Higher platelet activity is present in patients with restenosis after percutaneous coronary intervention compared with patients with an occlusion of coronary artery bypass graft.

The aim of the study was to compare platelet activity between patients with an occlusion of bypass graft after coronary artery bypass graft surgery and restenosis after percutaneous coronary intervention (PCI); that is, between patients with reappearance of ischemia after two different kinds of coronary revascularization. Thirty patients were studied in a cross-sectional designed study. Fifteen of them were patients with the worst bypass graft patency from Prague-4 study (control protocol-driven coronary angiography performed at 1 year after surgery; originally 47 bypass grafts implanted, 94% of venous grafts occluded). The remaining 15 were patients with restenosis 3-12 months after PCI. Blood samples were drawn at least 12 weeks after coronary angiography. Platelet activity was determined by membrane expression of P-selectin (CD62P, % of positive cells) by flow cytometry, aggregability by ADP aggregometry. Data are expressed as mean +/- SEM. Both groups were similar with respect to age, BMI and presence of diabetes mellitus. No patient suffered from acute coronary syndrome. P-selectin expression was significantly higher in the patients with restenosis compared with patients with bypass graft occlusion (1.96 +/- 0.07 vs. 0.77 +/- 0.03, P < 0.001, Wilcoxon test). ADP aggregometry was not different between groups (55.5 +/- 1.1 vs. 56.1 +/- 0.8, P = NS). Higher platelet activity is present in the patients with restenosis after PCI compared with the patients with the occlusion of bypass graft. Platelet activity play more important role in the development of restenosis after PCI compared with the occlusion of bypass graft after coronary artery bypass graft surgery, at least in the period up to 1 year after revascularization.

Fibrinolytic inhibitors in off-pump coronary surgery: a prospective, randomized, double-blind TAP study (tranexamic acid, aprotinin, placebo).

OBJECTIVE: To evaluate and compare hemostatic effects of tranexamic acid vs. aprotinin vs. placebo in off-pump coronary artery bypass (OPCAB) surgery and, in addition, to assess the safety of fibrinolytic inhibitors therapies. METHODS: In a prospective, randomized, double-blind study finally 91 patients undergoing OPCAB were investigated (group A, n=32, tranexamic acid 1g before skin incision and continuously 200mg/h; group B, n=29, aprotinin 1,000,000IU before skin incision and 250,000IU/h; group C, n=30, placebo). RESULTS: Highly significant inter-group differences were found in cumulative blood loss within 4h (geometric means [95% confidence intervals]-group A: 89.3 [72.7, 109.8] mL, group B: 72.3 [49.2, 106.3] mL and group C: 192.3 [151.8, 243.5] mL) (P<0.001), within 8h (group A: 152.1 [120.7, 191.6] mL, group B: 130.3 [88.1, 192.8] mL and group C: 283.8 [226.0, 356.3] mL) (P=0.001), and within 24h postoperatively (group A: 410.3 [337.6, 498.6] mL, group B: 345.8 [256.0, 398.2] mL and group C: 619.8 [524.3, 732.8] mL) (P<0.001). At all time points, placebo group C was significantly distinct from the groups treated with fibrinolytic inhibitors (groups A and B). However, no differences between groups A and B were found. Both mean hemoglobin and hematocrit values 24h postoperatively were different between the groups (P=0.018 and P=0.077, respectively), acheiving the lowest value in group C. Number of re-transfuzed patients was highest in group C, but without statistical significance (either packed red blood cells, P=0.119 or fresh-frozen plasma, P=0.118). We observed one postoperative myocardial infarction in aprotinin treated group B and one temporary postoperative myocardial ischemia in placebo group C, no cerebrovascular or pulmonary embolism was noticed. Treated groups A and B did not demonstrate postoperative increase in mean levels of myocardial enzymes, compared with group C. Significantly higher mean values of D-dimer were found in group C 24h postoperatively (P<0.001). CONCLUSIONS: Both tranexamic acid and aprotinin seem to be similarly effective in the reduction of postoperative blood loss in OPCAB. Tranexamic acid appears to be cost-effective and safe alternative to aprotinin.

One-year coronary bypass graft patency: a randomized comparison between off-pump and on-pump surgery angiographic results of the PRAGUE-4 trial.

BACKGROUND: Off-pump coronary bypass surgery has become a widely used technique during recent years. However, limited data are available with regard to 1-year patency of bypass grafts implanted on the beating heart in unselected consecutive bypass surgery candidates. The aim of this study was to compare 1-year angiographic patency of bypass grafts done on the beating heart (off pump) with those done classically (on pump). METHODS AND RESULTS: The PRAGUE-4 trial randomized 400 consecutive nonselected cardiac surgery candidates into group A (on pump; n=192) and group B (off pump; n=208). One-year follow-up coronary angiography was done in 255 patients. The arterial graft patency after 1 year was 91% in both groups. Saphenous graft patency was 59% (on pump) versus 49% (off pump; P=NS). Saphenous graft patency per patient was lower in the off-pump group: 0.7 patent anastomosis per patient versus 1.1 patent anastomosis in the on-pump group (P<0.01). There were 46% on-pump patients with all grafts patent versus 52% off-pump patients (P=NS). Grafts anastomosed distally to collateralized chronic total occlusions of native coronary arteries remained patent in 100% on the left anterior descending artery compared with 23% on other arteries (P<0.0001). CONCLUSIONS: The patency of arterial coronary bypass grafts done on the beating heart is excellent and equal to grafts done on pump. The off-pump procedure in the unselected patient population results in fewer patent saphenous grafts per patient.

Off-pump versus on-pump coronary surgery: final results from a prospective randomized study PRAGUE-4.

BACKGROUND: Off-pump coronary artery bypass surgery is becoming increasingly popular despite the lack of sufficient evidence from randomized trials. The aim of our prospective, randomized, single-center study was to examine the role of off-pump revascularization among nonselected patients. METHODS: A total of 400 consecutive nonselected patients (mean age 63 years) scheduled for isolated coronary revascularization were randomized by a cardiologist into two groups: A (on-pump) and B (off-pump). The cardiac surgeon was allowed to change the operative technique at any time after randomization. The only exclusion criterion was an emergency procedure. The primary end point was any of the following within 30 days: death, myocardial infarction, stroke, or new renal failure requiring hemodialysis. The study was analyzed on the intention-to-treat principle. RESULTS: The primary end point occurred in 4.9% of patients in group A versus 2.9% in group B (not significant). Mortality was 1.1% in group A versus 2.0% in group B (not significant). Preoperative crossover occurred in 5.4% of patients in each group (not significant). Intraoperative conversion was necessary in 9.8% of patients in group B versus 1.1% of patients in group A (p < 0.001). Group B patients had fewer distal anastomoses (2.3 versus 2.7 in group A; p < 0.001), less blood loss (560 versus 680 mL; p < 0.001), lower postoperative creatine kinase MB levels (0.15 versus 0.56 microkat/L; p < 0.001) and lower total hospital costs (3,451 versus 4,387; p < 0.001). CONCLUSIONS: In our study off-pump technique was applicable in 85% of nonselected patients and is at least as clinically safe and effective as on-pump surgery.