Pulmonary metabolism of endothelin 1 during on-pump and beating heart coronary artery bypass operations.

BACKGROUND: Coronary artery bypass operations are associated with increased circulating levels of the powerful vasoconstrictor endothelin 1. The pulmonary circulation is an important site for both production and clearance of endothelin 1. Lung endothelial injury resulting from cardiopulmonary bypass could modify pulmonary endothelin 1 metabolism through an increase in production, a reduction in removal, or a combination of both. METHODS: Pulmonary endothelin 1 kinetics were quantified by using the indicator-dilution technique in patients undergoing coronary artery bypass grafting with (n = 11) or without cardiopulmonary bypass (ie, beating heart; n = 10). Mixed venous endothelin 1 levels were also measured in samples from the pulmonary artery, and systemic levels were obtained from the radial artery. RESULTS: Pulmonary artery endothelin 1 levels were similar before and after cardiopulmonary bypass, with means of 1.59 +/- 0.37 pg/mL and 1.33 +/- 0.15 pg/mL (P =.45), respectively. Systemic endothelin 1 levels, however, increased after bypass from 1.64 +/- 0.22 pg/mL to 2.07 +/- 0.16 pg/mL (P =.01). In the beating heart group, endothelin 1 levels before and after the operation were similar in the pulmonary artery (1.25 +/- 0.27 pg/mL and 1.45 +/- 0.31 pg/mL, respectively; P =.38), as well as in the radial artery (1.70 +/- 0.26 pg/mL and 1.73 +/- 0.35 pg/mL, respectively; P =.92). The capacity to clear endothelin 1 from the pulmonary circulation, as computed from the permeability-surface area product for endothelin 1, was not affected by cardiopulmonary bypass before and after the operation (25.19 +/- 2.67 mL/s and 23.12 +/- 4.39 mL/s, respectively; P =.49). It was similar and also unaffected in the beating heart group. CONCLUSION: Coronary artery bypass grafting with cardiopulmonary bypass is associated with an increase in systemic endothelin 1 levels. The mechanism involved is not related to a decreased pulmonary clearance of endothelin 1 from the systemic circulation but rather to an increased endothelin 1 release by the lungs.

Fifteen-year experience with the mitral Carpentier-Edwards PERIMOUNT pericardial bioprosthesis.

BACKGROUND: This multicenter study concerning the mitral PERIMOUNT valve previously reported clinical results at 12 years; this report updates the performance to 15 years postoperatively. METHODS: The 435 patients (mean age 60.7+/-11.6 years; 41.1% male) underwent implantation with the PERIMOUNT valve between 1984 and 1989 at seven institutions. Follow-up was complete for 96.1% of the cohort. The mean follow-up was 8.1+/-4.4 years (range 0 to 15.4 years) for a total of 3492 patient-years. RESULTS: There were 34 (7.8%) operative deaths, one (0.2%) valve related. The late mortality rate was 5.3%/patient-year (2.2%/patient-year valve related). At 14 years, the overall actuarial survival rate was 37.1%+/-3.3% (63.1%+/-4.4% valve related). Actuarial freedom from complications at 14 years was as follows: thromboembolism, 83.8%+/-3.2% (1.1%/patient-year); hemorrhage, 86.6%+/-3.2% (1.1%/patient-year); and explant due to structural valve deterioration (SVD), 68.8%+/-4.7%. Actual freedom from explant due to SVD was 83.4%+/-2.3%. Rates of structural failure decreased with increasing age at implant. CONCLUSIONS: The Carpentier-Edwards PERIMOUNT Pericardial Bioprosthesis is a reliable choice for a tissue valve in the mitral position, especially in patients more than 60 years of age.

Experience with the 19-mm Carpentier-Edwards pericardial bioprosthesis in the elderly.

BACKGROUND: Valve replacement in small aortic root remains a surgical challenge. The objective of this study was to compare results of the 19-mm bioprosthesis with those of larger prostheses in the elderly. METHODS: The 443 patients, 70 years of age and older, who underwent aortic valve replacement with Carpentier-Edwards pericardial bioprostheses were reviewed. RESULTS: There were 93 patients with a mean age of 76+/-4 years with implantation of 19-mm prostheses and 350 patients with a mean age of 75+/-4 years with larger bioprostheses. Associated aortoplasty was performed in 10 patients (11%) with 19-mm bioprostheses and in 8 patients (2%) with larger bioprostheses (p = 0.001). There were 11 deaths (12%) within 30 days of surgery in patients with 19-mm prostheses and 22 deaths (6%) among those with larger prostheses (p = 0.1). The 7-year survival rate averaged 61%+/-7% in patients with 19-mm prostheses and 67%+/-4% in those with larger prostheses (p = 0.8). The 7-year freedom rates from all valve-related events averaged 96%+/-2% and 93%+/-2%, respectively (p = 0.6). CONCLUSIONS: Aortic valve replacement with the 19-mm Carpentier-Edwards pericardial bioprosthesis offers excellent midterm results in the elderly.

Aortic valve replacement with mechanical and biologic prosthesis in middle-aged patients.

BACKGROUND: Mechanical prostheses are used in young patients and bioprostheses in the elderly because of the higher rate of structural failure of bioprostheses. The objective of the present study was to compare results after aortic valve replacement with mechanical (Carbo-Medics) and biologic (Carpentier-Edwards pericardial) in middle-aged patients. METHODS: Five hundred twenty-one patients, aged between 55 and 65 years, who underwent aortic valve replacement with mechanical (n = 363) or biologic (n = 158) prostheses were reviewed. RESULTS: The 10-year actuarial survival rate averaged 66%+/-6% in patients implanted with mechanical valves compared with 75%+/-4% in patients implanted with biologic valves (p = 0.2). The 10-year freedom rate from thromboembolism, hemorrhage, and endocarditis averaged 92%+/-7%, 97%+/-2%, and 99%+/-1%, respectively, in patients with mechanical valves compared with 91%+/-3% (p = 0.03), 99%+/-1% (p = 0.4), and 95%+/-2% (p = 0.01), respectively, in those with biologic valves. The 10-year freedom rate from all valve-related complications averaged 90%+/-7% and 83%+/-4%, respectively (p = 0.01). CONCLUSIONS: The freedom rate from all valve-related complications was higher among patients with mechanical valves compared with biologic valves 10 years after aortic valve replacement in middle-aged patients.

Results following valve replacement for ischemic mitral regurgitation.

BACKGROUND: Although several authors have favoured mitral repair in ischemic mitral regurgitation (IMR), mitral valve replacement is a valuable option and most often a necessity in patients with structural IMR. OBJECTIVE: To review the authors' experience with valve replacement for patients with acute and chronic IMR. The effect of preserving the valve leaflets and the subvalvular apparatus during replacement was also evaluated. PATIENTS AND METHODS: The authors' experience with mitral valve replacement for IMR between 1990 and 1999 was retrospectively analyzed at the Montreal Heart Institute, Montreal, Quebec. Results obtained with mitral valve replacement due to degenerative disease were used for comparative purposes. RESULTS: Ninety-two patients with IMR and 213 patients with degenerative mitral regurgitation underwent valve replacement with mechanical prostheses (262 of 305 [86%]) or biological prostheses (43 of 305 [14%]). Fifteen patients (15 of 92 [16%]) died within 30 days of mitral valve replacement among IMR patients compared with eight (eight of 213 [4%)] among patients with degenerative mitral valve disease (P=0.01). The seven-year survival average following mitral valve replacement was 66+/-7% in patients with ischemic disease compared with 72+/-4% in patients with degenerative disease (P=0.07). Cardiopulmonary bypass time (odds ratio [OR] 1.01) and emergency operation (OR 2.5) were correlated with the 30-day mortality; the patient's age (OR 1.04) was the only risk factor correlated with the seven-year mortality after valve replacement. The five-year survival of patients with papillary muscle rupture averaged 59+/-12% compared with 78+/-7% in those with functional IMR. CONCLUSIONS: Preoperative risk factors and higher early mortality in patients with mitral valve replacement for ischemic disease contribute to a lower seven-year survival than with mitral valve surgery for degenerative disease. The short and long term survival of the patients in the acute structural mitral disease subgroup was significantly worse.

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.

[Isolated tricuspid valve replacement. Long-term results]. / Remplacement valvulaire tricuspide isolé. Résultats à long terme.

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.

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.

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.

Effect of mycophenolate mofetil in heart transplantation.

OBJECTIVE: To study the effect of mycophenolate mofetil (MMF), a new immunosuppressive drug that acts by inhibiting de novo pathways of purine synthesis, and rabbit antithymocyte globulin (RATG) on the lymphocyte subpopulation after heart transplantation. DESIGN: A review of clinical and laboratory records. SETTING: The Montreal Heart Institute. PATIENTS: Thirty-one patients who underwent heart transplantation. In 9 patients, neoral cyclosporine, prednisone and azathioprine were administered (group 1). In 14 patients RATG was added during the first 3 postoperative days (group 2) and in 8 patients RATG and combination immunosuppression was given, but MMF was used instead of azathioprine (group 3). The demographic characteristics of donors and recipients were similar among the 3 groups. MAIN OUTCOME MEASURES: The proportion of CD2, CD4 and CD8 receptor-positive lymphocytes, expressed as a mean (and standard deviation) percentage of the total lymphocyte population, measured at 7, 15 and 30 days and 6 months after transplantation. RESULTS: At 7 days after transplantation, CD2 lymphocytes averaged 55% (18%), 16% (15%) and 14% (11%) in groups 1, 2 and 3 respectively (p < 0.05), CD4 averaged 36% (11%), 9% (12%) and 7% (8%) in groups 1, 2 and 3 (p < 0.05), and CD8 averaged 14% (6%), 4% (3%) and 4% (3%) in groups 1, 2 and 3 (p < 0.05). At 15 days after transplantation CD2 averaged 69% (10%), 42% (16%) and 47% (20%) in groups 1, 2 and 3 respectively (p < 0.05), and CD8 averaged 16% (7%), 16% (6%) and 19% (7%) (p = NS). At 30 days after transplantation the percentages of CD2, CD4 and CD8 lymphocytes were similar among the groups. The freedom rate from acute rejection averaged 22% (14%), 9% (8%) and 50% (18%) (p < 0.05) in groups 1, 2 and 3 at 6 months after transplantation, and the freedom rate from infection averaged 56% (17%), 36% (13%) and 38% (17%) for the 3 groups at this time period (p = NS). CONCLUSIONS: A short course of RATG causes severe, transitory depletion of CD2, CD4 and CD8 lymphocyte subpopulations. MMF decreases the incidence of early acute rejection after heart transplantation without affecting the lymphocyte subpopulation when compared with azathioprine.

Ten-year follow-up of critically ill patients undergoing heart transplantation.

BACKGROUND: The long-term result following heart transplantation appears very good despite complications of coronary atherosclerosis and cancer. Critically ill patients supported with mechanical devices remain a growing and difficult group in which long-term results need to be defined. The objective of this study was to review the 10-year follow-up of critically ill patients who underwent heart transplantation after support with mechanical devices. METHODS: We retrospectively analyzed all patients who underwent heart transplantation from 1986 to 1999 at the Montreal Heart Institute. RESULTS: Twenty-two patients (22/199, 11%) underwent heart transplantation after support with intra-aortic balloon pumps (n = 17) and total artificial hearts (n = 5). One hundred seventy-seven patients (177/199, 89%) underwent heart transplantation without pre-operative mechanical assistance. Patients with pre-operative mechanical assistance were younger (41 +/- 12 vs 48 +/- 10 years old, p = 0. 002), underwent a shorter waiting time to transplantation (2 +/- 2 vs 19 +/- 27 weeks, p = 0.004), and donor hearts had longer ischemic time (166 +/- 63 vs 137 +/- 49 minutes, p = 0.002) compared with patients without pre-operative mechanical assistance. One-month, 1-, 5-, and 10-year survival averaged 86% +/- 7%, 67% +/- 10%, 67% +/- 10%, and 59% +/- 12%, respectively, in patients with pre-operative mechanical assistance compared with 95% +/- 2%, 88% +/- 2%, 81% +/- 3%, and 74% +/- 4%, respectively, in patients without assistance, a significant difference (p = 0.04) that is mainly related to higher operative mortality in the former group. Although, we found no difference between the 2 groups in the 10-year freedom rate from acute rejection, infection, cancer, and coronary atherosclerosis, sepsis was the cause of 4 early deaths among patients with pre-operative mechanical assistance. CONCLUSION: Early and long-term survival was significantly decreased in critically ill patients with pre-operative mechanical assistance compared with other patients without pre-operative assistance. Sepsis is a dominant threat among patients who underwent heart transplantation with pre-operative mechanical assistance, and the lower survival is due mainly to the increased early mortality.

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.

Troponin levels in patients with myocardial infarction after coronary artery bypass grafting.

BACKGROUND: The objective of this study was to evaluate serum cardiac troponin T and I levels in patients in whom electrocardiogram, myocardial scan, and serum CK-MB levels of the MB isoenzyme of creatine kinase indicated perioperative myocardial infarction (MI) after coronary artery bypass grafting (CABG). METHODS: We studied 590 patients who underwent CABG at the Montreal Heart Institute between 1992 and 1996. Postoperative cardiac troponin T levels (493 patients), troponin I levels (97 patients), and activity of the MB isoenzyme of creatine kinase, electrocardiograms, clinical data, and clinical events were recorded prospectively. The diagnosis of perioperative PMI was defined by a new Q wave on the electrocardiogram, by serum levels of the MB isoenzyme of creatine kinase higher than 100 IU/L within 48 hours after operation, or both. RESULTS: After CABG, 22 patients in whom troponin T levels (22/493, 4.5%) and 6 patients in whom troponin I levels (6/97, 6.2%) were measured had sustained a perioperative MI according to current diagnostic criteria. In these patients, troponin T levels higher than 3.4 microg/L 48 hours after CABG best detected the presence of perioperative MI, with an area under the receiver operating characteristic curve of 0.95, a sensitivity of 90%, a specificity of 94%, a positive predictive value of 41%, a negative predictive value of 99%, and a likelihood ratio of 15. Serum troponin I levels higher than 3.9 microg/L 24 hours after CABG confirmed the perioperative MI with an area under the receiver operating curve of 0.86, a sensitivity of 80%, a specificity of 85%, a positive predictive value of 24%, a negative predictive value of 99%, and a likelihood ratio of 5. CONCLUSIONS: Serum troponin T levels higher than 3.4 microg/L 48 hours after CABG correlated best with the diagnosis of perioperative MI. Serum troponin T levels greater than 3.9 microg/L 24 hours after CABG also correlated with the diagnosis of perioperative MI, although a larger experience is needed to confirm the validity of the chosen cutoff value.

Ministernotomy for aortic valve replacement: a study of the preliminary experience.

OBJECTIVE: The aim of the study was to evaluate the technical feasibility and the postoperative course of aortic valve replacement through a ministernotomy. SETTING: The Montreal Heart Institute and the Hôpital Lariboisière, Paris, France. DESIGN: A case series from 2 institutions. PATIENTS: Fifty-one patients who underwent aortic valve replacement through a ministernotomy. The sternal incision was started at the level of the sternal notch extending down to the third or fourth intercostal space with a transverse section of the sternum at this level on both sides or limited to the right side (inverted T or L incision). Thirty-nine patients had aortic stenoses, 6 patients were operated for aortic insufficiency and 6 had mixed disease. The mean (and standard deviation) preoperative left ventricular ejection fraction was 0.56 (0.17). MAIN OUTCOME MEASURES: Cardiac bypass time, complications and outcome. RESULTS: The patients received Carbomedics and St. Jude mechanical valves, Hancock and Carpentier-Edwards bioprostheses. Thirty-eight patients were administered antegrade and retrograde cardioplegia, 10 patients antegrade and 3 retrograde blood cardioplegia only. The mean (and standard error) cardiopulmonary bypass time and aortic cross-clamp time were 104 (38) minutes and 72 (16) minutes respectively. Two patients (4%) died and 2 patients (4%) showed evidence of a stroke after the procedure. Hospital stay averaged 8 (5) days. CONCLUSION: We conclude that aortic valve replacement can be done through a ministernotomy approach with perioperative results similar to those obtained through a conventional sternotomy.

A 10-year experience with intravenous thymoglobuline in induction of immunosuppression following heart transplantation.

BACKGROUND: Intravenous thymoglobuline (125 mg a day for 3 days, Institut Mérieux, France) has been used to induce immunosuppression following heart transplantation. Cyclosporine and prednisone, with and without azathioprine or mycophenolate mofetil were used as maintenance immunosuppression. OBJECTIVE: The objective of the study was to determine the clinical effect of antibody induction of immunosuppression following heart transplantation. METHODS: A retrospective analysis of the clinical experience at the Montreal Heart Institute. From 1988 to 1998, 163 patients were administered a 3-day course of intravenous thymoglobuline immediately following heart transplantation (Group 1). From 1983 to 1987 and during an isolated period in 1994, intravenous and oral cyclosporine was used immediately following heart transplantation in 48 patients (Group 2). Routine endomyocardial biopsies were performed in all patients and only moderate and severe rejection was treated. RESULTS: One, 5- and 10-year actuarial survival rate averaged 85%+/-3, 77%+/-4 and 67%+/-5 in Group 1 compared with 88%+/-5, 81%+/-6 and 76%+/-6 in Group 2 (p = 0.5). At 1 year, the freedom rate from an episode of acute rejection averaged 43%+/-4 in Group 1 and 30%+/-7 in Group 2 (p = 0.03) and the freedom rate from an episode of infection averaged 44%+/-4 in Group 1 and 31%+/-7 in Group 2 (p = 0.2). At 1, 5 and 10 years, the freedom rate from graft coronary artery disease averaged 93%+/-2, 68%+/-5 and 50%+/-7 in Group 1 compared with 93%+/-4, 58%+/-8 and 30%+/-8 in Group 2 (p = 0.1) and the freedom rate from cancer averaged 98%+/-1, 91%+/-3 and 67%+/-8 in Group 1 compared with 100%, 95%+/-3 and 77%+/-8 in Group 2 (p = 0.2). There was no side-effect related to the systemic injection of thymoglobuline. CONCLUSION: In a cyclosporine based protocol of immunosuppression, induction with an initial 3-day course of intravenous thymoglobuline is associated with a lower rate of acute rejection. Moreover, the risk of infection and of developing cancer is not increased whereas there was a trend towards a lower incidence of coronary atherosclerosis 5 and 10 years after transplantation.

Antegrade/retrograde cardioplegia for valve replacement: a prospective study.

BACKGROUND: From 1994 to 1996, 75 patients undergoing valve replacement were randomized to antegrade (36 patients, group 1) or antegrade/retrograde (39 patients, group 2) administration of cold blood cardioplegia. METHODS: Groups were comparable for age, sex, valve disease, and ventricular dysfunction. The aortic valve was replaced in 27 patients from group 1 and 24 patients from group 2, the mitral valve in 8 and 15 patients, and 1 patient in group 1 underwent double valve replacement (p = not significant). RESULTS: Lengths of cardiopulmonary bypass and aortic cross-clamp averaged, respectively, 10 minutes (p = not significant) and 12 minutes (p = < 0.05) shorter in group 2. Total amount of cardioplegia solution infused averaged 1,279 +/- 406 mL and 1,341 +/- 379 mL (p = not significant), respectively, in groups 1 and 2, and the period of infusion averaged 44% and 72% (p = < 0.01) of the total period of aortic cross-clamping. No death occurred in group 1 compared to two in group 2 (p = not significant). The perioperative myocardial infarction and stroke rates were comparable in both groups. Peak enzyme release at 24 hours was similar both for creatine kinase-MB fraction (26 versus 37 IU/L) and for troponin T (2.1 versus 2.5 IU/L). CONCLUSIONS: Our study shows no significant advantage of the antegrade/retrograde administration of cardioplegia over the antegrade route in routine valvular replacement, other than a slightly shorter aortic cross-clamping time.

[Results of surgery after failed mitral percutaneous dilatation]. / Résultats de la chirurgie après échec de la dilatation mitrale percutanée.

OBJECTIVES: Percutaneous balloon mitral valve commissurotomy (BMC) is an alternative to surgical commissurotomy. Complications following BMC includes mitral regurgitation, iatrogenic atrial septal defect, residual mitral stenosis, and pericardial hemorrhage. This study analyzes the outcomes of surgery following failed BMC for mitral stenosis. METHODS: In a series of 298 patients treated with BMC, 53 patients (17.7%) had a complication that necessitated a surgical treatment. Twenty-eight patients needed an immediate surgery before the discharge (group I) and 25 patients were operated on an elective basis (group II). RESULTS: In group I, 27 patients have been operated and one died before the operation. In 21 patients an acute mitral regurgitation occurred, 3 patients had a residual mitral stenosis, and 3 had a left atrial perforation. The operation consisted of 26 mitral valve replacements, 20 concomitant reparations of iatrogenic atrial septal defect, and one open mitral valve commissurotomy. Operative mortality was 3.7% (1 out of 27). In group II, 25 patients have been operated at a mean 18 +/- 14 months after BMC. In the 25 patients the operation was indicated for significant mitral regurgitation (2 + and more). The operation consisted of 25 mitral valve replacements, 9 concomitant reparations of iatrogenic atrial septal defect, 3 patients had also coronary artery bypasses. The operative mortality was 8% (2 out of 25). The echocardiographic score was similar for both groups, it was 8.4 +/- 2.0 in group I and 8.0 +/- 1.5 in group II (P = NS). Despite these complications following failed BMC, surgery appears a safe procedure with an acceptable mortality.

Conversion of cyclosporine A to tacrolimus following heart transplantation.

BACKGROUND: Cyclosporine A (CyA) is ususally the immunosuppressive drug of choice in organ transplantation; however, some side effects have limited its use. Tacrolimus is a novel immunosuppressive drug that is more potent than CyA, and has been used as a rescue agent following heart transplantation when the use of CyA is undesirable or inefficient. PATIENTS AND METHODS: Since 1996, 14 heart transplant recipients under CyA were switched to tacrolimus therapy, for refractory rejection or intolerance, to conventional immunosuppression. RESULTS: After a mean of 35+/-7 months of treatment, tacrolimus was substituted for CyA therapy. The reason for substitution was refractory rejection in six patients, gingival hypertrophy in five patients, hypertrichosis in one patient, severe arterial hypertension in one patient and hepatotoxicity in one patient. Five patients underwent a successful rescue therapy and one patient died of refractory rejection despite the use of tacrolimus. All patients with CyA side effects recovered with tacrolimus. After conversion from CyA to tacrolimus, the number of episodes of acute rejection decreased from a mean of 0.42+/-0.17 to 0.14+/-0.09 episodes/patient/month under CyA and tacrolimus therapy (P=0.11), respectively. The mean dose of prednisone was 0.18+/-0.06 mg/kg/day before compared with 0.06+/-0.01 mg/kg/day after conversion from CyA to tacrolimus (P=0.09). Creatinine serum levels averaged 124+/-7 mmol/L under CyA treatment compared with 113+/-7 mmol/L with tacrolimus therapy (P=0.002). CONCLUSION: In patients with refractory rejections or intolerance to CyA after heart transplantation, conversion to tacrolimus-based immunosuppression is safe and effective.

Videoassisted thrombectomy of mechanical prosthetic heart valves.

BACKGROUND AND AIM OF THE STUDY: Thrombosis of a bileaflet mechanical heart valve is a life-threatening clinical event. Surgical thrombectomy of bileaflet mechanical prostheses remains an appropriate treatment in selected patients. METHODS: Between 1996 and 1998, five patients (three men, two women; average age 56 +/- 1 years; range: 56 to 66 years) with thrombosis of left-sided bileaflet mechanical valves were treated with videoassisted thrombectomy of the prosthesis. Four patients had thrombosis of a bileaflet mitral mechanical valve, and one patient had thrombosis of an aortic valve prosthesis. Preoperatively, patients were in either NYHA functional class IV (n = 4) or class I (n = 1). Surgery was performed through a right anterior thoracotomy or a median sternotomy. A rigid 30 degrees thoracoscope was inserted into the left atrium or aorta to visualize the thrombosed valve. The thrombus was extracted and the prosthesis under-surface examined and cleaned. Leaflet mobility, assessed with transesophageal echocardiography, was normal following surgical thrombectomy. RESULTS: Mean cardiopulmonary bypass time was 102 +/- 30 min; mean aortic cross-clamping time was 47 +/- 25 min. There was no hospital mortality; mean hospital stay was 9 +/- 1 days (range: 6 to 11 days). Anticoagulation with intravenous heparin was resumed 24 h after surgery. Three patients were discharged on coumarin treatment alone; two patients received aspirin plus coumarin. Mean postoperative follow up was 7 +/- 8 months (range: 1 to 21 months). One patient died 21 months after thrombectomy of a mitral prosthesis, with an unconfirmed diagnosis of recurrent mitral valve dysfunction. At 1-15 months after surgery, four patients are in NYHA class I, without evidence of prosthesis dysfunction. CONCLUSION: Videoassisted thrombectomy of a bileaflet mechanical heart valve is a treatment option in patients with acute thrombosis of the prosthesis.