在冠状动脉移植术中他汀类药物应用于静脉移植后狭窄机制研究进展

相比于左侧乳内动脉及桡动脉,大隐静脉在冠状动脉移植后的长期通畅率较低。一系列的临床试验和观察研究表明他汀类药物在静脉移植通畅率治疗上有显著的益处。除了能降低血脂外,他汀类药物可以在移植静脉的血管壁上直接抑制甲羟戊酸途径发挥多效性,并且可以降低小GTP酶比如Rho和Rac的香叶酰化。他汀类药物能够改善内皮功能的同时减少血管炎性反应及氧化应激,并且抑制平滑肌细胞的增殖与迁移。为了能将这些机制安全地运用到临床实践中,更多的临床试验需要聚焦于他汀类药物对静脉移植通畅率的干预作用,文章将对上述问题做一综述。     

High level of lipoprotein (a) as a predictor of poor long-term prognosis after coronary artery bypass surgery

Study aim was to investigate the association of lipoprotein (a) [Lp(a)] level with the development of cardiovascular complications in long-term follow-up period after coronary artery bypass grafting (CABG). Patients with chronic ischemic heart disease (IHD) (n = 361, 88% men, mean age 55 +/- 9 years) who had had CABG were included in the study. Before surgery we assessed presence of classical risk factors, left ventricular ejection fraction, concentrations of lipids and Lp(a) in blood serum. During follow-up (from 1 to 140, mean 66 +/- 34 months) we registered cardiac deaths, nonfatal myocardial infarctions (MI), strokes, repeat procedures of revascularization, and hospitalizations due to relapse or progression of angina pectoris. Information on prognosis was obtained from 263 patients. In 109 of them we registered 142 serious events including cardiac death n = 20 (14%), nonfatal MI n = 14 (10%), myocardial revascularization (n = 35), 29 (20%) with stenting), repeat CABG n = 6 (4%), hospitalization due to angina pectoris n = 53 (37%), stroke n = 4 (3%), noncardiac outcome n = 16 (10%). In subjects with hyperlipidemia (a) [HLp(a) - Lp(a) > 30 mg/l] survival after CABG was lower (log rank p < 0.001): 11 of 93 (11.3%) and 9 of 170 (5.2%) patients died among those with Lp(a) > 30 and < 30 mg/I, respectively. Relative risk (RR) of any cardiovascular complication was 3.24 (95% confidence interval [CI] 2.18 to 4.83, p < 0.001), of death - 2.89 (95% CI 1.31 to 6.35, p < 0.01), and of MI A 1.01 (95% CI 1.00 to 1.02; p = 0.02). RR of development of MI and cardiac death in patients with HLp(a) in 5 years was 2.61 (95% CI 1.11 to 5.74; p = 0.02), in 10 years - 2.95 (95% CI 1.50 to 5.79; p < 0.001). In patients with chronic IHD high level of Lp(a) can serve as independent predictor of unfavorable events including death and nonfatal MI during 10 years after CABG.     

Social support as a predictor of participation in cardiac rehabilitation after coronary artery bypass graft surgery

PURPOSE: Cardiac rehabilitation promotes recovery and enhances quality of life after a coronary artery bypass graft (CABG), but participation in such rehabilitation is low. The role of social support in promoting participation has been suggested by prior studies, but is not clearly defined. The purpose of this study was to investigate the role of social support as an independent predictor of participation in cardiac rehabilitation. METHODS: This study examined 944 patients who underwent first isolated CABG between May 1999 and February 2001, then were followed for 6 months after surgery. Social support before CABG and 6 weeks after CABG was assessed using the Enhancing Recovery in Coronary Heart Disease (ENRICHD) Social Support Inventory (ESSI) and evaluated for its association with participation in cardiac rehabilitation. RESULTS: Of 944 patients, 524 (56%) reported participation in rehabilitation. The participants were younger, better educated, more often employed, and less financially strained. The participants also had a lower prevalence of cardiovascular disease risk factors and better physical function. According to unadjusted analysis, the patients with low social support (ESSI 相似文献   

Self-reported functional status as a predictor of coronary artery bypass graft surgery outcome in elderly patients

BACKGROUND: Surgeons have traditionally relied mainly on clinical intuition in the selection of elderly candidates for coronary artery bypass grafting (CABG). The overall increasing number of patients undergoing CABG and limited resources require that a more rational approach be used to screen out candidates who are least likely to benefit from the surgery. Hypothesis: Preoperative functional status is a more sensitive predictor of mortality and poor postoperative functional status than age. PATIENTS AND METHODS: Retrospective preoperative and postoperative geriatric assessment was obtained for 123 patients who had undergone CABG at the Montreal General Hospital. Montreal, Quebec. Preoperative and postoperative health and functional status were assessed using the Canadian version of the Medical Outcomes Study 36-Item Short-Form (SF-36) 1 to 1.5 years following surgery. The questionnaires were compiled according to the method described by Stewart et al and scores were transformed linearly to a 0 to 100 scale. In addition to functional status, the presence of comorbidities and other risk factors known to influence the outcome of CABG were recorded. RESULTS: There was no significant difference in the likelihood of having a poor functional status before or after surgery, or death as an outcome of CABG in the young elderly group versus the old elderly group. Preoperative functional status was found to predict postoperative functional status; however, there was no significant association between preoperative functional status and the presence of comorbidity. The presence of comorbidity did not affect the postoperative functional status, but increased the likelihood of death. CONCLUSION: Functional status was demonstrated to be a significant predictor of CABG outcome. When compared with age, functional status was also found to be a more reliable predictor of CABG outcome, which had not been previously demonstrated. Women were found to be more likely to have a poor preoperative functional status than their male counterparts. This may account in part for the decreased success rate of CABG in elderly women.     

Right coronary artery stenosis: An independent predictor of atrial fibrillation after coronary artery bypass surgery

Objectives. This study attempted to determine the importance of severe proximal right coronary artery disease as a predictor of atrial fibrillation in patients after coronary artery bypass surgery.Background. Studies in patients undergoing noncardiac surgery have suggested that ischemia in the right coronary artery distribution is associated with a high incidence of atrial fibrillation. However, the importance of right coronary artery disease as a predictor of atrial fibrillation after bypass surgery is unknown.Methods. The occurrence of sustained postoperative atrial fibrillation was studied prospectively in 168 consecutive patients undergoing coronary artery bypass grafting. Patients were followed up postoperatively until discharge. Severe right coronary artery stenosis was defined as ≥70% lumen narrowing.Results. Of 104 patients with proximal or mid right coronary artery stenosis, 45 (43%) had atrial fibrillation postoperatively compared with 12 (19%) of the 64 patients without significant right coronary disease (p = 0.001). Univariate predictors of atrial fibrillation included right coronary artery stenosis (p = 0.001), advancing age (p = 0.0001) and lack of beta-adrenergic blocking agent therapy after bypass surgery (p = 0.0004). Multivariate adjusted risk of developing atrial fibrillation after bypass surgery increased with the presence of severe right coronary artery disease (odds ratio 3.69, 95% confidence interval [CI] 1.61 to 8.48), advancing age (odds ratio 2.24/10 years, CI 1.48 to 3.41) and male gender (odds ratio 2.36, CI 1.01 to 5.49). The use of beta-blockers postoperatively was associated with a protective effect (odds ratio 0.4, CI 0.17 to 0.80).Conclusions. The presence of severe right coronary artery stenosis is an independent and powerful predictor of atrial fibrillation after coronary artery bypass surgery. In association with age, gender and postoperative beta-blocker therapy, these variables can be used to identify patients at increased risk for developing this arrhythmia.     

Serum Lp(a) lipoprotein concentration is not associated with clinical and angiographic outcome five years after coronary artery bypass graft surgery.

OBJECTIVE: To examine the association between serum Lp(a) lipoprotein concentration and clinical and angiographic outcomes five years after coronary artery bypass graft (CABG) surgery. SETTING: A regional cardiothoracic centre, Freeman Hospital, and the University Clinical Investigation Unit, Royal Victoria Infirmary, Newcastle upon Tyne. PATIENTS AND DESIGN: 353 consecutive patients (56 female, 297 male, mean age 57-2 years) undergoing first time CABG surgery for stable angina were studied prospectively. MAIN OUTCOME MEASURES: Late cardiac death (beyond 30 days) and non-fatal myocardial infarction; prevalence of angina five years after surgery in 291 (94%) survivors and vein graft patency (evaluated by patient) in 118 survivors five years after surgery. Serum Lp(a) concentration and lipid profiles were measured before operation, and 3, 6, 12, and 60 months after surgery. Lipid profiles were also measured 24 months after surgery. RESULTS: Weighted Lp(a) concentration (by tertile) was not associated with late cardiac death or with the combination of late cardiac death and non-fatal myocardial infarction, with the presence of angina, or with vein graft occlusion. The association remained non-significant if analysis was restricted to the upper tertile of LDL cholesterol (> 4.1 mmol/l) or to patients under the age of 55 years at the time of surgery. CONCLUSIONS: Serum Lp(a) concentration did not predict late cardiac death, the combination of late cardiac death and non-fatal myocardial infarction, or the prevalence of angina or vein graft occlusion five years after CABG surgery.     

Radial artery graft vs. saphenous vein graft for coronary artery bypass surgery

Objectives

Coronary artery bypass grafting (CABG) is the best therapeutic option for multivessel coronary artery diseases. The internal thoracic artery is usually used for the left anterior descending coronary artery. However, it is still not clear what the best conduit is for non-left anterior descending coronary arteries. This research sought to assess the efficacy of the radial artery versus the saphenous vein in this context.

Methods

A systematic literature search was performed for randomized clinical trials (RCT) published in MEDLINE, EMBASE, and the Cochrane Library. RCTs reporting angiographic comparisons and clinical events of the radial artery versus the saphenous vein were included.

Results

Six trials (1,860 participants, 1,188 radial artery grafts, 1,178 saphenous vein grafts) were included in this review. The radial artery was associated with a significantly lower incidence of graft failure (p?<?0.05) and of repeat coronary operation (p?<?0.05). There was no significant trend toward decreased cardiac death and myocardial infarction with the use of a radial artery (p?>?0.05; p?>?0.05). As determined by the GRADE method, the evidence quality was low for repeat operation and very low for other variables.

Conclusion

The radial artery can be weakly recommended as a selective conduit but cannot always be considered better than the saphenous vein.     

冠状动脉搭桥术后静脉桥狭窄和新生易损斑块形成机制的研究进展

冠状动脉搭桥术术后发生桥血管病变是一种常见的现象,血栓形成、内皮功能障碍、血管痉挛和氧化应激是导致病变的重要机制。相比于动脉桥,静脉桥更易于发生病变,这与静脉本身的解剖形态和功能特征有着很大的关系。急性血栓形成、血管内膜增生和易损斑块形成是静脉桥不同时期发生病变的重要机制。使用抗血小板和调脂药物等冠心病二级预防药物有助于提高桥血管的开通率。寻找桥血管病变的预测因子及相关基因通路有望从细胞及分子学水平为静脉桥疾病提供新的研究方向。本文拟对冠状动脉搭桥术后发生静脉桥狭窄和新生易损斑块病变形成机制的研究进展作一综述。     

Pleural effusions after coronary artery bypass graft surgery

After coronary artery bypass graft surgery, most patients will have a small, unilateral, left-sided pleural effusion, and approximately 10% of patients will have a larger effusion. These large effusions can be separated into (1) early effusions occurring within the first 30 days of surgery that are bloody exudates with a high percentage of eosinophils, and (2) late effusions occurring more than 30 days after surgery that are clear yellow lymphocytic exudates. The primary symptom of pleural effusion after coronary artery bypass graft surgery is dyspnea; chest pain and fever are uncommon. Most patients with large pleural effusions after coronary artery bypass graft surgery are treated successfully with one to three therapeutic thoracenteses.     

Opportunities for gene therapy in preventing vein graft failure after coronary artery bypass surgery

The poor patency rates for coronary artery bypass grafting (CABG) using autologous saphenous vein necessitate the need for continued research into the potential clinical utility of gene therapy. Bypass grafting is ideally suited for gene therapy, as graft can be genetically modified ex vivo prior to grafting in the coronary vasculature. Research to date has demonstrated effective blockade of late vein graft failure through overexpression of a variety of transgenes that modulate the proliferative, migratory and/or apoptotic indexes of cells in the graft wall. This has resulted in a substantial wealth of preclinical data that support advancement to clinical trials. Future translation into clinical trials will ensure that this exciting and highly relevant area of gene therapy is fully evaluated for potential routine clinical practice to improve patency rates of bypass graft procedures involving saphenous vein.     

The simplified modification of diet in renal disease equation as a predictor of renal function after coronary artery bypass graft surgery

Background

After open-heart surgery, a percentage of patients have impaired renal function. This deterioration is even seen in patients with serum creatinine (s-creatinine) values that fall within the normal laboratory range, therefore s-creatinine is not an accurate reflection of renal function. Glomerular filtration rate (GFR) is a better indication of renal status. GFR can be calculated with the simplified modification of diet in renal disease (MDRD) equation – a formula that takes age, gender, race and s-creatinine level into account. The purpose of this study was to investigate the relationship between estimated GFR pre-operatively and renal impairment postoperatively.

Methods

All patients who had an isolated coronary artery bypass graft (CABG) done by one surgeon in one hospital between January 2005 and October 2007 had their s-creatinine levels determined pre-operatively. Using a computer desktop calculator, the patient’s age, gender and race were used together with the s-creatinine value to estimate the GFR. Prior to CABG, all patients were grouped into the five stages of chronic kidney disease. Renal outcome postoperatively was compared with the estimated pre-operative GFR.

Results

Nineteen per cent of the 451 patients had chronic kidney disease pre-operatively, as defined by the National Kidney Foundation, according to their estimated GFR. Twenty-three per cent of these patients had renal impairment after surgery. Of the patients with reasonable renal function pre-operatively only 4% had further deterioration of renal function. Mortality did not differ significantly, but patients with postoperative renal impairment stayed in hospital on average 2.4 days longer than those who had no renal impairment postoperatively.

Conclusions

Patients with chronic kidney disease before CABG have a six times greater chance of developing further renal impairment postoperatively than those with reasonable renal function beforehand. There is therefore a significant relationship between estimated GFR before CABG and deterioration of kidney function after surgery. The GFR, as calculated with the simplified MDRD, is a predictor of the risk of having renal dysfunction after CABG.