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Biomedical subjects

S Milo

Publications and source records attributed to S Milo.

At least 19 recordsLinked to original sources
PubMed2002

Bypass surgery versus stenting for the treatment of multivessel disease in patients with unstable angina compared with stable angina.

BACKGROUND: Earlier reports have shown that the outcome of balloon angioplasty or bypass surgery in unstable angina is less favorable than in stable angina. Recent improvements in percutaneous treatment (stent implantation) and bypass surgery (arterial grafts) warrant reevaluation of the relative merits of either technique in treatment of unstable angina. Methods and Results- Seven hundred fifty-five patients with stable angina were randomly assigned to coronary stenting (374) or bypass surgery (381), and 450 patients with unstable angina were randomly assigned to coronary stenting (226) or bypass surgery (224). All patients had multivessel disease considered to be equally treatable by either technique. Freedom from major adverse events, including death, myocardial infarction, and cerebrovascular events, at 1 year was not different in unstable patients (91.2% versus 88.9%) and stable patients (90.4% versus 92.6%) treated, respectively, with coronary stenting or bypass surgery. Freedom from repeat revascularization at 1 year was similar in unstable and stable angina treated with stenting (79.2% versus 78.9%) or bypass surgery (96.3% versus 96%) but was significantly higher in both unstable and stable patients treated with stenting (16.8% versus 16.9%) compared with bypass surgery (3.6% versus 3.5%). Neither the difference in costs between stented or bypassed stable or unstable angina ($2594 versus $3627) nor the cost-effectiveness was significantly different at 1 year. CONCLUSIONS: There was no difference in rates of death, myocardial infarction, and cerebrovascular event at 1 year in patients with unstable angina and multivessel disease treated with either stented angioplasty or bypass surgery compared with patients with stable angina. The rate of repeat revascularization of both unstable and stable angina was significantly higher in patients with stents.

Acute Disease↗
PubMed2002

Vancomycin sequestration during cardiopulmonary bypass surgery.

OBJECTIVE: The present study was designed to analyze vancomycin disposition in adult patients undergoing coronary bypass grafting during and following cardiopulmonary bypass (CPB). METHODS: Coronary bypass surgery was performed on 11 adults with a mean age (SD) of 62.9 (9.0) years old, who received a mean (SD) vancomycin prophylactic dose of 12.7 (1.0) mg/kg in a mean period of 41 (0.7) min. Using a two-compartment open model for pharmacokinetic analysis, the following parameters were obtained: alpha half-life, minutes (t(1/2alpha)); beta half-life, hours (t(1/2beta)); apparent volume of distribution, (V(d) l/kg); volume of the central compartment, (V(c) l/kg), constant between the "central to the peripheral" compartment, (k(12)); constant between the "peripheral to the central" compartment, (k(21)); total area under the concentration-time curve, (AUC mg/lxh) and a vancomycin clearance, (Cl(van) ml/min), respectively. RESULTS: The mean (SD) calculated pharmacokinetic parameters were: t(1/2alpha)17.6 (6) min, t(1/2beta) 8.4 (3.8) h, V(d) 0.803 (0.259) l/kg, V(c) 0.270 (0.162) l/kg, k(12) 0.03 (0.015), k(21) 0.012 (0.012), total AUC 10377.2 (3687.6) mg/lxh. The mean (SD) vancomycin clearance by the CPB machine was 9.51 (2.66) l/h, and the mean (SD) total vancomycin sequestrated by CPB was 331.7 (84) mg. A significant difference (6.3%; p = 0.001) was measured between the mean measured AUC during CPB (1088.1 +/- 253.9) and the same calculated parameter (1160.2 +/- 282). Five minutes after starting CPB, a decrease in vancomycin level was detected; this difference was found to be nearly 11% in absolute values. CONCLUSIONS: This confirmatory study demonstrated that the vancomycin blood concentrations obtained during the study allow recommending a safety prophylactic dose of 12mg/kg in adults who undergo open-heart surgery under CPB conditions. Sequestration of vancomycin by the oxygenator or/and tubing system of the CPB machine had occurred and had been measured in this study.

Aged↗
PubMed2002

Vancomycin versus cefazolin prophylaxis for cardiac surgery in the setting of a high prevalence of methicillin-resistant staphylococcal infections.

OBJECTIVE: This study was undertaken to compare the efficacy of vancomycin prophylaxis with that of cefazolin in preventing surgical site infections in a tertiary medical center with a high prevalence of methicillin-resistant staphylococcal infections. METHODS: All adult patients (> or = 18 years) scheduled for cardiac surgery requiring sternotomy were randomly assigned to receive vancomycin (1 g every 12 hours) or cefazolin (1 g every 8 hours). Prophylaxis was started during the induction of anesthesia and continued for only 24 hours. Patients were followed up for at least 30 days (1 year for those receiving a cardiac implant). Surgical site infections were stratified according to the National Nosocomial Infections Surveillance System risk index. RESULTS: Of the 885 patients included in the study, 452 received vancomycin and 433 received cefazolin. The overall surgical site infection rates were similar in the two groups (43 cases in the vancomycin group, 9.5%, vs 39 cases in the cefazolin group, 9.0%, P =.8). Superficial and deep incisional surgical site infection rates were also similar in the two groups. There was a trend toward more frequent organ-space infections and infections with beta-lactam-resistant organisms among patients receiving cefazolin, but this trend did not reach statistical significance. In contrast, surgical site infections caused by methicillin-susceptible staphylococci were significantly more common in the vancomycin group (17 cases, 3.7%, vs 6 cases, 1.3%, P =.04). The durations of postoperative hospitalization and the mortalities were similar in the two groups. CONCLUSIONS: This trial suggests that vancomycin and cefazolin have similar efficacy in preventing surgical site infections in cardiac surgery.

Adult↗
PubMed2001

Selective distribution of oxysterols in atherosclerotic lesions and human plasma lipoproteins.

The presence of oxidized sterols (oxysterols) in human serum and lesions has been linked to the initiation and progression of atherosclerosis. Data concerning the origin, identity and quantity of oxysterols in biological samples are controversial and inconsistent. This inconsistency may arise from different analytical methods or handling conditions used by different investigators. In the present study, oxysterol levels and distribution were analyzed by an optimized GC-MS method, in human atherosclerotic coronary and carotid lesions, in atherosclerotic apolipoprotein E deficient mice (E degrees mice) and in native and in vitro oxidized human low and high density lipoproteins. Oxysterol levels were analyzed with a limit of detection of 0.06 - 0.24 ng, with 25-hydroxycholesterol (25-OH) being the least sensitive. In human coronary and carotid lesions, obtained from endatherectomic samples, 27-hydroxycholesterol (27-OH) was the major oxysterol, with about 85% as sterols esterified to fatty acids. While total cholesterol and oxysterols levels were similar in both kinds of human lesions, oxysterol distribution was significantly different. In coronary lesions the mean levels of 27-OH and 7beta-hydroxycholesterol (7beta-OH) were 38% and 20% of total oxysterols, whereas in carotid lesions their mean levels were 66% and 5%, respectively. Unlike in human aortic lesions, 27-OH was entirely absent in E degrees mice, whereas the level of 7alpha-hydroxycholesterol (7alpha-OH) was 28% of the total oxysterols, vs. 5% in human coronary lesions. As 27-OH is an enzymatic product of cholesterol oxidation, this finding may indicate that such an enzymatic process does not take place in E degrees mice.

Animals↗
PubMed2000

Human serum paraoxonases (PON1) Q and R selectively decrease lipid peroxides in human coronary and carotid atherosclerotic lesions: PON1 esterase and peroxidase-like activities.

BACKGROUND: Human serum paraoxonase (PON1) exists in two polymorphic forms: one that differs in the amino acid at position 192 (glutamine and arginine, Q and R, respectively) and the second one that differs in the amino acid at position 55 (methionine and leucine, M and L, respectively). PON1 protects LDL from oxidation, and during LDL oxidation, PON1 is inactivated. METHODS AND RESULTS: The present study compared PON1 isoforms Q and R for their effect on lipid peroxide content in human coronary and carotid lesions. After 24 hours of incubation with PON1Q or PON1R (10 arylesterase units/mL), lipid peroxides content in both coronary and carotid lesion homogenates (0.1 g/mL) was reduced up to 27% and 16%, respectively. The above incubation was associated with inactivation of PON1Q and PON1R by 15% and 45%, respectively. Lesion cholesteryl linoleate hydroperoxides and cholesteryl linoleate hydroxides were hydrolyzed by PON1 to yield linoleic acid hydroperoxides and linoleic acid hydroxides. Furthermore, lesion and pure linoleic acid hydroperoxides were reduced to yield linoleic acid hydroxides. These results thus indicate that PON1 demonstrates esterase-like and peroxidase-like activities. Recombinant PON1 mutants in which the PON1-free sulfhydryl group at cysteine-284 was replaced with either alanine or serine were no longer able to reduce lipid peroxide content in carotid lesions. CONCLUSIONS: We conclude that PON1 may be antiatherogenic because it hydrolyzes lipid peroxides in human atherosclerotic lesions.

Arteriosclerosis↗
PubMed1999

Microbubbles associated with mitral valve prostheses in pediatric patients.

OBJECTIVES: To assess whether microbubbles are associated with mitral valve prostheses in children and to investigate their relationship to exercise. BACKGROUND: Bright, highly mobile echoes are seen in left heart chambers of patients with mechanical mitral valve prostheses. The clinical importance of those microbubbles is not yet known but they survive long enough to reach the cerebral circulation. No such studies have been reported in children. METHODS: There were 20 male and 10 female patients with a mean age of 10.4 years (range 2-16 years). Transthoracic echocardiography with calculation of cardiac output and ejection fraction was performed at baseline and after exercise following mechanical mitral valve replacement. Studies were evaluated for the presence of microbubbles. The mean time from operation to time of study was 18 months (range 0.2-89 months). RESULTS: Of the 30 children evaluated, 28 (93%) had evidence of microbubbles. Exercise increased the number of microbubbles in 15 of the 26 children. This was positively associated with an increase in cardiac output. CONCLUSIONS: (1) Microbubbles are commonly observed in children with mechanical mitral prostheses and are augmented by exercise. (2) This phenomenon is of a special concern in children due to their expected longevity with the prosthesis.

Adolescent↗
PubMed1999

Microbubbles and mitral valve prostheses - transesophageal echocardiographic evaluation.

OBJECTIVE: To assess whether microbubbles are associated with a specific type of mitral valve prosthesis and to investigate the relationship of microbubbles to ventricular function and mitral regurgitation. One of the types of spontaneous echocardiographic contrast observed in patients with prosthetic heart valves has been described as microbubbles. METHODS: Clinical data and videotapes of patients with a prosthetic mitral valve who had undergone transesophageal echocardiography at the UCLA Medical Center between May 1989 and February 1995 were retrospectively reviewed. There were 109 studies (74 patients) available for review by two independent observers. RESULTS: Microbubbles occurred in 49 of the 66 studies of St. Jude valves ( 74%), eight of the 12 studies of Bjork Shiley valves (67%), four of four studies of Medtronic valves (100%) and zero of 23 studies of tissue valves (0%). Patients with an estimated ejection fraction greater than 45% were found to have a much higher likelihood of having microbubbles observed. There was no statistically significant association between the degree of mitral regurgitation and the observation of microbubbles. CONCLUSIONS: Microbubbles are a common phenomenon occurring in patients with mechanical mitral prostheses compared with tissue mitral valve prostheses. Their formation depends on the systolic ventricular function, suggesting a cavitation-like phenomenon participating in their formation perhaps due to the rate or velocity of the valve closure.

Adolescent↗
PubMed1999

Myocardial protection in operations requiring more than 2 h of aortic cross-clamping.

OBJECTIVE: Long periods of aortic cross-clamping time during cardiac surgery are associated with high rates of morbidity and mortality because of damage to the myocardium. Recently, we have used a method of myocardial protection based on the principles of hyperkalemic cardioplegic arrest. We use antegrade administration of warm, undiluted blood followed by continuous retrograde infusion of tepid, undiluted blood supplemented with potassium and magnesium. In this study, we have retrospectively reviewed our experience with this method of cardioprotection in operations requiring more than 2 h of cross-clamp time. METHODS: We retrospectively reviewed the medical records of 1280 patients who underwent myocardial revascularization, valve repair or replacement, or a combination of both operations between January 1, 1994 and December 31, 1997. Patients were divided into two groups: the short cross-clamp group (SXC) (n = 1144) had cross-clamp times < 120 min (mean, 78 +/- 20 min; range, 35-119 min) and the long cross-clamp group (LXC) (n = 136) had cross-clamp times > 120 min (mean, 154 +/- 31 min; range, 120-277 min). We compared preoperative, operative, and postoperative variables between the two groups. RESULTS: Significantly more patients in the long cross-clamp group (43.4%) underwent the combined operation than in the short cross-clamp group (2.3%), and the rate of reoperation was significantly higher in the long cross-clamp group (12%) than in the short cross-clamp group (5%). Despite these differences in operative complexity, we found no difference in hospital mortality rates between the two groups. The only significant postoperative differences were that the long cross-clamp group had a greater need for inotropic agents (43 vs. 29%), higher serum levels of creatine kinase (880 +/- 583 vs. 613 +/- 418) and CK-MB (10.9 +/- 6.4 vs. 5.9 +/- 5.2), and a longer hospital stay (9.6 vs. 6.1 days). CONCLUSION: Long, complex operations requiring more than 2 h of cross-clamping can be performed safely with our method of cardioprotection based on continuous retrograde infusion of tepid, hyperkalemic, undiluted blood.

Aged↗
PubMed1999

Bilateral coronary fistulae to pulmonic valve in presence of severe three-vessel coronary artery disease.

A 62-year-old man was admitted to the coronary care unit due to anginal pain and palpitations--coronary angiography revealed three-vessel coronary artery disease. The unexpected finding was the presence of coronary to pulmonary artery fistulae bilaterally, from both the proximal RCA and the proximal LAD. Right heart catheterization revealed normal right ventricular and pulmonary artery pressure and absence of hemodynamically significant left to right shunt. The patient underwent a triple coronary bypass including the closure of bilateral fistulae, which were draining into the left sinus of the pulmonary valve. One month after the operation he was in good health and had no complaints. Bilateral coronary artery fistulae is a rare anomaly diagnosed in 0.002-0.0013% of adult coronary angiograms. (Int J Cardiovasc Intervent 1999; 2: 249-251).

Journal Article↗
PubMed1998

Long-term follow-up of patients with severe rheumatic tricuspid stenosis.

BACKGROUND: Tricuspid stenosis is a part of the chronically rheumatic heart. Although rare, when tricuspid stenosis does occur, it occurs in the setting of coexistent mitral and aortic valve disease. The natural course of patients with severe tricuspid stenosis is not well defined. The aim of this study is to present close follow-up of patients with chronic rheumatic heart disease and severe tricuspid stenosis. METHODS AND RESULTS: We retrospectively studied 13 patients (11 women and 2 men) with severe tricuspid stenosis who were followed closely for 6 to 31 years. The mean tricuspid pressure gradient ranged from 3 to 9 mm Hg. Twelve patients underwent surgery for mitral and/or aortic valve lesions without complications. Concomitant tricuspid valve surgery was performed on six patients: two De Vega procedures, two Kay plications, and two implantations of Carpentier rings. All these also had leaflet commissurotomy. After surgery, the mean tricuspid gradient decreased in three patients, did not change in two, and increased in one. All 13 patients were treated with diuretics, digoxin, warfarin, and spirinolactone or ACE inhibitors. On their last follow-up visit, every patient had increased jugular venous pressure. Hepatomegaly was found in 6 of 13, leg edema in 4 of 13, and ascites in 1 of 13. CONCLUSIONS: Most tricuspid stenos patients are women with severe mitral and aortic valve disease. After successful repair of the mitral or aortic valve, and regardless of the type of tricuspid valve surgery, severe tricuspid stenosis was found to be very well tolerated by all the patients over many years of follow-up.

Adolescent↗
PubMed1998

Hemodynamic performance of four mechanical bileaflet prosthetic valves in the mitral position: an echocardiographic study.

OBJECTIVES: The CarboMedics, Duromedics, Sorin Bicarbon and the St. Jude Medical valves are bileaflet mechanical prostheses of modern but different design. Choosing a valve with the best hemodynamic profile is of clinical importance in patients with small ventricles and a small mitral annulus. METHODS: The hemodynamic performance of these valves in the mitral position was compared in 76 asymptomatic, ambulatory patients with normally functioning prosthesis and left ventricle, using Doppler echocardiography. Of the 76 patients studied, 22 had the CarboMedics, 16 had the Duromedics, 17 had the Sorin Bicarbon and 21 had the St. Jude prosthesis. The patients ages ranged from 18 to 81 years. There were 44 women and 32 men. The time from implantation to echocardiographic study ranged from 1 to 55 months. RESULTS: The echocardiographic study was performed earlier after surgery in the Sorin Bicarbon group. There was no significant difference in women/man ratio, incidence of atrial fibrillation, left ventricular or left atrial diameters between the four groups. The mean prosthesis size was significantly smaller for Sorin Bicarbon and Duromedics valves compared to the CarboMedics and the St. Jude valves (mean+/-SD, 27.2+/-1.3, 27.1+/-1.1 and 30.0+/-1.9 and 30.0+/-2.7 mm, respectively, P<0.001). Despite its smaller size the Sorin Bicarbon valve had significantly larger effective valve area by Doppler compared to the CarboMedics valve (290+/-40 vs 250+/-60 mm2, respectively, P=0.014). The ratio of effective valve area to prosthesis size was significantly larger for the Sorin Bicarbon valve when compared with any other type of prosthesis. CONCLUSIONS: (1) The Sorin Bicarbon bileaflet valve offered the best hemodynamic results that may be explained by the valve's large leaflet opening angle and small thickness of the leaflets. (2) Since the Sorin Bicarbon is the newest bileaflet valve, durability of this valve remains uncertain.

Adolescent↗
PubMed1997

A fatal case of Behçet's disease associated with multiple cardiovascular lesions.

Behçet's disease is recognised as a chronic multisystem disorder with vasculitis as its underlying pathological process. Cardiac involvement is rare and often associated with poor prognosis. A large right atrial thrombus, pulmonary aneurysms and aortic pseudoaneurysm that developed 17 years after surgery for bilateral renal artery stenosis is presented in a 26-year-old Behçet's disease patient. He was admitted to the hospital with fever of unknown origin associated with chest pain, dyspnea, cough, haemoptysis and pulmonary opacity in chest X-ray. Initial pulmonary CT demonstrated small subpleural infiltrates bilaterally, one of which was round and suspected as being metastatic. Examination of open lung biopsy demonstrated haemorrhagic infarct surrounded by some occluded pulmonary arteries. Subsequent CT showed pulmonary aneurysms compatible with Behçet's disease. Echocardiography demonstrated a large pedunculated mass in the right atrium. Injection of urographin showed a right atrial mass and a large right pulmonary artery aneurysm. The atrial mass was completely excised during open heart surgery and was identified as being an organising thrombus. Eight weeks later while taking prednisone, he was readmitted because of an infected mid sternal wound. CT showed slight separation of the stemum, retrosternal fluid, pulmonary arteries aneurysm and ascending aorta aneurysm. The next day, the patient died from massive bleeding from his ruptured ascending aortic pseudoaneurysm. Bizarre presentation of arterial and venous thromboses or arterial aneurysm formation, particularly in young patients, should suggest Behçet's disease.

Adult↗
PubMed1997

Severe humoral hypercalcemia in primary isolated non-Hodgkin's lymphoma of the heart.

The etiology of hypercalcemia was investigated in a patient with primary isolated non-Hodgkin's lymphoma of the heart. There was no evidence of bone involvement, and parathyroid hormone and calciterol levels were suppressed. Plasma parathyroid-hormone-related protein (PTHrP 1-86) detected by immunoradiometric assay was increased (15 pmol/l compared with < 0.3 pmol/l in a control). We demonstrated that PTHrP was the humoral mediator of severe hypercalcemia in our patient.

Heart Neoplasms↗
PubMed1997

Punch pulmonary valvectomy: another alternative to treat critical pulmonary stenosis.

For neonates with severe valvar stenosis, or valvar pulmonary atresia with an imperforate pulmonary valve, we present a simple but effective closed procedure using a specially designed valvectomy punch. Seven neonates, who were not suitable for any type of transcatheter procedure, were treated. There were two late deaths, neither directly related to the operation; 4 patients are developing well. This approach using the valvectomy punch is a fast, safe, and effective procedure.

Cardiac Surgical Procedures↗
PubMed1997

Alternative techniques for surgical management of recoarctation.

OBJECTIVE: To evaluate the different surgical options in patients with recoarctation and minimal collaterals. METHODS: Thirty-three cases operated on between January 1980 and January 1995 were reviewed. Initial repair was end-to-end anastomosis in 16 patients, subclavian artery aortoplasty in 10, synthetic patch aortoplasty in 4 and bypass conduit in 3 patients. Age at reoperation was 7.5 +/- 5.2 years (1-17 years). Pressure gradient was 20-48 Torr (33 +/- 9). Upper extremity resting or exercise systemic hypertension was present in all. In 18 patients recoarctation was repaired using subclavian artery aortoplasty (n = 15) or synthetic patch aortoplasty (n = 3); alone in 9, with temporary heparinized bypass in 2, or in addition to placement of ascending aorta to descending aorta conduit as a permanent bypass through a left thoracotomy in 9. In 13 patients a conduit was interposed between ascending aorta and descending aorta through a right thoracotomy. In one patient recoarctation segment was patched on cardiopulmonary bypass through a midsternotomy. RESULTS: There was no mortality or complications. All patients had no echocardiographic pressure gradients across recoarctation on 5 +/- 3.4 years follow-up. Persistent systemic hypertension following recoarctation repair was present in 3/8 patients (37%) operated on at age greater than 10 years, but has been resolved in all 25 patients less than 10 years of age (P = 0.02). CONCLUSIONS: Use of ascending aorta to descending aorta conduit, either alone through a right thoracotomy, or as permanent bypass in combination with patching the recoarctation through a left thoracotomy provides safe and excellent relief of obstruction.

Adolescent↗