Demet Özkaramanlı Gür

Comparison of endothelial function of coronary artery bypass grafts in diabetic and nondiabetic patients: Which graft offers the best?

Objective: Diabetes associated endothelial dysfunction, which determines both long and short term graft patency, is not uniform in all coronary artery bypass surgery (CABG) grafts. Herein this study, we aimed to investigate the degree of endothelial dysfunction in diabetic radial artery (RA), internal mammarian artery (IMA) and saphenous vein (SV) grafts in vitro tissue bath system. Methods: This is a prospective experimental study. Fifteen diabetic and 15 non-diabetic patients were included to the study. A total number of 96 graft samples were collected; 16 graft samples for each graft type from both diabetic and non-diabetic patients. Arterial grafts were harvested with pedicles and SV grafts were harvested by ‘no touch’ technique. Vasodilatation response of vascular rings to carbachol, which induces nitric oxide (NO) mediated vasodilatation, was designated as the measure of endothelial function. Results: The IMA grafts had the most prominent NO mediated vasodilatation in both diabetic and non-diabetic patients, concluding a better preserved endothelial function than SV and RA. The ‘no-touch’ SV and RA grafts had similar vasodilatation responses in non-diabetic patients. In diabetic patients, on the other hand, RA grafts exhibited the least vasodilatation response (ie. worst endothelial function), even less vasodilatation than ‘no touch’ SV grafts (p<0.0001). Conclusion: Deteriorated function of RA grafts in diabetic patients, even worse than SV grafts made evident by this study, encourages the use of ‘no touch’ technique as the method of SV harvesting and more meticulous imaging of RA before its use as a graft in diabetic patients.

Role of sympathetic cotransmitter galanin on autonomic balance in heart failure: an active player or a bystander?

Objective: Galanin, a cotransmitter similar to neuropeptide Y (NPY), aggravates autonomic imbalance in systolic heart failure (HF) by attenuating vagal tonus after burst sympathetic activity. In animal HF models, galanin antagonists have improved cardiac function. To determine whether galanin is a promising therapeutic target in HF, we studied its concentrations in HF patients and evaluated its correlation with NPY, markers of humoral activity such as pro-BNP and copeptin, and echocardiographic parameters of HF severity. Methods: After recording demographic and echocardiographic characteristics of 87 individuals (57 HF patients and 30 control subjects), fasting serum concentrations of galanin, NPY, copeptin, and pro-BNP were determined. Results: Unlike pro-BNP, copeptin, and NPY, which were significantly elevated in HF patients (p<0.001, p<0.001, and p=0.001, respectively), galanin was similar in HF patients and control subjects (p=0.9). NPY correlated with the echocardiographic parameters of HF severity (r=–0.22, p=0.03 for EF; r=0.3, p=0.005 for Tei index of RV; r=–0.23, p=0.03 for TAPSE; and r=0.24, p=0.024 for E/e¢) and pro-BNP (r=0.22, p=0.046). NPY levels were also associated with beta blocker (BB) use, wherein BB significantly decreased NPY in both HF patients and control subjects. Galanin correlated with humoral biomarkers, pro-BNP and copeptin (r=0.39, p<0.001 and r=0.41, p<0.001, respectively). Although current smoking, BB therapy, pro-BNP, copeptin, and body mass index were associated with galanin in univariate analyses, the multiple linear regression model revealed that pro-BNP was the only significant determinant of galanin levels in HF patients. Conclusion: Our findings confirmed the role of NPY in autonomic balance and suggest that galanin is associated with the proadrenergic state, but its role in HF in humans remains unclear.

Vitamin D levels in white coat and sustained hypertension.

ObjectiveThe plasma levels of vitamin D in patients with white coat hypertension (WCHT) have not been studied previously. The aim of this study was to evaluate vitamin D levels in WCHT and compare with sustained hypertension (SHT) and with normotension (NT). Patients and methodsFifty-three normotensive, 42 WCHT, and 59 SHT patients were recruited in this study. The participants were matched for age, sex, and BMI. The vitamin D levels were determined using the electrochemiluminescence immunoassay method. ResultsPlasma vitamin D levels were significantly lower in SHT than in the WCHT and NT groups (26.4±4.9, 34.3±3.6, and 36±5 ng/ml, respectively), and were similar in the WCHT and NT groups. There was a negative correlation between vitamin D levels and blood pressure parameters such as clinic systolic blood pressure (SBP), clinic diastolic blood pressure (DBP), 24-h SBP, 24-h DBP, daytime SBP, daytime DBP, night-time SBP, and night-time DBP (r=−0.554, −0.419, −0.629, −0.427, −0.559, −0.534, −0.607, −0.462, respectively, and all P<0.001) in the entire study group. Clinic SBP (B±SE=−0.97±0.037, P=0.009) and 24-h SBP (B±SE=−0.138±0.055, P=0.013) were identified as predictors for vitamin D levels in the entire study group. ConclusionOur data show that sustained hypertensive patients have lower vitamin D levels than white coat hypertensive and normotensive individuals. White coat hypertensive patients without other cardiovascular risk factors have higher vitamin D levels than sustained hypertensive patients, suggesting that they have a lower cardiovascular risk.

Body mass index as a determinant of postoperative morbidity

BACkGRouND: The impact of obesity on postoperative mortality and morbidity in coronary artery bypass grafting (CABG) operations is a widely studied but poorly defined topic. oBjECTIVE: To investigate the effect of body mass index (BMI) on inhospital mortality and morbidity after isolated CABG surgery. METhoDS: Prospectively collected data of a series of 1057 consecutive patients who underwent on-pump isolated CABG surgery were retrospectively analyzed. Patients were divided into five groups according to WHO BMI categorization (defined as underweight [BMI <20 kg/m2]; normal weight [BMI ≥20 kg/m2 to <25 kg/m2]; overweight [BMI ≥25 kg/m2 to <30 kg/m2]; obese [BMI ≥30 kg/m2 to <35 kg/m2]; and morbidly obese [BMI ≥35 kg/m2]). RESulTS: Of 1057 patients, 13 patients (1.2%) were underweight, 298 (28.2%) were normal weight, 462 (43.7%) were overweight, 218 (20.6%) were obese and 66 (6.2%) were morbidly obese. The mean age was significantly lower in underweight patients, who were also more likely to be male. In contrast, obese and morbidly obese patients were older, and more likely to have comorbidities such as diabetes and hypertension. The incidence of postoperative bronchodilator use (P<0.001), leg wound infection (P=0.038), sternal dehiscence (P=0.039) and development of new-onset atrial fibrillation (P<0.001) was significantly higher in obese and morbidly obese groups. In contrast, postoperative prolonged ventilation (P<0.001), need for blood transfusions (P<0.001) and revision for bleeding (P=0.041), as well as gastrointestinal complications (P<0.001), were significantly higher in underweight patients. Multivariate logistic regression analysis showed that female sex, older age and diabetes mellitis, but not BMI, were independent risk factors for early mortality after CABG surgery. CoNCluSIoN: No effect of BMI on early postoperative mortality after CABG surgery could be demonstrated. However, in terms of morbidity, postoperative bleeding and revision for bleeding were increased in underweight patients while sternal dehiscence, wound infections and occurrence of atrial fibrillation were increased in obese and morbidly obese patients.

Inflammatory Mediators Across the Spectrum of Ankle-Brachial Index

Aim: Peripheral artery disease (PAD) is a manifestation of atherosclerosis with poor prognosis. It is generally complicated by vascular calcification, which is located either in the intima as patchy infiltrates; or circumferentially in the media, also known as medial arterial calcification (MAC). Obstructive PAD is reflected by low anklebrachial index (ABI ≤ 0.9), whereas MAC is revealed by high ABI (ABI > 1.4). Considering the increase in cardiovascular mortality at both ends of the ABI spectrum, this study aimed to explore the underlying pathology through cytokines with established prognostic significance; namely pentraxin-3(PTX3), high sensitivity C-reactive protein (hsCRP), copeptin, soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), NT-proBNP, and neopterin. Methods: We categorized 180 patients with previous multivessel coronary artery bypass grafting surgery into three groups based on their ABI measurements; 60 patients with ABI ≤ 0.9, 60 patients with ABI within 0.91 and 1.4 (normal ABI), and 60 patients with ABI > 1.4 constituted the “PAD,” “normal,” “MAC” groups, respectively. The circulating levels of the biochemical markers were determined. Results: In the PAD group, the cytokine levels with predominantly proatherogenic actions such as PTX3, hsCRP, copeptin, and sTREM-1 were increased and these cytokine levels declined as the ABI increased. In the MAC group, the cytokine concentrations with pleiotropic actions such as NT-proBNP and neopterin increased and; NT-proBNP and neopterin concentrations decreased as ABI decreased. The linear regression analysis revealed that neopterin (β = 0.72), PTX3 (β = −0.32), and copeptin (β = −0.48) were independent predictors of ABI. Conclusions: These findings suggest that different inflammatory pathways influence the pathology at the opposing ends of the ABI spectrum. Consequently, we suggest that PTX3, copeptin, and neopterin are promising biomarkers for future research.

Tools to improve the diagnostic accuracy of exercise electrocardiograms in patients with atypical angina pectoris

OBJECTIVE Although frequently utilized, an exercise electrocardiogram (ECG) provides limited diagnostic accuracy in patients with atypical angina pectoris. The purpose of this study was to determine the possible incremental value of pretest probability (PTP) scores and exercise parameters in discriminating coronary artery disease (CAD) and to identify PTP cutoff values. METHODS In a retrospective cohort of 207 patients with atypical angina (76 women, 131 men; mean age: 57.6±8.2 years) who underwent coronary angiography (CAG) after a positive exercise ECG, the PTP was calculated according to the CAD Consortium basic and clinical models along with exercise parameters of blood pressure (BP), heart rate (HR), exercise duration, maximal metabolic equivalents (METs), HR reserve, HR recovery, chronotropic index, BP reserve, BP recovery, and ST/HR ratio. Patients were categorized into true positive (TP) or false positive (FP) groups, depending on the ultimate determination of a presence of obstructive CAD. RESULTS A TP result was associated with older age, male gender, hypertension, diabetes, hyperlipidemia, and higher basic and clinical PTP, as well as higher maximal BP, maximal ST deviation and ST/HR, but lower maximal METs, chronotropic index, and HR recovery. The basic and clinical PTP, and the chronotropic index could predict a TP test result irrespective of gender. Logistic regression analysis revealed that clinical PTP was the only independent predictor of TP results. A cutoff score of 18 for the basic and 21 for the clinical PTP were determined to discriminate CAD. CONCLUSION This study has shown that, among various electrocardiographic and hemodynamic parameters, the clinical PTP and the chronotropic index are the most helpful tools to discriminate patients with CAD among patients with atypical angina.

The fate of small side branches following drug eluting stent implantation

Objectives Although drug eluting stents (DES) have documented convenience in bifurcation lesions, possible unfavorable effects on small side branch ostium (SBO) remain a question. We aimed to explore the effects of DES on small jailed SBs (1.5–2.25 mm) which originated from the lesion on the main vessel and were not treated with either stenting or balloon dilatation. Methods Angiographic data of 107 consecutive patients (129 SB) with Medina 1,1,1 or 1,1,0 lesions were evaluated at the time of procedure and at the follow-up. Results Of all DES used, 70 (54.7%) was sirolimus-eluting, 39 (30.5%) was paclitaxel-eluting and 20 (14.8%) was zotarolimus-eluting. The diameter of SBs was 1.84 ± 0.41 mm with a stenosis of 20.7 ± 26.6% at SBO at baseline. The lesion at the SBO had progressed after the procedure when the pre vs postprocedure values and follow-up vs pre-procedure values are compared (20.7 ± 26.6% vs 29.4 ± 27.4%; p < 0.0001 and 25.4 ± 25.1 vs 20.7 ± 26.6%; p = 0.004 respectively). A significant reduction in stenosis was revealed over the follow-up (29.4 ± 27.4 vs 25.4 ± 25.1 respectively; p = 0.013). The severity of the disease at the SBO at baseline was the only parameter that affected the severity of SB stenosis in acute, longterm and follow-up. Additional parameters with influence on SB patency at different times were female gender, stent deployment with low pressure, cTFC of the main lesion, age, cTFC of the lesion, late loss index and the preprocedure TIMI flow grade of the SB. Conclusions Although there was a significant deterioration of SBO immediately after stenting, follow-up data showed that the lesion at SBO improved but remained worse than baseline.

Vasodilation Responses to Non-Selective α-Adrenergic Blockage of Coronary Bypass Grafts in Diabetic and Non-Diabetic Patients: In Vitro Study

BACKGROUND Adrenergic tonus is increased in atherosclerotic coronary arteries. In this study, we aimed to demonstrate in vitro effects of phentolamine, a reversible nonselective alpha (α) adrenergic blocker, on coronary artery bypass grafts (CABG) and compare its effects in diabetic and nondiabetic patients. METHODS A total number of 30 patients (15 diabetic and 15 nondiabetic) who were assigned to elective CABG surgery were enrolled into the study. For both groups of patients, 16 internal mammarian artery (IMA) samples, 16 saphenous vein (SV) samples and 16 radial artery (RA) samples were collected and studied in the tissue bath system. The vasodilatation responses to increasing doses of phentolamine were recorded. RESULTS When grafts were compared in terms of amount of vasodilatation to phentolamine, IMA had the most prominent vasodilatation followed by RA and SV respectively. Although the vasodilatation responses in nondiabetic patients were numerically higher than diabetic patients, there was no statistically difference between the groups. CONCLUSION Phentolamine, a nonselective α adrenergic blocker, is proven to have equal vasodilatory effects in diabetic and nondiabetic CABG grafts and can safely be used both intravenously and topically in the perioperative period.

The effect of distension pressure on endothelial injury and vasodilatation response in saphenous vein grafts: conversion of a bypass graft to a dead pipe

Introduction Endothelial damage caused by high pressure applied for spasm relaxation during graft preparation is one of the most plausible theories explaining early graft failure. Aim of the study We aimed to demonstrate the extent of endothelial damage in saphenous vein grafts distended to different pressure levels by using immunohistochemical methods and in vitro tissue baths. Material and methods Saphenous vein grafts (SVGs) of 25 patients who underwent isolated elective CABG surgery were used in this study. By using a specific mechanism, SVGs were distended to five different pressure levels for two minutes: 0 mmHg, 50 mmHg, 100 mmHg, 200 mmHg, 300 mmHg. In vitro tissue baths and immunohistochemical examinations were performed. Results None of the grafts distended to 300 mmHg pressure were functional in the tissue bath system. The relaxation response to carbachol of SVGs distended to 0, 50, 100 and 200 mmHg was 97.87 ± 4.47%, 98.52 ± 3.95%, 93.78 ± 3.64%, and 30.87 ± 4.11%, respectively. There were no statistically significant differences in terms of relaxation responses between samples distended to 0, 50, and 100 mmHg (p = 0.490). The relaxation response of samples distended to 200 mmHg was significantly decreased (p = 0.021). The endothelia of samples distended to 0 mmHg were almost intact in CD31 staining. Endothelial cell loss occurred at all tested distension pressures at different degrees. Conclusion In vitro and immunohistochemical studies revealed that distending an SVG used for coronary artery bypass grafting with pressures of 100 mmHg or less results in less endothelial damage and increases graft patency.

Pacemaker extrusion: a rare clinical problem mainly in elderly adults.

common cause of adult large bowel obstruction in the United States, following cancer and diverticulitis, but accounts for fewer than 10% of cases. In the largest retrospective analysis of individuals with SV, the peak incidence of SV was in the mid-70s for men and women, and it affected an older population in the United States than other countries in which it is more endemic. SV is more common in men, African Americans, individuals with diabetes mellitus, and institutionalized or debilitated individuals. SV is characterized clinically by abdominal distention and pain in the setting of nausea and constipation; vomiting is unlikely. The diagnosis of SV can usually be made with plain abdominal radiography, and computed tomography or magnetic resonance imaging can be used as confirmatory tests if necessary. Common radiographic findings include absence of rectal gas, distention of the sigmoid colon in a coffee bean–like configuration, and a sigmoid colon transition point. Given the significant rates of recurrence (up to 60%) and mortality (up to 60%), treatment typically involves sigmoidoscopy with decompression, followed by sigmoid resection with primary anastomosis, but nonoperative management should be considered because of the comorbidity and associated risks with surgery in elderly adults. One survey investigating the ethics of abdominal surgery in individuals with dementia and bowel obstruction showed that 65% of respondents identified surgery as inappropriate and 26% deemed any intervention unacceptable. The current patient was deemed a poor surgical candidate but underwent flexible sigmoidoscopy with decompression. While this resulted in temporary improvement of her symptoms, the volvulus ultimately returned and she was transitioned to hospice care.