Coronary collateral perfusion in patients with coronary artery disease: effect of metoprolol.

BACKGROUND: The use of ultrathin Doppler angioplasty guidewires has made it possible to measure collateral flow quantitatively. Pharmacologic interventions have been shown to influence collateral flow and, thus, to affect myocardial ischaemia. METHODS: Twenty-five patients with coronary artery disease undergoing PTCA were included in the present analysis. Coronary flow velocities were measured in the ipsilateral (n = 25) and contralateral (n = 6; two Doppler wires) vessels during PTCA with and without i.v. adenosine (140 microg/kg.min) before and 3 min after 5 mg metoprolol i.v., respectively. The ipsilateral Doppler wire was positioned distal to the stenosis, whereas the distal end of the contralateral wire was in an angiographically normal vessel. The flow signals of the ipsilateral wire were used to calculate the collateral flow index (CFI). CFI was defined as the ratio of flow velocity during balloon inflation divided by resting flow. RESULTS: Heart rate and mean aortic pressure decreased slightly (ns) after i.v. metoprolol. The collateral flow index was 0.25+/-0.12 (one fourth of the resting coronary flow) during the first PTCA and 0.27+/-0.14 (ns versus first PTCA) during the second PTCA, but decreased with metoprolol to 0.16+/-0.08 (p<0.0001 vs. baseline) during the third PTCA. CONCLUSIONS: Coronary collateral flow increased slightly but not significantly during maximal vasodilatation with adenosine but decreased in 23 of 25 patients after i.v. metoprolol. Thus, there is a reduction in coronary collateral flow with metoprolol, probably due to an increase in coronary collateral resistance or a reduction in oxygen demand.     

关于骨质疏松超声诊断仪器亟待厘清的若干基本概念

继双能X线吸收仪之后,定量超声测骨仪器逐渐从群体筛查发展为筛查兼诊断手段,从补充、辅助工具进化成为潜在的主力。然而,在骨质疏松和骨折问题的本质,超声测骨仪器的产品名称、检测参数、派生参数、声学特性参数与骨矿密度相关性、产品性能表征与检验等方面,国内外均存在严重误读。本文就所涉及的一系列基本概念作了系统厘清,以期推动该类产品的科学、健康发展。     

肱－踝脉搏波传导速度和踝臂指数对冠状动脉疾病的预测价值

目的：探讨肱－脉搏波传导速度及踝臂指数对冠状动脉疾病的预测价值。方法入选472例疑似冠状动脉粥样硬化性心脏病（ CAD）的患者,根据CAG的结果,分为非CAD组（冠状动脉管腔狭窄＜5％）和CAD组（冠状动脉管腔狭窄≥50％）。收集患者的基线资料,对所有患者进行肱－踝脉搏波传导速度（ BaPWV）及踝臂指数（ ABI）的测量。用Logistic回归模型评价BaPWV、ABI及其他相关指标对冠状动脉病变程度的预测能力。结果（1）糖尿病、BaPWV＞1400 cm／s、典型胸痛,2组比较差异有统计学意义（P值均＜0．001）;ABI＜0．9,2组比较无统计学差异（P＞0．05）。（2）Logistic多因素回归分析显示,典型胸痛症状,PWV＞1400 cm／s和糖尿病史为CAD的独立预测因子（P值均＜0．001）。 OR值分别为8．442（95％可信区间5．063～14．077）,5．507（95％可信区间3．401～8．897）,3．027（95％可信区间1．854～4．941）。结论典型胸痛症状、PWV＞1400 cm／s和糖尿病病史是预测CAD的有效因素之一,BaP－WV作为无创伤检查方法可以有效预测冠状动脉疾病发生。而ABI＜0．9则没有表现出统计学意义。     

Correlation between 25-hydroxyvitamin D level and arterial elasticity in middle-aged and elderly cadres in Guiyang,China: A retrospective observational study

There is evidence that serum 25-hydroxyvitamin D [25-(OH) D] levels may be associated with cardiovascular disease and its risk factors. This study aimed to investigate the relationship between 25-(OH) D levels and blood pressure (BP), blood lipids, and arterial elasticity in middle-aged and elderly cadres in China.In this retrospective study, we included 401 civil servants and cadres aged >42 years who underwent medical examinations at Guiyang Municipal First People''s Hospital, China in 2018. The participants were assigned to deficiency (≤20 ng/mL), insufficiency (20–30 ng/mL), and sufficiency (≥30 ng/mL) groups according to 25-(OH) D levels in their blood. Demographics, brachial–ankle pulse wave velocity (baPWV), BP, ankle–brachial index (ABI), and blood lipids were compared among groups. The associations between 25-(OH) D and other parameters were evaluated using linear regression analysis.Median (range) 25-(OH) D levels in the deficiency (n = 162), insufficiency (n = 162), and sufficiency (n = 77) groups were 15.32 (2.93–19.88), 25.12 (20.07–29.91), and 33.91 (30.23–82.42) ng/mL, respectively. There were significant differences in systolic BP, pulse pressure, baPWV (left and right sides), ABI (left side), high-density lipoprotein-cholesterol, and triglycerides (TGs; all P < .05) among groups. Multivariate linear regression revealed that TG, left baPWV, and right baPWV were significantly negatively correlated with 25-(OH) D levels (all P < .05).In this study, 25-(OH) D levels were found to be associated with TG, left baPWV, and right baPWV values. 25-(OH) D deficiency may be associated with reduced arterial elasticity.     

Clinical significance of apelin in the treatment of type 2 diabetic peripheral neuropathy

Background:Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes. As apelin is an adipocytokine closely associated with diabetes, this study explored the clinical significance of serum apelin levels in patients with type 2 DPN before and after treatment.Methods:In total, 44 patients with T2DM without DPN (non-DPN group), 41 patients with DPN who received antihyperglycemic treatment (DPN-A group), 44 patients with DPN who received antihyperglycemic treatment combined with nutritional neurotherapy (DPN-B group), and 40 healthy control individuals (NC group) were selected continuously enrolled in the present study. Enzyme-linked immunosorbent assays (ELISA) were performed to determine serum levels of apelin and tumor necrosis factor-α (TNF-α). Related apelin, fasting blood glucose (FBG), glycosylated hemoglobin A1c, TNF-α, body mass index, fasting C peptide, and nerve conduction velocity (NCV) were recorded in each group before and after treatment.Results:Serum levels of apelin and TNF-α were higher in patients with diabetes than those in the NC group, as well as in the DPN group as compared to the non-DPN group; furthermore, some NCV values were significantly reduced in the DPN group. After treatment, the serum levels of apelin, TNF-α, and FBG reduced in patients with diabetes; moreover, apelin levels were found significantly lower in the DPN-B group as compared to the DPN-A group, while some NCV values significantly increased in the DPN-B group. Apelin was negatively correlated with part of NCV values and positively correlated with TNF-α and FBG (P < .01).Conclusion:Our results show that the increase in serum apelin levels is an important clinical reference index for DPN, while a decrease indicates that the DPN treatment is effective.     

Exercise E/e′ Is a Determinant of Exercise Capacity and Adverse Cardiovascular Outcomes in Chronic Kidney Disease

ObjectivesThis study sought to assess the relationship between E/e′ and exercise capacity in patients with chronic kidney disease (CKD) and evaluate its prognostic role.BackgroundPatients with CKD have diastolic dysfunction, reduced physical fitness, and elevated risk of cardiovascular disease.MethodsPatients with stage 3 and 4 CKD without previous cardiac disease underwent resting and exercise stress echocardiograms with assessment of exercise E/e′. Patients were compared to age-, sex-, and risk factor–matched control individuals and were followed annually for 5 years for cardiovascular death and major adverse cardiovascular event(s) (MACE). Exercise capacity was assessed as metabolic equivalents (METs), with reduced exercise capacity defined as METs of ≤7. Raised exercise E/e′ was defined as >13.ResultsA total of 156 patients with CKD (age 62.8 ± 10.6 years; male: 62%) were compared to 156 matched control individuals. Patients with CKD were more likely to be anemic (p < 0.01) and had increased left ventricular mass (p < 0.01), larger left atrial volumes (p < 0.01), and higher resting (p < 0.01) and exercise E/e′ (p < 0.01). Patients with CKD achieved lower exercise METs (p < 0.01), and more patients with CKD had METs of ≤7 (p < 0.01). Receiver-operating characteristic curves showed exercise E/e′ (area under the curve [AUC]: 0.89; 95% CI: 0.84 to 0.95; p < 0.01) as the strongest predictor of reduced exercise capacity in patients with CKD. Over a follow-up period of 41.4 months, a raised exercise E/e′ of >13 was an independent predictor of cardiovascular death and MACE on unadjusted and adjusted hazard models.ConclusionE/e′ is a strong predictor of exercise capacity and METs achieved by patients with CKD. Exercise capacity was reduced in patients with CKD, presumably consequent to diastolic dysfunction. Elevated exercise E/e′ in patients with CKD is an independent predictor of cardiovascular death and MACE.     

Ultrasound velocity criteria for carotid in-stent restenosis.

OBJECTIVE: To examine duplex ultrasound (US) criteria for carotid in-stent restenosis (ISR). BACKGROUND: Carotid artery stent (CAS) placement is an alternative to surgery for the treatment of carotid stenosis in high surgical risk patients. US is the primary method used to follow carotid stent patency. This study investigates US velocity measurements in carotid ISR. METHODS: Two hundred sixty consecutive patients with CAS placement from June 2000 to June 2004 were followed with serial US. ISR was determined by using the standard US velocity criteria for nonstented carotid artery using peak systolic velocity (PSV), end-diastolic velocity (EDV), and internal carotid artery to common carotid velocity ratio (ICA/CCA ratio). Patients suspected of having carotid ISR > or =50% by US, underwent invasive angiography with stenosis graded by NASCET criteria. Results were compared to patients with nonstented carotid artery stenosis using Two-tailed Student's t-test. RESULTS: PSV and ICA/CCA ratio increased to a greater degree in ISR. In 50-69% stenotic arteries, the mean ICA/CCA ratio was 2.76 +/- 0.7 in the ISR group compared to 2.04 +/- 0.3 in the nonstented carotid group (P < 0.05). In > or =70% stenotic arteries, there were increases in PSV (520 +/- 93 vs. 362 +/- 60, P < 0.05) and ICA/CCA ratio (7.58 +/- 2 vs. 4.51 +/- 1.3, P < 0.05) in ISR versus nonstented carotid arteries, respectively. CONCLUSION: PSV and ICA/CCA ratio in ISR increased to a greater extent for angiographic stenosis > or =50%. PSV 240 cm/sec and ICA/CCA ratio 2.45 are optimal thresholds for > or =50% ISR, and PSV 450 cm/sec and ICA/CCA ratio 4.3 are optimal thresholds for > or =70% ISR.     

Subclinical nerve dysfunction in children and adolescents with IDDM

Summary The purpose of this study was to investigate whether young insulin-dependent diabetic patients still develop peripheral nerve dysfunction when using modern multiple insulin injection therapy and to elucidate if this correlated with various disease parameters. Seventy-five patients, 7 to 20 years old with a duration of diabetes of more than 3 years, and 128 age-matched healthy control subjects underwent bilateral studies of median, peroneal, and sural nerves. Presence of diabetes lowered motor conduction velocity (p<0.0001), sensory conduction velocity (p<0.0001) and sensory nerve action potential (p<0.05) in all examined nerves. The mean change in conduction velocity induced by diabetes was –4.8 m/s in the peroneal nerve, –3.3 m/s in the median motor nerve, –2.6 m/s in the sural nerve and –2.4 m/s in the median sensory nerve. Fifty-seven percent of the patients had abnormal conduction (values outside 95% predictive interval) which was seen most often in the motor nerves, especially in the peroneal nerve (41%) followed by the median nerve (24%). In multiple regression analysis, long-term poor metabolic control and increased body length correlated with nerve dysfunction identified in most examined parameters. Three patients had signs or symptoms suggestive of neuropathy. It is concluded that despite modern multiple insulin injection therapy, with reasonably good metabolic control, nerve dysfunction is still common in children and adolescents with insulin-dependent diabetes mellitus. Risk factors are increased height and long-term poor metabolic control.Abbreviations IDDM Insulin-dependent diabetes mellitus - MIT multiple insulin injection therapy - MCV motor nerve conduction velocity - CMAP compound muscle action potential - DML distal motor latency - SCV sensory nerve conduction velocity - SNAP sensory nerve action potential     

Relationships between central arterial stiffness,lean body mass,and absolute and relative strength in young and older men and women

Relationships between muscular strength and arterial stiffness as well as between muscle mass and arterial stiffness have been observed suggesting a link between the neuromuscular system and vascular health. However, the relationship between central arterial stiffness and absolute and relative strength along with muscle mass has not been investigated in both sexes across a broad age range. The purpose of this study was to examine the relationship between central arterial stiffness and absolute and relative strength as well as between central arterial stiffness and lean body mass (LBM) in men and women across a broad age range. LBM, central arterial stiffness and strength were measured on 36 men and 35 women between the ages of 18 and 75 years. Strength was measured on five machine resistance exercises and summed as one measure of overall strength (absolute strength). Relative strength was calculated as total strength divided by LBM (relative strength). Central arterial stiffness was inversely related to both absolute (r = ?0·230; P = 0·029) and relative strength (r = ?0·484; P < 0·001) but not LBM (r = 0·097; P = 0·213). The relationship between central arterial stiffness and relative strength was attenuated but still present when controlling for either age, per cent body fat, LBM or mean arterial pressure. These results suggest that, across a wide age range, the expression of relative muscular strength has a stronger relationship with central arterial stiffness compared to either LBM or absolute strength. This suggests that muscle function more than muscle mass may be coupled with vascular health.     

Long‐term persistent fetomaternal hemorrhage

It is not clear that how long the affected fetuses can tolerate fetomaternal hemorrhage (FMH). Incidental serial measurements of the fetal peak systolic velocity of the middle cerebral artery and the retrospective analysis of stocked blood available incidentally indicated that our patient had suffered from FMH for at least 2 weeks prior to delivery.