Hypertensive heart disease: MR tissue phase mapping reveals altered left ventricular rotation and regional myocardial long-axis velocities.

OBJECTIVES: The aim of this study was the evaluation of left ventricular (LV) segmental 3D velocities in patients with hypertensive heart disease using magnetic resonance (MR) tissue phase mapping (TPM). METHODS: LV radial, long-axis and rotational myocardial velocities were assessed by TPM in patients with LV hypertrophy and preserved EF (n = 18, age = 53 ± 12 years) and volunteers (n = 20, age = 51 ± 4 years). Systolic and diastolic peak and time-to-peak velocities were mapped onto a 16-segment LV model. 3D myocardial motion was displayed on an extended visualisation model. Correlation coefficients were calculated to investigate differences in regional dynamics. RESULTS: Patients revealed diastolic dysfunction as expressed by decreased peak long-axis velocities in all (except apical) segments (basal, P ≤ 0.01; two midventricular segments, P = 0.02, P = 0.03). During systole, hypertrophy was associated with heterogeneous behaviour for long-axis velocities including an increase in anteroseptal apical and midventricular regions (P = 0.001), a reduction in mid-inferior segments (P = 0.03) and enhanced septal velocities (P < 0.05). Segmental correlation analysis revealed altered dynamics of LV base rotation and increased dyssynchrony of lateral long-axis motion. CONCLUSIONS: Patients with hypertensive heart disease demonstrated alterations in systolic long-axis motion, basal rotation and dyssynchrony. Longitudinal studies are needed to investigate the value of regional wall motion abnormalities regarding disease progression and outcome.

Magnetic resonance tissue phase mapping: analysis of age-related and pathologically altered left ventricular radial and long-axis dyssynchrony.

PURPOSE: To employ magnetic resonance tissue phase mapping (TPM) for the assessment of age-related left ventricular (LV) synchrony of radial and long-axis motion in healthy volunteers and in hypertensive heart disease, dilated cardiomyopathy (DCM), and left bundle branch block (LBBB). MATERIALS AND METHODS: TPM (spatial/temporal resolution = 1.3 × 2.6 mm(2)/13.8 msec) was employed to measure radial and long-axis myocardial velocities in 58 healthy volunteers of three age groups and 37 patients (hypertensive, n = 18; DCM, n = 12; DCM and LBBB n = 7). Regional times-to-peak velocities (TTP) in systole and diastole were derived for all LV segments. Four measures of dyssynchrony were defined as the standard deviation of systolic and diastolic TTP for radial and long-axis motion. RESULTS: Systolic radial and diastolic long-axis dyssynchrony was increased (P < 0.01) in all patient groups compared to controls. Multiple regressions revealed a significant relationship of dyssynchrony with LV ejection fraction and mass for systolic radial (P < 0.001 resp. P = 0.02), diastolic radial (P < 0.001 resp. P < 0.05), and long-axis (P < 0.001 resp. P = 0.001) motion. Diastolic dyssynchrony correlated with the LV remodeling index (P < 0.05) and increased with age (P < 0.03). Systolic long-axis dyssynchrony was not influenced by disease or LV function. CONCLUSION: Radial systolic and long-axis diastolic dyssynchrony were the most sensitive markers for altered dyssynchrony in hypertensive heart disease or DCM. Future studies are needed to evaluate the diagnostic value of TPM-derived dyssynchrony parameters.

Elderly valve replacement with bioprostheses and mechanical prostheses. Comparison by composites of complications.

AIM: The goal of aortic valve replacement (AVR) surgery in the elderly (= or >75 years) is to extend survival and minimize valve-related morbidity, mortality and reoperation. As the elderly population lives longer, those with implanted valves are at risk of suffering valve related complications. We hypothesize that bioprostheses are appropriate for the elderly. METHODS: The follow-up evaluation of 966 patients with valves (AVR, 666; mitral valve replacements [MVR], 226; multiple valve replacements [MR], 74) implanted between 1975 and 1999 was examined. There were 879 bioprotheses (BP) and 87 mechanical prostheses (MP). The mean age was 78.9+/-3.3 years (range 75-94.6 years). Concomitant coronary artery bypass was performed in AVR in 51.7%, MVR in 50.4% and MR in 28.4%. Valve type, valve lesion, coronary artery bypass (previous/concomitant), age and gender were considered as independent predictors of composites and survival. The total follow-up was 3905 patient-years. RESULTS: Early mortality was for AVR 9.6% (64), MVR 15.0% (34) and MR 25.7% (19). The late mortality was for AVR 8.8%, MVR 10.4% and MR 8.8%/patient-year. The only independent predictor of survival and valve-related mortality, morbidity and reoperation was age for survival in those with AVR, hazard ratio 1.15 [CL 1.03-1.27] p=0.0094). The BP reoperative rate was 0.5%/patient-year (reoperation was fatal in 6/15) of total, MP reoperative rate was 0% [reasons for reoperation structural valve deterioration (4), non-structural dysfunction (6), prosthetic valve endocarditis (5), reoperation fatality due to non-structural dysfunction (2), prosthetic valve endocarditis (4)]. Overall patient survival at 10 and 15 years, respectively, was 30.5+/-2.4% and 3.6+/-2.2% irrespective of valve position and type. Overall actual and actuarial freedom from valve-related morbidity at 15 years was 96.8+/-0.9% and 93.7+/-2.3%, respectively. Actual and actuarial overall freedom from valve-related mortality at 15 years was 84.3+/-2.4% and 58.4+/-0.9%, respectively. Overall actual and actuarial freedom from valve related reoperation at 15 years was 95.8+/-1.6% and 74.8+/-16.9%, respectively. CONCLUSIONS: BP valves are further confirmed to be a good option for AVR in patients = or >75 years of age.

Performance of bioprostheses and mechanical prostheses assessed by composites of valve-related complications to 15 years after mitral valve replacement.

OBJECTIVE: Predominant concerns of patients undergoing valve replacement surgery are risks of death, stroke, antithrombotic bleeding, and reoperation related to the replacement prosthesis. The purpose of this study was to compare valve-related reoperation, morbidity (permanent impairment), and mortality between bioprostheses and mechanical prostheses for mitral valve replacement. METHODS: Between 1982 and 1998, a total of 959 bioprostheses were implanted in 943 patients, and a total of 961 mechanical prostheses were implanted in 839 patients. Total follow-ups were 5730 years for bioprostheses and 5271 years for mechanical prostheses. Eight variables were considered as predictors of risk for the composites of valve-related complications. RESULTS: The linearized occurrence rates for valve-related reoperation were 3.7 events/100 patient-years for bioprostheses and 0.5 events/100 patient-years for mechanical prostheses ( P < .001), with all age groups differentiated except older than 70 years. Valve-related morbidity was undifferentiated for bioprostheses and mechanical prostheses. Valve-related mortalities were 1.7 events/100 patient-years for bioprostheses and 0.7 events/100 patient-years for mechanical prostheses ( P < .001). Predictors of valve-related reoperation were age and valve type. The only predictor of valve-related morbidity was age, whereas age and valve type were predictors for valve-related mortality. Actual freedom from valve-related reoperation favored mechanical prostheses in all age groups except older than 70 years (91.7% +/- 2.0% for bioprostheses at 15 years and 96.7% +/- 1.5% at 12 years for mechanical prostheses). Actual freedom from valve-related morbidity was not different between bioprostheses and mechanical prostheses. Actual freedom from valve-related mortality favored mechanical prostheses in all groups except older than 70 years. CONCLUSION: Comparative evaluation gives high priority in mitral valve replacement for mechanical prostheses relative to bioprostheses for freedom from valve-related reoperation and valve-related mortality but not valve-related morbidity. Freedom from valve-related reoperation and valve-related mortality favors mechanical prostheses for all age groups except older than 70 years. Valve-related morbidity, due to neurologic or functional impairments, does not differentiate between bioprostheses and mechanical prostheses.

Tricuspid valve replacement: porcine bioprostheses and mechanical prostheses.

The clinical performance of tricuspid valve replacement with bioprostheses and mechanical prostheses was assessed in a series of 5,489 total valve replacement operations performed from 1975 to 1992. There were 97 (1.8%) tricuspid valve replacements in 94 patients (16 men, 78 women) with a mean age of 55.4 +/- 13.8 years. Bioprostheses (mean patient age, 55.9 +/- 14.1 years) were used in 83 operations and mechanical prostheses (mean patient age, 52.1 +/- 11.9 years) were used in 14 operations. There were 30 isolated tricuspid valve replacements and 67 tricuspid valve replacements incorporated in multiple valve replacements. The total cumulative follow-up was 360 patient-years (bioprostheses, 321 years; mechanical prostheses, 39 years) (96.8% complete). The mean follow-up was 3.7 years (bioprostheses, 3.9 years; mechanical prostheses, 2.8 years) (p = not significant). The early mortality was 14.4% (bioprostheses, 14.5%; mechanical prostheses, 14.3%) (p = not significant) (isolated replacement, 13.3%; multiple replacement, 14.9%). The late mortality was 9.2% per patient-year (isolated replacement, 12.2% per patient-year; multiple replacement, 7.9% per patient-year). The freedom from structural valve deterioration at 5 and 7 years was 100% for mechanical prostheses and 97.1% +/- 2.9% for bioprostheses (p = not significant). For isolated tricuspid valve replacement, the freedom from structural valve deterioration for bioprostheses was 90.9% +/- 8.7% at 5 years and at 7 years (p = not significant). For the mechanical prostheses, the freedom was 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

Porcine bioprostheses in the elderly: clinical performance by age groups and valve positions.

Porcine bioprostheses have been recommended and used for cardiac valve replacement in the elderly. A review of 1,984 patients with 2,042 operations, performed between 1975 and 1992, has afforded a detailed evaluation of clinical performance by valve positions and age groups within the elderly population. The numbers of operations performed by age groups were 65 to 69 years, 719; 70 to 74 years, 745; 75 to 79 years, 431; 80 to 84 years, 119; and 85 years or older, 28. The early mortality rate overall was 9.5% (195 patients), range 6.9% to 17.8% by age groups (p < 0.05), and 11.9% with concomitant procedures and 7.6% without (p < 0.05). The total cumulative follow-up was 10,060 patient-years (mean, 4.9 years). The late mortality rate was 7.0%/patient-year (for age groups, 5.8% to 13.4%/patient-year) (p = not significant). The patient survival at 15 years ranged from 25% +/- 4% for 65 to 69 years to 9% +/- 5% for 75 to 79 years (p < 0.05). The freedom from valve-related complications and composites at 10 years revealed differences (p < 0.05) by age groups only for structural valve deterioration: 85% +/- 2% for 65 to 69 years versus 98% +/- 2% for 80 to 84 years. The overall freedom from structural valve deterioration at 10 years for aortic valve replacement was 98% +/- 1%; for mitral valve replacement, 79% +/- 3%; and for multiple replacement, 86% +/- 7% (p < 0.05, aortic valve replacement > mitral valve replacement).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of porcine bioprostheses and mechanical prostheses in multiple valve replacement operations.

The performance of porcine bioprostheses and mechanical prostheses in multiple valve replacement operations was evaluated in 494 patients with 553 operations between 1975 and 1992. Porcine bioprostheses were implanted in 351 multiple replacement operations and 202 operations were performed with mechanical prostheses. The mean age of the bioprosthesis group was 59.1 +/- 14.4 years and of the mechanical prostheses group, 55.9 +/- 13.3 years. Concomitant procedures, primarily coronary artery bypass grafting, were performed in 27.4% (96 patients) of the bioprosthesis group and 20.8% (42 patients) of the mechanical prosthesis group (p = not significant [NS]). The early mortality for the bioprosthesis group (BP) was 12.0% (42 patients), whereas for the mechanical prosthesis (MP) group it was 10.9% (22 patients) with no difference (p = NS) for the performance with or without concomitant procedures, primarily coronary artery bypass grafting. The total cumulative follow-up was 1,914 years for BP and 458 years for MP group. The late mortality was different between the groups (p < 0.05), 6.1%/patient-year for BP and 3.7%/patient-year for MP. The difference in late mortality was not different (p = NS) for performance of concomitant procedures and not different (p = NS) for the absence of concomitant procedures, 5.6%/patient-year for BP and 2.2%/patient-year for MP. The freedom from thromboembolism- and antithromboembolic-related hemorrhage favored the biological population (p < 0.05) at 10 years with 79.7% +/- 3.4% for BP and 75.4% +/- 5.0% for MP. The freedom from structural valve deterioration was 100% for MP, whereas for the BP group, 94.7% +/- 1.6% at 5 years and 65.9% +/- 4.3% at 10 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Mitroflow pericardial bioprosthesis experience in aortic valve replacement > or =60 years of age.

BACKGROUND: The Mitroflow pericardial bioprosthesis (model 11), a second-generation pericardial prosthesis, has clinical performance assessment to 10 years. The authors previously recommended the prosthesis for aortic valve replacement in patients 70 years or older. The purpose of the current assessment is to report on performance in patients 60 years or older undergoing aortic valve replacement. METHODS: This bioprosthesis was implanted in 161 patients (mean age, 69.5+/-6.3 years; range, 60 to 94 years) with aortic valve replacement from 1982 to 1992. There were 84 patients 60 to 69 years (mean, 64.5+/-3.1 years) and 77 patients 70 years or older (mean, 74.8+/-4.3 years). Of the total population, concomitant procedures were performed in 63 patients (39.1%); of these, coronary artery bypass grafting was performed in 39 (24.2%). RESULTS: The early mortality was 4.8% (4 patients) for the 60 to 69-year age group and 10.4% (8) for those 70 years or older (not significant). The late mortality was 4.4%/patient-year (27) for those 60 to 69 years and 6.9%/ patient-year (35) for those 70 years or older (not significant). The patient survival for those 60 to 69 years was 58.0%+/-6.3% and for those 70 years or older, 45.3%+/-5.9% at 10 years (p < 0.05). The valve-related mortality for those 60 to 69 years was 0.82%/patient-year (5) and for those 70 years or older, 1.58%/patient-year (8) (not significant). The reoperation rate for those 60 to 69 years was 3.29%/patient-year (20) and for those 70 years or older, 1.0%/patient-year (5) (p < 0.05). The structural valve deterioration rate for those 60 to 69 years was 3.13%/ patient-year (19) and for those 70 years or older, 1.2%/ patient-year (6) (p < 0.05). CONCLUSIONS: The Mitroflow pericardial bioprosthesis remains recommended for aortic valve replacement in patients 70 years and older.

Carpentier-Edwards supraannular porcine bioprosthesis: second-generation prosthesis in aortic valve replacement.

BACKGROUND: The Carpentier-Edwards supraannular porcine bioprosthesis experience for more than 18 years has been evaluated by actuarial and actual analysis to determine the clinical performance in aortic valve replacement. METHODS: From 1981 to 1998, 1,823 patients (mean age 68.5 years, range 20 to 90 years) underwent 1,846 procedures. Previous coronary artery bypass was performed in 3.1% (56) and previous valve repair/replacement in 6.0% (110). Concomitant coronary artery bypass grafting was performed in 41.5% (756). RESULTS: The overall valve-related complication rate was 4.5%/patient-year (567 patients) with a fatality rate of 0.9%/patient-year (110 patients). The patient survival, at 15 years, was 33.0%+/-3.7% for the 61 to 70 years age group and 13.5%+/-2.4% for the older than 70 years group. At 15 years, the overall actual, cumulative freedom from reoperation was 83.2%+/-1.4%, valve-related mortality was 88.0%+/-1.2%, and valve-related residual morbidity was 92.0%+/-0.8%. The actual freedom from structural valve deterioration at 15 years was 84.2%+/-2.8% for the 61 to 70 years group and 97.1%+/-0.9% for the older than 70 years group. CONCLUSIONS: The Carpentier-Edwards porcine bioprosthesis provides excellent freedom from structural valve deterioration, and overall freedom from valve-related morbidity, mortality, and reoperation for aortic valve replacement for up to 15 years. The prosthesis is recommended for patients older than 70 years and for patients 61 to 70 years, especially when extended survival is not anticipated.

Reoperation in biological and mechanical valve populations: fate of the reoperative patient.

From 1975 through 1992 inclusive, reoperative valve replacement (REOP) was required by 12.9% of patients (708/5,499). Of 1,355 patients with mechanical prostheses (MP), 46 (3.4%) came to REOP versus 662 of 4,144 patients (16%) with biological prostheses (BP). Early REOP mortality rate was 17.4% (8/46) for MP and 10.6% (70/662) for BP (p = not significant). It was higher with age greater than 75 years (p < 0.05) and trended higher with concomitant procedures and with increasing number of REOPs (p = not significant). The percentage freedom from REOP at 5 and 10 years for all BP was 96.0% +/- 0.4% and 74.9% +/- 1.1% compared with 93.6% +/- 1.2% and 87.9% +/- 2.5% for MP. The most common cause of REOP in the BP patients was structural valve deterioration, which was uncommon in patients with MP (72% versus 2% of REOP but only 15% versus 0.1% of initial implants). Nonstructural dysfunction was the leading cause of REOP in the MP group (65% versus 11%). Prosthetic valve endocarditis (18% versus 10%) and thromboembolic complications (10% versus 1%) were also more frequent causes of REOP in MP patients. However, the increased relative role of these factors with MP is due to the minimal incidence of structural valve deterioration. When related to the original choice of MP versus BP, only thromboembolic complication (3.8 times) was more prevalent as a cause of REOP in patients receiving MP at their previous procedure (p = not significant). For patients who previously received BP, structural valve deterioration (69 times) was more likely to lead to REOP than with MP (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Management of simple depressed skull fractures in children.

Surgical elevation is the treatment usually recommended for a simple depressed skull fracture if the depression is more than the full thickness of the adjacent skull, but there is no clinical evidence to support this management. On that basis, a progressively more conservative approach to the treatment of this condition was adopted, especially in young children. Experience with this mode of management over the period 1972 to 1984 is presented. Of 111 patients under 16 years of age with depressed skull fractures, 64 had simple and 47 compound fractures. Simple depressed skull fractures occurred in a younger age group after less significant trauma than compound fractures. In those patients who were treated surgically, there was an 11% incidence of dural laceration in patients with simple depressed fractures versus 67% for the patients with compound depressed fractures. There was no difference in outcome between surgically and nonsurgically treated patients with simple depressed fractures with respect to the occurrence of seizures, neurological dysfunction, or cosmetic appearance. Surgical treatment prolonged hospitalization, and the only case with a fatal outcome was found in the group of patients treated surgically. It is suggested that the standard treatment of simple depressed skull fractures in the pediatric age group should not include surgery. Surgery is indicated when there is definite evidence of dural penetration and in the older child with an unacceptable cosmetic appearance.

Surgical management of acute sigmoid diverticulitis.

PURPOSE: To determine the frequency of use of resection and primary anastomosis in the management of acute sigmoid diverticulitis at Royal Columbian Hospital. METHODS: A retrospective chart review of all patients undergoing emergency surgery for acute sigmoid diverticulitis between 1989 and 2000 at the Royal Columbian Hospital, New Westminster, BC, was carried out in order to determine the frequency of resection and primary anastomosis. Patients who underwent bowel preparation were excluded. RESULTS: Ninety-seven cases met the criteria. There were 33 cases of resection and primary anastomosis (34%). Five of these cases were protected with a proximal diverting stoma giving an incidence of 85% unprotected primary anastomosis in a group of patients undergoing emergency surgery for acute sigmoid diverticulitis. There was 1 anastomotic leak, 7 wound infections, and 3 deaths with an average length of stay of 9 days. CONCLUSIONS: The practice of resection and primary anastomosis for acute sigmoid diverticulitis at the Royal Columbian Hospital has an acceptable morbidity and mortality.

An evaluation of prognostic scoring systems in patients with follicular thyroid cancer.

BACKGROUND: Prognostic scoring systems for thyroid cancer have not been investigated in patients with pure follicular cancer; thus, the purpose of this study was to compare the following prognostic indices: the European Organization for Research and Treatment of Cancer (EORTC) method; the Age, Grade, Extent, Size (AGES) score; and the Age, Metastasis, Extent, Size (ALIES) score. PATIENTS AND METHODS: A retrospective study reviewing 122 patients actively treated between 1955 and 1990 was conducted. Scoring systems were calculated and survival analysis completed. AGES low-risk patients were analyzed with respect to known risk factors. RESULTS: The AGES scoring system significantly defined low- and high-risk groups (P = 0.0041); the ratio of deaths between high-versus low-risk groups was 1.9:1. EORTC scores distinguished four risk groups (P = 0.002). The AMES scoring system did not significantly assign risk. In multivariate analysis of low-risk AGES patients, age, perithyroidal tissue involvement, and positive frozen section reached statistical significance. CONCLUSIONS: The AGES and EORTC scoring systems best defined low- and high-risk groups of patients with pure follicular cancer, although the separation between groups was low.

Clinical parameters predictive of malignancy of thyroid follicular neoplasms.

Needle aspiration biopsy is commonly employed in the evaluation of thyroid nodules. Unfortunately, the cytologic finding of a "follicular neoplasm" does not distinguish between a thyroid adenoma and a follicular cancer. The purpose of this study was to identify clinical parameters that characterize patients with an increased risk of having a thyroid follicular cancer who preoperatively have a "follicular neoplasm" identified by needle aspiration biopsy. A total of 395 patients initially treated at Vancouver General Hospital and the British Columbia Cancer Agency between the years of 1965 and 1985 were identified and their data were entered into a computer database. Patients with thyroid adenomas were compared to patients with follicular cancer using the chi-square test and Student's t-test. Statistically significant parameters that distinguished patients at risk of having a thyroid cancer (p less than 0.05) included age greater than 50 years, nodule size greater than 3 cm, and a history of neck irradiation. Sex, family history of goiter or neoplasm, alcohol and tobacco use, and use of exogenous estrogen were not significant parameters. Patients can be identified preoperatively to be at an increased risk of having a follicular cancer and accordingly appropriate surgical resection can be planned.

Mechanical preparation of the large bowel for elective surgery. Comparison of whole-gut lavage with the conventional enema and purgative technique.

In this prospective, randomized study, 121 elective colorectal surgery patients had whole-gut lavage (n = 67) or enemas and purgatives (n = 54). Patient characteristics were well matched. Intravenous metronidazole and tobramycin were administered preoperatively initially in 53 patients, with the remaining 68 patients receiving the drugs perioperatively. Bowel preparation was satisfactory (minimal or no contents remaining) in 92.8 percent of patients with whole-gut lavage and 92.6 percent with enemas and purgatives (p = 0.72). Nasogastric tube insertion was poorly tolerated by 39 percent of the patients receiving whole-gut lavage, and enema tube insertion by 23 percent with enemas and purgatives. Fluid infusion tolerance was similar with both techniques. Abdominal wound sepsis occurred in 22 patients (18.8 percent), being unrelated to mechanical preparation or antimicrobial prophylaxis (p = 0.19). Colostomy closure was associated with a 42.8 percent sepsis rate. Excluding this group, wound sepsis with the remaining procedures was 13 percent (statistically significant, p = 0.03). Other complications included intraabdominal abscesses (3.3 percent), anastomotic leaks (2.5 percent), eviscerations (1.6 percent), and an operative mortality of 1.6 percent. We have concluded that whole-gut lavage and enemas and purgatives are equally efficacious mechanically with similar associated wound sepsis rates.

Efficacy of 131I ablation following thyroidectomy in patients with invasive follicular thyroid cancer.

The role of thyroid ablation following thyroidectomy for invasive follicular cancer remains controversial. The use of iodine 131 (131I) ablation as adjuvant therapy may facilitate follow-up of patients in whom serum thyroglobulin levels and 131I total body scans are used to detect metastatic disease. It is uncertain if 131I ablation improves survival of patients with follicular thyroid cancer. Thus, the purpose of this study was to determine if survival is enhanced following ablation, with particular reference to those patients with minimally invasive cancer. Between the years 1955 to 1988, 142 patients with invasive thyroid follicular cancer were treated at the British Columbia Cancer Agency, of whom 71 had minimal invasion and no extrathyroidal extension of tumor. In this group of patients, 46 underwent hormone suppression only, 17 had ablation, and 8 had neither. The average follow-up was 9 years and extended beyond 15 years in many patients. Data were entered in a mainframe computer, and Kaplan-Meier survival analysis was used, comparing crude survival, disease-specific survival, and disease-free survival. There was no significant difference between groups. In patients with follicular thyroid cancer and capsular invasion only, 131I ablation does not improve survival compared with patients treated with thyroid hormone suppression only.

CarboMedics mechanical prosthesis: performance at eight years.

BACKGROUND AND AIM OF THE STUDY: The bileaflet St. Jude Medical mechanical prosthesis has been implanted for over 20 years. The purpose of this study was to evaluate the clinical performance of the bileaflet CarboMedics (CM) prosthesis, which was introduced in 1986. METHODS: The CM prosthesis was implanted in 1,258 patients (709 males, 549 females; mean age 60.9 +/- 12.3 years) between 1989 and 1997. The prosthesis distribution was aortic valve replacement (AVR) 613; mitral valve replacement (MVR) 447; and multiple replacement (MR) 231. Coronary artery bypass (CAB) was performed in 334 (26.6%) patients; previous procedures had been performed in 346 (27.5%). The age distribution was <60 years (n = 527), 61-70 years (n = 424) and >70 years (n = 307). Risk factors assessed were age or age groups, gender, CAB, previous surgery, rhythm, valve position, status and NYHA functional class. The total follow up was 4,765.0 patient-years (pt-yr), and was 98.4% complete. RESULTS: The early mortality rate was 5.6% (AVR 4.8%, MVR 3.7%, MR 11.5%). The late mortality rate was 3.7%/pt-yr (n = 174), and valve-related mortality 1.1%/pt-yr (n = 50). The total thromboembolism (TE) rate was 4.1%/pt-yr (n = 195) (p = NS by valve position); the major TE rate was 1.9%/pt-yr and fatal TE rate 0.31%/pt-yr (n = 15). The valve thrombosis rate was 0.31%/pt-yr (n = 15; 11 MVR, four MR). The fatal thrombosis rate was 0.06%/pt-yr (n = 3; two MVR, one MR). The hemorrhage rate was 2.7%/pt-yr (n = 128) and fatal hemorrhage rate 0.4%/pt-yr (n = 20). The reoperation rate was 1.0%/pt-yr (n = 46), fatal 0.1%/pt-yr (n = 5). The actuarial freedom from overall TE at eight years was 77.3 +/- 2.8%; major TE 88.5 +/- 1.6%, and hemorrhage 76.4 +/- 3.2% (all p = NS by valve position). There were no independent predictors of overall TE and TE exclusion of early events. The only predictor for TE major was status (emergency > urgent > elective). The actuarial freedom from valve-related mortality at eight years was 91.4 +/- 1.8% (p = NS by position) (actual freedom 93.0 +/- 1.3%). The actuarial freedom from valve-related reoperation was 91.1 +/- 2.4% (p <0.05; AVR > MVR and MR, MVR > MR) (actual freedom 92.2 +/- 2.7%). Overall survival rate at eight years was 68.2 +/- 2.3% (p <0.05; AVR > MVR and MR, MVR > MR). CONCLUSION: The clinical performance of the CarboMedics mechanical prosthesis is satisfactory when implanted in the mitral, aortic and multiple positions.

Bileaflet mechanical prostheses performance in mitral position.

OBJECTIVE: The experience with the Carbomedics (CM) and the St. Jude Medical (SJM) bileaflet mechanical prostheses was evaluated to determine thromboembolic and hemorrhagic complications and predictive risk factors. METHODS: From 1989 to 1994, a total of 625 patients had mitral valve replacement (CM, 240; SJM, 385); 32.5% (203), concomitant procedures and 32.8% (205), previous cardiac surgery, primarily valve replacement procedures. RESULTS: The pre-operative variables did not distinguish the populations, except for previous surgery CM 37.9% and SJM 29.6% (P < 0.05). The pre-operative variables (type of prostheses, cardiac rhythm, coronary artery bypass, NYHA III/IV, advancing age, gender, urgency status and previous surgery) were not predictive of overall thromboembolism (TE), major TE, minor TE, prosthesis thrombosis and hemorrhage (P not significant; P = NS). The linearized rate of total TE events for overall MVR was 5.0%/patient-year (CM 4.4; SJM 5.4). The < or = 30 day major crude rate was 0.44%, while the > 30 day late major event rate was 2.0%/patient-year. Of the total TE events 91% of < or = 30 days and 75%, > 30 days had an INR < 2.5 at or immediately prior to the event. The thrombosis rate (included in TE events) was 0.63%/patient-year (ten events, four managed successfully with thrombolysis, five successfully with reoperation, and one fatality identified at autopsy). The freedom, at 5 years, from major/fatal TE, thrombosis and hemorrhage from anticoagulation was 88.2%, and 89.5% exclusive of early events. CONCLUSIONS: This non-randomized prospective observational evaluation of the CarboMedics and St. Jude Medical prostheses has not revealed any differentiation in performance of the prostheses. The study serves as a single institution experience with the potential for future comparative evaluation.

Actuarial versus actual freedom from structural valve deterioration with the Carpentier-Edwards porcine bioprostheses.

BACKGROUND: The clinical performance of porcine bioprostheses for valve replacement surgery has been evaluated for over three decades by actuarial analysis as the standard for reporting time-related results. The incidence of structural valve deterioration (SVD) is used for the selection of prostheses for various subsets of patients. Actual or cumulative incidence analysis may provide a superior method to determine durability of bioprostheses. OBJECTIVE: To compare actuarial versus actual methodology in determining the durability of porcine bioprostheses for aortic (AVR) and mitral valve replacement (MVR). PATIENTS AND METHODS: Carpentier-Edwards porcine bioprostheses were implanted between 1975 and 1995 in 2237 AVR and 1582 MVR. The mean age for AVR patients was 65.4+/-12 years and for MVR patients 61.7+/-12 years. The cumulative follow-up for AVR was 14,810 years (mean 6.6+/-4.7) and for MVR 9718 years (mean 6. 1+/-4.5). RESULTS: For AVR the actual freedom from SVD was 87.4+/-2. 0% and 95.6+/-1.8% in those aged 61 to 70 years and more than 70 years, respectively; the actuarial freedom was 75.9+/-4.2% and 82. 3+/-7.9%, respectively. For MVR the actual freedom from SVD was 69. 4+/-2.5% and 92.9+/-1.9% for those aged 61 to 70 years and more than 70 years, respectively; the actuarial freedom was 25.5+/-5.7% and 79. 5+/-6.0%, respectively. Predictors of freedom from SVD for AVR were identified as advancing age, falling into the age groups 61 to 70 and those older than 70 years, and intermediate valve sizes; predictors for MVR were advancing age and age older than 70 years. CONCLUSIONS: Comparison of methods of durability assessment revealed that actual freedom from SVD supports porcine bioprostheses for AVR in patients more than 60 years of age and for MVR in patients more than 70 years of age. This evaluation with experience to 15 years supports the indications for use of porcine bioprostheses.

Comparison of new iron chelating agents in the prevention of ischemia/reperfusion injury: a swine model of heart-lung transplantation.

The preservation of the heart and lung for transplantation remains a major concern in extended ischemic intervals. This experimental endeavor evaluates and compares the efficacy of iron chelating agents such as high molecular weight deferoxamine and 21-aminosteroid (U74006F) in a swine model of heart-lung transplantation. Heat-lung blocks were exposed to 4 h and 45 min of ischemia and 2 h of reperfusion. Animals were divided into three groups. Group A was a control without pharmacological intervention. In groups B and C, 21-aminosteroid (U74006F), 10 mg/kg, and high molecular weight deferoxamine, 50 mg/kg, were used, respectively. The results of functional parameters (cardiac index, stroke index, lung water, PO2, PCO2, alveolar-arterial gradient, and alveolar-arterial ratio) demonstrated superior heart and lung function for group C, where high molecular weight deferoxamine was used. Alterations of heart and lung function were significantly more (p less than .001) for control animals and for group B where U74006F was used. This study suggests that formation of hydroxyl radicals was affected by chelation of iron with high molecular weight deferoxamine, which reflects better heart and lung function and consequently less damage to this group of animals. The compound 21-aminosteroid U74006F failed to protect the heart and lung from ischemic-reperfusion injury in this model of heart-lung transplantation.