vitamin-b-12 and Coronary-Restenosis

Restenosis after percutaneous coronary angioplasty (PTCA) remains an important limitation of this procedure.. To assess the relationship between homocysteine levels and restenosis after PTCA, and discuss the potential benefit of homocysteine-lowering therapy.. MEDLINE-based literature review.. The conflicting literature on the association between homocysteine levels and restenosis after PTCA can partially be explained by differences in methodology. Depending on the type of studies considered, a pooling of data resulted in a 22%-36% risk reduction of restenosis in lesions exposed to low homocysteine levels. The strongest reduction was found in balloon-only treated lesions (42%), while only a trend (14%) was seen in stented lesions. Based on the only available trial, homocysteine-lowering therapy yielded a 54% restenosis rate reduction, 76% in balloon-only treated lesions and 31% in stented lesions. Furthermore, homocysteine-lowering therapy provided a significant clinical benefit with a 40% relative reduction in major adverse events at 6 months' follow-up.. This review suggests that plasma homocysteine is a modifiable risk factor for restenosis, which when lowered improves outcome after PTCA. This inexpensive treatment with virtually no side-effects could therefore be considered as adjunctive therapy for patients undergoing PTCA, while awaiting results from further studies.

Topics: Angioplasty, Balloon, Coronary; Biomarkers; Coronary Restenosis; Folic Acid; Homocysteine; Humans; Risk Assessment; Risk Factors; Treatment Outcome; Vitamin B 12; Vitamin B 6

Vitamin therapy to lower homocysteine levels has recently been recommended for the prevention of restenosis after coronary angioplasty. We tested the effect of a combination of folic acid, vitamin B6, and vitamin B12 (referred to as folate therapy) on the risk of angiographic restenosis after coronary-stent placement in a double-blind, multicenter trial.. A total of 636 patients who had undergone successful coronary stenting were randomly assigned to receive 1 mg of folic acid, 5 mg of vitamin B6, and 1 mg of vitamin B12 intravenously, followed by daily oral doses of 1.2 mg of folic acid, 48 mg of vitamin B6, and 60 microg of vitamin B12 for six months, or to receive placebo. The angiographic end points (minimal luminal diameter, late loss, and restenosis rate) were assessed at six months by means of quantitative coronary angiography.. At follow-up, the mean (+/-SD) minimal luminal diameter was significantly smaller in the folate group than in the placebo group (1.59+/-0.62 mm vs. 1.74+/-0.64 mm, P=0.008), and the extent of late luminal loss was greater (0.90+/-0.55 mm vs. 0.76+/-0.58 mm, P=0.004). The restenosis rate was higher in the folate group than in the placebo group (34.5 percent vs. 26.5 percent, P=0.05), and a higher percentage of patients in the folate group required repeated target-vessel revascularization (15.8 percent vs. 10.6 percent, P=0.05). Folate therapy had adverse effects on the risk of restenosis in all subgroups except for women, patients with diabetes, and patients with markedly elevated homocysteine levels (15 micromol per liter or more) at baseline.. Contrary to previous findings, the administration of folate, vitamin B6, and vitamin B12 after coronary stenting may increase the risk of in-stent restenosis and the need for target-vessel revascularization.

Topics: Aged; Coronary Angiography; Coronary Disease; Coronary Restenosis; Coronary Vessels; Double-Blind Method; Drug Therapy, Combination; Female; Folic Acid; Homocysteine; Humans; Hyperhomocysteinemia; Male; Middle Aged; Risk Factors; Stents; Treatment Failure; Vitamin B 12; Vitamin B 6

Topics: Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Coronary Vessels; Double-Blind Method; Female; Folic Acid; Homocysteine; Humans; Logistic Models; Male; Middle Aged; Prospective Studies; Stents; Vitamin B 12; Vitamin B 6

We have previously demonstrated an association between elevated total plasma homocysteine levels and restenosis after percutaneous coronary angioplasty. We designed this study to evaluate the effect of lowering plasma homocysteine levels on restenosis after coronary angioplasty.. A combination of folic acid (1 mg), vitamin B12 (400 microg), and pyridoxine (10 mg)--referred to as folate treatment--or placebo was administered to 205 patients (mean [+/-SD] age, 61+/-11 years) for six months after successful coronary angioplasty in a prospective, double-blind, randomized trial. The primary end point was restenosis within six months as assessed by quantitative coronary angiography. The secondary end point was a composite of major adverse cardiac events.. Base-tine characteristics and initial angiographic results after coronary angioplasty were similar in the two study groups. Folate treatment significantly lowered plasma homocysteine levels from 11.1+/-4.3 to 7.2+/-2.4 micromol per liter (P<0.001). At follow-up, the minimal luminal diameter was significantly larger in the group assigned to folate treatment (1.72+/-0.76 vs. 1.45+/-0.88 mm, P=0.02), and the degree of stenosis was less severe (39.9+/-20.3 vs. 48.2+/-28.3 percent, P=0.01). The rate of restenosis was significantly lower in patients assigned to folate treatment (19.6 vs. 37.6 percent, P=0.01), as was the need for revascularization of the target lesion (10.8 vs. 22.3 percent, P=0.047).. Treatment with a combination of folic acid, vitamin B12, and pyridoxine significantly reduces homocysteine levels and decreases the rate of restenosis and the need for revascularization of the target lesion after coronary angioplasty. This inexpensive treatment, which has minimal side effects, should be considered as adjunctive therapy for patients undergoing coronary angioplasty.

Topics: Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Restenosis; Coronary Stenosis; Coronary Vessels; Disease-Free Survival; Double-Blind Method; Drug Therapy, Combination; Female; Folic Acid; Homocysteine; Humans; Hyperhomocysteinemia; Male; Middle Aged; Multivariate Analysis; Prospective Studies; Pyridoxine; Vitamin B 12

Recent studies have shown that a common mutation (nucleotide 677 C-->T) in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to a mild rise in plasma homocysteine levels and increase the incidence of coronary artery disease. Therefore, this study was designed to further investigate whether the effects of MTHFR 677 C to T mutation, plasma homocysteine, serum vitamin B12, and folate can influence restenosis after successful coronary stenting.. We investigated 260 patients each with a lesion after successful coronary stent placement. All patients received a repeated angiography after 6 months, or earlier if clinically indicated. Angiographic in-stent restenosis (ISR) was defined as >or=50% diameter stenosis at follow-up. Genotyping for MTHFR was based on a polymerase chain reaction technique. Also fasting plasma homocysteine, vitamin B12, and folate levels were measured at the same time. The ISR rate was higher among the patients with the TT genotype than in those with the non-TT genotypes (64.0% versus 32.9%, P=0.002). There was no significant difference in plasma homocysteine levels among patients with the TT genotype and patients with the non-TT genotypes (15.9+/-7.6 versus 15.5+/-6.6 micromol/L, P=0.75). However, among the patients with the TT genotype, those with higher plasma homocysteine levels (>or=12 micromol/L) demonstrated a significantly higher ISR rate (75.0% versus 33.5%, P=0.001). Logistic regression analysis revealed that the combined presence of the MTHFR TT genotype and lower than average serum vitamin B12 (>or=550 pg/mL) resulted in the most significant difference in the risk of ISR (OR=3.57, CI=1.51-8.46, P=0.004; OR=2.36, CI=1.35-4.15, P=0.003).. MTHFR 677TT polymorphism and low serum vitamin B12 each individually increased the risk of coronary ISR. Furthermore, the combination of these parameters resulted in a greater increase in risk.

Topics: Adult; Aged; Aged, 80 and over; Chi-Square Distribution; Coronary Angiography; Coronary Restenosis; Female; Folic Acid; Genotype; Humans; Hyperhomocysteinemia; Logistic Models; Male; Methylenetetrahydrofolate Reductase (NADPH2); Middle Aged; Polymorphism, Genetic; Stents; Taiwan; Vitamin B 12

Topics: Angioplasty, Balloon, Coronary; Coronary Disease; Coronary Restenosis; Drug Therapy, Combination; Folic Acid; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperhomocysteinemia; Platelet Aggregation Inhibitors; Risk Factors; Stents; Vitamin B 12; Vitamin B 6

Topics: Aged; Bibliometrics; Cardiology; Clopidogrel; Cohort Studies; Coronary Restenosis; Drug Resistance; Estrogen Receptor alpha; Female; Folic Acid; Genetic Predisposition to Disease; Heart Diseases; Humans; Male; Mass Screening; Middle Aged; Myocardial Infarction; Natriuretic Peptide, Brain; Platelet Aggregation Inhibitors; Predictive Value of Tests; Recurrence; Risk; Stents; Ticlopidine; Vitamin B 12; Vitamin B 6

Topics: Angioplasty, Balloon, Coronary; Contraindications; Coronary Restenosis; Folic Acid; Humans; Hyperhomocysteinemia; Stents; Vitamin B 12; Vitamin B 6

Topics: Coronary Restenosis; Drug Combinations; Folic Acid; Homocystine; Humans; Randomized Controlled Trials as Topic; Treatment Outcome; Vitamin B 12; Vitamin B 6

We investigated the influence of elevated homocysteine plasma levels and 2 polymorphisms, 677C/T and 1298A/C, of the methylenetetrahydrofolate reductase (MTHFR) gene on the risk of restenosis after stenting in patients with symptomatic coronary artery disease.. Homocysteine levels and MTHFR genotypes were determined in 800 consecutive patients treated with coronary artery stenting. Angiographic restenosis (> or =50% diameter stenosis at 6-month follow-up) was present in 25.8% of the patients with low homocysteine levels (at or below the median of 11.6 micromol/L; n=400) and 24.1% of the patients with high homocysteine levels (>11.6 micromol/L; n=400; P=0.62). Rates of angiographic restenosis were 26.0%, 23.5%, and 26.9% in carriers of the 677CC, 677CT, and 677TT genotypes (P=0.75), respectively, and 24.4%, 25.9%, and 24.0% in patients with the 1298AA, 1298AC, and 1298CC genotypes (P=0.90), respectively. The need for restenosis-driven reintervention (clinical restenosis) was 18.8% in subjects with low homocysteine concentrations and 19.0% in subjects with high homocysteine concentrations during the first year after the intervention (P=0.93). Rates of clinical restenosis were 19.5%, 17.1%, and 23.3% in carriers of the 677CC, 677CT, and 677TT genotypes (P=0.37), respectively, and 17.6%, 18.6%, and 24.7% in patients with the 1298AA, 1298AC, and 1298CC genotypes (P=0.27), respectively.. Elevated levels of homocysteine and 2 polymorphisms of the MTHFR gene are not associated with restenosis after stenting in coronary arteries.

Topics: Aged; Coronary Artery Disease; Coronary Restenosis; Female; Folic Acid; Follow-Up Studies; Genetic Predisposition to Disease; Genotype; Homocysteine; Humans; Male; Methylenetetrahydrofolate Reductase (NADPH2); Middle Aged; Polymorphism, Genetic; Postoperative Complications; Prosthesis Implantation; Stents; Thrombosis; Treatment Outcome; Vitamin B 12

Coronary in-stent restenosis represents a clinical problem. Because homocysteine is being discussed as a new risk factor for atherosclerosis and thrombosis, this study investigated the relations of homocysteine, folate, and vitamin B(12) to the rate of in-stent restenosis. Patients undergoing successful percutaneous transluminal coronary angioplasty of native coronary lesions with stent implantation were investigated for fasting total serum homocysteine, folic acid, and vitamin B(12). The rate of in-stent restenosis was determined angiographically after 6 months, or earlier if clinically indicated. Of 292 enrolled patients, 262 (90%) (189 men and 73 women) underwent control angiography on an average of 6.3 +/- 1.0 (SD) months after intervention. The rate of in-stent restenosis was 36%. Univariate and multivariate analyses revealed no significant differences between patients with or without restenosis with regard to total homocysteine (median [interquartile range]: 12.9 [11.2 to 14.8] and 12.4 [10.3 to 15.4] micromol/L, respectively), folate (16.1 [12.4 to 20.5] and 15.4 [12.5 to 19.5] nmol/L, respectively), or vitamin B(12) (239.0 [182.5 to 322.1] and 258.4 [205.8 to 330.5] pmol/L, respectively). These results suggest that homocysteine, folate, and vitamin B(12) are not related to the angiographically determined rate of coronary in-stent restenosis after 6 months.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Disease; Coronary Restenosis; Female; Folic Acid; Homocysteine; Humans; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Risk Factors; Stents; Vitamin B 12