Elevated level of pro-inflammatory eicosanoids and EPC dysfunction in diabetic patients with cardiac ischemia.

BACKGROUND: Circulating endothelial progenitor cells (EPCs) are recruited from the blood system to sites of ischemia and endothelial damage, where they contribute to the repair and development of blood vessels. Since numerous eicosanoids including leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs) have been shown to exert potent pro-inflammatory activities, we examined their levels in chronic diabetic patients with severe cardiac ischemia in conjunction with the level and function of EPCs. RESULTS: Lipidomic analysis revealed a diabetes-specific increase (p<0.05) in inflammatory and angiogenic eicosanoids including the 5-lipoxygenase-derived LTB (4.11±1.17 vs. 0.96±0.27 ng/ml), the lipoxygenase/CYP-derived 12-HETE (117.08±35.05 vs. 24.34±10.03 ng/ml), 12-HETrE (17.56±4.43 vs. 4.15±2.07 ng/ml), and the CYP-derived 20-HETE (0.32±0.04 vs. 0.06±0.05 ng/ml) the level of which correlated with BMI (p=0.0027). In contrast, levels of the CYP-derived EETs were not significantly (p=0.36) different between these two groups. EPC levels and their colony-forming units were lower (p<0.05) with a reduced viability in diabetic patients compared with non-diabetics. EPC function (colony-forming units (CFUs) and MTT assay) also negatively correlated with the circulating levels of HgA1C. CONCLUSION: This study demonstrates a close association between elevated levels of highly pro-inflammatory eicosonoids, diabetes and EPC dysfunction in patients with cardiac ischemia, indicating that chronic inflammation impact negatively on EPC function and angiogenic capacity in diabetes.

Limb performance and patient satisfaction after radial artery harvesting: endoscopic versus open techniques.

BACKGROUND: The differences in hand functionality after harvesting the radial artery for coronary artery bypass grafting (CABG) in an endoscopic technique relative to open technique are unclear. METHODS: One hundred and sixty-four patients who had CABG and their non dominant hand radial artery was harvested either in an open technique (n = 92) or in an endoscopic technique (n = 72) in a period of 9.8 +/- 3.5 months after the operation were studied. Surgical technique was surgeon specific. Patients were asked either five questions (endoscopic group), or six questions (open group), to assess how radial artery harvesting affected them. RESULTS: Significantly more patients in the open group experienced significant limitations in their work and regular daily activities (12% versus 0%, p = 0.02), social activities (13% versus 0%, p = 0.005), and experienced significant pain (8% versus 0%, p = 0.04) compared with the endoscopic group. More patients in the open group complained that their arm incision disturb them (24% versus 10%, p = 0.01). Forty-two patients (46%) in the open group would prefer smaller incision. A "limitation score" variable was created from the first four questions to reflect overall functionality. Severe limitation was present in 3% of the open group versus 0% in the endoscopic group (p = 0.04). Female sex and open harvesting technique were found to be independently associated with higher limitation score. CONCLUSIONS: After a mean of 9.8 months after surgery, patients reports good overall upper-limb function. However, more patients in the open technique had significant disabilities and dissatisfaction.

Monitoring platelet reactivity during prasugrel or ticagrelor washout before urgent coronary artery bypass grafting.

OBJECTIVES: Patients with acute myocardial infarction pretreated with prasugrel or ticagrelor may require urgent coronary artery bypass grafting (CABG). However, prasugrel and ticagrelor withdrawal period is recommended for 5-7 days before planned CABG to enable full platelet recovery. We hypothesized that monitoring sequential platelet reactivity (PR) could identify patients with early platelet recovery who may benefit from earlier surgery before the guideline-recommended 5-7 day delay. PATIENTS AND METHODS: We performed preoperative PR assays in 35 patients with acute myocardial infarction who received prasugrel (60%) or ticagrelor (40%) and required an urgent CABG. When platelet inhibition levels were favorable, on the basis of the VerifyNow assay, surgery was endorsed. CABG-related bleeding parameters were collected and compared with two matched control groups composed of patients who received fewer potent antiplatelet regimens. RESULTS: On the basis of platelet function monitoring, we identified 21 (56.7%) patients with a relatively earlier platelet recovery who underwent CABG before the end of the conventional washout period (5-7 days). For these patients, the washout periods were shortened to an average time of 2.6±1.0 days for ticagrelor and 3.8±1.5 days for prasugrel. CABG-related bleeding parameters were comparable with the two matched control groups. CONCLUSION: A strategy of performing preoperative PR assays can identify patients who recover platelet function in less than 5-7 days after ticagrelor or prasugrel discontinuation. This strategy may provide the basis for performing urgent CABGs earlier than the currently recommended delay. Future, larger studies are required to establish these preliminary findings.

Platelet function changes as monitored by cone and plate(let) analyzer during beating heart surgery.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) is believed to reduce cardiopulmonary bypass (CPB)-related complications, including platelet damage. A hypercoagulable state instead of coagulopathy has been reported following OPCAB surgeries due to CPB. Whether platelet function is changed when the injurious effect of CPB is eliminated was investigated. METHODS: Platelet function was determined with the cone and plate(let) analyzer (CPA) method. The 2 parameters, average size (AS) and surface coverage (SC) of platelet aggregates, were measured with the CPA method to assess platelet aggregation and adhesion. These parameters were evaluated, and their values were compared at several stages of OPCAB surgery. The correlations of postoperative bleeding with platelet function at different stages of the surgery and with other factors, such as platelet count, hematocrit, and transfusions, were studied. RESULTS: Both AS and SC increased during several stages of the operation, and postoperative values (mean +/- SD) were significantly higher than preoperative values (30.4 +/- 8.1 microm 2 versus 23.3 +/- 6.9 microm 2 for AS [ P =.02] and 7.6% +/- 3.6% versus 5.2% +/- 1.8% for SC [ P =.04]). The mean total bleeding volume was 875 micro 415 mL. Preoperative AS and SC were the only parameters significantly ( P =.01) and linearly ( r = 0.7) related to postoperative bleeding. CONCLUSIONS: An increased platelet function, as determined by the CPA method, is found following OPCAB surgery. This phenomenon is probably at least partially responsible for the thrombogenic state after OPCAB surgery. Lack of platelet injury attributed to CPB may divert the system toward a more thrombogenic state. Preoperative platelet function, as evaluated by the CPA method, is an independent risk factor determining postoperative bleeding.

Improvement in mitral regurgitation after aortic valve replacement.

BACKGROUND: Concomitant mitral valve regurgitation is often present in patients with aortic stenosis. The additional MV replacement is associated with high operative risk. Previous studies have shown an amelioration of MV regurgitation after aortic valve replacement but most of the patient groups were heterogenous. OBJECTIVES: To determine whether AV replacement for aortic stenosis has any effect on MV regurgitation. METHODS: We reviewed two-dimensional echocardiography and color flow Doppler assessment of both aortic stenosis and MV regurgitation severity in 30 patients. Patients with previous MV surgery, organic MV disease, occlusive carotid artery disease, ejection fraction < 50%, and coexisting significant AV regurgitation were excluded. Preoperatively, MV regurgitation was mild in 23 patients (77%) and moderate in 7 (23%); in no patient was the condition severe. All patients had severe atrial stenosis (peak average aortic gradient 86 +/- 22 mmHg in the mild MV regurgitation group and 83 +/- 26 mmHg in the moderate group). The patients were divided into two groups according to the severity of MV regurgitation (associated mild, and moderate). Group 2, with moderate MV regurgitation, was the most problematic in terms of decision making for concomitant MV surgery. Therefore, additional assessment of several parameters was required. RESULTS: There was a significant decrease in MV regurgitation area (7.6 +/- 1.9 vs. 3.0 +/- 1.2 cm2, P < or = 0.012) and percent (28 +/- 5% vs. 12 +/- 6%, P < or = 0.001) between pre- and postoperative evaluation. Thus, the severity of the condition in all patients with moderate MV regurgitation decreased after AV replacement; in the mild group it remained unchanged in 53% or improved in 47%. There was no association between the preoperative gradient on the aortic valve and the degree of MV regurgitation. CONCLUSIONS: In our population of patients with severe atrial stenosis there were no patients with coexisting severe MV regurgitation. The decision to repair or replace a severely leaking mitral valve is an easy one, as in mild MV regurgitation. The clinical problem often presents in patients with severe aortic stenosis and moderate MV regurgitation. We believe that additional MV surgery is not necessary, at least in patients with preserved left ventricular function and without organic MV disease.

The effect of cardiac angiography timing, contrast media dose, and preoperative renal function on acute renal failure after coronary artery bypass grafting.

OBJECTIVE: Our objective was to assess the effect of the timing of cardiac angiography, contrast media dose, and preoperative renal function on the prevalence of acute renal failure after cardiac surgery. METHODS: Data on 395 consecutive patients who underwent coronary artery bypass grafting were prospectively collected. Creatinine clearance was estimated by the Cockcroft-Gault equation. Patients were divided into 3 groups according to the time between cardiac angiography and surgery (group A, < or = 1 day; group B, > 1 day and < or = 5 days; group C, > 5 days). Patients who underwent a salvage operation or were receiving dialysis before surgery were excluded. Acute renal failure was defined as 25% decrease from baseline of estimated creatinine clearance and estimated creatinine clearance of 60 mL/min or less on postoperative day 3. Owing to differences in preoperative characteristics between groups, propensity score analysis was used to adjust those differences. RESULTS: Acute renal failure developed in 13.6% of patients. Hospital mortality was 3.3% and was higher in patients in whom acute renal failure developed (22%) versus those in whom it did not (0.3%; P < .001). Multivariable analysis identified preoperative estimated creatinine clearance of 60 mL/min or less (odds ratio [OR], 7.1), operation within 24 hours of catheterization (OR = 3.7), use of more than 1.4 mL/kg of contrast media (OR = 3.4), lower hemoglobin level (OR = 1.3), older age (OR = 1.1), and lower weight (OR = 0.95) as independent predictors of postoperative acute renal failure. Analysis of interaction between contrast dose and time of surgery revealed that high contrast dose (>1.4 mL/kg) predicted acute renal failure if surgery was performed up to 5 days after angiography. CONCLUSIONS: Whenever possible, coronary bypass grafting should be delayed for at least 5 days in patients who received a high contrast dose, especially if they also have preoperative reduced renal function.

Vasoreactivity and histology of the radial artery: comparison of open versus endoscopic approaches.

OBJECTIVE: Radial artery harvesting using the less invasive endoscopic technique involves dissection in a narrow tunnel and may cause an injury or induce vasospasm to the conduit. To assess this hypothesis, radial artery segments harvested endoscopically or conventionally were studied for reactivity and integrity. METHODS: Rings of radial arteries from 80 CABG patients who had their radial artery harvested either open (n=40) or endoscopic (n=40), were attached to a force transducer then subjected to norepinephrine (NE, 10(-6)M), acetylcholine (ACh, 10(-5)M), followed by sodium nitroprusside (SNP, 10(-7) to 10(-5)M) to test endothelial dependent and non-dependent relaxation. Vessels' integrity was assessed by microscopic staining with hematoxylin-eosin for muscle layers, Masson trichrome for collagen content and von Gieson for elastica layers. RESULTS: Contraction and relaxation in response to NE, ACh and SNP were similar in both techniques. Arterial layers, collagen content and elastic lamina were preserved in all radial rings. Both techniques were found to be equally efficient in physiological and microscopic tests. CONCLUSIONS: The similar reactivity and integrity of the radial artery in both techniques should encourage the less invasive endoscopic approach.

Impact of intraoperative transesophageal echocardiography in patients undergoing valve replacement.

BACKGROUND: The role of intraoperative transesophageal echocardiography (IOTEE) in valve replacement surgery is not well established. The aim of this study was to explore the impact of immediate postpump IOTEE in valve replacement surgery at a single tertiary medical center. METHODS: The departmental database was screened for valve replacement operations (mechanical or bioprosthetic valves) performed during a 55-month period that were succeeded by immediate postpump IOTEE. Data was gathered regarding the impact of IOTEE on the immediate postoperative course. RESULTS: The study group included 417 patients (44.8% male, 55.2% female, age 65.2 +/- 13.9 years). Prepump IOTEE was performed in 352 patients (84.4%). A single valve was replaced in 336 patients (80.6%) and two or more valves were replaced in 81 patients (19.4%). Overall 501 valves were inserted: mitral, 237 (131 mechanical, 106 biological); aortic, 221 (89 mechanical, 132 biological); tricuspid, 43 (2 mechanical, 41 biological). Unexpected pathologic echocardiographic findings on postpump IOTEE necessitated immediate surgical correction in 15 patients (3.6%): perivalvular leak in 8 patients (4 mitral, 4 aortic), immobilized leaflet in 4 patients (3 mitral, 1 tricuspid), coronary obstruction by an aortic bioprosthesis in 2 patients, and incompetent xenograft in 1 patient. Prolonged removal of air was necessary in 45 patients (10.8%). In 47 patients (11.3%) the postpump IOTEE contributed to the evaluation of difficult weaning from the bypass pump and to its appropriate therapeutic management (volume expansion, inotropic agents, vasodilators, or mechanical assistance). CONCLUSIONS: Immediate postpump IOTEE is an important diagnostic and therapeutic role in valve replacement surgery and should be widely implemented.