Arteries In Diabetic Patients Research Articles

Long-term Outcomes after Angioplasty of Isolated, Below-the-knee Arteries in Diabetic Patients with Critical Limb Ischaemia

It has been shown that concomitant percutaneous transluminal angioplasty (PTA) of above-the-knee (ATK) and below-the-knee (BTK) arteries is highly beneficial for limb salvage in patients with critical limb ischaemia (CLI), but few published studies have specifically investigated outcomes in diabetic patients with CLI associated with isolated small BTK-vessel disease. This study aimed to evaluate the long-term results of successful PTA for limb salvage in such patients. From among the 634 patients with CLI in our database, we retrospectively selected a consecutive series of 101 diabetics (16%) with 107 critically ischaemic limbs (33 Rutherford 5 and 74 Rutherford 6) and no critical ATK lesion, who underwent PTA on isolated BTK lesions. The limb salvage rate was 93% after a mean follow-up of 1048+/-525 days (2.9+/-1.4 years). Transcutaneous oxygen tension significantly increased after 1 month (18.1+/-11.2 vs. 39.6+/-15.1; p<0.05). After 1 year, target-vessel re-stenosis had occurred in 42% of the non-amputated limbs, nine patients (9%) had died because of medical conditions unrelated to PTA and three patients had undergone repeat PTA for recurrent CLI. In our selected patient population with ischaemic diabetic foot and isolated BTK lesions, a successful endovascular procedure led to a high percentage of limb salvage at long-term follow-up.

Significance of Phlebosclerosis in Non-healing Ischaemic Foot Ulcers of End-stage Renal Disease

Objectives To determine the influence of haemodialysis on the poor healing of ischaemic ulcers in end-stage renal failure patients regardless of successful revascularization. Materials and methods We investigated the microscopic findings of subcutaneous small vessels in the amputated limbs of 78 patients (27 diabetic/haemodialysis, 26 diabetic/non-haemodialysis and 25 non-diabetic/non-haemodialysis patients) who underwent foot/toe or limb amputation because of ischaemic foot ulcers in the period between 1998 and 2006. All the haemodialysis patients were diabetic. Multivariate logistic analysis was conducted to identify important clinical factors related to the histological findings. Results Marked medial thickening was observed in both small veins and arteries in diabetic patients compared with non-diabetic patients. In diabetics, there was significant medial thickening of small veins, which was greater in haemodialysis patients than in non-haemodialysis patients (Dunnett test, P < 0.05). Multivariate analysis indicated that haemodialysis treatment (odds ratio 14.12, P < 0.01), ABI value (odds ratio 5.41, P < 0.01) and poor stump wound healing (odds ratio 6.19, P = 0.03) were important factors related to medial thickening of small veins. Conclusions Our data suggest that medial thickening of small veins, or phlebosclerosis, might affect the healing of ischaemic ulcers in end-stage renal failure, although the strong influence of diabetes cannot be ignored.

Comparison of Intravascular Ultrasound and Angiographic Assessment of Coronary Reference Segment Size in Patients With Type 2 Diabetes Mellitus

During percutaneous coronary intervention, the reference segment is assessed angiographically. This report described the discrepancy between angiographic and intravascular ultrasound (IVUS) assessment of reference segment size in patients with type 2 diabetes mellitus. Preintervention IVUS was used to study 62 de novo lesions in 41 patients with type 2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden was measured as plaque CSA/external elastic membrane (EEM) CSA. Using IVUS, the reference lumen diameter was 2.80 +/- 0.42 mm and the reference EEM diameter was 4.17 +/- 0.56 mm. The angiographic reference diameter was 2.63 +/- 0.36 mm. Mean difference between the IVUS EEM diameter and angiographic reference diameter was 1.56 +/- 0.55 mm. The mean difference between the IVUS reference lumen diameter and angiographic reference lumen diameter was 0.18 +/- 0.44 mm. Plaque burden in the reference segment correlated inversely with the difference between IVUS and quantitative coronary angiographic reference lumen diameter (slope = -0.12, 95% confidence interval -0.17 to -0.07, p <0.001), but it was not related to the absolute angiographic reference lumen diameter. Thus, reference segment diameters in type 2 diabetic patients were larger using IVUS than angiography, especially in the setting of larger plaque burden. In conclusion, these findings combined with inadequate remodeling may explain the angiographic appearance of small arteries in diabetic patients.

Transluminal Angioplasty of Peroneal Artery Branches in Diabetics: Initial Technical Experience

The present study aimed to report the technical feasibility of percutaneous transluminal angioplasty (PTA) of obstructed or insufficient collateral branches (anterior and posterior perforating branches) from distal peroneal to foot arteries in diabetic patients with chronic critical limb ischemia (CLI) and chronic noncrossable occlusion of the anterior and posterior tibial arteries. Twenty-four diabetic CLI patients (age, 67 +/- 8 years; 87% males) undergoing collateral PTA were included. Baseline clinical angiographic and follow-up data were retrospectively reviewed. Collateral PTA was associated with a concomitant PTA of other sites in 21 (83%) cases. In 15 cases the treated collateral linked the peroneal with the plantaris communis; in 9 cases, the peroneal with the dorsalis pedis. Angiographic results of collateral PTA were good in 13 cases (<30% residual stenosis), whereas the result was considered moderate (30%-49% residual stenosis) in the remaining cases. Neither perforation nor acute occlusion of the treated collaterals or other relevant complications were observed. Mean follow-up was 32 +/- 17 months. Major amputation was necessary for two (8.3%) patients. Cumulative limb salvage rates at 2 and 4 years were 96% and 87%, respectively. In conclusion, this initial experience shows that PTA of the collateral branches from distal peroneal to foot arteries is a feasible technique. Future studies are required to define the clinical role of this novel approach.

Abstract 2148: Sirolimus-eluting Stent Versus Bare-metal Stent In Diabetic Patients: Results Of The Italian Multicenter, Randomized “Dessert” Study.

Background: The real benefit of DES in diabetic patients is still debated since few studies have performed a direct randomized comparison between DES and BMS in such a population. Methods : The “Dessert” study is a multicenter, randomized trial conducted in Italy to demonstrate the efficacy of sirolimus-eluting stents (SES) compared to BMS in de novo lesions in native coronary arteries of diabetic patients, treated with insulin and/or oral antidiabetics for at least 3 months. Intraprocedural abciximab or pre-procedural tirofiban were administered to all patients. The primary end point was in-stent late loss as assessed by centralized quantitative coronary angiography at 8-month follow up. Centrally adjudicated composite MACE (death, Q wave and non-Q wave myocardial infarction, emergent bypass surgery or repeat target lesion revascularization) and target vessel failure (TVF: death, treated vessel related AMI, TLR) at 30 days, 9 and 12 months, and binary restenosis 8 months post-procedure were the secondary endpoints. Results: One hundred fifty patients were randomized to SES (75 patients, 109 lesions) or BMS (75 patients, 109 lesions). The two groups were well balanced for clinical, anatomic and procedural characteristics. On average, 45% of patients had multivessel or multilesion PCI, reference diameter was 2.66±0.43 mm and lesion length was 14.9±7.1 mm. In-stent late lumen loss was reduced from 0.96±0.61 mm for BMS to 0.14±0.33 mm for SES (p&lt;0.001); in-segment binary restenosis resulted 38.8% vs 3.6% respectively (p&lt;0.001). Twelve-month clinical events were significantly lower in the sirolimus group: MACE 22.1% vs 38.6%, p=0.035; TLR 5.9% vs 30%, p&lt;0.001; TVF 14.7% vs 34.3%, p=0.008. One case of subacute stent thrombosis occurred in sirolimus group, and one late stent thrombosis in bare-metal group. At multivariable analysis, stent type confirmed as independent predictor of in-segment late loss (p&lt;0.001), binary restenosis (p&lt;0.001), 12 month TVF (p=0.010) and 12-month MACE (p=0.037). Conclusions: The randomized “Dessert” study demonstrated that SES are safe and efficacious in reducing both angiographic and clinical parameters of restenosis compared with BMS in diabetic patients with de novo 1 or 2 vessel coronary stenoses.

Abstract 1680: Spatial Distribution of Myocardial Infarction in Patients with Diabetes Mellitus

BACKGROUND: Acute coronary occlusions occur most frequently as a result of rupture of an atherosclerotic plaque. Previous studies have found greater extent of atherosclerotic disease in the coronary arteries of diabetic patients. While the burden of disease is higher in diabetics, less is known about the spatial distribution of myocardial infarction in this population. METHODS: We sought to compare the spatial distribution of myocardial infarction (STEMI and Non-STEMI) in patients with diabetes mellitus and in those without, based on quantitative coronary and statistical analysis. We analyzed 756 patients with STEMI (n = 556) and NSTEMI (n=200), of which 175 patients comprised the diabetic cohort, and mapped the location of the acute coronary occlusion. RESULTS: Coronary occlusions were not uniformly distributed throughout each of the major epicardial coronary arteries but tended to cluster within the proximal third of each of the vessels in both cohorts. There was no difference in the distribution of occlusions in diabetics vs. non-diabetics in any of the vessels (left anterior descending artery, P=0.35; left circumflex artery; P=0.33 right coronary artery, P=0.20; Figure). CONCLUSIONS: Acute coronary occlusions leading to STEMI and NSTEMI in both diabetics and non-diabetics tend to cluster in predictable “hot spots” within the proximal third of the coronary arteries. Identification of these high-risk zones for acute coronary occlusions will lead to future advances in vulnerable plaque detection technology and potentially locally directed preventive strategies. Spatial distribution of myocardial infarction in diabetics vs. non-diabetics using distance to lesion from the ostium of the coronary artery.

Intravascular ultrasound assessment of remodelling and reference segment plaque burden in type-2 diabetic patients

Intravascular ultrasound (IVUS) assesses arterial remodelling by comparing the lesion external elastic membrane (EEM) with the reference segments; however, reference segments are rarely disease-free. The aim was to assess lesion and reference segment remodelling and plaque burden in patients with type-2 diabetes mellitus. We used pre-intervention IVUS to study 62 de novo lesions in 43 patients with type-2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden was measured as plaque CSA/EEM CSA. The remodelling index was defined as lesion EEM CSA/mean reference EEM CSA. Reference segment plaque burden measured 0.54 +/- 0.09. The majority of lesions (83.9%) had negative remodelling (lesion EEM < reference). Similarly, the slope of the regression line relating EEM to plaque CSA within the lesion was less than the reference substantiating negative remodelling. The reference segment plaque burden correlated inversely with the difference between IVUS lumen and quantitative coronary angiographic artery size [slope = -0.12 (95% CI -0.17 to -0.07); P < 0.001] in all patients with type-2 diabetes mellitus. Lesions in type-2 diabetic patients are different from previous reports in non-diabetics. Lesions in type-2 diabetics are characterized by a large reference segment plaque burden and negative lesion site remodelling. These IVUS findings may explain the angiographic appearance of small arteries in diabetic patients.

Use of Both Internal Thoracic Arteries in Diabetic Patients Increases Deep Sternal Wound Infection

Use of both internal thoracic arteries has been limited in diabetic patients fearing an increased incidence of deep sternal wound infection. We analyzed this concern by querying The Society of Thoracic Surgeons Database. Diabetic patients who had isolated coronary artery bypass graft surgery during 2002 to 2004 were included if they had no prior bypass surgery, two or more distal bypasses, and a left internal thoracic artery bypass. Group B (both internal thoracic arteries) was compared with group L (left internal thoracic artery only). The incidence of deep sternal wound infection for all patients undergoing isolated first-time bypass surgery was less than 1%. Of these, 120,793 patients met criteria for inclusion: group B, 1.4% (1732); and group L, 98.6% (119,061). Group B had a higher crude (unadjusted) deep sternal wound infection rate of 2.8% (49) versus 1.7% (1969; p = 0.0005) in group L, with an estimated odds ratio of 2.23 (95% confidence interval, 1.69 to 2.96). Group B had a similar crude mortality rate of 1.7% (30) versus 2.3% (2785; p = NS) in group L, with an estimated odds ratio of 1.110 (95% CI, 0.78 to 1.59; p = NS). Patients in group B were younger, mostly male, had a lower serum creatinine level, and were more often current smokers; less commonly, they were insulin dependent, diagnosed with pulmonary or vascular disease, or on dialysis. Other risk factors for deep sternal would infection included female gender, insulin dependence, peripheral vascular disease, recent infarction, body mass index exceeding 35 kg/m2, and use of blood products. There is a significant increase in the incidence of deep sternal would infection in diabetic patients. This is further increased with the use of both internal thoracic arteries with no apparent short-term mortality difference.

Peripheral Arteries in Diabetic Patients: Standard Bolus-Chase and Time-resolved MR Angiography

To prospectively determine the diagnostic performance of a combination of standard bolus-chase magnetic resonance (MR) angiography and MR angiography with time-resolved imaging of contrast kinetics (TRICKS) for depicting severity of peripheral vascular disease of the lower extremity, including the pedal arteries, in diabetic patients with digital subtraction angiography (DSA) as the reference standard. An ethical committee approved this study; written informed consent was obtained from patients. Standard three-station and TRICKS MR angiography of the calf and foot were performed in 31 consecutive diabetic patients (23 men, eight women; mean age, 67 years; range, 43-81 years). Two readers separately assessed images of arterial segments as diagnostic or nondiagnostic and graded stenosis. Results were compared with those at DSA when the corresponding arterial segments were considered diagnostic at DSA. Wilcoxon signed rank test was used to determine if a significant difference between imaging techniques existed, and kappa statistics were used to determine interobserver agreement. The difference between standard MR angiography and DSA regarding the number of diagnostic segments in the thigh was not significant (P = .50). A significantly higher number of calf and foot segments was considered diagnostic at TRICKS MR angiography than at standard MR angiography (P < .025). Sixteen of 26 segments in the foot that were considered nondiagnostic at DSA were considered diagnostic at TRICKS MR angiography. Average sensitivity of standard MR angiography for depicting hemodynamically significant arterial stenosis was 84% (reader 1) and 83% (reader 2) in the thigh and 78% (reader 1) and 80% (reader 2) in the calf. For both readers, average specificity was 97% in the thigh and 90% in the calf. Sensitivity and specificity of TRICKS MR angiography in the calf and foot were improved compared with those at standard MR angiography. TRICKS MR angiography of the distal calf and pedal vessels is superior to standard MR angiography regarding the number of diagnostic segments and assessment of the degree of luminal narrowing.

Randomized blinded clinical trial of intracoronary brachytherapy with 90Sr/Y beta-radiation for the prevention of restenosis after stent implantation in native coronary arteries in diabetic patients

Background We report a double-blind, randomized clinical trial of intracoronary β-radiation for prevention of restenosis after stent implantation in native coronary de novo lesions in diabetic patients. Methods After successful stent implantation in native coronary de novo lesions, 106 lesions in 89 diabetic patients were randomly allocated to treatment with β-radiation with 18 Gy at 1 mm vessel depth ( n=53) or placebo treatment ( n=53). Results Angiographic analysis at 9 month follow-up revealed a late lumen loss of 0.7±0.9 mm in the radiotherapy group versus 1.2±0.8 mm in the control group at the injured segment ( P=0.006), 0.9±1.0 versus 1.3±0.7 mm at the radiated segment ( P=0.02), and 0.9±1.0 versus 1.3±0.7 mm at the target segment ( P=0.04) (defined as active source length plus 5 mm on proximal and distal sites). Binary restenosis rates were significantly lower in the radiation group in all subsegments (injured segment: 10.9 versus 37.3%, P=0.003; radiated segment: 21.7 versus 49.0%, P=0.005; target segment: 23.9 versus 49.0%, P=0.01). Target lesion revascularization for restenosis was required in nine lesions (17.6%) in the radiotherapy group versus 18 (34.0%) in the placebo group ( P=0.05). Late thrombosis occurred in four radiated patients (after premature discontinuation of antiplatelet therapy in all), resulting in a major adverse clinical event rate of 37.2% in the brachytherapy group versus 38.6% in the placebo group ( P=ns). Conclusions In diabetic patients with de novo coronary lesions, intracoronary radiation after stent implantation significantly reduced restenosis. However, this clinical benefit was reduced by the frequent occurrence of late thrombosis.

Transluminal angioplasty of isolated crural arterial lesions in diabetics with critical limb ischemia

We investigated the long-term clinical results of transluminal angioplasty of isolated infrapopliteal arteries in diabetic patients with severe ischaemic foot lesions and the influence of different parameters on primary success, the long-term outcome and the survival rate. Between January 2001 and May 2004 we performed 50 transluminal angioplasties in 52 (10 female, 42 male, mean age 69.3 years) diabetics with isolated lesions of crural arteries (tibio-peroneal trunk 41, anterior tibial 13, posterior tibial 5, peroneal artery 14) and limb threatening ischaemia (rest pain 12, tissue loss 40). In two patients the dilatation could not be performed due to vessel perforation and impossibility to catheter localization. The morphological classification of infrapopliteal lesions was determined according to guidelines provided by TransAtlantic Inter-Society Consensus (TASC) (17 type A, 16 type B, 13 type C, 4 type D). Initial technical success after angioplasty of crural arteries could be obtained in 96%. Kaplan-Meier analysis showed a cumulative limb salvage of 92%, 85% and 68,9% after 6 months, one and two years, respectively. Patients falling in TASC group C had significantly higher risk of amputation. Overall survival at I year was calculated at 85% and at 2 years at 65%. Our results suggest that depending on the extent of lesions transluminal angioplasty of infrapopliteal artery stenoses and occlusions is considered as an effective and save therapy modality to avoid limb loss in diabetics with critical ischemia.

Calcification of the Medial Layer of the Internal Thoracic Artery in Diabetic Patients: Relevance of Glycoxidation

Objective: The aim of this study was to evaluate the role of glycoxidation in the calcification of the internal thoracic artery (ITA) in diabetes mellitus (DM). Methods: ITA samples were obtained from 17 patients with type 2 DM (age 62.9 ± 10.5 years) and 12 age-matched, nondiabetic patients (age 62.5 ± 10.2 years) who underwent coronary artery bypass grafting. These samples were analyzed histopathologically and assessed for calcification by von Kossa staining and for glycoxidation by immunohistochemistry using anti-N^Ε-(carboxymethyl)lysine (CML) antibody. Morphometric evaluation of calcification of the medial layer, intimal thickness and intima-to-media ratio was performed using NIH image software. To evaluate the mechanism of the interaction between calcification and glycoxidation, we developed an in vitro model of calcification of collagen that was chemically modified by glucose, glutaraldehyde or epoxy compound. The calcium-binding activity of these collagens was determined in hydrolysates using atomic absorption spectrophotometry. Results: ITAs of both diabetic and nondiabetic patients were free of atherosclerosis, and no differences were found between the two groups with regard to intimal thickness and intima-to-media ratio. Areas of calcification were noticed in both groups in the tunica media, but not in the tunica intima. Calcium deposits were localized within the extracellular matrix, which was immunohistochemically positive for CML. The extent of medial layer calcification was significantly greater in diabetic patients than nondiabetic subjects, but was independent of known risk factors such as hypertension, hyperlipidemia, obesity and history of old myocardial infarction. The binding activity of collagen was time-dependently increased with in vitro incubation of glucose. A significant increase in the calcium-binding ability was observed in glucose- and glutaraldehyde-modified collagens, but not in epoxy compound-modified collagen. Conclusion: Our results suggest that glycoxidative modification of the extracellular matrix, in particular collagen, of the vascular wall may enhance the development of ITA calcification in diabetic patients.

Morbidity after procurement of radial arteries in diabetic patients and the elderly undergoing coronary revascularization

Background. The use of radial arteries for coronary revascularization is increasing. There remain concerns regarding alteration of upper extremity function after radial artery procurement. This study evaluates the functional morbidity in higher risk patients. Methods. Between April 1997 and September 1999, 374 patients underwent unilateral or bilateral radial artery procurement. A questionnaire was used to evaluate symptoms related to motor and sensory function and changes in appearance after radial artery harvest. Results. Two hundred eighty-nine patients were successfully interviewed. The average age was 63 years. Median follow-up was 9.5 months (range, 2 to 23 months). No patient suffered limb loss. Altered gross and fine motor function, residual pain, paresthesias, numbness, pallor, swelling, and altered temperature sensation were compared among diabetic patients, patients older than 70 years, and patients without these characteristics. Conclusions. Radial artery procurement for elective coronary revascularization can be done with minimal serious morbidity in higher risk patients. The most common symptoms were numbness and paresthesia. Despite the finding of greater residual pain in diabetic patients, we do not believe the use of radial artery conduits is contraindicated in these patients.

Pedal Bypass for Limb Salvage: Impact of Diabetes on Long-Term Outcome

Use of pedal bypass can salvage limbs of patients with critical ischemia. The aim of this study was to evaluate the results of surgical revascularization of pedal arteries in diabetic patients and to assess the impact of diabetes on long-term outcome. We performed a retrospective analysis of all consecutive pedal bypasses done between January 1, 1987 and December 31, 1997. Demographic data, surgical indications, operative variables, and postoperative results including graft patency and limb salvage were compared between diabetic and nondiabetic patients. The results of this comparison showed that pedal bypass can safely and effectively relieve critical ischemia in diabetic patients. Diabetics have less early graft thrombosis and superior long-term graft patency. Despite higher incidence of renal insufficiency or failure and more tissue loss, diabetics can achieve similar excellent limb salvage rates. This outcome justifies aggressive revascularization of pedal arteries in diabetic as well as nondiabetic patients with critical limb ischemia.

Is mediastinitis a preventable complication? A 10-year review

Background. The incidence of mediastinitis after cardiac surgical intervention is reported to be between 0.15% and 5% and is a major cause of postoperative morbidity. A number of risk factors have been identified, most of which are not modifiable. It is our contention that this complication can be reduced to a minimum by the consistent application of good operative technique and postoperative management. Methods. We reviewed the records of all 9,771 patients who underwent cardiac surgical procedures between 1987 and 1997. All operations were performed using a common skin preparation, draping, and antibiotic prophylaxis. Cases of mediastinitis were defined according to Centers for Disease Control and Prevention criteria and were identified from three sources: medical records database, hospital infection control, and the Society of Thoracic Surgeons database. Risk factors were assessed using χ 2 and Fisher’s exact tests. Results. Of 24 patients identified as having deep sternal wound infection (incidence, 0.25%), 2 died (mortality rate, 8.3%), 18 required reoperation (75%), and only 4 needed pectoral muscle flaps. Statistical analysis revealed only the presence of chronic obstructive pulmonary disease as a significant risk factor ( p < 0.01). Other factors, including diabetes, renal failure, smoking, sex, age, reoperation, morbid obesity, and steroid use, were not significant. The use of internal mammary arteries (single or bilateral) was not associated with mediastinitis. Postoperative complications, including prolonged ventilation, inotropic support, and the need for blood products, were not significant risk factors. The patients who developed mediastinitis were more likely to be readmitted to the hospital ( p < 0.005) and more likely to require reoperation ( p < 0.005). Conclusions. In a large patient series we found a low incidence of mediastinitis (0.25%) and an even lower incidence of required reoperation (0.19%). Except for the use of bone wax and the use of bilateral mammary arteries in diabetic patients, none of the previously identified risk factors are modifiable. We believe that with strict adherence to perioperative aseptic technique, attention to hemostasis, and precise sternal closure, a very low incidence of mediastinitis can be achieved.

Coronary Artery Diameter and Left Ventricular Function in Patients on Maintenance Hemodialysis Treatment: Comparison between Diabetic and Nondiabetic Patients

Background/Aims: This study examined the role of diabetes mellitus on determining left ventricular function by evaluating coronary artery diameter in patients with end-stage renal disease on maintenance hemodialysis treatment. Methods: We studied 12 diabetic and 12 nondiabetic patients on maintenance hemodialysis treatment without significant stenoses of the major epicardial coronary arteries. Patients were matched for age, sex distribution, duration of dialysis and incidence of major coronary risk factors. Left ventricular wall thickness (septal and posterior walls) and left ventricular diameter (end-diastolic and systolic phases), were measured by echocardiography. Hemodynamic measurements and coronary angiography were performed on the day of hemodialysis and coronary artery diameter at the proximal and mid portion of three major coronary arteries were measured using the computed densitometry method. Results: Right and left anterior descending and circumflex coronary artery diameters were all significantly smaller and the frequency of coronary artery calcification was higher in diabetic (58%) compared to nondiabetic (8%) patients. Although there were no significant differences in left ventricular wall thickness, left ventricular diameter, mean right atrial pressure and cardiac index between the two groups, left ventricular end-diastolic pressure was significantly higher in diabetic (22 ± 9 mm Hg) compared to nondiabetic patients (14 ± 5 mm Hg). Conclusion: Despite that there were no significant stenoses of the major epicardial coronary arteries, diffuse luminal narrowing of the epicardial coronary arteries in diabetic patients on maintenance hemodialysis treatment was associated with increased left ventricular end-diastolic pressure.

Sympathetic function test of vasoconstrictor changes in foot arteries in diabetic patients.

We studied the relationship between vasoconstrictor changes in foot arteries (pedal, metatarsal, and digital arteries) and autonomic neuropathy in diabetic patients to estimate the degrees of sympathetic dysfunction. Sixty-two patients and nineteen age-matched control subjects were studied. The resistance index (RI) and pulsatility index (PI) were measured as vascular hemodynamic parameters using Doppler sonography, and the increases in these hemodynamic parameters (%RI and %PI) from rest to a deep breath were measured as indexes of the degrees of sympathetic vasoconstrictor function. Cardiovascular autonomic function tests (AFTs) were performed and the score was compared to %RI and %PI values obtained. Of the 62 diabetic patients, 51 had various degrees of autonomic neuropathy. Both %RI and %PI in the diabetic patients were significantly less than those in the control subjects for all foot arteries tested (all P < 0.001). There were strongly inverse correlations between the %RI and %PI of foot arteries and the AFT score (r = -0.556 to -0.846, P < 0.0001). The %RI of the digital artery was the most strongly correlated with AFT score (r = -0.846, P < 0.0001) among foot arteries tested. The abnormality of sympathetic vasoconstriction was detectable in the majority of the diabetic patients with the early phase of autonomic neuropathy (%RI: 89.5%; %PI: 94.5%). We conclude that the %RI of the digital artery is a useful and reliable sympathetic function test of early phase in diabetic patients.

Diffuse Narrowing of Coronary Arteries in Diabetic Patients: The Earliest Phase of Coronary Artery Disease

Coronary arteries in diabetic patients appear to be narrower than in normal subjects, but this has not been examined systematically. To investigate this hypothesis we reviewed the data of 711 consecutive patients with angiographically ‘normal coronary arteries’. Excluded were patients with valvular, myocardial or pericardial disease, and patients with hypertension or hyperlipidemia. Thirteen diabetic patients (10 men) and 22 nondiabetic persons (8 men) constituted the study and control groups, respectively. The diameters of the coronary arteries and their branches were measured and adjusted for body surface area. The sum of the proximal left anterior descending (LAD), circumflex and right coronary arteries (RCA) was calculated and defined as total coronary diameter (TCD). The sum of the distal LAD, first diagonal, first marginal and distal RCA was calculated and defined as total distal coronary diameter (dTCD). The clinical data of both groups were comparable. Adjusted TCD for body surface area was 5.4 ± 1.1 and 6.5 ± 1.1 mm/m² (p < 0.05) in diabetics and nondiabetics, respectively, and adjusted dTCD was 4.9 ± 1.2 and 6.1 ± 1.2 mm/m² (p = 0.01) in diabetics and normal subjects, respectively. Specific arteries and branches that were significantly smaller in diabetics included: left main coronary artery, distal LAD, first diagonal, proximal RCA, distal RCA, right ventricular branch, and posterolateral and posterior descending artery of RCA origin. Gender was not a confounding factor since the control group had a larger proportion of women and still larger arteries than the diabetic group. In conclusion, coronary arteries and their branches in diabetic patients have smaller diameters than normal subjects. This may be due to increased coronary tone, diffuse mild atherosclerosis or both.

G7 Desferrioxamine but not l-arginine improves responses of angiographically normal coronary arteries of diabetic patients to cold pressor test and to flow increase

G7 Desferrioxamine but not l-arginine improves responses of angiographically normal coronary arteries of diabetic patients to cold pressor test and to flow increase

Impaired Contraction and Endothelium-Dependent Relaxation in Isolated Resistance Vessels from Patients with Insulin-Dependent Diabetes Mellitus

1. An increase in capillary blood flow and pressure has been implicated in the pathogenesis of diabetic microangiopathy. Abnormal vascular reactivity of the resistance vasculature may play a contributory role by permitting alterations in regional haemodynamics. 2. We have studied the contractile behavior of isolated resistance arteries from normotensive patients with insulin-dependent diabetes mellitus and non-diabetic matched control subjects. Contractile responses to potassium (123 mmol/l), noradrenaline (10(-8) to 3 x 10(-5) mol/l) and angiotensin II (10(-11) to 3 x 10(-8) mol/l) were recorded. Relaxation studies were performed in maximally contracted vessels using acetylcholine (10(-8) to 10(-5) mol/l) and bradykinin (10(-9) to 10(-6) mol/l) (endothelium-dependent) and sodium nitroprusside (10(-9) to 10(-5) mol/l) (endothelium-independent). 3. The maximal contractile responses to potassium (P < 0.05), noradrenaline (P < 0.01) and angiotensin II (P < 0.01) were depressed in diabetic patients. Relaxation to acetylcholine was impaired (P < 0.05), but was normal with bradykinin and sodium nitroprusside. 4. These results suggest that there may be a defect in the endothelial cell acetylcholine receptor excitation-coupling in diabetes mellitus rather than a decreased ability to synthesize and release endothelium-derived relaxing factor. Impaired contraction and endothelium-dependent relaxation of resistance arteries in diabetic patients may contribute to the development of diabetic microangiopathy by causing an increase in tissue blood flow, a rise in capillary pressure and, as a result, an increase in vascular permeability.