Off-Pump Coronary Artery Bypass Surgery May Produce a Hypercoagulable Patient

Abstract

<P>Background: The incidence of thromboembolic events following traditional open heart surgery has not been clinically significant. However, with beating heart surgery, for which cardiopulmonary bypass (CPB) is not required, the incidence of spontaneous intravascular thrombosis may be similar to that encountered after general surgeries. Compounding this risk is that many cases of off-pump coronary artery bypass (OPCAB) surgery are reserved for the elderly patient with multiple comorbidities. The few studies to date that have assessed the coagulation profile in OPCAB patients have been limited to the first 24 hours after surgery. </P><P>Methods: We prospectively studied 17 OPCAB and 6 on-pump patients over 4 days (hospital course) with daily thromboelastography. A coagulation index (CI) (reflecting R and K times, a angle, and maximum amplitude [MA]) was calculated for the patients, who served as their own controls. </P><P>Results: The OPCAB patients demonstrated 3 days postoperatively a 17% increase in coagulation compared with the baseline. Specifically, the CI consistently revealed an elevation in the a angle and the MA, both of which reflect increased fibrinogen and platelet activity. On the other hand, 3 days following surgery the CI of the CPB group was tightly clustered around their respective baseline CI values, which had recovered from a significant decrease immediately after surgery. </P><P>Conclusion: A state of hypercoagulability, as measured by thromboelastography, exists in the OPCAB patient beyond the first postoperative day, and this finding suggests that prophylactic postoperative anticoagulation therapy targeting fibrinogen and platelet activity may be indicated for these patients.</P>

Antithrombotic- and anticoagulation regimens in OPCAB surgery. A Nordic survey

“…Other studies have reported the same trend. Quigley et al (15) have proved clinical evidence of hypercoagulability measured by thromboelastography in patients undergoing OPCAB that exists beyond the first postoperative day. Casati et al (16) have investigated activation of coagulation and fibrinolysis comparing OPCAB and CABG with CPB.…”

Off-Pump Versus On-Pump Coronary Artery Surgery Identification of Fibrinolysis Using Rotation Thromboelastography; A Preliminary, Prospective, Randomized Study

“…The observation of significantly increased D-dimer levels in on-pump group B at the end of surgery and the equalization of elevated D-dimer levels between the on-pump and off-pump groups 24 hours after the surgery is in agreement with the findings of others. 10,11) The question of a possibly delayed increase in coagulant and fibrinolytic activity in off-pump surgery arises and slightly controversial clinical conclusions [23][24][25] should warrant further studies. Thromboelastography provides a complete graphical representation of blood coagulation and eventual subsequent lysis of the clot in almost real time.…”

Secondary Prevention After Coronary Artery Bypass Graft Surgery

“…Several reports have documented the existence of a relative hypercoagulable state after off-pump surgery, associated with higher levels of postoperative platelet activity and a decrease in platelet sensitivity to aspirin after OPCAB. [52][53][54][55][56][57][58][59][60] Moreover, in some early studies of graft patency after OPCAB, vein graft occlusion was noticeably higher both early and late after OPCAB compared with conventional CABG. 53,61 Questions were therefore raised about whether antiplatelet therapy with aspirin alone would be sufficient for patients after OPCAB, and as early as 2003, leading off-pump centers instituted policy changes to treat all OPCAB patients with both clopidogrel and aspirin after surgery for a duration of 3 months.…”