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Objective: Several centers have established that off-pump, multivessel coronary artery bypass grafting performed via a small thoracotomy (MVST) is feasible. However, this procedure can be challenging when posterolateral coronary targets need to be grafted. We hypothesized that use of cardiopulmonary bypass via peripheral access (MVST-PA) would improve outcomes compared with a completely off-pump approach (OP-MVST)., Methods: This was a prospective observational study of patients undergoing OP-MVST (n = 46) versus MVST-PA (n = 45) using bilateral internal mammary artery grafts onto the left anterior descending coronary artery and circumflex/right coronary artery distribution. Hemostasis was quantified by measuring platelet function (aggregometry), chest tube output, thrombolysis in myocardial infarction bleeding score (%hematocrit change at 24 hours), and transfusion requirements. The rate of mortality and major morbidity at 30 days was defined according to The Society of Thoracic Surgeons criteria. Estimated glomerular filtration rate (normalized to baseline levels) was determined daily until discharge., Results: The OP-MVST versus MVST-PA groups had similar risk factors at baseline and risks of composite morbidity/mortality at 30 days. However, renal failure was significantly increased after OP-MVST (10.87 vs 0%, P = 0.05), and MVST-PA affected hemostasis as evidenced by inhibition of platelet function (latency to response on aggregometry, 29.9 vs 17.9 seconds; P = 0.04) and higher transfusion requirement (2.31 vs 0.85 units of red blood cells/patient, P = 0.04; 55.6% vs 34.8% transfused; P = 0.059). However, 24-hour chest tube output was similar (645 vs 750 mL; P = 0.53)., Conclusions: In comparison with a completely off-pump strategy, use of cardiopulmonary bypass to assist MVST reduced the risk of renal dysfunction with only modest tradeoffs in other morbidities, for example, altered coagulation and higher transfusion requirements. These data justify further study of the effect of MVST-PA on renal complications.

Background: Off-pump coronary artery bypass (OPCAB) surgery is associated with a hypercoagulable state in which the platelet thrombin receptor, protease-activated receptor-1 (PAR-1), helps propagate a thrombin burst within saphenous vein grafts. Aprotinin, used in cardiothoracic surgery mainly for its antifibrinolytic properties, also spares platelet PAR-1 activation due to thrombin. We hypothesized that this PAR-1 antagonistic property provides an antithrombotic benefit during OPCAB surgery., Methods: Patients were randomly assigned to receive saline (n = 38) or a modified full-dose regimen of aprotinin (n = 37) IV during OPCAB surgery. Blood sampled perioperatively from the coronary sinus, skin wounds, and systemic circulation was analyzed to test coagulation and platelet function. Major adverse cardiovascular events were monitored by obtaining troponin I at 24 h (myocardial infarction), predischarge computed tomography angiography (vein graft thrombosis), and by clinical examination for stroke., Results: Coronary sinus blood obtained immediately after OPCAB surgery showed significantly less activation in the aprotinin group, as judged by reduced formation of platelet-leukocyte conjugates (P < 0.02) and platelet-derived microparticles (P < 0.05). The aprotinin group showed inhibition of platelet aggregation induced by thrombin (P = 0.007) but not adenosine diphosphate. Thrombin generation, defined by F1.2 levels, was significantly reduced by aprotinin in the coronary sinus but not in skin wound incisions. Major adverse cardiovascular events were significantly reduced in aprotinin-treated patients (5.4% vs 29.7%, P < 0.05). Aprotinin also demonstrated antifibrinolytic properties through diminished red blood cell transfusion (P < 0.04) and reduced blood loss postoperatively (603 +/- 330 vs 810 +/- 415 mL, P < 0.004)., Conclusion: This study demonstrates that aprotinin protects patients undergoing OPCAB surgery from a hypercoagulable state by diminishing thrombin-induced platelet activation and thrombin generation within saphenous vein grafts, while maintaining systemic hemostatic and antifibrinolytic benefits. These results support further investigation of aprotinin and other PAR-1 antagonists in OPCAB surgery.

Background: Minimally invasive coronary artery bypass grafting (miniCABG) decreases in-hospital morbidity versus traditional sternotomy CABG. We performed a prospective cohort study (NCT00481806) to assess the impact of miniCABG on costs and metrics that influence quality of life after hospital discharge., Methods: One hundred consecutive miniCABG cases performed using internal mammary artery (IMA) grafting +/- coronary stenting were compared with a matched group of 100 sternotomy CABG patients using IMA and saphenous veins, both treating equivalent number of target coronaries (2.7 vs. 2.9), off-pump. We compared perioperative costs, time to return to work/normal activity, and risk of major adverse cardiac/cerebrovascular events (MACCE) at 1 year: myocardial infarction (elevated troponin or EKG changes), target vessel occlusion (CT angiography at 1 year), stroke, or death., Results: For miniCABG, robotic instruments and stents increased intraoperative costs; postoperative costs were decreased from significantly less intubation time (4.80 +/- 6.35 vs. 12.24 +/- 6.24 hours), hospital stay (3.77 +/- 1.51 vs. 6.38 +/- 2.23 days), and transfusion (0.16 +/- 0.37 vs. 1.37 +/- 1.35 U) leading to no significant differences in total costs. Undergoing miniCABG independently predicted earlier return to work after adjusting for confounders (t = -2.15; P = 0.04), whereas sternotomy CABG increased MACCE (HR, 3.9; 95% CI, 1.4-7.6), largely from lower target-vessel patency., Conclusions: MiniCABG shortens patient recovery time, minimizes MACCE risk at 1 year, and showed superior quality and outcome metrics versus standard-of-care CABG. These findings occurred without increasing costs and with superior target vessel graft patency.

Objective: : Early benefits from transmyocardial laser revascularization (TMR) may be related to acute sympathetic denervation. This study hypothesized that TMR as an adjunct to off-pump coronary artery bypass (OPCAB) would improve myocardial runoff in the TMR-treated regions and increase graft flow., Methods: : Graft blood flow was measured in 145 consecutive OPCAB patients. In patients with graft flow <40 mL/min (n = 25), the myocardial region served by the graft was treated with TMR. Blood flow was reassessed 10 minutes after TMR and compared with graft flow in the nontreated regions. Postoperative outcomes, transcardiac thrombin production, coagulation activation, myocardial, and inflammatory markers were assessed. A control group not treated with TMR (n = 14) was selected with similar graft flows and other baseline characteristics., Results: : Risk factors, comorbidities, and preoperative medications were similar in all groups. TMR led to a 48% increase in bypass graft flow in 12 patients, but no significant change in flow in the remainder (n = 13). The control group also showed no change in graft flow measured during the same time-points. Compared with those that did not respond to TMR, responders showed a greater drop in pH during warm ischemia caused by distal anastomoses during OPCAB and significantly higher transcardiac gradients of F1.2, IL-8, TNFα, and VCAM., Conclusions: : TMR acutely improves venous bypass graft flow in regions with more severe myocardial acidosis and inflammation during and after OPCAB. Acute sympathetic denervation after TMR may provide mechanistic insight into the early clinical benefits of TMR as an adjunct to OPCAB.

OBJECTIVE: It is believed that off-pump coronary artery bypass grafting (OPCAB) leads to hypercoagulability, but efforts to document such a state have been unrevealing. We hypothesized that OPCAB increases the risk of developing a regional hypercoagulable state. METHODS: Blood was obtained from the aorta and coronary sinus (CS) after CABG performed off- (N=69) or on-pump (N=35) to determine the transcardiac gradients of F1.2 (thrombin production), XIIa (coagulation activation), myoglobin (ischemia) and IL-6, IL-8 using ELISA and platelet-derived microparticles using FACS. Platelet function was measured using aggregometry. Regional myocardial pH and SVG flow were recorded intraoperatively. SVG biopsies were analyzed for endothelial integrity (EI) using immunohistochemistry and graft patency was determined by predischarge CT angiography. RESULTS: Compared with on-pump, OPCAB provoked significantly higher transcardiac F1.2 (117±200 v. 31±38%), FXII-a (14±29 v. 2±4%), microparticles (14±-9.5% v. 6.4±-4.1%), IL-6 (119±183 v. 28±39%), and a trend toward increased IL-8 (67±94 v. 24±46%, P = 0.077). Myoglobin release after OPCAB, also greater than on-pump CABG (54±89 v. 8±14%, P < 0.01), correlated with regional pH change (R=-0.96, P < 0.0001), and F1.2 release (R=0.55, P = 0.0002). In contrast, systemic changes in these markers were all less after OPCAB. SVG flow was significantly reduced in OPCAB (39.4 versus 66.5 mL/min, P = 0.0002), but EI and graft patency rates were the same. CONCLUSIONS: Through the use of transcardiac assays, we illustrated that regional coagulation was enhanced after off- compared with on-pump CABG. If the findings of this pilot study are confirmed, OPCAB may require additional antithrombotic therapies to respond to this local hypercoagulable state.