Plasma level of homocysteine is inversely-associated with the development of collateral circulation in patients with single-vessel coronary artery disease

Folic acid ameliorates homocysteine-induced angiogenesis and portosystemic collaterals in cirrhotic rats

INTRODUCTION AND OBJECTIVES

Liver cirrhosis is characterized by increased intrahepatic resistance, splanchnic vasodilation/angiogenesis, and formation of portosystemic collateral vessels. Collaterals can cause lethal complications such as gastroesophageal variceal hemorrhage. Homocysteine is linked to vascular dysfunction and angiogenesis and higher levels have been reported in cirrhotic patients. It is also known that folic acid supplementation reverses the effects of homocysteine. However, the treatment effect in cirrhosis has yet to be investigated.

MATERIAL AND METHODS

Liver cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (CBDL). The CBDL rats randomly received (1) vehicle; (2) dl-homocysteine thiolactone (1g/kg/day); (3) dl-homocysteine thiolactone plus folic acid (100mg/kg/day); or (4) folic acid. On the 29th day, hemodynamic parameters, liver and renal biochemistry, protein expressions of proangiogenic factors, mesenteric vascular density and portosystemic shunting were evaluated.

RESULTS

In the cirrhotic rats, homocysteine increased mesenteric vascular density and the severity of shunting. It also up-regulated the protein expressions of mesenteric vascular endothelial growth factor (VEGF) and phosphorylated-endothelial nitric oxide synthase (p-eNOS). These effects were reversed by folic acid treatment (P<0.05).

CONCLUSION

Folic acid ameliorated the adverse effects of homocysteine in the cirrhotic rats, which may be related to down-regulation of the VEGF-NO signaling pathway.

Association of IGF-1 with coronary collateral circulation in stable coronary artery disease

Aim: The aim of the present study is to evaluate the relationship between coronary collateral circulation (CCC) grade and serum IGF-1 levels in patients diagnosed with stable coronary artery disease. Methods: Totally, 190 consecutive patients with stable coronary artery disease who underwent coronary angiography were included in this study. Results: The patients with good CCC had significantly higher IGF-1 levels compared with the poor ones. On the contrary, hs-CRP was significantly lower in the good CCC group. We also demonstrated that IGF-1 level was significantly related with the grade of CCC. Conclusion: We believe that measurement of IGF-1 level may help clinicians for predicting CCC development.

Homocysteine deteriorates intrahepatic derangement and portal-systemic collaterals in cirrhotic rats

In liver cirrhosis, the altered levels of vasoactive substances, especially endothelin-1 (ET-1) and nitric oxide (NO) lead to elevated intrahepatic resistance, increased portal-systemic collaterals and abnormal intra- and extra-hepatic vascular responsiveness. These derangements aggravate portal hypertension-related complications such as gastro-oesophageal variceal bleeding. Homocysteine, a substance implicated in cardiovascular diseases, has been found with influences on vasoresponsiveness and angiogenesis. However, their relevant effects in liver cirrhosis have not been investigated. In the present study, liver cirrhosis was induced by common bile duct ligation (BDL) in Sprague–Dawley rats. In acute study, the results showed that homocysteine enhanced hepatic vasoconstriction to ET-1 but decreased portal-systemic collateral vasocontractility to arginine vasopressin (AVP). Homocysteine down-regulated hepatic phosphorylated endothelial NO synthase (p-eNOS) and p-Akt protein expressions. Inducible NOS (iNOS) and cyclooxygenase (COX)-2 expressions were up-regulated by homocysteine in splenorenal shunt (SRS), the most prominent intra-abdominal collateral vessel. In chronic study, BDL or thioacetamide (TAA) rats received homocysteine or vehicle for 14 days. The results revealed that homocysteine increased hepatic collagen fibre deposition and fibrotic factors expressions in both BDL- and TAA-induced liver fibrotic rats. Portal-systemic shunting and expressions of mesenteric angiogenetic factors [vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), PDGF receptor β (PDGFRβ) and p-eNOS] were also increased in BDL rats. In conclusion, homocysteine is harmful to vascular derangements and liver fibrosis in cirrhosis.

The association of plasma vitamin A and E levels with coronary collateral circulation

OBJECTIVE

To investigate if plasma levels of vitamin A and E have an association with coronary collateral development.

METHODS

A total of 189 patients who underwent coronary angiography and had total occlusion in at least one major epicardial coronary artery were enrolled in the study. To classify coronary collateral circulation (CCC), the Rentrop scoring system was used. Patients were classified as having poor CCC (Rentrop grades 0-1) or good CCC (Rentrop grades 2-3), and all patients were also screened for hypertension, hypercholesterolemia, diabetes, and smoking history.

RESULTS

There were no differences in plasma vitamin A and E levels between the two groups (vitamin A: 2.37 ± 0.65 vs. 2.35 ± 0.78, p = 0.253; vitamin E: 47.1 ± 12.8 vs. 44.6 ± 15.1, p = 0.082), and plasma vitamin A and E levels were not associated with CCC. Serum high-sensitivity C-reactive protein (hs-CRP) levels were significantly higher in patients with poor CCC (4.68 ± 2.52 vs. 3.89 ± 1.78, p = 0.001). The higher frequency of diabetes and higher serum hs-CRP levels were found to be an independent predictor for poor CCC (odds ratio = 2.44, p = 0.006; odds ratio = 1.24, p = 0.007, respectively). And a higher frequency of total occluded RCA was found to be a positive predictor for good CCC (odds ratio = 2.36, p = 0.06) in a multivariate logistic regression analysis.

CONCLUSIONS

We found that serum hs-CRP levels, presence of diabetes, and total occlusion of RCA have an effect on coronary collateral development. We found no correlation between plasma vitamin A and E levels and CCC.

Use of serum homocysteine to predict stroke, coronary heart disease and death in ethnic Chinese. 12-year prospective cohort study

BACKGROUND

Prospective data about the association between serum total homocysteine (Hcy) and vascular disease in Asia is limited because few investigations have evaluated the cutpoint of Hcy for predicting the risk of vascular disease and death.

METHODS AND RESULTS

A community-based prospective cohort study of 2,009 participants, who were free from stroke, coronary heart disease (CHD) and cancer at baseline in 1994 were followed up to 2007 (median 11.95 years); there were 114 documented cases of stroke, 95 of CHD and 380 deaths. Cox proportional hazard model was used to examine the association between Hcy and the incidence of stroke, CHD, and all-cause death. The receiver-operating characteristic curve was performed for determining the cutpoint of Hcy in risk prediction. Hcy levels remained significantly associated with cardiovascular events and death in fully adjusted models. Participants with Hcy >9.47 micromol/L (sensitivity 81.1%, specificity 54.3%) had a 2.3-fold risk for cardiovascular events (95% confidence interval (CI), 1.24-4.18, P=0.008), and participants with Hcy >11.84 micromol/L (sensitivity 49.7%, specificity 84.0%) had a 2.4-fold risk for death (95%CI, 1.76-3.32, P<0.0001).

CONCLUSIONS

Hcy was significantly related to cardiovascular events and all-cause death, with the best cutpoint values as 9.47 and 11.84, respectively.

Plasma homocysteine concentration in patients with poor or good coronary collaterals

BACKGROUND

Elevated plasma homocysteine (Hcy) concentrations are associated with an increased risk of vascular disease. Hcy is known to inhibit endothelial cell proliferation in vitro. The purpose of the present study was to investigate the role of plasma Hcy concentrations on development of collateral circulation in single-vessel chronic total occlusion.

METHODS AND RESULTS

Collateral status was determined by Rentrop's classification. Of 817 patients, 56 cases of pure single-vessel chronic total occlusion were studied. Plasma Hcy concentrations in patients with single-vessel total coronary occlusion were higher compared with controls (17.3 +/-12.6 micromol/L vs 10.9+/-4.9 micromol/L, p=0.015). There was no significant difference in plasma Hcy concentrations of the good and poor collateral groups (17.2+/-13.7 micromol/L vs 15.3+/-9.3 micromol/L, p=0.834). Plasma Hcy concentrations in individual Rentrop subclasses 0, 1, 2 and 3 were as follows: 15.9 +/-9.1, 16.3+/-12.4, 17.1+/-14.1 and 20.1+/-13.5 micromol/L (p=0.893). There was a positive linear correlation between Rentrop subclass and angina pectoris duration (r=0.41, p=0.003). Angina pectoris duration was the only independent variable affecting the development of coronary collaterals in the present study (odds ratio [confidence interval]: 1.85 [1.12-2.91], p=0.014).

CONCLUSION

Patients with single-vessel chronic total occlusion had higher plasma Hcy concentrations than controls, but similar Hcy concentrations when compared according to the presence of poor or good coronary collaterals. There is a lack of association between plasma Hcy concentration and coronary collateral status in the current study.

Transcriptional profiling in coronary artery disease: indications for novel markers of coronary collateralization

BACKGROUND

The development of collateral circulation plays an important role in protecting tissues from ischemic damage, and its stimulation has emerged as one of principal approaches to therapeutic angiogenesis. Clinical observations have documented substantial differences in the extent of collateralization among patients with coronary artery disease (CAD), with some individuals demonstrating marked abundance and others showing nearly complete absence of these vessels. Recent studies have suggested that circulating monocytes play a major role in collateral growth. The present study was undertaken to determine transcriptional profiles of circulating monocytes in CAD patients with different extents of collateral growth.

METHODS AND RESULTS

Monocyte transcriptomes from CAD patients with and without collateral vessels were obtained by use of high-throughput expression profiling. Using a newly developed redundancy-based data mining method, we have identified a set of molecular markers characteristic of a "noncollateralgenic" phenotype. Moreover, we show that these transcriptional abnormalities are independent of the severity of CAD or any other known clinical parameter thought to affect collateral development and correlated with protein expression levels in monocytes and plasma.

CONCLUSIONS

Monocyte transcription profiling identifies sets of patients with extensive versus poorly developed collateral circulation. Thus, genetic factors may heavily influence coronary collateral vessel growth in CAD and affect prognosis and response to therapeutic interventions.

Determinants and prognostic significance of collaterals in patients undergoing coronary revascularization

There is evidence that coronary collaterals improve the prognosis in patients with acute myocardial infarction (MI). However, there is limited clinical information on the protective role of collaterals in patients with stable coronary artery disease. This information may help risk stratification and the development of novel therapies, such as arteriogenesis and angiogenesis. The relation between collaterals and cardiac death or MI at 1 year after coronary revascularization was studied in 561 patients who were enrolled in a randomized study that compared stent implantation with bypass grafting. Collaterals were assessed on an angiogram using Rentrop's classification and considered present with a Rentrop grade >1. Unadjusted and adjusted odds ratios for cardiac death or MI at 1 year were calculated using univariate and multivariate regression analyses. In addition, determinants of collaterals were assessed using univariate and multivariate analyses. Collaterals were present in 176 patients (31%). The adjusted odds ratio of cardiac death or infarction was 0.18 (95% confidence interval 0.04 to 0.78) in the presence of collaterals. Independent determinants of collaterals were age (odds ratio 0.97, 95% confidence interval 0.95 to 0.99), multivessel disease (odds ratio 1.60, 95% confidence interval 1.02 to 2.51), impaired ventricular function (odds ratio 1.85, 95% confidence interval 1.04 to 3.29), type C lesion (odds ratio 3.72, 95% confidence interval 2.33 to 5.95), and stenosis severity >90% (odds ratio 9.08, 95% confidence interval 4.65 to 17.73). In conclusion, in patients with a low risk profile, the presence of collaterals protects against cardiac death and MI at 1 year after coronary revascularization. Variables that reflect the duration and severity of the atherosclerotic and ischemic burden determine their presence.

Coronary collateral circulation: the effects of smoking and alcohol

OBJECTIVE

The presence or absence of coronary collaterals is of vital importance during acute ischemia. Smoking and alcohol have been suggested to play a role, but data are scarce. We examined the extent to which smoking and alcohol use affect the presence of coronary collateral circulation.

METHODS

Cross-sectional study in 242 patients, admitted for elective PTCA. Smoking was defined as past or current. Pack years were calculated and categorized into never-smokers (reference-category): <10, 10-19, 20-29, and >or=30 pack years. Alcohol consumption was defined as past or current, and categorized into never-users (reference-category): <1, 1-10, 11-20, and >or=21 units per week (UPW). Collaterals were graded with Rentrop's classification. Coronary collateral presence was defined as Rentrop-grade >or=1.

RESULTS

Current smoking (odds ratio (OR) 4.17; 95% confidence interval (CI) 1.79-9.71) was positively associated, while pack years of smoking was not related. Current alcohol intake showed a J-shaped tendency with coronary collateral presence, while past moderate alcohol consumption was inversely associated (OR 0.19; 95% CI 0.04-0.98).

CONCLUSIONS

Smoking and (to some extent) alcohol use are associated with collateral presence. The results support the view that life-style factors may affect the formation of coronary collaterals in patients with ischemic cardiac disease.

Serum level of lipoprotein (a) is inversely associated with the development of coronary collateral circulation

BACKGROUND

This study sought to determine the relationship between serum lipoprotein (a) levels and angiographically visible coronary collateral circulation and to evaluate whether lipoprotein (a) exerts any effect on vascular endothelial cell growth factor.

METHODS

The study population included 60 patients (39 men, mean age 59+/-13 years) with angiographically documented total occlusion in one of the major coronary arteries. Development of collaterals was classified by Rentrop's method. Patients were defined as having poorly developed collaterals for grades 0 and 1 (group 1), or well-developed collaterals for grades 2 and 3 (group 2). Serum lipoprotein (a) and vascular endothelial cell growth factor levels were determined by enzyme-linked immunosorbent assay.

RESULTS

In group 1, lipoprotein (a) levels were significantly higher and vascular endothelial cell growth factor levels were significantly lower than in group 2 (34+/-19 vs. 20+/-12 mg/dl, P<0.001, and 2.5+/-0.7 vs. 3.4+/-0.8 ng/dl, P<0.001, respectively). Poorly developed collaterals were significantly more frequent in patients with lipoprotein (a) levels >or=30 mg/dl than in patients with levels <30 mg/dl (72 vs. 37%, P=0.008). A strong negative correlation was observed between lipoprotein (a) and vascular endothelial cell growth, factor (r=-0.708, P<0.0001). Multivariate analysis revealed that a high level of lipoprotein (a) negatively affected the development of collaterals, whereas the duration of angina had a positive effect.

CONCLUSION

This study demonstrated for the first time that the high level of lipoprotein (a) negatively affects the formation of coronary collateral vessels in human beings. Reduced production or bioactivity of vascular endothelial cell growth factor caused by high levels of lipoprotein (a) may be the possible responsible mechanisms of hyperlipoprotein (a)-related poor collateral formation.

Cardiac ischemic score determines the presence of coronary collateral circulation

PURPOSE

The presence of coronary collaterals is of vital importance during acute ischemia, however, marked interindividual variability exists. We examined the extent to which the burden of cardiac ischemia, expressed as a cardiac ischemic score, affects coronary collateral presence.

METHODS

Cross-sectional study in 244 patients, admitted for elective coronary angioplasty. Collaterals were graded with Rentrop's classification. Coronary collateral presence was defined as Rentrop-grade > or =1. The cardiac ischemic score (range 0-4) was calculated by adding 1 point for each of the following four clinical factors present: angina pectoris on exertion, angina pectoris during emotions, previous myocardial infarction, and previous coronary intervention. These four clinical factors were chosen because they can be easily assessed in every patient. We used logistic regression with adjustment for gender, age, hypertension, diabetes mellitus, and hyperlipidemia.

RESULTS

The extent of the cardiac ischemic score (odds ratio 1.8 per score-point; 95% confidence interval 1.3-2.5) was strongly associated with coronary collateral presence. Additional adjustment for multivessel coronary disease left the relation essentially unchanged. Also, if the definition of collateral presence was limited to Rentrop-grade 2 and 3, results were effectively the same.

CONCLUSION

The extent of the cardiac ischemic score determines the presence of coronary collaterals, and may provide a new index for simple assessment of collateral vascular development.

Polymorphism of methylenetetrahydrofolate reductase gene (C677T MTHFR) is not a confounding factor of the relationship between serum uric acid level and the prevalence of hypertension in Japanese men

BACKGROUND

The association between serum uric acid (UA) and the prevalence of hypertension, and the relationship between methylenetetrahydrofolate reductase (MTHFR) polymorphism and hypertension remains unclear. The aim of the present study was to investigate whether the C677T MTHFR mutation genotype (VV) is independently associated with the prevalence of hypertension or blood pressure (BP), and examined any interaction of MTHFR and UA with BP.

METHODS AND RESULTS

Participants were randomly selected from all residents (aged 40-69 years) in a rural county of Japan, and the data for the men (n=335) were analyzed. ;Hypertension' was defined as systolic BP >or=140 and/or diastolic BP >or=90 mmHg and/or being administered antihypertensive medication. Serum UA level was independently associated with the prevalence of hypertension (odds ratio (95% confidence interval) =2.7 (1.2-5.9), p=0.047) for the highest tertile of serum UA (>or=398.5 micromol/L (6.7 mg/dl)) vs that of the lowest tertile (<321.2 micromol/L (5.4 mg/dl)), but the MTHFR mutation was not independently associated with prevalence of hypertension or BP. No interaction of the MTHFR mutation and serum UA with BP was found.

CONCLUSIONS

The mutation of C677T MTHFR was not independently associated with the prevalence of hypertension or BP levels although serum UA was. Furthermore, the relationship between serum UA and BP was not modulated by the MTHFR mutation in Japanese men.

High blood pressure is inversely related with the presence and extent of coronary collaterals

Patients with hypertension have an increased case fatality during acute myocardial infarction (MI). Coronary collateral (CC) circulation has been proposed to reduce the risk of death during acute ischaemia. We determined whether and to which degree high blood pressure (BP) affects the presence and extent of CC circulation. A cross-sectional study in 237 patients (84% males), admitted for elective coronary angioplasty between January 1998 and July 2002, was conducted. Collaterals were graded with Rentrop's classification (grade 0-3). CC presence was defined as Rentrop-grade > or =1. BP was measured twice with an inflatable cuff manometer in seated position. Pulse pressure was calculated by systolic blood pressure (SBP)-diastolic blood pressure (DBP). Mean arterial pressure was calculated by DBP+1/3 x (SBP-DBP). Systolic hypertension was defined by a reading > or =140 mmHg. We used logistic regression with adjustment for putative confounders. SBP (odds ratio (OR) 0.86 per 10 mmHg; 95% confidence interval (CI) 0.73-1.00), DBP (OR 0.67 per 10 mmHg; 95% CI 0.49-0.93), mean arterial pressure (OR 0.73 per 10 mmHg; 95% CI 0.56-0.94), systolic hypertension (OR 0.49; 95% CI 0.26-0.94), and antihypertensive treatment (OR 0.53; 95% CI 0.27-1.02), each were inversely associated with the presence of CCs. Also, among patients with CCs, there was a graded, significant inverse relation between levels of SBP, levels of pulse pressure, and collateral extent. There is an inverse relationship between BP and the presence and extent of CC circulation in patients with ischaemic heart disease.

Hyperhomocyst(e)inemia impairs angiogenesis in a murine model of limb ischemia

Hyperhomocyst(e)inemia (HH) is an established independent risk factor for coronary, cerebral and peripheral vascular diseases. Recent studies have indicated that certain cardiovascular risk factors, including diabetes and hypercholesterolemia, impair expression of vascular endothelial growth factor (VEGF) and endogenous angiogenesis. In this study, we investigate the impact of moderate HH on angiogenesis and VEGF pathway in a mouse model of hindlimb ischemia. Upon induction of unilateral hindlimb ischemia, endogenous angiogenesis, expression of VEGF, and phosphorylation of the VEGF receptor Flk-1 were evaluated in mice heterozygous for a deletion of the cystathionine beta-synthase gene (CBS) and compared with those observed in CBS+/+ mice. CBS+/- mice exhibit moderate HH, as demonstrated by measuring plasma total homocyst(e)ine (tHcy) levels, which were significantly higher in these animals compared with CBS+/+ mice (4.77 +/- 0.82 vs 2.10 +/- 0.28, p < 0.01). Twenty-eight days after induction of ischemia, hindlimb blood flow was significantly reduced in CBS+/- mice compared with CBS+/+ animals (0.49 +/- 0.03, n = 12 vs 0.71 +/- 0.09, n = 10; p < 0.05). In addition, there was a significant negative correlation between plasma homocyst(e)ine levels and the laser Doppler perfusion ratio in CBS+/- mice (p = 0.0087, r = -0.7171). While VEGF expression and Flk-1 phosphorylation were not impaired in the ischemic muscles of CBS+/- mice, phosphorylation of the endothelial cell survival factor Akt was significantly inhibited by homocyst(e)ine in a dose-dependent manner in human umbilical vein endothelial cell (HUVECs) in vitro. In conclusion, our findings demonstrate that endogenous angiogenesis is inversely related to plasma levels of homocyst(e)ine in genetically engineered, heterozygous mice with moderate HH. This impairment, however, is not dependent on reduced expression of VEGF or impaired phosphorylation of its receptor Flk-1. In contrast, our data suggest that impaired Akt phosphorylation mediates the impairment of angiogenesis associated with HH.

Hyperhomocysteinemia is associated with human coronary atherosclerosis through the reduction of the ratio of endothelium-bound to basal extracellular superoxide dismutase

BACKGROUND

Homocysteine is involved in coronary atherosclerosis through oxidative stress, so the present study investigated the association between plasma concentrations of homocysteine and extracellular superoxide dismutase (EC-SOD) in coronary artery disease (CAD).

METHODS AND RESULTS

The study group comprised 154 consecutive male patients with suspected CAD who had undergone angiography. Plasma concentrations of homocysteine and EC-SOD, which was determined before (basal) and after heparin therapy, were measured and the difference was designated as endothelium-bound EC-SOD. The EC-SOD ratio (endothelium-bound/basal EC-SOD) was also evaluated as an index of binding capacity. The plasma homocysteine concentration in the stenosis (+) group (n=97, 12.0+/-4.6 micromol/L) was significantly higher than that of the stenosis (-) group (n=57, 10.2+/-3.0 micromol/L, p=0.004). Plasma homocysteine correlated positively with the basal EC-SOD (r=0.377, p<0.001) and negatively with the EC-SOD ratio (r=-0.199, p=0.014). When the group was subdivided according to either homocysteine or the EC-SOD ratio, there were 2 groups with high homocysteine concentration and of these atherosclerosis was reduced in the group with a high EC-SOD ratio.

CONCLUSIONS

In CAD patients, homocysteine is involved in the significant release of EC-SOD from the endothelium. Furthermore, the higher EC-SOD binding capacity, even at high concentrations of homocysteine, suggested that homocysteine-induced atherosclerosis was suppressed.

The effects of tobacco smoke on the homocysteine level--a risk factor of atherosclerosis

Homocysteine may promote atherogenesis and thrombogenesis. There is evidence from case - control and cross-sectional cohort studies that there is a positive association between plasma homocysteine levels and coronary artery disease, cerebrovascular disease and peripheral vascular disease. There is also some evidence that certain life-style factors such as cigarette smoking may affect homocysteine levels. In this work is presented a review of recent opinion about the influence of tobacco smoking on homocysteine levels.

Total plasma homocysteine and restenosis after percutaneous coronary angioplasty: current evidence

BACKGROUND

Restenosis after percutaneous coronary angioplasty (PTCA) remains an important limitation of this procedure.

AIM

To assess the relationship between homocysteine levels and restenosis after PTCA, and discuss the potential benefit of homocysteine-lowering therapy.

METHOD

MEDLINE-based literature review.

RESULTS

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.

CONCLUSIONS

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.

Plasma homocysteine levels and late outcome after coronary angioplasty

OBJECTIVES

The aim of this study was to evaluate a possible relationship between homocysteine levels on admission and late outcome after successful percutaneous coronary intervention (PCI).

BACKGROUND

Increasing evidence suggests that mild to moderate elevation of total plasma homocysteine is a graded and potentially modifiable risk factor for cardiovascular disease and death that appears to be largely independent of other traditional risk factors.

METHODS

A total of 549 patients were included after successful PCI of at least one coronary stenosis (> or =50%). End points were cardiac death, nonfatal myocardial infarction (MI), target lesion revascularization (TLR), and a composite of major adverse cardiac events (MACE). The relationship between homocysteine levels and study endpoints was assessed.

RESULTS

After a median (+/- SD) follow-up of 58 +/- 20 weeks, 6 patients died of cardiac death, 14 were diagnosed with a new MI, and 71 underwent repeat TLR. A graded relationship between homocysteine levels (quartiles) and freedom from MACE was found (p = 0.01). Homocysteine levels (+/- SD) were associated with cardiac death (14.9 +/- 1.7 micromol/l vs. 9.6 +/- 4.3 micromol/l, p < 0.005), TLR (10.7 +/- 4.4 micromol/l vs. 9.5 +/- 4.3 micromol/l, p < 0.05), and overall MACE (11.0 +/- 4.4 micromol/l vs. 9.4 +/- 4.3 micromol/l, p < 0.005). These findings remained unchanged after adjustment for potential confounders.

CONCLUSIONS

Plasma homocysteine is an independent predictor of mortality, nonfatal MI, TLR, and overall adverse late outcome after successful coronary angioplasty.