Prognostic impact of coronary vasodilator dysfunction on adverse long-term outcome of coronary heart disease.

BACKGROUND: Endothelial vasodilator dysfunction is a characteristic feature of patients at risk for coronary atherosclerosis. Therefore, we prospectively investigated whether coronary endothelial dysfunction predicts disease progression and cardiovascular event rates. METHODS AND RESULTS: Coronary vasoreactivity was assessed in 147 patients using the endothelium-dependent dilator acetylcholine, sympathetic activation by cold pressor testing, dilator responses to increased blood flow, and dilation in response to nitroglycerin. Cardiovascular events (cardiovascular death, unstable angina, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary bypass grafting, ischemic stroke, or peripheral artery revascularization) served as outcome variables over a median follow-up period of 7.7 years. Patients suffering from cardiovascular events during follow-up (n=16) had significantly increased vasoconstrictor responses to acetylcholine infusion (P=0. 009) and cold pressor testing (P=0.002), as well as significantly blunted vasodilator responses to increased blood flow (P<0.001) and the intracoronary injection of nitroglycerin (P=0.001). Impaired endothelial and endothelium-independent coronary vasoreactivity were associated with a significantly higher incidence of cardiovascular events by Kaplan-Meier analysis. By multivariate analysis, all tests of coronary vasoreactivity were significant, independent predictors of a poor prognosis, even after adjustment for traditional cardiovascular risk factors or the presence of atherosclerosis itself. CONCLUSIONS: Coronary endothelial vasodilator dysfunction predicts long-term atherosclerotic disease progression and cardiovascular event rates. Thus, the assessment of coronary endothelial vasoreactivity can provide pivotal information as both a diagnostic and prognostic tool in patients at risk for coronary heart disease.

A positive family history of premature coronary artery disease is associated with impaired endothelium-dependent coronary blood flow regulation.

BACKGROUND: The aim of the study was to determine whether a positive family history of coronary artery disease is related to impaired coronary blood flow regulation. METHODS AND RESULTS: In 150 patients with angiographically normal or minimally diseased coronary vessels, risk factors for coronary artery disease, the extent of atherosclerosis and endothelium-dependent vasomotor responses to acetylcholine, and endothelium-independent blood flow regulation by papaverine or adenosine were assessed. Coronary blood flow responses to acetylcholine were reduced in a dose-dependent manner in patients with a positive family history (P=0.030). By multivariate analysis, hypercholesterolemia (P=0.001), age (P=0.002), and a positive family history (P=0.008) remained predictors of coronary blood flow increase to acetylcholine. The extent of atherosclerotic coronary artery disease was, by multivariate analysis, an additional independent predictor of acetylcholine-induced blood flow (P=0.014), but also of endothelium-independent blood flow regulation (P=0.001). A positive family history had additive effects in addition to the other risk factors, such as hypercholesterolemia or increased age. Angiotensin-converting-enzyme genotype polymorphism had no influence either on endothelium-dependent or endothelium-independent coronary blood flow responses. However, in a subset of 28 patients, homocysteine (which is, in part, genetically determined) was inversely related to maximal acetylcholine-induced blood flow regulation (r=-0.47, P=0.012). CONCLUSIONS: The results of this study demonstrate, for the first time, that a positive family history of coronary artery disease is an important predictor of impaired endothelium-dependent coronary blood flow regulation in humans. The influence of a positive family history is independent of other well known risk factors but instead aggravates endothelial vasodilator dysfunction associated with hypercholesterolemia and increased age, suggesting important interacting effects between genetic and environmental risk factors.

Infarct remodeling after intracoronary progenitor cell treatment in patients with acute myocardial infarction (TOPCARE-AMI): mechanistic insights from serial contrast-enhanced magnetic resonance imaging.

BACKGROUND: Experimental and initial clinical studies suggest that transplantation of circulating blood- (CPC) or bone marrow-derived (BMC) progenitor cells may beneficially affect postinfarction remodeling processes after acute myocardial infarction (AMI). To relate functional characteristics of the infused cells to quantitative measures of outcome at 4-month follow-up, we performed serial contrast-enhanced MRI and assessed the migratory capacity of the transplanted progenitor cells immediately before intracoronary infusion. METHODS AND RESULTS: In 28 patients with reperfused AMI receiving either BMCs or CPCs into the infarct artery 4.7+/-1.7 days after AMI, serial contrast-enhanced MRI performed initially and after 4 months revealed a significant increase in global ejection fraction (from 44+/-10% to 49+/-10%; P=0.003), a decrease in end-systolic volume (from 69+/-26 to 60+/-28 mL; P=0.003), and unchanged end-diastolic volumes (122+/-34 versus 117+/-37 mL; P=NS). Infarct size, measured as late enhancement (LE) volume, decreased significantly, from 46+/-32 to 37+/-28 mL (P<0.05). There was a significant correlation between the reduction in LE volume and global ejection fraction improvement. The migratory capacity of transplanted cells as assessed ex vivo toward a gradient of vascular endothelial growth factor for CPCs and stromal cell derived factor-1 for BMCs was closely correlated with the reduction of LE volume. By multivariate analysis, migratory capacity remained the most important independent predictor of infarct remodeling. CONCLUSIONS: Analysis of serial contrast-enhanced MRI suggests that intracoronary infusion of adult progenitor cells in patients with AMI beneficially affects postinfarction remodeling processes. The migratory capacity of the infused cells is a major determinant of infarct remodeling, disclosing a causal effect of progenitor cell therapy on regeneration enhancement.

Statin therapy, inflammation and recurrent coronary events in patients following coronary stent implantation.

OBJECTIVES: We sought to investigate whether statin therapy affects the association between preprocedural C-reactive protein (CRP) levels and the risk for recurrent coronary events in patients undergoing coronary stent implantation. BACKGROUND: Low-grade inflammation as detected by elevated CRP levels predicts the risk of recurrent coronary events. The effect of inflammation on coronary risk may be attenuated by statin therapy. METHODS: We investigated a potential interrelation among statin therapy, serum evidence of inflammation, and the risk for recurrent coronary events in 388 consecutive patients undergoing coronary stent implantation. Patients were grouped according to the median CRP level (0.6 mg/dl) and to the presence of statin therapy. RESULTS: A primary combined end point event occurred significantly more frequently in patients with elevated CRP levels without statin therapy (RR [relative risk] 2.37, 95% CI [confidence interval] [1.3 to 4.2]). Importantly, in the presence of statin therapy, the RR for recurrent events was significantly reduced in the patients with elevated CRP levels (RR 1.27 [0.7 to 2.1]) to about the same degree as in patients with CRP levels below 0.6 mg/dl and who did not receive statin therapy (RR 1.1 [0.8 to 1.3]). CONCLUSIONS: Statin therapy significantly attenuates the increased risk for major adverse cardiac events in patients with elevated CRP levels undergoing coronary stent implantation, suggesting that statin therapy interferes with the detrimental effects of inflammation on accelerated atherosclerotic disease progression following coronary stenting.

[Diabetes mellitus and coronary artery disease--a high risk combination]. / Diabetes mellitus und koronare Herzkrankheit--eine Risikokombination.

Patients with diabetes mellitus are often not recognized in clinical routine, but also not well characterized in clinical trials. As a diagnostic approach it is recommended to test fasting glucose and glycosylated hemoglobin (HbA1c) in every patient with coronary artery disease (CAD). HbA1c, in addition, provides important prognostic information. Patients with diabetes mellitus do have an enhanced cardiovascular risk in all stages and during all kind of interventions of CAD. However, diabetes is not equal to diabetes; risk modifying factors such as HbA1c, concomitant diseases and medication have to be considered. Absolute benefit of pharmacological therapies is also enhanced in patients with diabetes compared to non-diabetics. However, statins or anti-hypertensive treatment seem to be even more effective in reducing cardiovascular events than pure control of glucose levels alone. During percutaneous interventions (PCI) glycoprotein IIb/IIIa-inhibitors reduce mortality in diabetics, an effect which may be partially also achieved by Clopidogrel. Glitazones reduce restenosis rates; however, clinical end point studies are still ongoing. After PCI, restenosis may be a predictor of mortality in patients with diabetes. Whether drug eluting stents, besides effectively reducing restenosis, may also reduce hard clinical events in patients with diabetes remains to be demonstrated. Current available studies comparing PCI with bypass are limited due to not considered factors (stenosis morphology), randomization bias, and faster progress of technology compared to study termination. During an acute coronary syndrome/myocardial infarction, hyperglycemia is an adverse prognostic marker. However, so far studies using glucose-insulin-potassium (GIK) infusion have not been convincingly demonstrate to be beneficial.

Clinical importance of coronary endothelial vasodilator dysfunction and therapeutic options.

The vascular endothelium plays a key role in the control of vasomotor tone, local haemostasis and vascular wall proliferation processes. These responses are mediated by a variety of substances released from the endothelium in response to physiological stimuli, including prostacyclin, endothelin, and most importantly nitric oxide (NO). NO mediates vasodilation and furthermore inhibits platelet aggregation, expression of adhesion molecules for monocytes and adhesion of neutrophils, and it impairs growth of vascular smooth muscle cells. Risk factors for coronary atherosclerosis, such as hypercholesterolaemia, impair NO bioactivity, mainly due to an oxidative stress by superoxide radicals (O2-), which are able of rapidly inactivating endothelium-derived NO. Impaired NO bioactivity leads to unopposed paradoxical vasoconstriction of epicardial conductance vessels in response to physiological stimuli such as sympathetic activation as well as impaired vasodilator function of coronary resistance vessels. Therefore, endothelial dysfunction contributes to ischaemic manifestation of coronary artery disease. In addition, enhanced paradoxical vasoconstriction and a loss of endothelial antithrombotic activities might unfavourably modulate the course of acute coronary syndromes. Thus, the aim of therapeutic interventions is to increase NO bioavailability by either increasing NO production or decreasing O2- production in the endothelium. This goal can be reached, for example by ACE inhibitors, lipid-lowering drugs, increased shear-stress by physical exercise, oestrogens, and L-arginine, which have already been shown to improve endothelial vasodilator function. Nevertheless, it has to be determined whether ameliorated endothelial function will contribute to improved patients prognosis.

NADH/NADPH oxidase p22 phox gene polymorphism is associated with improved coronary endothelial vasodilator function.

AIMS: The NADH/NADPH oxidase system plays a central role in vascular superoxide anion production, which appears to cause coronary endothelial dysfunction. Recently, it has been suggested that the C242T polymorphism of the NADH/NADPH oxidase p22 phox gene can reduce susceptibility to coronary artery disease. We therefore tested whether this polymorphism is associated with an altered endothelium-dependent vasodilator capacity of human coronary arteries in vivo. METHODS AND RESULTS: The vasodilator function of epicardial arteries in 93 patients was assessed by endothelium-mediated, flow-dependent dilation and nitroglycerin, which is endothelium-independent. NADH/NADPH oxidase p22 phox polymorphism was determined by restriction fragment length polymorphism. Carriers of the CC genotype of the C242T p22 phox polymorphism (n = 44) revealed a significantly blunted endothelium-dependent dilator response (11 +/- 9.2% luminal area change vs 17 +/- 10%;P = 0.007), which was, by multivariate analysis, independent of other risk factors or atherosclerosis itself. There was only a trend towards decreased endothelium-independent dilation in patients bearing the p22 phox CC genotype (P = 0.07). CONCLUSIONS: The C242T polymorphism of the p22 phox gene is an important independent determinant of coronary endothelial vasodilator function. These results provide the first clinical evidence for the functional significance of a polymorphism of a gene related to superoxide anion production in the vascular wall.

[Coronary stent implantation in elderly patients: acute and long-term results]. / Koronare Stentimplantation bei alten Patienten. Akutergebnisse und Langzeitverlauf.

UNLABELLED: The number of elderly patients with coronary heart disease is rapidly growing. Morbidity, related with PTCA is increased in elderly patients, presumably because of the more complex adverse baseline characteristics. However, it has not been firmly elucidated whether routine use of coronary stents is associated with a more favourable outcome in this population. Therefore, we investigated the influence of age on acute procedural success, rate of restenosis (quantitative coronary angiography) and major cardiovascular events (death/myocardial infarction [MI]) 6 months after intra-coronary stent implantation in 1306 patients. Patients were categorised into < 65 years (n = 709),65-75 years (n = 443) and >75 years (n= 154). RESULTS: Older patients had a higher amount of multivessel disease (p < 0.001) and a lower left ventricular ejection fraction (p < 0.001). Nevertheless, the rate of acute success and restenosis were comparable between the different age groups. In contrast, older patients had significantly more adverse clinical events during long-term followup. (Death/MI < 65 years 3.0%, 65-75 years 3.9%, > 75 years 7.8%, p = 0.02). However, by multivariate analysis age was no longer an independent predictor of adverse clinical events (p = 0.26), which were predominantly determined by coexisting impaired left ventricular function (p < 0.001). CONCLUSION: After proper judgement of the clinical situation, coronary stent implantation should be considered in selected elderly patients. Thus, advanced age as a solely factor should not be regarded as a contraindication for coronary stent implantation.