minimum hemostatic pressure. Immediately after transfer to the recovery room, the initial compression was further reduced to maintain radial artery patency.

Radial artery patent hemostasis was verified via a pulse oximeter placed on the thumb and then by observing the continuous plethysmographic signal on the monitor during manual compression of the ulnar artery just proximal to the pisiform bone. The compression device was left in place until hemostasis was completed, usually 2 hours or more. Ultrasound was performed within 3 to 4 hours of band removal to verify radial artery patency. All patients were then discharged home the same day.

Low Dose Trumps Very Low Dose

The incidence of radial artery occlusion was lower with the higher heparin dose immediately after hemostasis and after ulnar artery compression, although the difference reached statistical significance only after ulnar compression. The 5,000-IU group also experienced a trend toward a shorter radial artery compression time (table 1).

Table 1. Outcomes According to Heparin Dose

 

2,000 IU Heparin
(n = 222)

5,000 IU Heparin
(n = 243)

P Value

Initial Occlusion

5.9%

2.9%

0.17

Final Occlusion After Compression

4.1%

0.8%

0.03

Compression Time, hrs

2.10 ± 0.78

2.25 ± 0.82

0.051


A trend also was seen for greater recanalization success with more potent anticoagulation after ulnar artery compression (71% in the 5,000-IU group vs. 31% in the 2,000-IU group; P = 0.16). Notably, the only factor to differ between patients with or without final radial artery occlusion was the heparin dose (P = 0.03).

Ulnar artery compression was well tolerated in all patients and not associated with any complications. In addition, there was no difference in the incidence of local hematoma between the 2 heparin groups (2.3% with 2,000 IU and 3.7% with 5,000 IU; P = 0.42).

Permanent Radial Occlusion Has Consequences

Avoiding permanent radial artery occlusion is important because the complication precludes additional radial access, according to the study authors. However, most cases are asymptomatic and results of a recent international transradial practice survey by Dr. Bertrand and colleagues (J Am Coll Cardiol Interv. 2010;3:1022-1031) showed that more than half of operators acknowledged that radial artery occlusion was not assessed at hospital discharge.

While the exact mechanism of how ulnar artery compression helps recanalize the radial artery remains elusive, the investigators hypothesize that the technique “produces a steep increase in radial artery flow promoting localized fibrinolysis, hence, reopening the [radial artery occlusion].”

Dr. Bertrand and colleagues acknowledge some limitations to their study. For example, because occlusion was assessed before hospital discharge, it is possible that most occlusions spontaneously recanalized later, they say. Moreover, because of the small number of events, the investigators were unable to perform multivariable analysis to identify independent predictors of radial artery occlusion. In addition, they did not include patients who underwent PCI, so the results cannot be extrapolated to procedures lasting longer with more intense anticoagulation or larger sheaths. Also, because the study was performed with heparin only, it is impossible to know whether the compression would be effective with other anticoagulants.

 

Source:
Bernat I, Bertrand OF, Rokyta R, et al. Efficacy and safety of transient ulnar artery compression to recanalize acute radial artery occlusion after transradial catheterization. Am J Cardiol. 2011;Epub ahead of print.

 

Republic).

  • The paper contains no statement regarding potential conflicts of interest.

 

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Disclosures
  • The study was supported by a grant from the Charles University Prague (Prague, Czech

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