When my INR was low a couple weeks ago, my coumadin mgr. told me about an article that said even if it was that low (1.4) for a few days, I could go 4-5 days w/out complication, or at least with slim chances of a complication (according to the article). Al had asked me for the article and I finally got a print-out from her.. you have to be a registered med. professional to go to the site and read it, so I thought I'd just paste it into my post if anyone is intersted in reading it. I'd love to hear any thoughts on it, too, as I've never had to bridge yet and am not sure what to think.
Safety of heparin "bridge" questioned when warfarin is stopped for minor procedures
January 16, 2008 Steve Stiles
Chicago, IL - Patients on chronic warfarin who go off the drug for up to five days while they undergo a minor invasive procedure appear to have a <1% risk of experiencing a thromboembolic event, suggests a prospective study that, moreover, pointed to a substantial risk of clinically important bleeding when some form of heparin is given as "bridge" therapy in warfarin's stead [1].
The findings speak to the dilemma providers face when taking patients off oral anticoagulation while they undergo a colonoscopy, dental procedures, or other such outpatient procedures, according to lead author Dr David A Garcia (University of New Mexico Health Sciences Center, Albuquerque). Many want to give short-acting parenteral anticoagulation during such procedures, accepting a potential for more bleeding complications in exchange for a reduced risk of potentially devastating thromboembolic events, he observed for heartwire. But prospective data for guiding such decisions have been in short supply.
We don't have good data about the benefit of perioperative heparin, whereas we are getting increasingly more evidence that perioperative heparin certainly comes with a risk.
"If there's an overriding message from our study, it's perhaps that the hemorrhagic risk associated with heparinlike perioperative anticoagulation is greater than previously appreciated and that it needs to be considered carefully in any risk/benefit analysis that one is doing around an interruption of warfarin for an elective procedure," Garcia said. "We don't have good data about the benefit of perioperative heparin, whereas we are getting increasingly more evidence that perioperative heparin certainly comes with a risk."
Anyway, he observed, the risk of thromboembolic complications during warfarin interruption appears to be quite low, at least in populations like the one his group studied: "outpatients undergoing elective, relatively minor invasive procedures, most of whom had their warfarin interrupted for only brief intervals, three to five days." Less than one-tenth of the study's >1000 patients had received bridge anticoagulation.
The group's findings, published in the January 14, 2008 issue of Archives of Internal Medicine, are consistent with those of other studies and with current guidelines "proposed by the American College of Chest Physicians, suggesting that low-risk patients may undergo four to five days of warfarin-therapy interruption without bridging therapy."
Their analysis covered 1293 instances of warfarin interruption in 1024 patients who underwent such outpatient procedures as colonoscopy, oral or dental surgery, or ophthalmic surgery. The patients averaged 72 years in age, and most had been on warfarin due to atrial fibrillation or mechanical heart valves or for management of venous thromboembolism. Only 8.3% of cases of warfarin interruption involved bridge anticoagulation therapy, which was nearly always with a low-molecular-weight heparin, according to the authors. Outcomes included the following:
There were only seven instances of thromboembolism (0.7%) within 30 days of the procedure. The rate was the same after exclusion of patients who received bridge therapy.
The rate of thromboembolism was 0.4% when the warfarin interruption lasted five days or less and 2.2% for those of seven or more days.
Six patients (0.6%), including four who had received bridge therapy, suffered a major bleeding complication, defined as hemorrhage that led to death or to hospitalization with a transfusion >2 U red packed cells or at a "critical" site (including, for example, intracranial or retroperitoneal bleeding).
Another 17 patients (1.7%), including 10 who had received bridge therapy, experienced "clinically significant, nonmajor bleeding."
Bleeding complication risk among patients who received or did not receive bridge anticoagulation therapy
Complication
Bridge anticoagulation (%)
No bridge anticoagulation (%)
Major hemorrhage
3.7 (Bridge)
0.2 (no bridge)
Significant nonmajor hemorrhage
9 (Bridge)
0.6 (no bridge)
To download table as a slide, click on slide logo below
"Although our paper doesn't provide any definitive answers, it questions whether the risk of bridging therapy, even in outpatients, can be justified by the potential benefit," Garcia said, cautioning that it doesn't apply to patients undergoing major surgery or who are hospitalized for an invasive procedure, whose thrombotic and bleeding risks would likely be higher. Randomized, placebo-controlled trials are now needed, he added, to settle the issue.
The study was funded by Bristol-Myers Squibb. Garcia reports receiving consulting honoraria and research support from Bristol-Myers Squibb, AstraZeneca, and Sanofi-Aventis. Coauthor Dr Elaine M Hylek (Boston University School of Medicine, MA) reports having served on advisory boards for Bristol-Myers Squibb and receiving research support from AstraZeneca and Bristol-Myers Squibb.
Safety of heparin "bridge" questioned when warfarin is stopped for minor procedures
January 16, 2008 Steve Stiles
Chicago, IL - Patients on chronic warfarin who go off the drug for up to five days while they undergo a minor invasive procedure appear to have a <1% risk of experiencing a thromboembolic event, suggests a prospective study that, moreover, pointed to a substantial risk of clinically important bleeding when some form of heparin is given as "bridge" therapy in warfarin's stead [1].
The findings speak to the dilemma providers face when taking patients off oral anticoagulation while they undergo a colonoscopy, dental procedures, or other such outpatient procedures, according to lead author Dr David A Garcia (University of New Mexico Health Sciences Center, Albuquerque). Many want to give short-acting parenteral anticoagulation during such procedures, accepting a potential for more bleeding complications in exchange for a reduced risk of potentially devastating thromboembolic events, he observed for heartwire. But prospective data for guiding such decisions have been in short supply.
We don't have good data about the benefit of perioperative heparin, whereas we are getting increasingly more evidence that perioperative heparin certainly comes with a risk.
"If there's an overriding message from our study, it's perhaps that the hemorrhagic risk associated with heparinlike perioperative anticoagulation is greater than previously appreciated and that it needs to be considered carefully in any risk/benefit analysis that one is doing around an interruption of warfarin for an elective procedure," Garcia said. "We don't have good data about the benefit of perioperative heparin, whereas we are getting increasingly more evidence that perioperative heparin certainly comes with a risk."
Anyway, he observed, the risk of thromboembolic complications during warfarin interruption appears to be quite low, at least in populations like the one his group studied: "outpatients undergoing elective, relatively minor invasive procedures, most of whom had their warfarin interrupted for only brief intervals, three to five days." Less than one-tenth of the study's >1000 patients had received bridge anticoagulation.
The group's findings, published in the January 14, 2008 issue of Archives of Internal Medicine, are consistent with those of other studies and with current guidelines "proposed by the American College of Chest Physicians, suggesting that low-risk patients may undergo four to five days of warfarin-therapy interruption without bridging therapy."
Their analysis covered 1293 instances of warfarin interruption in 1024 patients who underwent such outpatient procedures as colonoscopy, oral or dental surgery, or ophthalmic surgery. The patients averaged 72 years in age, and most had been on warfarin due to atrial fibrillation or mechanical heart valves or for management of venous thromboembolism. Only 8.3% of cases of warfarin interruption involved bridge anticoagulation therapy, which was nearly always with a low-molecular-weight heparin, according to the authors. Outcomes included the following:
There were only seven instances of thromboembolism (0.7%) within 30 days of the procedure. The rate was the same after exclusion of patients who received bridge therapy.
The rate of thromboembolism was 0.4% when the warfarin interruption lasted five days or less and 2.2% for those of seven or more days.
Six patients (0.6%), including four who had received bridge therapy, suffered a major bleeding complication, defined as hemorrhage that led to death or to hospitalization with a transfusion >2 U red packed cells or at a "critical" site (including, for example, intracranial or retroperitoneal bleeding).
Another 17 patients (1.7%), including 10 who had received bridge therapy, experienced "clinically significant, nonmajor bleeding."
Bleeding complication risk among patients who received or did not receive bridge anticoagulation therapy
Complication
Bridge anticoagulation (%)
No bridge anticoagulation (%)
Major hemorrhage
3.7 (Bridge)
0.2 (no bridge)
Significant nonmajor hemorrhage
9 (Bridge)
0.6 (no bridge)
To download table as a slide, click on slide logo below
"Although our paper doesn't provide any definitive answers, it questions whether the risk of bridging therapy, even in outpatients, can be justified by the potential benefit," Garcia said, cautioning that it doesn't apply to patients undergoing major surgery or who are hospitalized for an invasive procedure, whose thrombotic and bleeding risks would likely be higher. Randomized, placebo-controlled trials are now needed, he added, to settle the issue.
The study was funded by Bristol-Myers Squibb. Garcia reports receiving consulting honoraria and research support from Bristol-Myers Squibb, AstraZeneca, and Sanofi-Aventis. Coauthor Dr Elaine M Hylek (Boston University School of Medicine, MA) reports having served on advisory boards for Bristol-Myers Squibb and receiving research support from AstraZeneca and Bristol-Myers Squibb.
