Endothelial vasomotor dysfunction in the brachial artery is associated with late in-stent coronary restenosis.

OBJECTIVES: This study examined whether endothelial dysfunction in the brachial artery might be associated with late in-stent restenosis (ISR) after percutaneous coronary intervention (PCI). BACKGROUND: Simple and noninvasive identification of late ISR might help to select patients who require further angiographic evaluation. METHODS: Endothelium-dependent flow-mediated dilation (FMD) of the brachial artery was measured before (initial FMD) and at six months (follow-up FMD) after PCI in 141 consecutive patients who had elective and successful PCI with bare metal stents in de novo lesions of native coronary arteries for symptomatic coronary artery disease. Follow-up angiography was performed at six months after PCI in all patients. RESULTS: With multivariate logistic regression analysis, the impairment (< or = 4.8% dilation from baseline diameter) of FMD at follow-up showed the strongest association with late ISR (defined as > 50% diameter stenosis, n = 46) independently of other clinical and angiographic variables known to be associated with ISR (odds ratio 7.4, 95% confidence interval 2.8 to 19.2, p < 0.001), whereas the initial FMD did not have the association. The sensitivity of impaired FMD at follow-up (69%) in detecting ISR was higher than chest pain during the follow-up period (45%), with comparable specificity. The impaired FMD in combination with the chest pain increased the sensitivity to 90%. CONCLUSIONS: The impairment of FMD in the brachial artery at the time of follow-up was independently and closely associated with late ISR in native coronary arteries. The noninvasive assessment of FMD at the time of follow-up might be useful for identification of late ISR.

Remnant lipoproteinemia is a risk factor for endothelial vasomotor dysfunction and coronary artery disease in metabolic syndrome.

This study aimed to determine whether elevated levels of remnant lipoprotein, an atherogenic triglyceride-rich lipoprotein, might be associated with coronary artery disease (CAD) and endothelial vasomotor dysfunction in metabolic syndrome. The fasting serum levels of remnant lipoproteins (remnant-like lipoprotein particles cholesterol; RLP-C) were measured by an immunoseparation method in 210 patients with metabolic syndrome meeting ATP III criteria. Flow-mediated endothelium-dependent dilatation (FMD) in the brachial artery during reactive hyperemia was examined by high-resolution ultrasound technique. This study found that elevated RLP-C levels were a significant and independent risk factor for impaired FMD and angiographically proven coronary artery disease (CAD). Treatment with bezafibrate (n = 20) or atorvastatin (n = 20) for 4 weeks significantly reduced RLP-C levels, with a concomitant improvement in FMD. The % reduction in RLP-C levels from baseline after the treatment was independently correlated with the magnitude of improvement in FMD after adjustment for the % changes in levels of triglyceride, hsCRP, and IL-6, and HOMA index. Thus, elevated levels of RLP-C are a risk factor for CAD and endothelial vasomotor dysfunction, a predictor of coronary events, in metabolic syndrome. Measurement of RLP-C is useful for assessment of CAD risk and therapeutic effects in metabolic syndrome.

Increased ambulatory pulse pressure is a strong risk factor for coronary endothelial vasomotor dysfunction.

OBJECTIVES: This study was aimed to determine the relationship between pulse pressure (PP) and coronary vasomotor dysfunction, a predictor of coronary events. BACKGROUND: Pulse pressure is a strong risk factor for coronary artery disease (CAD). However, the mechanisms by which an increase in PP affects the pathogenesis of CAD are unclear. METHODS: Ambulatory blood pressure (BP) monitoring for 24 h was performed in 103 consecutive patients with normal coronary angiograms (51 hypertensive and 52 normotensive; age 42 to 70 years). The relationship between changes in coronary arterial diameter and blood flow during an intracoronary infusion of acetylcholine (ACh) (5, 10, 50 microg/min), and BP parameters, and other traditional risk factors was evaluated using univariate and multivariate linear regression analyses. RESULTS: With multivariate analyses, the 24-h PP showed an inverse correlation with the epicardial coronary dilator response to ACh independently of other covariates including age, smoking, and 24-h systolic BP in normotensive as well as hypertensive patients. Furthermore, multivariate analysis showed that the 24-h PP was inversely and independently correlated with the increase in coronary blood flow in response to ACh. The dilator response of epicardial coronary arteries to nitrate was not significantly correlated with 24-h PP. CONCLUSIONS: Increased 24-h PP is independently associated with endothelial vasomotor dysfunction in conduit and resistance coronary arteries irrespective of the presence of hypertension. Increased ambulatory PP may have an intimate relation to coronary endothelial vasomotor dysfunction.

Blunted reduction of pulse pressure during nighttime is associated with left ventricular hypertrophy in elderly hypertensive patients.

Increased pulse pressure (PP) is recognized as a risk factor for cardiovascular disease, especially in elderly patients. However, blood pressure (BP) is known to have a circadian variation. Therefore, this study asked whether or not PP has a circadian variation and, if so, whether a circadian variation of PP has clinical importance. Ambulatory BP monitoring (every 30 min for 48 h) was performed in 255 patients with untreated essential hypertension (24 to 82 years old; mean: 52+/-12 years). Left ventricular mass index (LVMI) was estimated from M-mode echocardiography. PP was decreased during nighttime (10+/-11% reduction from daytime PP). Multivariate linear regression analysis showed that, among four variables-the degree of nighttime PP reduction, daytime PP, 48-h systolic BP, and nondipper hypertension-the degree of nighttime PP reduction had the strongest (inverse) correlation with LVMI in a subgroup of elderly patients (> or =60 years old, n =67) (standardized regression coefficient=-0.32, p =0.02), whereas this association was not significant in the whole patient population unclassified by age. Furthermore, a blunted reduction of nighttime PP in combination with nondipper hypertension was an incremental risk for increase in LVMI in the elderly patients. In conclusion, PP is reduced during nighttime, but the degree of reduction varies among patients. The blunted reduction of nighttime PP is a risk for left ventricular hypertrophy, an established predictor of hypertension-induced cardiovascular events, and it may thus play a role in cardiovascular complications, especially in elderly patients with nondipper hypertension.

Correlation of plasma concentrations of B-type natriuretic peptide with infarct size quantified by tomographic thallium-201 myocardial scintigraphy in asymptomatic patients with previous myocardial infarction.

BACKGROUND: Secretion of A-type (atrial) and B-type (brain) natriuretic peptides (ANP and BNP) increases in relation to left ventricular (LV) dysfunction in patients with myocardial infarction (MI). However, it is unknown what determines the concentrations of ANP and BNP in asymptomatic MI patients with preserved LV function, so the aim of the present study was to examine if they are associated with MI size. METHODS AND RESULTS: Plasma concentrations of ANP and BNP in the peripheral blood were measured in 88 asymptomatic (New York Heart Association class I) patients with previous MI. The infarct size was quantitatively calculated from rest thallium-201 myocardial single photon emission computed tomography. In multivariate linear regression analysis that included MI size, hemodynamic parameters, and age as covariables, only BNP concentrations had a significant association with MI size (p=0.0001). In contrast, ANP concentrations were not significantly correlated with MI size in either the univariate or multivariate analysis. CONCLUSIONS: BNP but not ANP concentrations increased in proportion to the scintigraphic MI size despite the lack of heart failure in asymptomatic patients with previous MI. Thus, the increase in plasma BNP concentrations reflects the MI size, an important determinant of prognosis, in asymptomatic patients with MI.