肝素抗體存在與否能決定心臟手術後的存活率


  Nov 2, 2005 (蒙特婁訊)-根據一項發表於美國胸腔醫學會年會中的回溯性試驗結果,肝素/血小板因子4(HPF4)檢驗呈陽性是預測心臟手術後發生併發症的獨立危險因子,不論是否發生肝素造成的血小板低下。
  
  這項觀察性試驗結果暗示,HPF4抗體篩檢可以降低接受心臟手術病患的風險。
  
  威斯康辛州密爾瓦基Aurora St. Luke's 醫學中心資深心臟胸腔外科醫師,同時也是該中心外科心律不整計畫主持人David C. Kress醫師表示,我們發現不論病患是否發生肝素造成的血小板低下,病患同樣可能發生併發症;是否有抗體,而並非是否發生血小板低下可以預測併發症。
  
  Kress醫師估計大約有5%的美國醫院有篩檢HPF4抗體,一般而言,HPF4抗體呈陽性表示過去使用過肝素,而且會使病患產生HIT的風險增加。
  
  Kress醫師與其同事追蹤接受冠狀動脈繞道手術以及/或是瓣膜手術的病患達2.5年,在手術前篩檢1,209位病患的血液。
  
  研究者發現,1,114位病患中有60位(5.4%)在手術前HPF4抗體呈現陽性,這些病患發生急性肢體缺血的風險增加(5.0%相較於0.9%;P=.03),而且接受腎臟透析的機率也較高(11.7%相較於4.3%;P=.02)、發生腸胃道併發症的機率(15.0%相較於5.7%;P=.01)、接受呼吸器治療超過96個小時的比例同樣較高(21.7%相較於8.8%;P=.01)。
  
  HPF4抗體呈陽性的病患住在加護病房的時間也比較長(56相對於42個小時;P<.05),而且在術後住院天數平均多出2天(7天相較於9天;P<.01)。
  
  Kress醫師表示,他希望這樣的數據可以鞭策外來的試驗,找尋心臟手術中使用肝素的替代品。
  
  Kress醫師指出,尋找肝素替代物在生物科技的這項領域的未來已經成熟,當我們已經有許多實驗數據支持使用更安全的心肺繞道手術,外科醫師渴望採用這些新技術。
  
  座談會座長同時也是華盛頓Tacoma Madigan陸軍醫學中心呼吸照護主任Alexander Niven醫師表示,這項試驗強調了需要有更多研究HIT的試驗以及其臨床上的重要性。
  
  Niven醫師向Medscape表示,這是項引發假設有趣的試驗,在臨床上的重要性大部分是未知的。
  
  胸腔科專家Niven醫師表示,測試HIT的檢驗,其靈敏度與專一度受到質疑,這項試驗中使用0.4作為閥值是值得注意的。
  
  Niven醫師指出,要使用多少的光學效價來確認臨床上有意義的HIT,一直有爭議。
  
  他附帶表示,目前沒有足夠證據支持使用何種藥物是心肺繞道手術時的替代品。
  
  這項研究為獨立運作,研究者未接受任何經濟資助。

Presence of Heparin Antibodies

By
Medscape Medical News

Nov 2, 2005 (Montreal) — Testing positive for heparin/platelet factor 4 (HPF 4) is an independent predictor of complications associated with cardiac surgery, with or without heparin-induced thrombocytopenia (HIT), according to a retrospective study presented here at a late-breaking session during CHEST 2005, the annual meeting of the American College of Chest Physicians.

Results of the observational analysis suggest that screening for HPF4 antibodies would minimize risks to patients undergoing cardiac surgery.

"We found that patients were just as likely to develop the complications whether or not they developed the [heparin-induced] thrombocytopenia," said David C. Kress, MD, a senior cardiothoracic surgeon at Aurora St. Luke's Medical Center in Milwaukee, Wisconsin, and director of the center's surgical arrhythmia program. "It was the presence of the antibodies, not the presence of thrombocytopenia [that predicted complications]."

Dr. Kress estimated that just 5% of U.S. hospitals screen for HPF4 antibodies. Generally, presence of HPF4 antibodies indicates past exposure to heparin and puts the patient at risk for developing HIT.

Dr. Kress and colleagues followed patients who underwent coronary artery bypass graft surgery and/or valve surgery for 2.5 years, initially screening 1,209 patients through a blood test administered before surgery.

The investigators found that 60 (5.4%) of 1,114 patients tested positive for HPF4 antibodies before surgery. Those patients had an elevated incidence of acute limb ischemia (5.0% vs 0.9%; P = .03) and a higher incidence of renal dialysis (11.7% vs 4.3%; P = .02), gastrointestinal complications (15.0% vs 5.7%; P = .01), and prolonged ventilation exceeding 96 hours (21.7% vs 8.8%; P = .01).

The patients who tested positive for HPF4 antibodies also had a greater median length of stay in the intensive care unit (56 vs 42 hours; P < .05) and had a median of two more days in the hospital after surgery (7 vs 9 days; P < .01).

Dr. Kress said he hopes that the data will spur greater research to find substitutes for heparin in cardiac surgery.

"The future is ripe in this era of biotechnology to come up with a good heparin alternative," Dr. Kress pointed out. "As we get more data that there is a safe alternative to use in cardiopulmonary bypass procedures, surgeons will be eager to adopt that alternative."

Alexander Niven, MD, a comoderator of the session and director of respiratory services at Madigan Army Medical Center in Tacoma, Washington, said the study puts greater emphasis on the need to further study HIT and its clinical importance.

"This is an interesting hypothesis-generating paper," Dr. Niven told Medscape. "The clinical significance remains largely unclear."

Dr. Niven, a pulmonologist, said that the diagnostic assay to test for HIT is open to debate in terms of its specificity and sensitivity, noting that the study used 0.4 as its low end of the threshold.

"There is a question about what the optical titer should be to identify clinically significant HIT," Dr. Niven said.

He added that there are not sufficient data to support using substitutes for heparin "in a setting like cardiopulmonary bypass."

The study was independently funded. The author reported no pertinent financial disclosures.

CHEST 2005: Late-breaking session. Presented Nov. 1, 2005.

Reviewed by Gary D. Vogin, MD

    
相關報導
鎮靜劑、止痛劑與心臟手術之後的新生兒不良神經發展結果無關
2010/2/2 下午 01:58:00
Statins類藥物可以減少主動脈手術的費用及併發症
2009/10/29 上午 10:46:00
單純、簡單的消毒可以預防心臟手術後感染
2006/12/1 上午 09:36:00

上一頁
   1   2  




回上一頁