Bactericidal efficiency and mode of action: a comparative study of photochemistry and photocatalysis.

In order to compare the disinfection potential of photocatalysis and photochemistry, the effects of these two processes on bacteria in water were investigated under exposure to UV-A and UV-C. The well-known bacterial model Escherichia coli (E. coli) was used as the experimental organism. Radiation exposure was produced with an HPK 125 W lamp and the standard TiO(2) Degussa P-25 was used as the photocatalyst. Firstly, the impact of photocatalysis and photochemistry on the cultivability of bacterial cells was investigated. UV-A radiation resulted in low deleterious effects on bacterial cultivability but generated colonies of size smaller than average. UV-C photocatalysis demonstrated a greater efficiency than UV-A photocatalysis in altering bacterial cultivability. From a cultivability point of view only, UV-C radiation appeared to be the most deleterious treatment. A rapid epifluorescence staining method using the LIVE/DEAD Bacterial Viability Kit was then used to assess the modifications in bacterial membrane permeability. UV-A radiation did not induce any alterations in bacterial permeability for 420 min of exposure whereas only a few minutes of exposure to UV-C radiation, with the same total radiance intensity, induced total loss of permeability. Moreover, after 20 and 60 min of exposure to UV-C and UV-A photocatalysis respectively, all bacteria lost their membrane integrity, suggesting that the bacterial envelope is the primary target of reactive oxygen species (ROS) generated at the surface of TiO(2) photocatalyst. These results were further confirmed by the formation of malondialdehyde (MDA) during the photocatalytic inactivation of bacterial cells and suggest that destruction of the cell envelope is a key step in the bactericidal action of photocatalysis. The oxidation of bacterial membrane lipids was also correlated with the monitoring of carboxylic acids, which can be considered as representatives of lipid peroxidation by-products. Finally, damages to bacterial morphology induced by UV-C photocatalysis and photochemistry were investigated through Scanning electron microscopy (SEM). Bacterial cells were observed on microscopy pictures at exposure durations corresponding to a loss of cultivability. After 90 min of exposure to UV-C radiation, bacterial cells showed little alteration of their outer membrane whereas they suffered deep deleterious damages under UV-C photocatalysis exposure.

Diabetes in pregnancy may differentially affect neonatal outcomes for twins and singletons.

AIM: We tested the hypothesis that diabetes in pregnancy may differentially affect neonatal outcomes in twin vs. singleton pregnancies. METHODS: In a retrospective cohort analysis of twins (n = 422 068) and singletons (n = 14 298 367) born in the USA from 1998 to 2001, we evaluated the adjusted odds ratios of adverse neonatal outcomes comparing diabetic vs. non-diabetic pregnancies, controlling for maternal characteristics. Primary outcomes include macrosomia (birthweight for gestational age > 90th percentile), congenital anomalies, low 5-min Apgar score (< 4) and neonatal death. RESULTS: Diabetes in pregnancy was associated with a similarly increased risk of congenital anomalies (adjusted odds ratios 1.52 vs. 1.59) and smaller increased risks of preterm birth (adjusted odds ratios 1.27 vs. 1.49) and macrosomia (adjusted odds ratios 1.38 vs. 2.03) in twins vs. singletons, but reduced risks of low 5-min Apgar score (adjusted odds ratio 0.74) and neonatal death (adjusted odds ratio 0.76) in twins but not singletons. CONCLUSIONS: Diabetes in pregnancy may differentially affect neonatal outcomes in twins and singletons, indicating a need for further studies to differentiate the effects by clinical subtypes of diabetes in pregnancy, and to consider/evaluate differential clinical management protocols of diabetes in multiple vs. singleton pregnancies.

Optimal birth weight percentile cut-offs in defining small- or large-for-gestational-age.

AIMS: It remains questionable what birth weight for gestational age percentile cut-offs should be used in defining clinically important poor or excessive foetal growth. We aimed to evaluate the optimal birth weight percentile cut-offs for defining small- or large-for-gestational-age (SGA or LGA). METHODS: In a birth cohort-based analysis of 17 979 120 non-malformation singleton live births, U.S. 1995-2001, we assessed the optimal birth weight percentile cut-offs for defining SGA and LGA. The 25th-75th percentile group served as the reference. Primary outcomes are the risk ratios (RR) of neonatal death and low 5-min Apgar score (<4) comparing SGA or LGA versus the reference group. More than 2-fold risk elevations were considered clinically significant. RESULTS: The 15th birth weight cut-off already identified SGA infants at more than 2-fold risk of neonatal death at pre-term, term or post-term, except for extremely pre-term births <28 weeks (continuous risk reductions over increasing birth weight percentiles). LGA was associated with a reduced risk of low 5-min Apgar score at pre-term, but an elevated risk at term and post-term. The 97th cut-off identified LGA infants at 2-fold risk of low 5-min Apgar at term. CONCLUSION: The commonly used 10th and 90th birth weight percentile cut-offs for defining SGA and LGA respectively seem largely arbitrary. The 15th and 97th percentiles may be the optimal cut-offs to define SGA and LGA respectively.

Primary birthing attendants and birth outcomes in remote Inuit communities--a natural "experiment" in Nunavik, Canada.

BACKGROUND: There is a lack of data on the safety of midwife-led maternity care in remote or indigenous communities. In a de facto natural "experiment", birth outcomes were assessed by primary birthing attendant in two sets of remote Inuit communities. METHODS: A geocoding-based retrospective birth cohort study in 14 Inuit communities of Nunavik, Canada, 1989-2000: primary birth attendants were Inuit midwives in the Hudson Bay (1529 Inuit births) vs western physicians in Ungava Bay communities (1197 Inuit births). The primary outcome was perinatal death. Secondary outcomes included stillbirth, neonatal death, post-neonatal death, preterm, small-for-gestational-age and low birthweight birth. Multilevel logistic regression was used to obtain the adjusted odds ratios (aOR) controlling for maternal age, marital status, parity, education, infant sex and plurality, community size and community-level random effects. RESULTS: The aORs (95% confidence interval) for perinatal death comparing the Hudson Bay vs Ungava Bay communities were 1.29 (0.63 to 2.64) for all Inuit births and 1.13 (0.48 to 2.47) for Inuit births at > or =28 weeks of gestation. There were no statistically significant differences in the crude or adjusted risks of any of the outcomes examined. CONCLUSION: Risks of perinatal death were somewhat but not significantly higher in the Hudson Bay communities with midwife-led maternity care compared with the Ungava Bay communities with physician-led maternity care. These findings are inconclusive, although the results excluding extremely preterm births are more reassuring concerning the safety of midwife-led maternity care in remote indigenous communities.

Validation of biomarkers for impact evaluation of aqueous industrial waste in mesocosms.

The use of exposure biomarkers in measuring the impact of aqueous waste holds promise because such tools have short response times, are flexible in use and may give an indication about the type of pollution. However, their ecological significance has not yet been demonstrated. It is necessary to validate these responses under controlled conditions before using such biomarkers for biomonitoring. The TotalFinaElf company has developed a pilot scheme incorporating such controlled conditions. This pilot is a dynamic open mesocosm (16 channels 40 m in length supplied with river water). The research programme currently carried out in the "Pilot Rivers" aims at validating biochemical parameters (components of phases I and II (de)toxication metabolism and propionylcholinesterase activity), measured in a fresh water bivalve Corbicula fluminea as a biomarker of water quality. The comparison between biomarker responses and community ones (reference) gives information about the precocity and sensitivity of these biomarker responses. Pure substances (trichloroethylene (TCE), cadmium (CD) and anthracenic oil (AO)) have been injected during one month. Biomarker responses are as sensitive as the most sensitive community response in the presence of CD and AO. With TCE, community responses are more sensitive. Precocity of biomarker response is observed only in the presence of CD.

Effective surgical management of high-risk coronary patients using preoperative intra-aortic balloon counterpulsation therapy.

The proportion of high-risk coronary patients submitted to surgical myocardial revascularization (CABG) is steadily increasing. High-risk patients utilize more hospital resources and have a higher procedural cost than low-moderate risk CABG patients. An efficient management is essential to improve outcome and reduce costs. This report entails three study periods. In an initial retrospective study coronary high-risk criteria were established. At least two of the following factors were required: redo CABG, unstable angina, left main stem stenosis greater than 70%, preoperative left ventricular ejection fraction < 0.30 and diffuse coronary artery disease. Poor preoperative cardiac performance was the major contributing factor for poor outcome. Intra-aortic balloon counterpulsation therapy (IABP) was introduced as preoperative therapy. During a second study period prospective randomized studies found preoperative IABP-therapy efficient, significantly improving both preoperative cardiac index (P < 0.0001), decreasing postoperative mortality (P < 0.0001) and morbidity, shorten intensive care unit stay as well as total hospital stay (P < 0.0001). Drug consumption was significantly reduced (P < 0.0001). Optimal timing was found to be 2 h prior to aortic cross-clamping and the therapy was found highly cost-beneficial with an average 36% reduction of the total procedural cost. During a third study period, well beyond any study protocol period, preoperative IABP therapy was again found highly effective with a close to 100% utilization rate in high-risk patients and continuous efficacy with excellent outcome, despite acceptance of sicker patients. During this post-study evaluation period 1/3 of the high-risk patients presented with 4 of the established risk factors. The use of preoperative IABP therapy is therefore highly recommended for high-risk coronary patients undergoing CABG.

Economic impact of preoperative intraaortic balloon pump therapy in high-risk coronary patients.

BACKGROUND: The efficacy of preoperative intraaortic balloon pump therapy in high-risk coronary patients has been demonstrated earlier. METHODS: This study investigates the economic aspect by a detailed cost analysis of pooled information from two previously published randomized studies and 144 consecutive low-risk coronary artery bypass graft operations. Costs for patients receiving preoperative intraaortic balloon pump therapy before aortic cross-clamping (n = 62) were compared to those in a control group (n = 50). Detailed cost analysis was based on data provided by the hospital finance department. RESULTS: The total hospital costs were as follows: low-risk coronary artery bypass graft operations cost 35,335+/-1,694 Swiss francs ($23,400+/-$1,121); high-risk coronary artery bypass graft without preoperative intraaortic balloon pump therapy cost 65,892+/-31,719 Swiss francs ($43,637+/-$21,006); and high risk coronary artery bypass graft with preoperative intraaortic balloon pump therapy cost 41,948+/-10,379 Swiss francs ($27,780+/-$6,874) (p = 0.0015). There were no significant differences in average cost among the preoperative intraaortic balloon pump therapy subgroups. CONCLUSIONS: Preoperative intraaortic balloon pump therapy in high risk coronary patients is significantly cost-beneficial, With an average saving of 24,000 Swiss francs ($16,000) on the total hospital cost, a 36% cost reduction.

Molecular detection of cancer cells in bone marrow and peripheral blood of patients with operable breast cancer. Comparison of CK19, MUC1 and CEA using RT-PCR.

We have compared three different RT-PCR procedures to measure cytokeratin 19 (CK19), carcinoembryonic antigen (CEA) and mucin MUC1 gene expression in order to determine their diagnostic value in detecting tumour cells in bone marrow aspirates of patients with operable breast cancer. In an experimental model, the best sensitivity was observed for CK19 and MUC1 RT-PCR assays, although only the CEA and CK19 assays showed good specificity. The study of 42 patients showed that a 'CK19 positive/CEA positive' RT-PCR assay in bone marrow correlated positively with a positive axillary lymph node status (N(0) versus N(1-3), P<0.05). Both assays were also positive in 17% of node negative patients. RT-PCR assays were more sensitive in bone marrow than in peripheral blood. Our results suggest that CK19 and CEA RT-PCR assays are powerful methods for detecting disseminated breast cancer cells. A larger study with long-term follow-up is required in order to clarify their clinical usefulness.

Optimal timing of preoperative intraaortic balloon pump support in high-risk coronary patients.

BACKGROUND: Beneficial effects of preoperative intraaortic balloon pump (IABP) treatment, on outcome and cost, in high-risk patients who have coronary artery bypass grafting have been demonstrated. We conducted a prospective, randomized study to determine the optimal timing for preoperative IABP support in a cohort of high-risk patients. METHODS: Sixty consecutive high-risk patients who had coronary artery bypass grafting (presenting with two or more of the following criteria: left ventricular ejection fraction less than 0.30, unstable angina, reoperation, or left main stenosis greater than 70%) entered the study. Thirty patients did not receive preoperative IABP (controls), 30 patients had preoperative IABP therapy starting 2 hours (T2), 12 hours (T12), or 24 hours (T24), by random assignment, before the operation. Fifty patients had preoperative left ventricular ejection fraction mean, less than 0.30 (less than 0.26+/-0.08), (n = 40) unstable angina, 28% (n = 17) left main stenosis, and 32% (n = 19) were reoperations. RESULTS: Cardiopulmonary bypass was shorter in the IABP groups. There was one death in the IABP group and six in the control group. The complication rate for IABP was 8.3% (n = 5) without group differences. Cardiac index was significantly higher postoperatively (p<0.001) in patients with preoperative IABP treatment compared with controls. There were no significant differences between the three IABP subgroups at any time. The incidence of postoperative low cardiac output was significantly lower in the IABP groups (p<0.001). Intubation time, length of stay in the intensive care unit and the hospital was shorter in the IABP groups (p = 0.211, p<0.001, and p = 0.002, respectively). There were no differences between the IABP subgroups in any of the studied variables. CONCLUSIONS: The beneficial effect of preoperative IABP in high-risk patients who have coronary artery bypass grafting was confirmed. There were no differences in outcome between the subgroups; therefore, at 2 hours preoperatively, IABP therapy can be started.

The influence of age on the outcome of primary coronary artery bypass grafting.

BACKGROUND: With the steady increase in the number of elderly patients requiring coronary artery bypass grafting (CABG), scepticism still exists as to whether this operation is justified in older patients or not, and whether there is an upper age limit. The aim of this study was to examine the effects of increasing age on the outcome of CABG. METHODS: A retrospective review was performed on 2127 consecutive patients undergoing primary CABG from January 1990 through June 1996. The patients were arbitrarily divided into age groups: 69 years or less (n=1607), 70-75 years (n=371), 76-80 years (n=129) and older than 80 years (n=20). Mortality, morbidity and long-term survival for each group was compared. RESULTS: The groups containing the elderly patients showed an over-representation of women, as well as a higher frequency of arterial hypertension, hyperlipidemia, previous infarction and diabetes. More patients, amongst the elderly, had unstable angina and diffuse coronary disease requiring urgent surgery and coronary thrombendarterectomy compared to those <70 years. Hospital mortality did not differ between the groups, 1.8, 3.0, 2.3 and 5.0%. There was an increased incidence of low postoperative cardiac output and a higher incidence of gastro-intestinal complications amongst the elderly. The 5-year survival was 92.2% (<70 years), 87.0% (70-75 years) and 86.3% (76-80 years) and the cardiac event-free survival was 87.5% (<70 years), 78.4% (70-75 years) and 80.8% (76-80 years) at 5 years. CONCLUSIONS: An acceptable early mortality and medium-term survival (5 years) together with excellent functional medium-term results support the justification of primary CABG in older patients irrespective of age.

Sequential vein bypass grafting: tactics and long-term results.

The sequential bypass grafting technique has many advantages over coronary artery bypass grafting with single grafts. The aim of this study was to evaluate the consequences of sequential bypass graft failure. Between 1 January 1984 and 31 December 1996, 3846 patients underwent primary coronary artery bypass vein grafting. A total of 3490 patients received sequential vein bypass grafts and 356 patients received single vein bypass grafts (9%). There were 6177 sequential bypass grafts (3490 postero-lateral grafts (56%) and 2687 in the antero-lateral position (44%)) and 1468 single grafts (972 vein grafts and 496 internal thoracic artery grafts). Overall, there were 80 hospital deaths (2.1%). Mortality in relation to type of grafts used was: 13 deaths in 356 patients with only single graft (3.7%) and 67 deaths in 3490 patients who received sequential vein grafts (1.9%). Of 3766 hospital survivors, 3731 were followed for an average of 76 months. During follow-up, 85 patients died (2.3%), 15 patients (0.4%) underwent cardiac transplantation and 52 (1.4%) had re-do coronary artery bypass vein grafting. Graft-percutaneous transluminal coronary angioplasty was performed in 56 patients (1.5%), 37/1390 single bypass grafts (2.7%) and 19/6023 sequential bypass grafts (0.3%). There were 272/6023 symptomatic sequential graft occlusions (4.5%) (182 were in postero-lateral position and 90 in the antero-lateral position). There were 66/667 single vein graft occlusions (9.9%) and 15 symptomatic internal thoracic artery graft occlusions (2.1%) during follow-up. In 97% of patients, presenting symptoms of postero-lateral sequential bypass graft occlusion took the form of a renewed angina with a myocardial infarction rate of 3% and a mortality rate of 7%. Corresponding figures for antero-lateral sequential bypass grafts were 22, 78 and 68%, and anterior single vein bypass grafts were 70, 30 and 15%, respectively. The overall 10-year survival rate in patients with sequential bypass grafts was 81.2% and the cumulative patency rate (1464 angio-controls of 2576 sequential vein grafts) was 72.2%. A symptomatic occlusion of a postero-lateral sequential vein bypass results in a low incidence of myocardial infarction with low mortality, when the terminal anastomosis is connected to a high flow vessel. An antero-lateral sequential vein bypass graft has better long-term patency than single vein bypass, but should occlusion occur, it would usually be associated with a higher myocardial infarction and mortality rates than a single vein graft. The highest risk for failure of a sequential graft in the antero-lateral position occurs when the left anterior descending artery (LAD) is small or severely diseased. In this situation the single graft technique with internal thoracic artery appears to be safer.

Inflammatory response and oligo-element alterations following cardiopulmonary bypass in patients undergoing coronary artery bypass grafting.

Oligo-elements such as zinc (Zn), selenium (Se) and copper (Cu) have a significant influence on the function of the immune system. Various immunological and inflammatory changes are known to occur in patients undergoing cardiopulmonary bypass. The aim of this study was to evaluate changes in serum oligo-elements levels during and following cardiopulmonary bypass. The serum levels of Zn, Se and Cu were determined in 67 consecutive patients, with coronary artery disease admitted for coronary artery bypass grafting. Blood samples for oligo-elements, analysis were withdrawn into metal-free tubes just prior to the start of cardiopulmonary bypass; at 30, 60 and 90 min into cardiopulmonary bypass; following weaning from cardiopulmonary bypass; 30 min after termination of cardiopulmonary bypass; at 24 h; and on the 5th postoperative day. Trace elements analyses were performed using atomic absorption spectrophotometry. Interleukin 6 and 8, as well as serum albumin, creatine phosphokinase, lactate dehydrogenase and creatine phosphokinase-MB fractions were also analyzed. The mean age was 63 +/- 9 years and 91% (61) were men. The mean preoperative left ventricular function was 52 +/- 12%, Canadian Cardiovascular Society (CCS) angina class was 3.7 +/- 0.5 and 30% (20) of the operations were re-do's. All patients had normothermic cardiopulmonary bypass. Mean cardiopulmonary bypass-time was 85 +/- 31 min. One patient was lost for the recovery sampling (hospital mortality, 1.5%). Nine patients had a postoperative cardiac index < 2.0 liter/min per m2, which required pharmacological support and additional intra-aortic balloon pump in two of them. Other postoperative complications were few. There was a rapid depletion of S-selenium and S-Zn levels, which were halved at 30 min after cardiopulmonary bypass and remained low throughout the study period. The Cu/Zn ratio increased significantly at the start of cardiopulmonary bypass, which indicated an inflammatory reaction and was not normalized until the 5th postoperative day. Length of ischemia time, presence of diabetes. hypertension and hyperlipidemia did not influence the results, while a prolonged cardiopulmonary bypass-time > 120 min resulted in a higher Cu/Zn ratio than observed for shorter cardiopulmonary bypass-times. This indicates a more profound inflammatory response. Inflammatory parameters responded in the same manner as described earlier by others. These data indicate that severe loss of various oligo elements occur in patients undergoing coronary artery bypass grafting and suggests that a supplementary administration of zinc and perhaps also selenium could be appropriate during cardiopulmonary bypass.

Late pseudoaneurysm formation after repair of the descending aorta.

We report a case of a 71-year-old hypertensive female patient presenting with haemoptysis and retrosternal pain from a leaking pseudo-aneurysm associated with a Dacron onlay patch used to repair a coarctation of the aorta 27 years earlier. This case illustrates a late and potentially fatal complication of this type of operation and describes a recent technique to reach the exact diagnosis and location of the aneurysm.

[Symptomatic coronary disease associated with mitral insufficiency: surgical strategy]. / Maladie coronarienne symptomatique associée à une insuffisance mitrale: stratégie chirurgicale.

In recent years coronary artery bypass grafting (CABG) has been extended to include patients with very low left ventricular ejection fractions (LVEF), also frequently with co-existing mild to moderate mitral valve regurgitation (MR). The question is, should MR be corrected simultaneously with a myocardial revascularization or not? Between January 1990 and December 1996, 82 patients with preoperative LVEF < or = 0.25 and echocardiographic evidence of co-existing MR without chordal or papillary muscle rupture (Grade I-28%, II-35%, III-32% and IV-5%) underwent primary CABG. None of them underwent simultaneous mitral valve surgery. The mean preoperative LVEF was 0.17 +/- 0.04 (0.10-0.25), mean PAP 43.8 +/- 15.9 mmHg. An average of 4.4 +/- 1.5 grafts/ patient were placed. The overall mortality was 3.7% (3/82). Transient postoperative low cardiac output syndrome occurred in 24 patients (29%). Thirty-two patients (39%) had no postoperative complications at all. Seventy-nine hospital survivors were followed up over a period of 18 months (6-48 months) on average. There was one death (8 months post-operatively) and 2 graft occlusions, not requiring redo surgery. At the end of follow up echocardiography showed that 45 patients had no MR at all and 28 patients had MR-Grade I, a total of 73 patients (94%). Five patients had Grade II-III MR, none of them requiring mitral valve surgery. All patients improved their NYHA functional class, from 3.5 +/- 0.7 to 1.8 +/- 0.5 and the LVEF from 0.17 +/- 0.04 to 0.46 +/- 0.08, p < 0.001. Moderate to severe co-existing MR (Grade II-IV) seems to normalize after the myocardial revascularization and should therefore not be surgically corrected at the primary operation, if there are no echocardiographic evidence of chordal or papillary muscle rupture. Peroperative control echocardiography is recommended.

Preoperative intraaortic balloon pump enhances cardiac performance and improves the outcome of redo CABG.

BACKGROUND: Reoperative coronary artery bypass grafting (redo CABG) is associated with an increased operative risk compared with primary CABG. Because the hospital mortality in redo CABG is known to be influenced by poor left ventricular function (left ventricular ejection fraction < or = 0.40), unstable angina, and left main stem stenosis greater than or equal to 70%, a preoperative intraaortic balloon pump (IABP) support could be beneficial to improve the outcome in high-risk redo CABG. METHODS: Between June 1994 and October 1996, 48 high-risk patients underwent redo CABG and were randomized into the following groups: group 1 (24 patients) who received preoperative IABP treatment on average 2 hours before cardiopulmonary bypass, and group 2 (24 patients) who received no preoperative IABP and served as controls. Mean age was 65 years and 90% (43 patients) were men. Forty-one patients had preoperative left ventricular ejection fraction less than or equal to 0.40 (85%), 38% (18 patients) had left main stem stenosis greater than or equal to 70%, and 54% (26 patients) had unstable angina preoperatively. Preoperative patient characteristics did not differ between the groups. RESULTS: The time on cardiopulmonary bypass was shorter in group 1, 86 versus 110 minutes (p = 0.006). There were no hospital deaths in group 1, but four deaths occurred in the control group (p = 0.049). Cardiac index rose significantly preoperatively after introduction of the IABP in group 1. Cardiac index was significantly higher postoperatively in group 1 compared with group 2 and remained significantly higher during the first 24 hours after cardiopulmonary bypass. Significantly fewer patients in the IABP group had postoperative low cardiac output (4 versus 13 patients). Nine patients in group 2 required IABP support postoperatively for 4.1 +/- 1.7 days. Only 2 patients in group 1 needed IABP postoperatively, and their IABPs were successfully removed on the first postoperative day. The preoperative IABP-supported patients had a shorter intensive care unit stay, 2.4 +/- 0.8 days compared with group 2, 4.5 +/- 2.2 days (p = 0.007), as well as a shorter hospital stay. The preoperative IABP treatment was found to be cost-effective. CONCLUSIONS: Preoperative treatment with IABP in high-risk redo CABG patients is an effective modality to prepare these patients to have their myocardial revascularization in an as nonischemic situation as possible, which resulted in a significantly lower hospital mortality, fewer instances of postoperative low cardiac output, and shorter stays in both the intensive care unit and the hospital.

The effect of preoperative intra-aortic balloon pump support in high risk patients requiring myocardial revascularization.

The intra-aortic balloon pump (IABP) is an established additional support to pharmacologic treatment of the failing heart after myocardial infarction, unstable angina and cardiac surgery. The physiologic effect of IABP are: increased coronary perfusion and decreased left ventricular outflow impendance. The effects of preoperative IABP are not established. The aim of this study was to define indications and evaluate the effect of preoperative IABP support. Between January 1, 1990 and December 31, 1994, 1999 patients underwent CABG [318 REDOCABG, 15.9% and 1681 primary CABG, 84.9%]. From January to June 1994, 80 of 1811 patients (4.5%) required additional intra-aortic balloon pump (IABP) support postoperatively, 35 after REDO (21%) and 45 after primary CABG, 3%. Indication for IABP was failure to wean from cardiopulmonary bypass (CPB), despite maximal dose pharmacological support. The overall hospital mortality was 11.6% after REDO's and 2.1% after primary CABG, p < 0.001. In those where IABP was required the mortality rate was 67.7% after REDO and 36.8% after primary CABG, p < 0.01. Multivariate analysis identified preoperative unstable angina as independent risk factor for mortality (p < 0.001). REDO-CABG, LVEF < 40%, diffuse coronary artery disease and left main stem stenosis were identified as riskfactors for mortality when combined with one and another in a combination of at least two factors. In the IABP supported group mean ICU stay was 5.4 +/- 1.8 days. Thereafter the concept of preoperative use of IABP was introduced and presence of at least two of the above identified riskfactors served as indication for preoperative IABP treatment. The IABP was placed in the operating room at induction of anesthesia (1-1.5 hr prior to cross-clamping). Between June and December 1994, 19 of 188 patients received a preoperative IABP (9.0%). There were no balloon related complications. The mortality rate was 21%. Weaning from CPB was easy and in 30% of the cases the IABP was not necessary postoperative. In 90% of the pumps were removed within 24 hours postoperative. The mean ICU stay was 2.1 +/- 0.9 days. The first part of this study identified riskfactors for mortality after CABG and in the second series the efficacy of preoperative IABP treatment in "high-risk" patients was demonstrated. Preoperative IABP support in these patients seems also cost efficient due to lower mortality and shorter stay in intensive care unit in this group of patients.

Evaluation of preoperative intra-aortic balloon pump support in high risk coronary patients.

OBJECTIVE: The intra-aortic balloon pump (IABP) is an established additional support to pharmacological treatment of the failing heart after myocardial infarction, unstable angina and cardiac surgery. The effect of preoperative IABP in high risk patients was evaluated. METHODS: Between June 1994 and March 1996 all high risk patients for CABG (two or more of these criteria: Left ventricular ejection fraction (LVEF) < or = 40%, left main stem stenosis > or = 70%, REDO-CABG, unstable angina) were randomized into either of 3 groups: (1) IABP 1 day prior to surgery, (2) IABP 1-2 h prior to CPB and (3) no preoperative IABP, controls. EXCLUSION CRITERIA: cardiogenic shock preoperatively. Fifty-two patients have entered the study-group 1 (13 patients), group 2 (19 patients) and group 3 (20 patients). Preoperative patient characteristics and operative data revealed no group differences. There were 56% REDO's, unstable angina 59%, LVEF < or = 40%, 87% (34.0 +/- 11.6%) and left main stem stenosis in 35%. RESULTS: The CPB-time was shorter in groups 1 and 2 88.7 +/- 20.3 min than in group 3 105.5 +/- 26.8 min, P < 0.001, while ischemia time did not differ. Hospital mortality was higher in group 3, 25% vs. 6% (groups 1 and 2). Postoperative low cardiac output was seen in 12 patients (60%) in group 3 vs. 6 patients (19%) in groups 1 and 2, P < 0.05. Cardiac index increased significantly prior to CPB in groups 1 and 2. After CPB cardiac index was significantly higher in groups 1 and 2 compared to Group 3 and continued to increase. The IABP was removed after 3.1 +/- 1.0 days in group 3 vs. 1.3 +/- 0.6 days in groups 1 and 2, P < 0.001. In group 3, 11 patients required IABP postoperatively compared to only 4 patients in groups 1 and 2. ICU stay was shorter in groups 1 and 2--2.3 +/- 0.9 days vs. 3.5 +/- 1.1 days for group 3, P = 0.004. All patients received dopamin postoperatively, however in a lower dose in groups 1 and 2, 4.5 vs. 13.5 microg/kg/min. Dobutamine was added in 23% of the patients (group 1), 32% (group 2) and 95% (group 3). Adrenalin/amrinonum was required in 40% of the patients in group 3, 5% in group 2 and none in group 1. Group 1 patients had a better improvement of cardiac performance than group 2, while other parameters did not differ. Three months follow up of hospital survivors showed no group differences. CONCLUSIONS: The use of preoperative IABP in high risk patients lowers hospital mortality and shortens the stay in ICU, due to improved cardiac performance, compared to a controls. The procedure was cost-beneficial. One day preoperative IABP treatment improves cardiac performance more than 1-2 h preoperative IABP treatment, but does not significantly affect the outcome in terms of hospital mortality or postoperative morbidity.

The effect of preoperative intra-aortic balloon pump support in patients with coronary artery disease, poor left-ventricular function (LVEF < 40%), and hypertensive LV hypertrophy.

Poor left-ventricular function, hypertension, and left-ventricular hypertrophy in patients with coronary artery disease (CAD) undergoing coronary artery bypass grafting (CABG) are associated with increased operative risks. Between June 1994 and March 1996, 33 patients undergoing CABG, were randomized into 2 groups. One group (IABP group, n = 19) received IABP treatment on average for 2 hours prior to CPB, the other group (control group, n = 14) had no preoperative IABP, Cardiac performance was measured pre- and postoperatively by Swan-Ganz catheter. Mean age was 65 years and 90% were men. All patients had a preoperative LVEF < or = 40% (mean 32.6 +/- 11.1%), 3-vessel disease, established hypertension (WHO criteria), and LV hypertrophy (ventricular mass > or = 136 g/m2 [men] or > or = 110 g/m2 [women]). Ischemia time was similar in both groups while CPB-time was shorter in the IABP group, p < 0.05. There were no hospital deaths in the IABP group, but 3 in the control group suffered postoperative low cardiac output. Nine patients (64%) in the control group required IABP support postoperatively, but only 20% of the patients in the IABP group had a shorter ICU stay, 2.4 +/- 0.9 vs. 3.4 +/- 1.1 days, p < 0.01. Cardiac index increased significantly in the IABP group prior to CPB and was higher compared to control, p < 0.001. Five min after CBP cardiac index was higher in the IABP group than in the control group, p = 0.013, and continued to increase thereafter, while no further improvement was observed in controls. Preoperative IABP treatment in hypertensive patients with CAD, low LVEF and LV hypertrophy who are undergoing CABG is beneficial. An improved cardiac performance pre- and postoperatively was associated with a lower rate of hospital mortality and less postoperative morbidity, as well as shorter ICU stay. The treatment is cost-beneficial.

The influence of age on the results of reoperative coronary artery bypass grafting.

BACKGROUND: With a steady increase in the number of elderly patients requiring coronary artery bypass grafting (CABG), a larger portion of elderly patients will also become candidates for reoperative CABG. Scepticism still exists as to whether this operation is justified in older patients. The purpose of this study was to examine the effect of increasing age on the outcome after reoperative CABG. METHODS: Between January 1, 1990 and June 30, 1996 563 patients underwent isolated reoperative CABG, and were included in this retrospective analysis. Patients who had combined procedures were excluded. The patients were divided by age into two groups: those aged 69 years or less (n = 507), and those older than 70 years (n = 56). Hospital mortality and morbidity for each group was compared. Medium-term survival for each group was compared with that of their age-matched population derived from Swiss life tables. RESULTS: The patients aged 70 years and older had a higher New York Health Association functional class, and more patients had unstable angina requiring urgent surgery than did the younger patients. The elderly also showed an over-representation of diabetes and multifocal vascular disease (generalized arteriosclerotic disease), and there was a higher number of patients with triple-vessel disease and left stenosis (> or = 70%) in this group. Patients aged 70 years and older received fewer distal anastomoses (3.0 versus 3.6; P < 0.01), and had a longer cardiopulmonary bypass time compared with the younger patients, but the ischemia time was similar in both groups. Hospital mortality was higher in patients older than 70 years (7.1 versus 17.9%). There was an increased frequency of postoperative low cardiac output and a higher incidence of gastrointestinal complications and transient renal failure amongst the elderly patients (> or = 70 years). Despite a higher hospital mortality rate and slightly increased morbidity the 5-year survival was excellent, and comparable with the age-matched population in both groups [89.6% (< 70 years) and 76.2% (> or = 70 years)]. The cardiac event-free survival was 79.8% (< 70 years), and 69.9% (> or = 70 years) after 5 years. CONCLUSION: An acceptable early mortality and long-term survival together with good functional long-term results support the justification of reoperative CABG in older patients, at least up to the age of 80 years.

Reoperative coronary artery bypass procedures: risk factors for early mortality and late survival.

OBJECTIVES: The number of coronary artery disease reoperations is increasing. The aim of this paper is to identify risk factors and evaluate the results of REDO coronary artery bypass grafting (CABG). MATERIAL: Between January 1984 and October 1994, 594 patients underwent REDO-CABG and 3157 underwent primary-CABG. The mean age was 62 years with 84% men. Hypertension, hyperlipidemia, insulin dependent diabetes, smoking and renal insufficiency were all more frequent in the REDO-group. A significantly higher number of patients undergoing REDO-CABG were in the Canadian Cardiovascular Society (CCS) angina class 3 and 4, had instable angina, had left main stem stenosis of greater than 70% and 3-vessel disease compared to those undergoing primary-CABG. The mean preoperative left ventricular function (LVEF) was 49.8 (REDO) vs. 58.2%, with a P value of less than 0.001. RESULTS: The overall postoperative mortality rate for REDO-operations was 9.6 (57/594) vs. 2.8% for primary-CABG. Patients with a reoperative interval of more than 1 year had an 8.9% mortality rate, compared to those reoperated less than 1 year after the initial CABG, where the mortality was 21% with a P value of less than 0.05. Postoperative low cardiac output syndrome, intraaortic balloon pump support, prolonged ventilatory support (> 24 h), hemorrhage and gastrointestinal complications were prominent features of the REDO-group (all P < 0.01). Urgent operation, CCS class 3 and 4, LVEF of less than 40%, generalized arteriosclerotic disease and advanced age (> 80 years) were independent risk factors for postoperative death in both groups. Preoperative renal insufficiency, diabetes and short interval from primary-CABG were added risk factors in the REDO-group. The 5-years survival rate after REDO-CABG was 89%, while the cardiac event-free survival rate was 79% and at 7 years 84 and 62%, respectively. CONCLUSIONS: Reoperative CABG is effective, but has an increased operative mortality and morbidity. The long-term results are encouraging. Unstable angina, poor preoperative left ventricular function, renal insufficiency, insulin dependant diabetes and an interval shorter than 1 year of the initial operation were independent riskfactors for mortality.