Association of lipoprotein(a) level with short- and long-term outcomes after CABG: The role of lipoprotein apheresis.

OBJECTIVE: To evaluate the association of lipoprotein(a) [Lp(a)] level with short- and long-term outcomes after coronary artery bypass grafting (CABG) and to assess the effect of a 12 month course of weekly lipoprotein apheresis on vein graft patency and coronary atherosclerosis course in post-CABG patients with hyperlipidemia. METHODS: This study was performed in patients after successful CABG and consisted of three parts: a) a retrospective part with computed tomography assessment of vein graft patency in patients with first-year recurrence of chest pain after CABG (n = 102); b) a prospective trial with evaluation of cardiovascular outcomes during follow up time up to 15 years in relation to baseline Lp(a) levels (n = 356); c) an 12-months interventional controlled study in 50 patients with low-density lipoprotein cholesterol (LDL-C) levels >2.6 mmol/L prior to the operation despite statin treatment that allocated into 2 groups: active (n = 25, weekly apheresis by cascade plasma filtration (CPF) plus atorvastatin), and control (n = 25, atorvastatin alone). RESULTS: Patients subjected to computed tomography were divided in two groups: 66 (65%) with at least one vein graft occlusion and 36 (35%) without occlusions. Lp(a) levels were significantly higher in patients with occluded grafts with a median (95% confidence intervals (CI)) of 24 (17-42) mg/dL vs. 12 (6-24) mg/dL in patients with patent grafts, p < 0.01. Over a mean of 8.5 ± 3.5 years (range 0.9-15.0 years), the primary and secondary endpoints were registered in 46 (13%) and 107 (30%) patients, respectively. Patients with Lp(a) ≥30 mg/dL were at significantly greater risk for the primary endpoint (hazard ratio (HR) 2.98, 95% confidence interval (CI) 1.76-5.03, p < 0.001) and secondary endpoint (HR 3.47, 95%CI 2.48-4.85, p < 0.001) than patients with Lp(a) values <30 mg/dL. During the CPF procedure LDL-C levels decreased by 59 ± 14%, Lp(a) levels by 49 ± 15. The frequency of vein graft occlusions at study end was 14.3% (11 of 77) in the apheresis group and 27.4% (23 of 84) in the control group, p < 0.05. Progression of atherosclerosis was obtained in 26 (14.2%) segments of native coronary arteries in the apheresis group and in 50 (25.0%) segments of the control group. Regression signs were found in 30 (16.4%) and 19 (9.5%) segments, stabilization in 127 (69.4%) and 131 (65.5%) segments, respectively (χ2 = 9.37, p < 0.01). A Lp(a) level higher than 30 mg/dL was associated with a three-fold increased risk of vein grafts occlusion during first year after CABG, p < 0.001. CONCLUSION: Our data suggest that elevated Lp(a) is associated with a significantly increasing rate of one-year vein graft occlusions and adverse long-term cardiovascular outcomes whereas the use of lipoprotein apheresis improves vein graft patency during the first year after CABG.

Cascade plasma filtration during the first year after CABG in patients with hyperlipidemia refractory to statins.

OBJECTIVE: To evaluate the effect of a 12-month course of weekly lipid apheresis on vein graft patency after coronary artery bypass grafting (CABG) in patients with hyperlipidemia refractory to statins. METHODS: In a 12-month prospective controlled clinical trial we enrolled 34 male patients (mean age 57 ± 8 years) who passed through successful CABG and low-density lipoprotein cholesterol (LDL-C) level >2.6 mmol/L prior to the operation despite statin treatment. Patients were allocated into 2 groups: active (n = 17, weekly apheresis by cascade plasma filtration (CPF) plus atorvastatin), and control (n = 17, atorvastatin alone). Graft patency was evaluated by multislice computed tomography at 3 months and by angiography at 12 months after an operation. RESULTS: Both groups were comparable in clinical and biochemical characteristics. During each CPF procedure, LDL-C level decreased by 64 ± 9%, apoB - by 65 ± 8%, Lp(a) - by 52 ± 15%,; these changes were significant compared to baseline and the control group. Mean net difference in LDL-C level between apheresis and control groups was 1.1 ± 0.3 mmol/L. Vein graft patency at study end was 88.2% (45 of 51) in the apheresis group versus 72.7% (40 of 55) in the control group (p = 0.05). Use of apheresis was associated with decreased vein graft occlusions by 46%: relative risk 0.54; 95% confidence interval 0.27 to 1.02; p = 0.05. CONCLUSION: Our data suggest that the use of lipoprotein apheresis with CPF results in a better vein graft patency during the first year after CABG in patients with hyperlipidemia refractory to statins.

Association of lipoprotein(a) excess with early vein graft occlusions in middle-aged men undergoing coronary artery bypass surgery.

OBJECTIVE: To assess the relationship of lipoprotein(a) to early vein graft occlusions in patients after coronary artery bypass grafting. METHODS: We studied 102 male patients (mean age 52.3 +/- 8.6 years) with chest pain occurrence during the first year (mean time 5.3 +/- 3.0 months) after surgical myocardial revascularization. Graft patency was examined by electron-beam computed tomography (n = 102) and quantitative coronary angiography (n = 31). RESULTS: Patients were divided into 2 groups according to graft patency data: 66 (65%) with occlusions and 36 (35%) without occlusions at follow-up. No significant differences were found between the groups concerning age, smoking, family history of coronary heart disease, previous myocardial infarction, hypertension, serum lipids, and apolipoprotein B. Lipoprotein(a) level was significantly higher in patients with occluded grafts with a median (95% confidence intervals) of 24 mg/dL (17-42 mg/dL) versus 12 mg/dL (6-24 mg/dL) in patients with patent grafts, P <.01. More patients with nonoccluded grafts were taking statins postoperatively: 42% versus 18% of patients with occluded grafts, P <.05. The sensitivity and specificity of electron-beam computed tomography in revealing vein graft occlusion was close to 100%. CONCLUSION: There is an association between high lipoprotein(a) level and vein graft occlusions in middle-aged men during the first year after coronary artery bypass grafting. Use of statins is associated with a lower rate of vein graft occlusion. Electron-beam tomography could be useful for assessing graft occlusions.