Optimal Anticoagulation during Off Pump Coronary Artery Bypass in Patients Recently Exposed to Clopidogrel

Abstract

PurposeThe aim of this study was to find an optimal range of activated clotting time (ACT) during off-pump coronary artery bypass surgery (OPCAB) yielding ischemic protection without the risk of hemorrhagic complications in patients with recent exposure to dual antiplatelet therapy.Materials and MethodsThree hundred and five patients who received aspirin and clopidogrel within 7 days of isolated multi-vessel OPCAB were retrospectively studied. Combined hemorrhagic and ischemic outcome was defined as the occurrence of 1 of the following: significant perioperative bleeding (>30% of estimated blood volume), transfusion of packed red blood cell (pRBC) ≥2 U, or myocardial infarction (MI). This was compared in relation to the tertile distribution of the time-weighted average ACT-212-291 sec (first tertile), 292-334 sec (second tertile), 335-485 sec (third tertile).ResultsThe amount of perioperative blood loss was 937±313 mL, 1014±340 mL, and 1076±383 mL, respectively (p=0.022). Significantly more patients in the third tertile developed MI (4%, 4%, and 12%, respectively, p=0.034). The incidence of significant perioperative blood loss and transfusion of pRBC ≥2 U were lower in the first tertile than those of other tertiles without statistical significance. In the multivariate analysis, the first tertile was associated with a 52% risk reduction of combined hemorrhagic and ischemic outcomes (95% confidence interval: 0.25-0.92, p=0.027).ConclusionA lower degree of anticoagulation with a reduced initial heparin loading dose should be carefully considered for patients undergoing OPCAB who have recently been exposed to clopidogrel.

High activated clotting time, or venous graft, or off-pump coronary artery bypass grafting? Too early to call off the party!

“…Some of them included only patients with a high pretest probability (eg, enlarged, positron emission tomography-positive lymph nodes) or excluded patients with lymph nodes that would not likely be accessed by EBUS. 2,3 The sensitivity in our study, which included patients with normal-sized lymph nodes and inaccessible lymph nodes by EBUS, and excluded patients with bulky lymph nodes, is lower than that in the previous reports. Especially in patients with normal mediastinum on computed tomography and positron emission tomography, we encountered difficulty detecting mediastinal metastases by EBUS-TBNA.…”

“…We thank Smith 1 and Saha 2 for their comments in response to our article regarding graft patency in the Danish On-pump Versus Off-pump Randomization Study. 3 They have noted that a high proportion of the graft obstructions were found at the proximal anastomoses, which they believe should not be influenced by the use of cardiopulmonary bypass.…”

“…1 An added advantage of maintaining a lower ACT during OPCAB is lesser blood loss. 3 In the long-term survival study of Kim and colleagues, 4 significantly higher incidences of diabetes and hypertension in the OPCAB group may have contributed to a higher long-term all-cause mortality, rather than inferior graft patency of OPCAB per se. It is interesting to note that in that study 4 2 operators (operators C and D) were associated with higher long-term mortalities after OPCAB, and they performed more conventional CABG than OPCAB procedures.…”

“…1 Recently, it was noted that during OPCAB an ACT longer than 350 seconds is associated with a significantly higher rate of postoperative myocardial infarction. 3 It is presumed that at a longer ACT there may be platelet activation leading to a detrimental effect, 3 very similar to the situation with percutaneous coronary intervention, in which a longer ACT is always avoided for the same reason. Physiology during OPCAB is similar to that during percutaneous coronary intervention rather than to that during conventional CABG.…”

Comparison of two doses of heparin on outcome in off-pump coronary artery bypass surgery patients: A prospective randomized control study

“…used activated clotting time (ACT) as a measure of systemic heparinization instead of standardizing the dose of heparin. [ 12 ] Tanaka et al . studied the effects of varying doses of heparin used for systemic heparinization in patients undergoing OPCAB and concluded that total dose of heparin and protamine required in OPCAB was lower than that of surgery conducted under CPB.…”