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Biomedical subjects

R Cartier

Publications and source records attributed to R Cartier.

At least 37 records · Page 2Linked to original sources
PubMed2000

Bolus endovascular PDGFR-beta antisense treatment suppressed intimal hyperplasia in a rat carotid injury model.

BACKGROUND: Intimal thickening in accelerated arteriopathies relies on the migration of medial vascular smooth muscle cells (VSMCs) and their proliferation within the neointima. Activation of platelet-derived growth factor receptor-beta (PDGFR-beta) expressed in injured VSMCs is responsible for the migration of medial VSMCs to the intima. In the present study, we wanted to assess whether a single local endovascular delivery of antisense PDGFR-beta in injured rat carotid arteries would be sufficient to prevent intimal hyperplasia and how it might contribute to the vascular healing process. METHODS AND RESULTS: A bolus of antisense PDGFR-beta delivered into injured rat carotid arteries reduced PDGFR-beta protein overexpression by >90% from day 3 to 28 after injury. At day 28 after injury, compared with injured untreated carotids, treatment with antisense PDGFR-beta reduced intimal hyperplasia by 58% and medial VSMC migration by 49% and improved vascular reendothelialization by 100% and vascular reactivity (EC(50)) to acetylcholine by 5-fold. CONCLUSIONS: A single-bolus luminal delivery of antisense PDGFR-beta to injured rat carotids reduced intimal hyperplasia, improved the reendothelialization process, and led to the recovery of endothelium-dependent regulation of vascular tone.

Animals↗
PubMed2000

Torsades de pointes secondary to intravenous haloperidol after coronary bypass grafting surgery.

PURPOSE: Postoperative delirium occurs in about 2% of patients undergoing major cardiac surgery including coronary artery bypass grafting surgery (CABG). Haloperidol (Sabex, Boucherville, Canada) is a drug commonly used in the intensive care unit for the treatment of delirium and is usually considered safe even at high doses and is rarely implicated in the development of malignant ventricular arrhythmias such as torsades de pointes. The purpose of this study is to report such a complication of use of haloperidol after myocardial revascularization. CLINICAL FEATURES: The patient reported underwent uneventful triple bypass surgery. Administration of large intravenous doses of haloperidol was necessary for control of psychomotor agitation due to delirium. Torsades de pointes occurred in the absence of QT prolongation on the third postoperative day following use of the drug with no other obvious etiological factor. CONCLUSION: Awareness of this rare complication is key to judicious use of this drug in the post CABG patient in whom such an arrhythmia may have very deleterious consequences because of the underlying cardiac condition.

Anti-Dyskinesia Agents↗
PubMed2000

Immediate and long-term results of valve replacement for native and prosthetic valve endocarditis.

BACKGROUND: The objective of the present study was to compare current results of prosthetic valve replacement following acute infective native valve endocarditis (NVE) with that of prosthetic valve endocarditis (PVE). Prosthetic valve replacement is often necessary for acute infective endocarditis. Although valve repair and homografts have been associated with excellent outcome, homograft availability and the importance of valvular destruction often dictate prosthetic valve replacement in patients with acute bacterial endocarditis. METHODS: A retrospective analysis of the experience with prosthetic valve replacement following acute NVE and PVE between 1988 and 1998 was performed at the Montreal Heart Institute. RESULTS: Seventy-seven patients (57 men and 20 women, mean age 48 +/- 16 years) with acute infective endocarditis underwent valve replacement. Fifty patients had NVE and 27 had PVE. Four patients (8%) with NVE died within 30 days of operation and there were no hospital deaths in patients with PVE. Survival at 1, 5, and 7 years averaged 80% +/- 6%, 76% +/- 6%, and 76% +/- 6% for NVE and 70% +/- 9%, 59% +/- 10%, and 55% +/- 10% for PVE, respectively (p = 0.15). Reoperation-free survival at 1, 5, and 7 years averaged 80% +/- 6%, 76% +/- 6%, and 76% +/- 6% for NVE and 45% +/- 10%, 40% +/- 10%, and 36% +/- 9% for PVE (p = 0.003). Five-year survival for NVE averaged 75% +/- 9% following aortic valve replacement and 79% +/- 9% following mitral valve replacement. Five-year survival for PVE averaged 66% +/- 12% following aortic valve replacement and 43% +/- 19% following mitral valve replacement (p = 0.75). Nine patients underwent reoperation during follow-up: indications were prosthesis infection in 4 patients (3 mitral, 1 aortic), dehiscence of mitral prosthesis in 3, and dehiscence of aortic prosthesis in 2. CONCLUSIONS: Prosthetic valve replacement for NVE resulted in good long-term patient survival with a minimal risk of reoperation compared with patients who underwent valve replacement for PVE. In patients with PVE, those who needed reoperation had recurrent endocarditis or noninfectious periprosthetic dehiscence.

Adult↗
PubMed2000

Outcome with high blood lactate levels during cardiopulmonary bypass in adult cardiac operation.

BACKGROUND: High blood lactate levels during cardiopulmonary bypass (CPB) are associated with tissue hypoperfusion and may contribute to postoperative complications or death. The objective of this study was to determine an association between blood lactate levels during CPB and perioperative morbidity and mortality. METHODS: We reviewed 1,376 patients who underwent cardiac operation with CPB. Patients with abnormal preoperative blood lactate levels were excluded (n = 101). Blood lactate concentration during CPB, clinical data, and perioperative events were recorded. RESULTS: Peak blood lactate levels of 4.0 mmol/L or higher during CPB were present in 227 patients (18.0%). Postoperative mortality was higher in this group than in the patients who had peak blood lactate levels of less than 4.0 mmol/L during CPB (11.0% versus 1.4%; p < 0.001, relative risk [RR] = 9.0). Postoperative hemodynamic instability occurred in 29.5% of patients with elevated levels of lactate during CPB compared with 10.9% of patients with lower lactate levels (p < 0.001, RR = 3.4). Overall, major postoperative complications occurred in 43.2% and 21.8% of patients in each group, respectively (p < 0.001, RR = 2.7). Logistic regression analysis revealed that peak blood lactate levels of 4.0 mmol/L or higher during CPB were strongly associated with postoperative mortality (p = 0.0001) and morbidity (p = 0.013). CONCLUSIONS: Blood lactate concentration of 4.0 mmol/L or higher during CPB identifies a subgroup of patients with increased risk of postoperative morbidity and mortality.

Adult↗
PubMed2000

Systematic off-pump coronary artery revascularization in multivessel disease: experience of three hundred cases.

OBJECTIVE: We sought to report our recent experience with off-pump coronary artery revascularization in multivessel disease. METHODS: Between October 1996 and December 1998, 300 off-pump beating heart operations were performed at the Montreal Heart Institute by a single surgeon, representing 94% of all procedures undertaken during this same time frame (97% for 1998). This cohort of patients was compared with 1870 patients operated on with cardiopulmonary bypass from 1995 to 1996. RESULTS: Mean age, sex distribution, and preoperative risk factors were comparable for the two groups. On average, 2.92 +/- 0.8 and 2.84 +/- 0.6 grafts per patient were completed in the beating heart and cardiopulmonary bypass groups, respectively. A majority of patients (70%) had either a triple or quadruple bypass. Coronary anastomoses were achieved with myocardial mechanical stabilization and heart "verticalization." Ischemic time was shorter in the beating heart group (29.8 +/- 0.9 vs 45 +/- 0.4 minutes, P <.05). Similarly, the need for transfusion was significantly less in the beating heart group (beating heart operations, 34%; cardiopulmonary bypass, 66%; P <.005). Reduced use of postoperative intra-aortic counterpulsation, as well as a lower rise in creatine kinase MB isoenzyme, was observed in the beating heart group. Operative mortality rates (beating heart operations, 1. 3%; cardiopulmonary bypass, 2%) and perioperative myocardial infarction (beating heart operations, 3.6%; cardiopulmonary bypass, 4.2%) were comparable for the two groups. CONCLUSION: In a majority of patients, off-pump complete coronary artery revascularization is an acceptable alternative to conventional operations, yielding good results given progressive experience, rigorous technique, and adequate coronary artery stabilization.

Cardiopulmonary Bypass↗
PubMed2000

Reinfusion of mediastinal blood after heart surgery.

BACKGROUND: Several authors studying autotransfusion of shed mediastinal blood in patients undergoing heart operations have published conflicting results regarding reduction of the need for homologous blood transfusion. The effect on coagulation parameters is also unclear. METHODS: In a prospective randomized study, 198 patients who underwent coronary artery bypass grafting or a valvular operation were divided into 2 groups: a group with autotransfusion of shed mediastinal blood after an operation and a control group. Continuous reinfusion of mediastinal blood was done until no drainage was present or for a period of 12 hours after the operation. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored. RESULTS: The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P =.01). The number of re-explorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was higher in the autotransfused patients compared with control patients (1200 +/- 201 mL vs 758 +/- 152 mL, P =.0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations. CONCLUSION: Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion in patients undergoing various cardiac operations. The cause of increased shed blood in patients undergoing autotransfusion remains unclear.

Analysis of Variance↗
PubMed2000

Factors predictive of oxygen consumption during the immediate postoperative period in open heart surgery.

BACKGROUND: Postoperative oxygen consumption (VO2) is critical during the recovery period that follows open heart surgery and depends on patient characteristics and surgical factors. OBJECTIVE: To explore the surgical and patient-related factors that may influence VO2 during the early postoperative period. DESIGN: Prospective study. SETTING: Postoperative intensive care unit. PATIENTS: Study participants were 50 consecutive patients undergoing elective open heart surgery. There were 39 men and 11 women, with a mean age of 58+/-10 years. MEASUREMENTS AND MAIN RESULTS: VO2, oxygen extraction and arterial lactate were measured 1, 4, 12 and 24 h postoperatively. VO2 increased significantly during the first 12 h and stabilized thereafter. Oxygen extraction remained stable through the first 24 h. Covariance analysis on repeated measures showed that the extracorporeal circulatory period (P<0.01), age (P<0.01), body temperature (P<0.05) and use of noradrenalin (P<0.05) were predictive factors influencing postoperative VO2. Although arterial lactate increased significantly during the first 12 h period, no correlation with VO2 was found. However, covariance analysis showed that female sex, patient age (older than 65 years) and bypass period were positive correlating factors for the increase in arterial lactate. CONCLUSIONS: Patient VO2 need is decreased early after open heart surgery and returns to normal after 12 h. Surgical and patient-specific factors are responsible for these changes. Arterial lactate measurements were not found to be reliable indexes of VO2 need during this period.

Elective Surgical Procedures↗
PubMed2000

Clinical outcome after isolated tricuspid valve replacement: 20-year experience.

OBJECTIVE: To examine the early and late results of isolated tricuspid valve replacement (TVR). DESIGN AND SETTING: All isolated TVRs performed at the Montreal Heart Institute, Montreal, Quebec between January 1978 and January 1998 were retrospectively reviewed. Follow-up data on patients were obtained through the valve clinic. PARTICIPANTS: From a total of 79 TVR and 375 tricuspid annuloplasties performed during the study period, 29 patients who underwent 32 isolated TVRs (six mechanical valves and 26 bioprostheses) were included. Patient age ranged from 25 to 70 years (mean 48), and 62% were female. Twenty-seven patients (84%) were in New York Heart Association (NYHA) functional classes III and IV. Previous valve surgery had been performed in 22 patients (69%) among whom nine had undergone TVR. RESULTS: Postoperatively, a permanent pacemaker was implanted in nine patients (28%), and reoperation because of bleeding was required in two patients. Mean follow-up was 67.7 months (93% complete). Serial echocardiography showed prosthesis dysfunction in three patients, requiring two valve re-replacements at 12.8 and 7.7 years after initial surgery. All patients, except three, showed an improvement of their NYHA class. Six patients (19%) died in hospital and seven patients died during late follow-up at a mean of 38.1 months after surgery, including one valve-related death (mechanical valve thrombosis). The actuarial survival rate of all patients was 63% after five years and 47% after 10 years. CONCLUSION: Isolated TVR remains a high risk procedure. Most survivors, however, should expect a better quality of life by the improvement in their NYHA class.

Adult↗
PubMed2000

Endoscopic saphenectomy for coronary artery bypass surgery: comparison of two techniques with and without carbon dioxide insufflation.

OBJECTIVE: To compare the clinical results of an initial experience with two techniques of endoscopic saphenectomy with and without gas insufflation. DESIGN: A retrospective study was performed between September 1998 and March 1999 on 40 patients who underwent endoscopic saphenectomy for coronary artery bypass graft without (group 1, n=15) and with (group 2, n=25) carbon dioxide insufflation. INTERVENTIONS: In both groups, the site of harvesting was at the knee through a 2 cm incision. In group 1, dissection was performed using a hand-held dissector while in group 2 dissection was performed after ensuring that there was a seal at the knee and insufflation of carbon dioxide. Collaterals were controlled with an endoclipper in group 1 and bipolar scissors in group 2. Intraoperative procedure time, length of the harvested vein and aspect of the thigh (ecchymosis, hematoma, infection) were recorded. RESULTS: Vein trauma occurred in four patients in group 1 (four of 15, 27%) and in one in group 2 (one of 25, 4%). Hematomas developed in four patients in group 1 (four of 15, 27%) and in one patient in group 2 (one of 25, 4%). Wound infection occurred in no patients in group 1 and in one patient in group 2. One patient in group 2 suffered carbon dioxide embolism with no untoward consequences. Conversion to an open technique was necessary in five patients in group 1 (five of 15, 33%) and in two patients in group 2 (two of 25, 8%). CONCLUSIONS: Endoscopic saphenectomy both with and without carbon dioxide insufflation is associated with a low infection rate, but vein trauma and wound hematomas are more common without carbon dioxide insufflation.

Angioscopes↗
PubMed2000

Left main coronary artery stenosis: early experience with surgical revascularization without cardiopulmonary bypass.

BACKGROUND: To determine the safety of surgical revascularization without cardiopulmonary bypass (CPB) in left main stem (LMS) coronary stenosis. METHODS AND RESULTS: Between October 1996 and April 1998, 67 consecutive patients with a > or =50% LMS stenosis underwent coronary revascularization without bypass (BH) and were compared to a contemporary group of 160 patients revascularized with conventional bypass (CPB). Mean ages in both groups were similar: 63.1 and 64.5 years in BH and CPB groups respectively (p=0.91). Significant triple vessel disease occurred in 40 (80%) and 75 (47.5%) patients in BH and CPB groups respectively (p=NS). Average grafts per patient was numbered 3.1 in BH group and 2.9 in CPB group (p=NS). The perioperative infarction rate (defined arbitrarily as a CK-MB >100 U/l) was 4% (2 patients, excluding 1 preoperative infarct) and 3.1% (5 patients, excluding 2 preoperative infarcts) in groups BH and CPB respectively (p=0.28). Postoperative blood transfusion requirements were less in BH group (19 patients, 38%) compared to CPB group (103 patients, 64.4%), (p=0.04). Postoperative inotropic requirements were similar in both groups; BH group (15 patients, 30%) and CPB group (72 patients, 45%). Mean hospital stay was 6.4 and 7.6 days in BH and CPB groups respectively (p=0.49). The hospital mortality rate was 0% and 3.8% (6 patients) in BH and CPB groups respectively (p=NS). CONCLUSIONS: Our early experience suggests that non-CPB surgical revascularization in LMS stenosis is a feasible and safe alternative to conventional cardiopulmonary bypass.

Adult↗
PubMed2000

[Isolated tricuspid valve replacement. Long-term results].

The purpose of this study was to examine the early and late results in 29 patients who underwent 32 (6 mechanical and 26 bioprostheses) isolated tricuspid valve replacement (TVR) from a total of 79 TVR and 375 tricuspid annuloplasties performed at the Montréal Heart Institute, between January 1978 and January 1998. Patients' ages ranged from 25 to 70 years (mean 48 years), and 62% were females. Twenty-seven patients (84%) were in New York Heart Association (NYHA) functional class III and IV. Previous valve surgery had been performed in 22 patients (69%) of which 9 had undergone TVR. Postoperatively, permanent pacemaker was implanted in 9 patients (28%), and immediate reoperation was required in 2 patients because of bleeding. Mean follow-up period was 67.7 months (93% complete). Serial echocardiography showed 3 prosthesis dysfunctions, leading to a second replacement in 2 patients at 12.8 and 7.7 years after initial surgery. All but three patients showed an improvement of their NYHA class. Hospital mortality occurred in 6 patients (19%) and 7 patients died during late follow-up: mean 38.1 months after surgery, including one valve-related death (mechanical valve thrombosis). Actuarial survival rate of all patients was 63% after 5 years, and 47% after 10 years. Isolated TVR remains a high-risk procedure. Most survivors, however, should expect a better quality of life with improvement in their NYHA class.

Adult↗
PubMed1999

Comparison of long-term clinical results of double versus single internal mammary artery bypass grafting.

BACKGROUND: The long-term benefits of double versus single internal mammary artery (IMA) coronary bypass grafting have not yet been established. METHODS: Six hundred patients were studied retrospectively 10 years after coronary revascularization using saphenous vein grafts (SVGs) only or single or double IMA grafts. RESULTS: Patients with double IMA grafts were younger and were more likely to have diabetes, left main coronary stenosis, and three-vessel coronary artery disease than patients with SVGs or single IMA grafts. Patients with SVGs and double IMA grafts had a greater number of diseased coronary vessels and a greater number of coronary bypass grafts per patient than patients with single IMA grafts (mean +/- SEM, 2.8 +/- 1.0, 2.8 +/- 0.7, 2.1 +/- 0.8 grafts per patient, respectively, p < 0.0001). Actuarial survival rates 10 years after placement of SVGs and single and double IMA grafts averaged 83% +/- 6%, 90% +/- 4%, and 87% +/- 8%, respectively (p = 0.03). Cox regression analysis showed that diabetes (relative risk, 2.03; 95% confidence interval, 1.55 to 2.66) and chronic pulmonary obstructive disease (relative risk, 2.20; 95% confidence interval, 1.58 to 3.80) increased, whereas an IMA graft on the left anterior descending coronary artery significantly decreased, the risk of death after operation (relative risk, 0.45; 95% confidence interval, 0.36 to 0.57) throughout the follow-up period. CONCLUSIONS: Use of an IMA graft on the left anterior descending coronary artery improves survival compared with use of an SVG. Although patients with double IMA grafts had a greater number of poor prognosis risk factors before operation, their 10-year survival rate was similar to that of patients with a single IMA graft.

Adult↗
PubMed1999

Off-pump revascularization of the circumflex artery: technical aspect and short-term results.

BACKGROUND: Beating heart surgery is a technique currently used for revascularization of the anterior and inferior territory. However, revascularization of the circumflex artery is more problematic. With a specific apparatus and surgical technique, we have extended the use of beating heart surgery to more than 90% of patients with multivessel disease, including those necessitating circumflex artery revascularization. METHODS: Between October 1996 and November 1997, 140 patients underwent beating heart surgery by the same surgeon (R.C.). Among these patients, 111 required reconstruction of the circumflex artery territory and were followed up prospectively. They represent the cohort of patients presented in this study. There were 90 men and 21 women averaging 64+/-9.9 years of age. Mean left ventricular ejection fraction was 55%+/-13.7%, and a significant left main coronary artery disease was present in 27% of the patients. Five patients had prior coronary revascularization. RESULTS: An average of 3.1+/-0.1 grafts/patient were performed. Complete revascularization was achieved in 95%. Only 1 patient needed conversion to cardiopulmonary bypass because of spontaneous ascending aortic dissection. Perioperative and postoperative bleeding were 446+/-245 mL and 644+/-442 mL, respectively. Homologous transfusions were required in 40% of the patients. Myocardial infarction occurred in 2.7% and operative mortality in 0.7% (1 patient). Average hospital stay was 6.6+/-3.1 days, and no patient exhibited early recurrence of angina. Early coronary angiograms (first 8 patients) demonstrated a 100% patency with 95% freedom from significant stenosis. CONCLUSIONS: Complete coronary artery revascularization is feasible on the beating heart without the assistance of cardiopulmonary bypass with a low morbidity and mortality and excellent early angiographic results. Long-term follow-ups are needed to substantiate the potential long-term benefits of this technique.

Adult↗
PubMed1999

Systematic off-pump coronary artery revascularization: experience of 275 cases.

BACKGROUND: The author reports his short-term experience with systematic off-pump coronary artery revascularization in multivessel disease. METHODS: Between September 1996 and October 1998, 275 off-pump revascularizations (83% of case load during this period; 97% since January 1998) were performed by a single surgeon (R.C.). The patient base of 216 men/59 women averaged 63 +/- 10 years. Main indication was unstable angina (60%). All surgeries were performed through a median sternotomy, with mechanical stabilization, and a heart "verticalizing" technique to enable access to the circumflex territory. RESULTS: An average of 2.91 +/- 0.83 (range 1 to 5) grafts/patient was achieved, with 70% of cases being triple or quadruple bypasses. Single or double internal thoracic arteries was utilized in 95% of cases. Complete revascularization was attained in 93% of surgeries. Total ischemic time averaged 28 +/- 10 (range 8 to 65) minutes. Myocardial infarction incidence was 4%, with only 1 patient requiring postoperative aortic counter-pulsation assistance. One early percutaneous transluminal coronary angioplasty was needed to restore an occluded posterior descending artery. Three operative deaths resulted. One conversion to cardiopulmonary bypass was required. A transfusion rate of 32% was observed, half the rate of conventional coronary artery bypass grafting at our institute. CONCLUSIONS: With gradual experience, proper operative technique, and surgical apparatus, beating heart bypass surgery may be used systematically as a suitable, safe alternative to conventional on-pump coronary artery bypass grafting, permitting complete revascularization in a majority of patients with excellent short-term results.

Aged↗