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Noticias
Samir B Pancholy
(UPDATED) Compressing the ulnar artery in addition to standard patent hemostasis significantly lowers the risk of radial artery occlusion after a transradial-access coronary intervention, a new study shows.
In a trial of 3,000 patients undergoing diagnostic cardiac catheterization, the 30-day incidence of radial-artery occlusion was 0.9% among those randomized to prophylactic ipsilateral ulnar compression and standard hemostasis and 3.0% among patients treated with standard hemostasis alone (P=0.0001).
The researchers, led by Samir Pancholy, MD (Commonwealth Medical College, Clarks Summit, PA), state that ulnar artery compression during radial artery hemostasis “is an effective, safe, and inexpensive technique to lower the risks of radial artery occlusion” following transradial catheterization. Given the simplicity, combined with the “highly significant efficacy and safety,” prophylactic ulnar compression should become the default protocol used alongside other established best practices for radial operators and staff, they say.
Speaking with TCTMD, Pancholy said a recent literature review of data published in the last 2 years suggests the mean incidence of radial artery occlusion is approximately 10% at 24 hours. While some of these cases “open up,” at 30 days a fraction of these arteries remain permanently occluded. Calling the condition a very significant problem, Pancholy said that no matter how benign it might be for the patient, radial-artery occlusion removes a very good access site for subsequent procedures.
“Most of these patients with atherosclerotic disease require multiple procedures over time,” he said, citing repeat procedures and staged interventions. “Also, once you close the radial artery, we really don’t know what final effect it will have on the hand. We go by the patient who comes back to complain, but we don’t know if there are other measurable, less aggressive changes in the hand. As one of my teachers used to say, ‘God gave you a radial artery for a reason.’ It makes sense for a lot of reasons to worry about patency.”
In an ultrasound substudy of ulnar artery, the PROPHET-II researchers did not observe any ulnar trauma and there were no clinical signs of digital ischemia. “There really is no downside,” said Pancholy. “It’s pretty smooth.”
Mamas Mamas, BMBCh (University of Keele, Stoke-on-Trent, England), a radial operator not involved in the present study, told TCTMD that radial artery occlusion is a significant clinical problem. One recent meta-analysis of more than 31,000 patients suggested the rate of occlusion is 7.7% at 24 hours and 5.5% at one week. The risk of occlusion also increases with consecutive procedures, “meaning that occlusion of the radial artery will prevent subsequent procedures being undertaken through this access site,” he said.
Sunil Rao, MD (Duke Clinical Research Institute, Durham, NC), another radial operator not involved in PROPHET-II, said there might be concern that compression of the radial and ulnar arteries simultaneously would result in significant hand ischemia, but this was not observed, suggesting rich blood flow to the hand. Like Mamas, Rao said radial artery occlusion is an issue for interventional cardiologists, and while it is benign for most patients, some individuals will have symptoms from occlusion, particularly those with small caliber radial arteries.
“The current method of concomitant ulnar compression may be an attractive way to maintain radial patency,” said Rao.
Be Kind to the Radial Artery
Known as PROPHET-II, and published October 3, 2016 in JACC: Cardiovascular Interventions, the study was conducted at two large tertiary care centers in India and the Czech Republic. All patients were treated with a 200 µg bolus injection of nitroglycerin, 2.5 mg of verapamil, and 5,000 IU of unfractionated heparin and the diagnostic angiography was performed using 5-F catheters. For standard patent hemostasis, an inflatable band (TR Band, Terumo Interventional Systems) was placed over the arterial puncture site.
In addition to the 30-day results, the incidence of radial-artery occlusion with ulnar compression was significantly lower immediately after removing the device for radial-artery hemostasis (1.5% vs 13.9%; P=0.0001). At 24 hours, the incidence of radial artery occlusion was 4.3% in the standard hemostasis arm and 1.0% in patients who received ulnar compression with standard hemostasis (P=0.0001).
Regarding the findings, Pancholy said that once physicians start doing prophylactic ulnar artery compression alongside hemostasis of the radial artery, “it takes about four or five cases to see the difference and it’s so immediately obvious that you become a believer pretty quickly.”
In an editorial accompanying the study, Ferdinand Kiemeneij, MD, and Gerard Boink, MD (Tergooi Hospital, Blaricum, the Netherlands) state that the most important clinical consequence of radial artery occlusion is that it is limits use of the radial artery, which is a safe access site associated with significantly lower rates of bleeding, for future procedures.
“Our general recommendation, after almost 25 years of transradial access experience, is to be kind to the radial artery and give it back to the patient who allowed us to use this vessel for the procedure that we have proposed to perform,” write Kiemeneij and Boink. “As a result, the patient can enjoy the benefits of radial access in case of future necessity for coronary procedures.”
The editorialists note that the puncture technique, sheath, and pharmacologic cocktail used in PROPHET-II is fairly representative of clinical practice. They point out the trial excluded several patient subgroups, including ad hoc percutaneous interventions, patients with a history of ipsilateral transradial access, scleroderma, warfarin therapy, and heparin intolerance. Pancholy, however, believes the results would translate to other patient groups.
“In a very strict, purist sense, you could say it was only 5-French diagnostics, and we don’t know what would happen in PCI or when using 6-French or higher [catheters], but the reason we restricted the population to a 5-F diagnostic catheterization is that these are confounders that affect radial artery occlusion. We really didn’t want any noise in our statistical analysis.”
Mamas said the low rate of radial artery occlusion in PROPHET-II was “very impressive,” showing that with optimal care, maintenance of radial patency can be achieved in 99% of cases. At their center, if radial occlusion is detected, they compress the ulnar artery to increase the recanalization rate. He added that they plan to adopt the protocol in PROPHET-II.
“The diagnostic caths undertaken in the PROPHET-II study were 5-French and so I would expect that the rates of radial occlusion would be slightly higher for cases undertaken with 6-French catheters,” said Mamas. “The main limitation to this technique is that at present commercially available radial compression devices only compress the radial artery and do not allow co-compression of the ulnar artery. Once commercially available devices are manufactured that allow the separate compression of radial and ulnar arteries, I think that this technique will—and should—become standard practice.”
Ulnar and Radial Artery: Codependent Vessels
The European Society of Cardiology recommends radial access as the “default technique” for patients requiring PCI for STEMI and NSTEMI. In addition, a consensus statement from the European Association of Percutaneous Cardiovascular Interventions and Working Groups on Acute Cardiac Care and Thrombosis also recommend radial access for coronary interventions.
Pancholy, who began performing transradial coronary interventions 14 years ago, first published their patent hemostasis protocol in 2008. The protocol was designed to reduce the incidence of radial artery occlusion, with the researchers recommending reduced compression pressure at the site of radial artery puncture. While the protocol reduced radial-artery occlusion to approximately 2% to 3% of cases in their laboratory, they were unable to lower the incidence any further. Noting that the ulnar and radial arteries are interconnected and codependent, the transradial operators experimented with compressing the ulnar artery.
“If you compress the ulnar artery to occlude flow, flow in the radial artery goes up by 40% or 50%,” said Pancholy. “When we noticed that in the ultrasound lab, we wondered if there was a role for ulnar-artery compression right after the catheterization. The mechanism of closure [of the radial artery] is mostly thrombosis, and the best treatment of thrombosis is the maintenance of flow. So we thought if we could maintain radial flow, that would be ideal. And one of the best ways to augment radial flow is to compress the ulnar artery.”
To TCTMD, Mamas said that operators will often downsize to 5-F catheters or use slender sheaths, as well as give 5,000 IU of heparin, even in diagnostic cases, to avoid radial spasm. “Many operators consider the PCI/cardiac catheterization to be finished once the stent has been deployed or coronary images have been acquired, but operators should consider management of the access site as an integral and important part of the procedure, as important as the cardiac cath itself,” he said.