Relative importance of patient, procedural and anatomic risk factors for early vein graft thrombosis after coronary artery bypass graft surgery

Johns Hopkins School of Medicine, Baltimore, MD, USA.
The Journal of cardiovascular surgery (Impact Factor: 1.46). 12/2011; 52(6):877-85.
Source: PubMed


The aim of the present study was to investigate the relative importance of a wide array of patient demographic, procedural, anatomic and perioperative variables as potential risk factors for early saphenous vein graft (SVG) thrombosis after coronary artery bypass graft (CABG) surgery.
The patency of 611 SVGs in 291 patients operated on at four different hospitals enrolled in the Reduction in Graft Occlusion Rates (RIGOR) study was assessed six months after CABG surgery by multidetector computed tomography coronary angiography or clinically-indicated coronary angiography. The odds of graft occlusion versus patency were analyzed using multilevel multivariate logistic regression with clustering on patient.
SVG failure within six months of CABG surgery was predominantly an all-or-none phenomenon with 126 (20.1%) SVGs totally occluded, 485 (77.3%) widely patent and only 16 (2.5%) containing high-grade stenoses. Target vessel diameter ≤ 1.5 mm (adjusted OR 2.37, P=0.003) and female gender (adjusted OR 2.46, P=0.01) were strongly associated with early SVG occlusion. In a subgroup analysis of 354 SVGs in which intraoperative graft blood flow was measured, lower mean flow was also significantly associated with SVG occlusion when analyzed as a continuous variable (adjusted OR 0.984, P=0.006) though not when analyzed dichotomously, <40 mL/min versus ≥ 40 mL/min (adjusted OR 1.86, P=0.08).
Small target vessel diameter, female gender and low mean graft blood flow are significant risk factors for SVG thrombosis within six months of CABG surgery in patients on postoperative aspirin therapy. This information may be useful in guiding revascularization strategies in selected patients.

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    • "In the present study, prediabetes was found to be associated with diffuse coronary narrowing and small vessel disease particularly in distal coronary arteries for both genders, particularly in the LAD (Tables 1 and 2). Since patients with small vessels present a higher risk for an adverse outcome after PCI [10] [11] or CABG especially in the LAD coronary artery [14] [15] [16] [17], this finding is particularly important for early detection of prediabetes in daily cardiology practice. "
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    ABSTRACT: A significant number of patients may not benefit from conventional techniques of myocardial revascularization due to diffuse coronary artery disease (CAD) or small coronary arterial sizes because of smaller arteries causing anastomotic technical difficulties and poor run-off. Diabetic patients have a more severe and diffuse coronary atherosclerosis with smaller coronary arteries limiting the possibility to perform a successful and complete revascularization, but this has not been examined in prediabetics. To evaluate whether there is an association between prediabetes and the coronary arterial size. We prospectively studied 168 consecutive patients with CAD and 172 patients with normal coronary artery anatomy (NCA). Patients were divided into three groups according to hemoglobin (Hb) A1c levels as "normal," "prediabetic," and "diabetic" groups, and the coronary artery sizes and Gensini scores were analyzed. There were 78 female patients and 90 male patients in the CAD group, and 87 female patients and 85 male patients in the NCA group. There was a statistically significant difference in distal and proximal total coronary arterial size among the CAD and NCA groups for both genders. There was a positive correlation between the HbA1c subgroups and Gensini score (Spearman's ρ: 0.489, p<0.001 in female group; Spearman's ρ: 0.252 p=0.016 in male group). We found that prediabetic patients have a smaller coronary size and diffuse coronary narrowing for both genders, particularly in distal coronary arterial tree of left anterior descending coronary artery. The early detection of prediabetes in daily cardiology practice may provide more appropriate coronary lesion for percutaneous or surgical revascularization.
    Full-text · Article · Sep 2013 · Journal of Cardiology
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    ABSTRACT: Radial artery (RA) grafts are an attractive second arterial conduit after the left internal thoracic artery (LITA) for coronary artery bypass graft (CABG) surgery. However, long-term outcomes and the need for subsequent reintervention have not been defined. We performed a retrospective cohort study of our single institution's 16-year experience with 1851 consecutive patients (average age, 58 years; 82% men, 36% diabetic) undergoing primary, isolated CABG with the LITA, RA, and saphenous vein as needed. Average grafts per patient were 3.8, with 2.4 arterial grafts per patient. Survival was determined using the Social Security Death Index. Grafts were nonpatent if they had a >50% stenosis, a string sign, or were occluded. Five patients (0.3%) died in hospital and 0.8% had a myocardial infarction, 1.1% a stroke, and 0.6% renal failure. Kaplan-Meier-estimated 1-, 5-, 10-, and 15-year survival was 99%, 96%, 89%, and 75%, respectively. Of the cohort, 278 symptomatic patients underwent cardiac catheterization at our institution an average of 5.0±3.8 years (range, 0.1-12 years) after CABG. Overall RA (n=420 grafts) patency was 82% and SV (n=364 grafts) patency, 47% (P<0.0001). LITA (n=287 grafts including 9 sequential grafts) patency was 85% and right internal thoracic artery (n=15 grafts) patency was 80% (P=0.6). RA patency was not different from LITA patency (P=0.3). Overall freedom from catheterization, percutaneous coronary intervention, and CABG was 85%, 97%, and 99%, respectively. RA grafting is a highly effective revascularization strategy providing excellent short and long-term outcomes with very low rates of reintervention. RA patency is similar to LITA patency and is much better than SV patency. RA grafting should be more widely utilized in patients undergoing CABG.
    Full-text · Article · Sep 2012 · Circulation
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    ABSTRACT: Background: Elevated urine 11-dehydro TXB(2) , an indicator of persistent thromboxane generation in aspirin-treated patients, correlates with adverse cardiovascular outcome and has recently been identified as an independent risk factor for vein graft thrombosis after cardiac bypass surgery in the Reduction in Graft Occlusion Rates (RIGOR) study. The polyclonal antibody-based ELISA used to measure 11-dehydro TXB(2) in these studies is no longer clinically available and has been supplanted by an FDA-cleared second-generation monoclonal antibody-based ELISA. Objectives: To compare the laboratory and clinical performance of the first- and second-generation assays in a well-defined study population. Methods: 11-dehydro TXB(2) was quantified in 451 urine samples from 229 RIGOR subjects using both ELISA. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and spiking studies were used to investigate discordant assay results. The association of 11-dehydro TXB(2) to clinical outcome was assessed for each assay using multivariate modeling. Results: Median 11-dehydro TXB(2) levels were higher by monoclonal antibody- compared to polyclonal antibody-based ELISA (856 versus 399 pg/mg creatinine, p<0.000001), with the latter providing values similar to UPLC-MS/MS. This discrepancy was predominantly due to cross-reactivity of the monoclonal antibody with 11-dehydro-2,3-dinor TXB(2) , a thromboxane metabolite present in similar concentration but with poor direct correlation to 11-dehydro TXB(2) . In contrast to the first-generation ELISA, 11-dehydro TXB(2) measured by the monoclonal antibody-based ELISA failed to associate with risk of vein graft occlusion. Conclusion: Quantification of urine 11-dehydro TXB(2) by monoclonal antibody-based ELISA was confounded by interference from 11-dehydro-2,3-dinor TXB(2) which reduced the accuracy and clinical utility of this second-generation assay. © 2012 International Society on Thrombosis and Haemostasis.
    Full-text · Article · Oct 2012 · Journal of Thrombosis and Haemostasis
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