Nitrogen uptake and macronutrients distribution in mango (Mangifera indica L. cv. Keitt) trees.

We assessed the effects of N fertigation regime on nutrient uptake and distribution in leaves and fruit of mango cv. Keitt grown in a lysimeter for four years. We applied three treatments: N1 - no N fertilization (less than 2 mg/L in the tap water); N2 - 10 mg/L N; and N3 - 20 mg/L N. Deficient N conditions (N1) resulted in low vegetation and fruit yield, high fruit:leaf ratio, high photosynthetic activity, high leaf P and K concentrations, as well as high sugar content and low acidity in the fruit. Excess N concentration (N3) enhanced vegetative growth and reduced fruit yield and gas exchange. The calculated annual nitrogen uptake heavily depended on the nitrogen supply, being highest for the N2 treatment (196 g/tree) as compared with the N1 (25 g/tree) or N3 (185 g/tree) treatments. Fruits were a major N sink being 82% (in N1), 26% (in N2), and 5% (in N3) of the total annual N supplied. The N accumulation rate in the fruit of the N1 and N2 treatment were above the N quantities supplied via fertigation, suggesting that N reserve in the vegetative tissues supplied the fruit's high N demand. These findings highlight the link between mango's N requirements and fruit yield, as well as the risks of excessive N fertilization.

MR Imaging Correlates for Molecular and Mutational Analyses in Children with Diffuse Intrinsic Pontine Glioma.

BACKGROUND AND PURPOSE: Recent advances in molecular techniques have characterized distinct subtypes of diffuse intrinsic pontine gliomas. Our aim was the identification of MR imaging correlates of these subtypes. MATERIALS AND METHODS: Initial MRIs from subjects with diffuse intrinsic pontine gliomas recruited for a prospective clinical trial before treatment were analyzed. Retrospective imaging analyses included FLAIR/T2 tumor volume, tumor volume enhancing, the presence of cyst and/or necrosis, median, mean, mode, skewness, kurtosis of ADC tumor volume based on FLAIR, and enhancement at baseline. Molecular subgroups based on EGFR and MGMT mutations were established. Histone mutations were also determined (H3F3A, HIST1H3B, HIST1H3C). Univariate Cox proportional hazards regression was used to test the association of imaging predictors with overall and progression-free survival. Wilcoxon rank sum, Kruskal-Wallis, and Fisher exact tests were used to compare imaging measures among groups. RESULTS: Fifty patients had biopsy and MR imaging. The median age at trial registration was 6 years (range, 3.3-17.5 years); 52% were female. On the basis of immunohistochemical results, 48 patients were assigned to 1 of 4 subgroups: 28 in MGMT-/epidermal growth factor receptor (EGFR)-, 14 in MGMT-/EGFR+, 3 in MGMT+/EGFR-, and 3 in MGMT+/EGFR+. Twenty-three patients had histone mutations in H3F3A, 8 in HIST1H3B, and 3 in HIST1H3C. Enhancing tumor volume was near-significantly different across molecular subgroups (P = .04), after accounting for the false discovery rate. Tumor volume enhancing, median, mode, skewness, and kurtosis ADC T2-FLAIR/T2 were significantly different (P ≤ .048) between patients with H3F3A and HIST1H3B/C mutations. CONCLUSIONS: MR imaging features including enhancement and ADC histogram parameters are correlated with molecular subgroups and mutations in children with diffuse intrinsic pontine gliomas.

Salt stress aggravates boron toxicity symptoms in banana leaves by impairing guttation.

Boron (B) is known to accumulate in the leaf margins of different plant species, arguably a passive consequence of enhanced transpiration at the ends of the vascular system. However, transpiration rate is not the only factor affecting ion distribution. We examine an alternative hypothesis, suggesting the participation of the leaf bundle sheath in controlling radial water and solute transport from the xylem to the mesophyll in analogy to the root endodermis. In banana, excess B that remains confined to the vascular system is effectively disposed of via dissolution in the guttation fluid; therefore, impairing guttation should aggravate B damage to the leaf margins. Banana plants were subjected to increasing B concentrations. Guttation rates were manipulated by imposing a moderate osmotic stress. Guttation fluid was collected and analysed continuously. The distribution of ions across the lamina was determined. Impairing guttation indeed led to increased B damage to the leaf margins. The kinetics of ion concentration in guttation samples revealed major differences between ion species, corresponding to their distribution in the lamina dry matter. We provide evidence that the distribution pattern of B and other ions across banana leaves depends on active filtration of the transpiration stream and on guttation.

Visual failure and recovery after thrombosis of a giant carotid ophthalmic aneurysm following vascular bypass and carotid artery ligation.

Thrombosis via Hunterian ligation, with or without high-flow bypass, is the definitive treatment for unclippable giant aneurysms; however, secondary deterioration may occur. We present a 67-year-old woman with an unclippable giant (33mm) carotid ophthalmic aneurysm. High-flow external carotid artery to middle cerebral artery bypass and proximal cervical internal carotid artery Hunterian ligation achieved complete thrombosis. Subsequent expansion of the thrombosed aneurysm created mass effect with hydrocephalus, leading to marked cognitive and visual decline. Aneurysmal decompression led to improved vision and near-normal neurological function.

Effects of environmental parameters and irrigation on the turgor pressure of banana plants measured using the non-invasive, online monitoring leaf patch clamp pressure probe.

Turgor pressure provides a sensitive indicator for irrigation scheduling. Leaf turgor pressure of Musa acuminate was measured by using the so-called leaf patch clamp pressure probe, i.e. by application of an external, magnetically generated and constantly retained clamp pressure to a leaf patch and determination of the attenuated output pressure P(p) that is highly correlated with the turgor pressure. Real-time recording of P(p) values was made using wireless telemetric transmitters, which send the data to a receiver base station where data are logged and transferred to a GPRS modem linked to an Internet server. Probes functioned over several months under field and laboratory conditions without damage to the leaf patch. Measurements showed that the magnetic-based probe could monitor very sensitively changes in turgor pressure induced by changes in microclimate (temperature, relative humidity, irradiation and wind) and irrigation. Irrigation effects could clearly be distinguished from environmental effects. Interestingly, oscillations in stomatal aperture, which occurred frequently below turgor pressures of 100 kPa towards noon at high transpiration or at high wind speed, were reflected in the P(p) values. The period of pressure oscillations was comparable with the period of oscillations in transpiration and photosynthesis. Multiple probe readings on individual leaves and/or on several leaves over the entire height of the plants further emphasised the great impact of this non-invasive turgor pressure sensor system for elucidating the dynamics of short- and long-distance water transport in higher plants.

Minimally invasive versus conventional aortic valve replacement: a 10-year experience.

AIM: Data on the impact of minimally invasive approach on clinical outcomes after isolated aortic valve replacement (MIAVR) are limited and somewhat controversial. The aim of the study was to compare the outcomes of patients undergoing MIAVR and conventional aortic valve replacement (CAVR) in a large cohort of patients operated over a decade. METHODS: The study population consisted of 466 consecutive patients undergoing isolated AVR between 1995 and 2005. Outcomes of 164 patients undergoing MIAVR were compared to 302 patients undergoing CAVR. Univariable and multivariable analyses were performed to identify predictors of outcomes. RESULTS: Operative mortality and major complication rates were similar among the groups. Univariate analysis revealed that MIAVR was associated with reduced incidence of allogeneic blood transfusions (31% vs. 41%, P=0.03) and a shorter hospital stay (5+/-2 vs. 7+/-5 days, P<0.0001). In multivariable analysis, predictors for blood transfusions were age (OR=2.15), non elective operation (OR=1.36), female gender (OR=1.13), prolonged cardiopulmonary bypass time (OR=1.12) and CAVR (OR=2.57). Predictors of prolonged hospital stay were peripheral vascular disease (OR=4.83), diabetes mellitus (OR=3.2), aortic cross clamp time (OR=1.17), and CAVR (OR=4.46). CONCLUSION: MIAVR is a safe and effective procedure resulting in significant reduction of allogeneic blood transfusions and a shorter length of hospital stay.

Towards multimaterial multifunctional fibres that see, hear, sense and communicate.

Virtually all electronic and optoelectronic devices necessitate a challenging assembly of conducting, semiconducting and insulating materials into specific geometries with low-scattering interfaces and microscopic feature dimensions. A variety of wafer-based processing approaches have been developed to address these requirements, which although successful are at the same time inherently restricted by the wafer size, its planar geometry and the complexity associated with sequential high-precision processing steps. In contrast, optical-fibre drawing from a macroscopic preformed rod is simpler and yields extended lengths of uniform fibres. Recently, a new family of fibres composed of conductors, semiconductors and insulators has emerged. These fibres share the basic device attributes of their traditional electronic and optoelectronic counterparts, yet are fabricated using conventional preform-based fibre-processing methods, yielding kilometres of functional fibre devices. Two complementary approaches towards realizing sophisticated functions are explored: on the single-fibre level, the integration of a multiplicity of functional components into one fibre, and on the multiple-fibre level, the assembly of large-scale two- and three-dimensional geometric constructs made of many fibres. When applied together these two approaches pave the way to multifunctional fabric systems.

Functional small-diameter neovessels created using endothelial progenitor cells expanded ex vivo.

Arterial conduits are increasingly preferred for surgical bypass because of inherent functional properties conferred by arterial endothelial cells, especially nitric oxide production in response to physiologic stimuli. Here we tested whether endothelial progenitor cells (EPCs) can replace arterial endothelial cells and promote patency in tissue-engineered small-diameter blood vessels (4 mm). We isolated EPCs from peripheral blood of sheep, expanded them ex vivo and then seeded them on decellularized porcine iliac vessels. EPC-seeded grafts remained patent for 130 days as a carotid interposition graft in sheep, whereas non-seeded grafts occluded within 15 days. The EPC-explanted grafts exhibited contractile activity and nitric-oxide-mediated vascular relaxation that were similar to native carotid arteries. These results indicate that EPCs can function similarly to arterial endothelial cells and thereby confer longer vascular-graft survival. Due to their unique properties, EPCs might have other general applications for tissue-engineered structures and in treating vascular diseases.

Early discharge after coronary artery bypass graft surgery: are patients really going home earlier?

OBJECTIVE: This study was undertaken to determine whether early discharge after coronary artery bypass grafting allows patients to return home earlier or merely increases the use of outpatient nursing and inpatient rehabilitation services. METHODS: Patterns of discharge were analyzed in 407 patients undergoing bypass grafting in 1990, when there were no early extubations or fast track protocols, and compared with 379 patients in 1998, when these protocols were used. RESULTS: Patients in 1998 had a higher prevalence of class IV angina (35.3% vs 22.8%; P =.006), urgent/emergency surgery (58.3% vs 44.9%; P =.015), and lower ejection fractions (48.9% +/- 16.4% vs 52.9% +/- 13.5%; P =.0002). Despite these increased risk factors, 1998 patients spent less time receiving ventilatory support (10.2 +/- 9.2 vs 26.7 +/- 15.7 hours; P <.001) and had a shorter length of stay (5.4 +/- 2.5 vs 9.2 +/- 4.3 days; P <.001). However, fewer 1998 patients were discharged home (56.7% vs 97.0%; P <.0001). A higher percentage of 1998 patients (43.3% vs 2.9%; P <.00001) were discharged to extended care facilities where their average length of stay was 10.6 +/- 15.1 days. Readmission to the Boston Medical Center was also more common in 1998 patients (5.3% vs 0.5%; P <.0001). CONCLUSIONS: Early extubation and fast track protocols have resulted in earlier discharge from acute care facilities. However, the anticipated earlier return to home has been offset by the increased use of outpatient nursing services, discharges to extended care facilities, and hospital readmissions.

Pulmonary tumor embolism as a presenting feature of cavoatrial hepatocellular carcinoma.

Pulmonary tumor embolism as a presenting feature of hepatocellular carcinoma is rare. It has been reported only once previously. In that case, other signs and symptoms of liver disease were present. We report the case of a patient with cavoatrial hepatocellular carcinoma presenting with isolated pulmonary tumor embolism, without any clinical or laboratory evidence of liver disease. Hepatocellular carcinoma should be included in the differential diagnosis as a rare cause of pulmonary tumor embolism.

Nitroglycerin is preferable to diltiazem for prevention of coronary bypass conduit spasm.

BACKGROUND: Diltiazem is widely used to prevent radial artery spasm after coronary bypass grafting (CABG). However, recent in vitro and in vivo studies have shown that nitroglycerin is a superior conduit vasodilator compared to diltiazem. A clinical comparison of these agents in patients undergoing CABG has not been previously performed. METHODS: One hundred sixty-one consecutive patients undergoing isolated CABG with the radial artery were prospectively randomized to 24-hour intravenous infusion of nitroglycerin or diltiazem followed by 6-month treatment with a daily dose of isosorbide mononitrate (n = 84) or diltiazem CD (n = 77). Analyses were performed on "intention-to-treat" basis. RESULTS: Crossovers because of low cardiac output, complete heart block, or sinus bradycardia occurred in 5 patients in the diltiazem group and none in the nitroglycerin group (p = 0.05). Operative mortality (nitroglycerin, 1.2% versus diltiazem, 1.3%), major morbidity (14% versus 16%), perioperative myocardial infarction (1.2% versus 0%), peak serum creatinine phosphokinase MB fraction levels (27 versus 21 U), intensive care unit stay (34+/-19 versus 38+/-30 hours) and total hospital length of stay (4.7+/-1.4 versus 4.7+/-1.3 days) were similar (p = not significant for all). Cardiac pacing was required more often in the diltiazem group (28% versus 13%, p = 0.01). Follow-up longer than 2 months was available in 145 patients (90%). Follow-up mortality (nitroglycerin, 1.2%; diltiazem, 1.3%), myocardial infarction (6%, versus 5%), and reintervention (8% versus 6%) rates and average angina class (1.3+/-0.7 versus 1.1+/-0.4) were similar (p = not significant for all). Thallium stress test obtained in 117 patients showed abnormal perfusion in the radial artery territory in only 4 patients (3%), 2 in each group (p = not significant). Treatment with diltiazem was more costly ($16,340 versus $1,096). CONCLUSIONS: Nitroglycerin is preferable to diltiazem for prevention of conduit spasm. Nitroglycerin is safe, effective, better tolerated, and less costly than diltiazem, and therefore, should be the agent of choice.

Heparin-bonded cardiopulmonary bypass circuits reduce bleeding and transfusion requirements in proximal aortic surgery.

BACKGROUND: Methods to improve hemostasis in aortic surgery continue to evolve. Use of heparin-bonded cardiopulmonary bypass circuits (HBC) has been shown previously to effectively reduce bleeding and improve outcomes in coronary and valve operations. OBJECTIVE: To evaluate the impact of HBC on bleeding and transfusion requirements in proximal aortic surgery. METHODS: Data on 140 consecutive patients undergoing 144 operations of the proximal aorta were collected. Between July 1987 and July 1994, conventional cardiopulmonary bypass circuits (CONV) were used (n = 53). In July 1994, we switched to "tip-to-tip" HBC (n = 91). This study compared clinical outcomes and transfusion requirements between these two groups. RESULTS: Indications for surgery, baseline characteristics, and operative profile of the study groups were similar. Overall operative mortality and reoperation for bleeding were 9% and 13%, respectively. Compared with CONV, use of HBC was associated with decreased mortality (3% vs 18%, p = 0.004), reoperation for bleeding (7% vs 24%, p = 0.005), and hospital length of hospital stay (10 +/- 11 vs 20 +/- 30 days, p = 0.002). Although the incidence of allogeneic blood transfusion was similar (HBC 75% vs CONV 87%, p = 0.12), the magnitude of blood products utilization was much lower in the HBC group (total blood products per patient: 24 +/- 29 vs 49 +/- 47 donor units, p = 0.0002). In the multivariate analyses, use of HBC was identified as an independent predictor of reduced mortality, morbidity, and reduced magnitude of allogeneic blood transfusions. CONCLUSION: Use of HBC in proximal aortic surgery resulted in reduced bleeding and blood transfusion, improving clinical outcomes. Undoubtedly, multiple factors account for the overall improved results. However, use of HBC is an important component of an overall blood conservation strategy.

Favorable impact of stents after emergent coronary artery bypass for failed angioplasty.

BACKGROUND: This study was undertaken to determine the impact of the use and availability of coronary stents on outcomes in patients requiring emergent coronary artery bypass graft (CABG) surgery following a failed percutaneous transluminal coronary angioplasty (PTCA). METHODS: Patients were divided into two groups based on the year of their CABG for a failed PTCA and the availability of stents: group 1, 1992 to 1994, stents not available (n = 34); and group 2, 1995 to 1997, stents available (n = 26). RESULTS: CABG patients in the group where stents were not available were more likely to have had an abrupt coronary occlusion (26 of 34 versus 3 of 26; p < 0.0001) and less likely to have had a dissection (8 of 34 versus 23 of 26; p < 0.0001) as their indication for emergent CABG. Patients in the stent era had a lower incidence of perioperative myocardial infarction (5 of 26 versus 17 of 34; p < 0.01) and a decreased mortality rate (0 of 26 versus 6 of 34; p < 0.03). In the 9 patients where stents were employed, patency of the lumen was restored in 8 patients and there was only 1 myocardial infarction. CONCLUSIONS: Stents have had a favorable impact on patients requiring an emergent CABG following a failed PTCA.

Papillary fibroelastoma: increasing recognition of a surgical disease.

Papillary fibroelastomas are uncommon benign tumors usually involving the heart valves, which historically have been diagnosed at autopsy. With the advent of echocardiography, however, the number of patients diagnosed in life has increased. Papillary fibroelastomas represent a surgically treatable cause of cerebrovascular and cardiovascular ischemia and infarction making their identification clinically important. We report three unusual cases of papillary fibroelastoma; two patients presenting with symptoms of cerebrovascular ischemia and one presenting with myocardial infarction. We also present a comprehensive review of the literature and provide a compilation of all case reports to date.

Enhanced nitric oxide-mediated vascular relaxation in radial artery compared with internal mammary artery or saphenous vein.

BACKGROUND: The superior long-term patency of internal mammary artery coronary bypass grafts compared with venous grafts has been attributed in part to increased endothelium-derived nitric oxide (. NO) production. Interest in the radial artery as an alternative bypass conduit has recently been revived; however, its biological characteristics remain incompletely defined. The purpose of this study was to compare the.NO-mediated vasomotor properties of the radial artery to those of the internal mammary artery and saphenous vein. METHODS AND RESULTS: Matched segments of radial artery, internal mammary artery, and saphenous vein (n=24 patients) were examined by use of organ-chamber methodology. Endothelium-dependent and -independent vasomotor responses were assessed by dose-response curves to acetylcholine, N(G)-nitro-L-arginine methyl ester (L-NAME), 8-bromo-cyclic 3',5'-guanosine monophosphate (8-bromo-cGMP), and nitroglycerin. Maximum.NO-mediated radial artery relaxation in response to acetylcholine (86+/-10%) was significantly greater than internal mammary artery (56+/-9%) or saphenous vein (11+/-5%, both P<0.0001). Similarly, acetylcholine-stimulated cGMP accumulation in radial artery (9.1+/-1.7 pmol/mg protein) was also greater than internal mammary artery (6.2+/-0.3 pmol/mg protein) or saphenous vein (1.4+/-0.2 pmol/mg protein, both P<0.05). Estimated basal endothelial.NO production, assayed as the percent maximum contraction in response to L-NAME, was greater in radial artery (39+/-5%) than internal mammary artery (23+/-6%) or saphenous vein (5+/-2%, both P<0.05). Maximum relaxation of all vessels to nitroglycerin was similar, although the sensitivity of radial artery to nitroglycerin was greater (EC(50)=33+/-7 nmol/L) than the internal mammary artery (203+/-32 nmol/L) or saphenous vein (97+/-12 nmol/L, both P<0.05). Vascular cGMP in response to 0.1 micromol/L nitroglycerin was significantly higher in the radial artery (8.3+/-1. 4 pmol/mg protein) compared with the internal mammary artery (3. 5+/-1.3 pmol/mg protein) or saphenous vein (1.4+/-0.3 pmol/mg protein, both P<0.0001). Relaxation to 8-bromo-cGMP was identical for all 3 conduits. CONCLUSIONS: These data indicate that. NO-dependent relaxation of radial artery is greater than that of internal mammary artery or saphenous vein. This difference is related to endothelial production of.NO and/or vessel sensitivity to. NO. Such favorable physiological characteristics of radial artery could conceivably contribute to improved long-term patency of this conduit compared with saphenous vein.

Prolongation of rat skin and cardiac allograft survival by low molecular weight heparin.

BACKGROUND: We have previously reported that very low doses of low molecular weight heparin compounds (LMWH) inhibit a variety of T-cell-mediated reactions by down-regulation of TNF-alpha production. This study tested the efficacy of LMWH in organ transplantation. METHODS: Skin and heterotopic heart transplantations were performed between recipient Wistar rats and donor BN rats. Two doses of LMWH were given sc, 1 and 20 micrograms, each in three protocols, with day of grafting as Day 0: (A) Daily: -1, 0, 1 ellipsis, (B) Late Weekly: -1, 6, 13 ellipsis, and (C) Early Weekly: -7, 0, 7 ellipsis. Doses and schedules were selected based on efficacy in autoimmune models. Skin graft rejection was defined by complete separation of the graft, and heart transplant rejection was defined as cessation of heartbeat. RESULTS: Treatment with 1 microgram (26.8 +/- 2.0 days) and 20 micrograms (24.5 +/- 2.3 days) of LMWH using the Early Weekly protocol significantly prolonged skin allograft survival compared to controls (17.8 +/- 4.4 days), P < 0.001 for both, whereas other protocols did not. Compared to controls (8.3 +/- 1.4 days), treatment with both 1 and 20 micrograms of LMWH using all three protocols significantly prolonged cardiac allograft survival. The efficacy, however, varied considerably. Increase in graft survival ranged from 18% (1 microgram, Daily, 9.8 +/- 0.7 days, P = 0.02) to more than twofold (20 micrograms, Early Weekly, 20.8 +/- 5.5 days, P < 0.001) according to the dose and schedule of LMWH. CONCLUSIONS: Treatment with very low doses of nonanticoagulant LMWH preparations having anti-TNF-alpha activity significantly prolongs rat skin and cardiac allograft survival in a dose- and schedule-dependent manner.

Improved clinical outcomes after operation of the proximal aorta: a 10-year experience.

BACKGROUND: This study evaluated the impact of recent advances (particularly noninvasive diagnosis, retrograde cerebral perfusion, heparin-bonded circuits, and use of collagen-impregnated grafts and antifibrinolytic agents) on clinical outcomes of patients undergoing proximal aortic operations. METHODS: One hundred eight consecutive patients undergoing 111 proximal aortic operations over 10 years were studied. The cohort was divided into two groups: early, 1987 to 1993 and late, 1994 to 1997. RESULTS: Baseline patients profiles, indications for operation (aneurysm, 66 patients; dissection, 45 patients), priority of the operation, and surgical procedures were comparable for both groups. Mortality and morbidity for the entire cohort were 13.5% (15 of 111) and 66% (73 of 111), respectively. Compared with the early group, the late group was characterized by significantly higher use of noninvasive diagnostic modalities (69% versus 10%), exclusive use of heparin-bonded circuits and collagen-impregnated grafts (100% versus 0% for both), use of antifibrinolytic agents (79% versus 8%), and the introduction of retrograde cerebral perfusion (43% versus 0%) (p<0.00001 for all). These changes in practice were associated with a substantial decrease in operative mortality (26% [13 of 49] versus 3% [2 of 62], p = 0.001), overall morbidity (77% [38 of 49] versus 56% [35 of 62], p = 0.02), blood transfusions (55.6+/-48 donor units versus 29.3+/-35 donor units, p = 0.003), and a shorter hospital stay (21.6+/-31 days versus 12.1+/-15 days, p = 0.07). Average long-term follow-up for 99% (107 of 108) of patients was 29.6+/-30 months (1 to 120 months). Ten-year actuarial survival was 57.3%+/-8% with 93% being in New York Heart Association functional class I or II. CONCLUSIONS: Recent advances, particularly noninvasive diagnosis and improved operative management, have led to a substantial reduction in mortality and morbidity after proximal aortic operation. Improved short- and long-term outcomes were achieved both in acute dissection and aneurysm procedures, although patients remain at risk for long-term distal aortic complications.

Effect of gender on postoperative outcomes and hospital stays after coronary artery bypass grafting.

BACKGROUND: Compared to men, women undergoing coronary artery bypass grafting appear to have a higher morbidity and mortality, particularly in the perioperative period. This study was designed to answer the questions of whether such differences in clinical outcomes between men and women still exist with improvements in surgical techniques and determine whether it is gender or associated comorbid conditions in women that lead to higher morbidity. METHODS: An analysis of a single center's contemporary experience (1994 to 1997) of 1,743 consecutive patients undergoing primary coronary artery bypass grafting was performed. Only reoperations were excluded. Data were collected prospectively and presented as mean +/- standard deviation (p<0.05). RESULTS: Women represented 30.0% of patients. Compared with men, women were older (68.4 versus 63.8 years; p<0.05), and had more urgent surgical interventions (70.0% versus 56.7%; p<0.05), a higher incidence of diabetes (42.1% versus 26.7%; p<0.05), hypertension (82.0% versus 73.9%; p<0.05), lower body surface area (1.73+/-0.18 m2 versus 2.03+/-0.19 m2; p<0.05), and hematocrit (31.7%+/-3.9% versus 36.2%+/-3.9%; p<0.05). Ejection fraction, incidence of previous myocardial infarction, chronic obstructive pulmonary disease, left main (LM) disease, renal insufficiency, extent of coronary disease, and preoperative intraaortic balloon pump were similar. Women received fewer arterial grafts (91.0% versus 95.5%; p<0.05) and distal anastomoses (3.31+/-0.88 versus 3.49+/-0.94 p<0.05). Despite these differences, there were no statistical differences in the incidence of postoperative death (1.5% versus 1.0%), myocardial infarction (0.6% versus 0.6%), or cerebrovascular accident/transient ischemic attack (1.1% versus 0.4%) between men and women. Women had a higher inotropic support (10.2% versus 4.4%; p<0.05) and longer hospital stays (7.3+/-5.7 days versus 6.3+/-4.2 days; p<0.05). Using multivariate analysis, female gender was not an independent predictor of death or postoperative complications but was a predictor of length of hospital stay, use of arterial grafts, and extent of coronary revascularization. CONCLUSIONS: After accounting for differences in their risk variables, the incidences of death, perioperative myocardial infarction and cerebrovascular accident/ transient ischemic attack after coronary artery bypass grafting in women and men were not statistically significant. Perioperative complications are related to comorbid risk factors but not to female gender itself. Further studies are warranted.

Nitroglycerin is superior to diltiazem as a coronary bypass conduit vasodilator.

BACKGROUND: Recent reports of improved radial artery patency have been attributed, in part, to routine use of diltiazem to prevent vasospasm. However, diltiazem is costly, and its use may be associated with negative inotropic and chronotropic side effects. This study compares the vasodilatory properties of diltiazem to those of nitroglycerin. METHODS: In vitro, with the use of organ chambers, the vasodilatory properties of diltiazem and nitroglycerin were compared in matched segments of radial artery, internal thoracic artery, and saphenous vein that were harvested from the same patients (n = 11). The vasodilatory response of the radial artery to intravenous diltiazem or nitroglycerin was compared in vivo (n = 10) with the use of ultrasonographic measurements of radial artery diameter. RESULTS: The maximum relaxation of radial artery (100% +/- 4%), internal thoracic artery (96% +/- 4%), and saphenous vein (100% +/- 3%) to nitroglycerin were significantly greater than the response to diltiazem (33% +/- 6%, 22% +/- 7%, and 34% +/- 5%, respectively; P <.001). The thromboxane mimetic, U46619, induced radial artery spasm with a median effective concentration of 3.7 +/- 0.8 nmol/L. Physiologic concentrations of nitroglycerin (0.1+/- micromol/L) significantly inhibited the radial artery response to U46619 (median effective concentration, 6.2 +/- 1.1 nmol/L; P =.046), whereas diltiazem (1 micromol/L) did not (median effective concentration, 3.7 +/- 0.8 nmol/L; P =.64). In vivo, nitroglycerin increased radial artery diameter 22% +/- 3%, which was significantly greater than diltiazem (3% +/- 0.5%; P =.001). CONCLUSION: Nitroglycerin is a superior conduit vasodilator and is more effective in preventing graft spasm than diltiazem. Nitroglycerin should be strongly considered as the drug of choice to prevent conduit spasm after coronary bypass grafting.

Improved clinical outcomes in patients undergoing coronary artery bypass grafting with coronary endarterectomy.

BACKGROUND: Coronary artery bypass grafting (CABG) with coronary endarterectomy (CE) has been associated with increased morbidity and mortality. We sought to evaluate the impact of recent advances in operative and perioperative management on outcomes after CE. METHODS: One hundred fifty-one consecutive patients undergoing first-time CABG with CE between 1991 and 1997 were compared with a concurrent group of 757 patients undergoing CABG without CE (Control). RESULTS: Age, gender, left ventricular ejection fraction, percent nonelective were similar in both groups. Compared with control, the CE group had a higher incidence of hypertension (80% versus 71%, p = 0.02), diabetes (42% versus 32%, p = 0.01), prior myocardial infarction (MI) (68% versus 59%, p = 0.05), peripheral vascular disease (36% versus 16%, p < 0.001), renal failure (15% versus 4%, p < 0.001), and three-vessel coronary disease (81% versus 70%, p = 0.007), resulting in higher Society of Thoracic Surgeons database predicted mortality (4.9+/-5.9% versus 3.9+/-4.6%, p = 0.05). Despite the higher risk profile of the CE group, hospital mortality (CE 2.0%, Control 1.2%) and the incidence of major complications such as cerebrovascular accident (CVA) (0.7% versus 1.5%), major respiratory complications (8% versus 5%), and postoperative MI (3% versus 1.4%) were similar between the groups (all p = NS). In a multiple logistic regression analysis, prolonged cardiopulmonary bypass time was an independent predictor of postoperative MI (odds ratio 1.2, CI 1.05 to 1.39, p < 0.01) and the use of heparin-bonded cardiopulmonary bypass circuits of reduced MI rate (odds ratio 0.25, CI 0.08 to 0.76, p < 0.01). Mean follow-up for 94% of patients was 30+/-19 months (range 1 to 83 months). Five-year survival after CE was 70+/-5%, with 96% of patients in Canadian Cardiovascular Society class I/II. CONCLUSIONS: In a contemporary series of carefully selected patients, mortality and major complications after CE are now similar to CABG without CE. CE itself is not an independent predictor of postoperative MI. Functional class of hospital survivors is excellent.