Biomedical subjects

W R Jamieson

Publications and source records attributed to W R Jamieson.

At least 19 recordsLinked to original sources

PubMed1995

Influence of coronary artery bypass and age on clinical performance after aortic and mitral valve replacement with biological and mechanical prostheses.

The influence of prosthetic type, age, and coronary artery bypass grafting (CABG) on valve-related complications by valve position was evaluated in a population of 2353 bioprosthesis patients (mean age, 66.5 years; range, 13 to 89 years) and in a population of 1112 mechanical prosthesis patients (mean age, 59.1 years; range, 13 to 91 years). The follow-up was complete to 96% and 98%, respectively, for the bioprosthesis and mechanical prosthesis groups. The patient groups were evaluated by actuarial assessment of survival and valve complications and composites. Preoperative factors were evaluated for determination of significant independent predictors by multivariate proportional-hazard regression analysis. CABG was an influential factor in the actuarial analysis. Survival was superior for aortic mechanical replacements without CABG and for mitral replacements, both biological and mechanical, without CABG (P < .05). The freedom from thromboembolism (TE) and antithromboembolic hemorrhage (ATH) was greater for biological prostheses with and without CABG for aortic replacements (P < .05) but not for mitral replacements (P = NS). The freedom from valve-related mortality was not influenced by CABG for either position (P = NS). The freedom from valve-related reoperation was greater for biological prostheses with CABG than without CABG for both aortic and mitral replacements (P < .05). The evaluation of covariates as independent predictors revealed CABG to be a nonpredictor for aortic valve replacement (AVR) (P = NS) but a predictor of survival and valve-related reoperation for mitral valve replacement (MVR) (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Unilateral versus bilateral internal mammary revascularization. Survival and event-free performance.

BACKGROUND: The influence of unilateral (UL) and bilateral (BL) mammary artery revascularization, within age groups < or = 60 years and > 60 years, on patient survival, ischemic-related events, and interventional management was studied in 1142 patients who had coronary artery bypass graft surgery between 1984 and 1992. METHODS AND RESULTS: UL revascularization was performed in 765 (67%) and BL in 377 (33%) patients with supplemental vein grafts. The overall early and hospital mortality rate was 2.7%. For UL in the age group < or = 60 years, it was 1.1%; for BL < or = 60 years, 1.3% (P = NS); for UL > 60 years, 4.3%; and for BL > 60 years, 2.8% (P = NS). Twenty-five preoperative patient characteristics representing demographics, extent of disease, concomitant disease, ventricular dysfunction, previous surgery, and status did not differentiate the patient groups (P = NS). Patient survival at 5 years was not different: 94% for UL < or = 60 years, 95% for BL < or = 60 years, 91% for UL > 60 years, and 86% for BL > 60 years (P = NS). The freedom from ischemic-related events was not different at 5 years (P = NS). The freedom from recurrent angina was 78% for UL < or = 60 years, 88% for BL < or = 60 years, 82% for UL > 60 years, and 83% for BL > 60 years (P = NS). The myocardial infarction freedom was 98% for UL < or = 60 years, 96% for BL < or = 60 years, 99% for UL > 60 years, and 97% for BL > 60 years (P = NS). The freedom from sudden unexpected death and cardiac death did not differentiate the groups (P = NS). The freedom from angioplasty and reoperation did not differentiate the groups (P = NS). The freedom from all ischemic-related and interventional events was 76% for UL < or = 60 years, 84% for BL < or = 60 years, 81% for UL > 60 years, and 79% for BL > 60 years (P = NS). A trend exists for less angina pectoris in the bilateral population < or = 60 years, which reflects in the trend in the freedom from overall events. CONCLUSIONS: UL and BL mammary artery revascularizations have the same early mortality regardless of age but do not reveal any advantage for BL revascularization at 5 to 7 years.

Female↗

PubMed1995

Medtronic Intact porcine bioprosthesis: clinical performance to seven years.

The clinical performance of the Medtronic Intact porcine bioprosthesis was evaluated in 1,084 patients (mean age 66.4 years, range 9 to 91 years) who had a total of 1,099 implantations between 1985 and 1992, inclusive. There were 709 aortic valve replacements, 297 mitral valve replacements, and 80 multiple valve replacements. Concomitant procedures were performed in 432 (39.3%). The age group distribution (years) was 35 or younger in 20 patients, 36 to 50 in 64, 51 to 64 in 274, 65 to 69 in 225, 70 or older in 500. The total follow-up time was 2,741 patient-years (mean, 2.5 years) and was 97.5% complete. The early mortality rate was 7.1% and late mortality was 3.9% per patient-year. The overall patient survival at 7 years was 70% +/- 3%. The freedom from major thromboembolism was 94% +/- 1% at 7 years (p = not significant for valve positions). The freedom from reoperation at 7 years was 93% +/- 1%; freedom from valve-related mortality was 89% +/- 2%. The freedom from structural valve deterioration at 7 years was 97% +/- 1% (aortic valve replacement 97% +/- 1%; mitral valve replacement 97% +/- 2%). The freedom from structural valve deterioration among age groups was not different for the overall population, aortic valve replacement, or mitral valve replacement. Hemodynamic assessment revealed obstructive properties for aortic valve replacement sizes of 21 and 23 mm and for mitral valve replacement sizes of 25 and 27 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

PubMed1995

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)

Actuarial Analysis↗

PubMed1995

Structural deterioration in Carpentier-Edwards standard and supraannular porcine bioprostheses.

The Carpentier-Edwards standard (CE-S) porcine bioprosthesis was implanted in 1214 operations (1975 to 1985) and the Carpentier-Edwards supraannular (CE-SAV) bioprosthesis was implanted in 2,489 operations (1982 to 1992 inclusive). The early mortality was 7.6% and 7.4% for the CE-S and CE-SAV groups, respectively; the late mortality was 5.3% per patient-year and 4.9% per patient-year, respectively. The cumulative follow-up was 9,968 patient-years for the CE-S group and 12,784 patient-years for the CE-SAV group. Concomitant procedures were performed in 26.8% of the patients who received a CE-S and in 40.9% of those who received a CE-SAV (p < 0.05). The mean age of the patients receiving a CE-S was 57.3 years (range, 8 to 85 years) and was 64.1 years (range, 6 to 89 years) in those receiving a CE-SAV. The CE-S group consisted of 578 atrial valve replacements (AVRs), 512 mitral valve replacements (MVRs), and 115 multiple valve replacements (MRs). The CE-SAV group consisted of 1,335 AVRs, 938 MVRs, and 200 MRs. There was a total of 165 cases of structural valve deterioration (SDV) in the CE-SAV group (AVR, 35; MVR, 98; and MR, 32). The effect of trimming the aortic wall was also considered: 20 of the 931 trimmed prostheses used for MVRs and MRs and none of the 207 reduced-trimmed prostheses exhibited SVD. The cumulative follow-up was 5,422 years for the patients with trimmed prostheses and 470 for those with reduced-trimmed prostheses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

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)

Actuarial Analysis↗

PubMed1995

Carpentier-Edwards supraannular porcine bioprosthesis: clinical performance to twelve years.

The Carpentier-Edwards supraannular porcine bioprosthesis, a second-generation biologic prosthesis, has had clinical performance assessment to 12 years. This bioprosthesis was used in 2,489 operations in 2,444 patients between 1982 and 1992, inclusive (mean age 64.1 years, age range 6 to 89 years). There were 1,335 aortic valve replacements (AVR), 938 mitral valve replacements (MVR), and 200 multiple valve replacements (MR). Concomitant procedures were performed in 1,017 cases (40.9%). The age group distribution was: 35 years or younger, 83 patients; 36 to 50 years, 245; 51 to 64 years, 728; 65 to 69 years, 458; and 70 years and older, 975. The total follow-up was 12,785 patient-years (mean, 5.1 years) and was 96% complete. The early mortality rate was 7.4% (185 patients), and the late mortality was 4.9%/patient year (623). Concomitant procedures influenced both early and late mortality (p < 0.05). The overall patient survival at 12 years was 44% +/- 3% (p < 0.05, AVR > MVR, MR). The freedom from thromboembolism was not different by valve position. The freedom from major thromboembolism at 12 years was 82% +/- 4% (p = not significant by valve position). The overall freedom from antithromboembolic hemorrhage was 96% +/- 1% at 12 years (p < 0.05, AVR > MVR > MR). The overall freedom from valve-related reoperation at 12 years was 58% +/- 5% (p < 0.05, AVR > MVR, MR), and from valve-related mortality 89% +/- 2% (p < 0.05, AVR > MVR > MR). The freedom from residual morbidity (permanent impairment) at 12 years was 87% +/- 4% (p = not significant by valve position).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

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)

Actuarial Analysis↗

PubMed1995

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)

Adolescent↗

PubMed1995

Clinical performance of biological and mechanical prostheses.

Prosthetic valve replacement remains the most viable alternative for the treatment of severely diseased heart valves. The cumulative experience of mechanical protheses and bioprostheses was evaluated for a 10-year performance comparison: Carpentier-Edwards standard porcine bioprosthesis (CE-S), 1,214 operations; Carpentier-Edwards supraannular porcine bioprosthesis (CE-SAV), 2,489; and mechanical prostheses, 1,364 operations (St. Jude Medical, Carbomedics, Duromedics, and Björk-Shiley Monostrut). The freedom from thromboembolism and hemorrhage at 10 years was 82% for CE-S, 78% for CE-SAV, and 65% for mechanical prostheses (p < 0.05). The relationship existed for major thromboembolism and hemorrhage, 91% (CE-S), 87% (CE-SAV), and 88% (mechanical) (p < 0.05), without clinical relevance. The freedom from structural valve deterioration and valve-related reoperation favored mechanical prostheses (p < 0.05) at 10 years (structural failure: 78% for CE-S, 81% for CE-SAV, and 99% for the mechanical group; reoperation: 74% for CE-S, 76% for CE-SAV, and 88% for mechanical prostheses). The freedom from fatal reoperation was not clinically different: 96% for CE-S, 99% for CE-SAV, and 99% for mechanical prostheses (p < 0.05) at 10 years. The freedom from valve-related mortality was not different (p = not significant) at 10 years: 87% for CE-S; 92% for CE-SAV; and 91% for mechanical. The freedom from permanent impairment or residual morbidity, primarily from thromboembolism, was 95% for CE-S, 92% for CE-SAV, and 95% for mechanical group (p < 0.05) but not clinically relevant.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

PubMed1995

Mitroflow pericardial bioprosthesis: clinical performance to ten years.

The Mitroflow pericardial bioprothesis, a second generation pericardial prosthesis, has clinical performance assessment to 10 years. This bioprosthesis was used in 445 operations in 445 patients between 1982 and 1992 inclusive (mean age, 59.1 years; age range, 19 to 94 years). There were 253 aortic valve replacements (AVR), 155 mitral valve replacements (MVR), 31 multiple valve replacements (MR), and 6 tricuspid valve replacements. Concomitant procedures were performed in 40 patients (14.2%). The age group distributions (years) were less than or equal to 35 years, 28 patients; 36 to 50 years, 79; 51 to 64 years, 167; 65 to 69 years, 70; and 70 years or more, 101 patients. The total follow-up was 1,524 patient-years (mean, 5.4 years), 96% complete. The early mortality was 6.3%/patient-year (28 patients) and the late mortality was 4.1%/patient-year (96 patients). Concomitant procedures did not influence either early or late mortality (p = not significant [NS]). The overall patient survival at 10 years was 58% +/- 5% (p = NS by valve position). The overall freedom from structural valve deterioration (SVD) at 8 years was 69% +/- 3% and at 10 years, 45% +/- 7%; and at 8 years AVR 80% +/- 4%, MVR 58% +/- 6%, and MR 38% +/- 11% (p < 0.05, AVR > MVR > MR). The freedom from thromboembolism (TE) was 87% +/- 2%, overall at 10 years, and was not different by valve position (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Pregnancy and bioprostheses: influence on structural valve deterioration.

The long-term performance of bioprostheses was evaluated in women 35 years of age or less to determine the influence of pregnancy on structural valve deterioration. Between 1972 and 1992, 237 female patients received 255 biological prostheses. Of the total operations, 53 were performed in patients who experienced pregnancy (P) and 202 in patients who were never pregnant (nonpregnant [NP]). The mean age of the P group was 23.0 +/- 5.8 years (standard deviation) (12 to 34 years) and of the NP group it was 27.1 +/- 6.3 years (8 to 35 years) (p < 0.05). The mean follow-up for the NP group was 6.8 years and for the P group it was 7.9 years. The late mortality was 2.26%/patient-year overall, 2.71%/patient-year for the NP group and 0.89%/patient-year for the P group (p = not significant [NS]). The P group of 52 patients had 94 pregnancies: 70 deliveries (74.5%) and 24 abortions (25.5%) (therapeutic, 14 [15%]). There were a total of 143 valve-related complications (P, 35; NP, 108); the majority for structural valve deterioration (SVD) 43% (109 patients), P 51% (27 patients) and NP 41% (82 patients) (p = NS). The valve-related reoperation rate paralleled the SVD rate at 42% (107 patients), P 51% (27 patients) and NP 40% (80 patients) (p = NS). The overall reoperative mortality rate was 6.0%. The interval from initial implant to reoperation was 99.6 +/- 3.6 months (p = NS groups P and NP).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Carpentier-Edwards standard porcine bioprosthesis: clinical performance to seventeen years.

BACKGROUND: The role of porcine bioprostheses in cardiac valve replacement has been under review for several years. The literature deals primarily with age as a determinant of durability, as well as the intermediate-term performance of various prostheses. The performance of the Carpentier-Edwards first-generation standard porcine bioprosthesis is presented over the long-term with further documentation on age determinants. METHODS: The "Guidelines for Reporting Morbidity and Mortality After Cardiac Valvular Operations" were used for definitions of valve-related complications, categorization, and statistical methods. The valve-related complications were evaluated in a time-related manner by actuarial life-table techniques. The Lee-Desu statistic test was used for comparison of performance by valve positions and age groups. Hazard function rates were demonstrated for complications and composites. RESULTS: Of the Carpentier-Edwards porcine bioprostheses implanted in 1,195 patients (1,214 operations, 1,315 valves) commencing in 1975 the early mortality was 7.6% (92). The early mortality without concomitant procedures was 6.1% and with 11.7%. The late mortality was 5.3% per patient-year; 4.6% patient-year without and 7.5% per patient-year with concomitant procedures. The valve-related causes of late mortality (131) were thromboembolism (41), antithromboembolic hemorrhage (14), prosthetic valve endocarditis (20), nonstructural dysfunction (12), and structural valve deterioration (44). The valve-related deaths (early, 7; late, 124) were 21.2% of the total 617 total deaths. Reoperation for valve-related complications was performed in 406 patients (4.1% per patient-year), of which 327 were for structural valve deterioration (3.3% per patient-year). Mortality for reoperation was 0.5% per patient-year (49 patients) or 12.1%. Of the 49 deaths, 33 were caused by structural valve deterioration. The linearized occurrence rate for thromboembolism was 1.6% per patient-year (major, 0.9% per patient-year, and minor, 0.7% per patient-year). The fatal thromboembolic rate was 0.4% per patient-year (41), undifferentiated by valve position. The freedom from thromboembolism was 76% at 17 years (p = not significant by valve position) (major, 87%; fatal, 93%). The freedom from prosthetic valve endocarditis was 92% at 17 years (p = not significant by valve position). The freedom from reoperation, at 15 years, was 38%: aortic (AVR), 55%; mitral (MVR), 20%; and multiple valve replacement (MR), 24% (p < 0.05 AVR > MVR, MR). The freedom from structural valve deterioration, at 15 years, was 41%; AVR, 58%; MVR, 21%; MR, 36% (p < 0.05 AVR > MVR, MR). The freedom from structural valve deterioration was greater for advancing age groups (p < 0.05); AVR > or = 70 years 96% at 12 years, and 65 to 69 years 94% at 12 years and 82% at 15 years; MVR > or = 70 years 85% at 12 years, and 65 to 69 years 54% at 12 years. The freedom from valve-related mortality was 73% at 17 years: AVR, 80%; ; MVR, 61%; and MR, 67% (p < 0.05 AVR > MVR, MR). The freedom valve-related residual morbidity was 94% (p = not significant by valve position). CONCLUSIONS: The Carpentier-Edwards standard porcine bioprosthesis continues to provide satisfactory clinical performance to 17 years. Thromboembolism is a more serious problem than structural failure: 92 major thromboembolic events with 41 fatalities compared with 44 fatalities of which 33 occurred with reoperation. The prosthesis is especially recommended for patients more than 65 years of age for AVR and more than 70 years of age for MVR.

Adult↗

PubMed1995

Acadesine: a new drug that may improve myocardial protection in coronary artery bypass grafting. Results of the first international multicenter study. Multinational Acadesine Study Group.

The effect of acadesine, an adenosine-regulating agent, on the incidence of myocardial infarction, all adverse cardiovascular outcomes (myocardial infarction, cardiac death, left ventricular dysfunction, life-threatening arrhythmia, or cerebrovascular accident) and mortality was assessed in 821 patients undergoing coronary artery bypass grafting. Patients were prospectively stratified to a high-risk group (age > 70 years, unstable angina, previous coronary bypass, unsuccessful angioplasty, or ejection fraction < 30%) or a non-high-risk group. They were randomized in a double-blind manner to placebo (n = 418) or acadesine (n = 403) by intravenous infusion over 7 hours (0.1 mg/kg per minute) and in the cardioplegic solution (placebo or acadesine; 5 micrograms/ml). Acadesine did not significantly affect the incidence of myocardial infarction in the overall study population, but it significantly reduced the incidence of Q-wave myocardial infarction in high-risk patients (placebo, 19.7%; acadesine, 10.0%; p = 0.032). The incidences of all adverse cardiovascular outcomes (placebo, 19.4%; acadesine, 18.4%) and overall mortality (placebo, 3.4%; acadesine, 2.7%) were similar between the two treatment groups. However, acadesine reduced the incidence of cardiac related events that contributed to deaths occurring during the first 3 postoperative days so that the incidence of death in this period was lower (placebo, 1.9%; acadesine, 0.2%; p = 0.038). No adverse events were related to acadesine treatment. Although overall there were no statistically significant between-group differences for the primary study end points, a secondary analysis in a prospectively defined high-risk subgroup suggests that acadesine may be beneficial in some patients.

Aminoimidazole Carboxamide↗

PubMed1994

Actuarial versus actual risk of porcine structural valve deterioration.

Actuarial analysis, using nonparametric (e.g., life table or Kaplan-Meier) or parametric (statistical modeling) methods, is used to describe and compare survival probabilities by allowing for partial survival times (censoring). Although devised to describe freedom from death, this method has been extended to nonfatal complications, such as freedom from tissue valve failure. However, the risk described for nonfatal events is that which a patient would experience provided he were immortal. And patients with valve disease have a relatively high risk of dying, generating the question: "What is the chance the valve will fail before the patient dies?" To answer this more practical (for individual patient management and population resource allocation) question requires an estimate of what we call actual failure, that is, the percentage of patients whose valve will actually fail before they die. This risk is less than the risk which the usual actuarial curve describes. This difference increases with patient age, because older patients have a lower risk of tissue failure and a higher risk of death than younger patients.

Actuarial Analysis↗

PubMed1994

The Medtronic Intact porcine bioprosthesis: clinical performance to eight years.

The Medtronic Intact porcine bioprosthesis was implanted in 274 patients, in 278 operations, between 1984 and 1992 inclusive. Of the total patient population, 171 patients had 175 aortic valve replacements (AVR), 75 had mitral valve replacement (MVR), two had tricuspid valve replacement and 26 had multiple valve replacement (MR). Concomitant procedures, primarily coronary artery bypass, was performed in 97 (34.9%). The follow up was 98.2% complete; total follow up was 758 patient-years, mean 2.8 years. The early mortality was 6.5% (18 patients) and the late mortality 4.0% per patient-year (30 patients). Of the late deaths, 10 were valve-related-thromboembolism (n = 2), anticoagulant-related hemorrhage (n = 1), prosthetic valve endocarditis (n = 4), non-structural dysfunction (n = 2), and structural valve deterioration (n = 1). Only one death occurred as a consequence of reoperation. The freedom from thromboembolism at six and eight years was-overall 86 +/- 4%; major 96 +/- 1%; fatal 99 +/- 1%. The overall linearized rate of thromboembolism was 3.0% per patient-year. The freedom from anticoagulant-related hemorrhage was 93 +/- 3%; non-structural dysfunction 87 +/- 9%; and structural valve deterioration 97 +/- 2% (AVR 97 +/- 2% at six and eight years, MVR 100% at six years). The freedom from SVD by age groups was- < or = 35 years 100%; 36-50 years 94 +/- 6%; 51-65 years 98 +/- 2%; and > or = 65 years 97 +/- 2% (p = NS). The freedom from valve-related mortality at six and eight years was 86 +/- 8%; residual morbidity 96 +/- 1%; and reoperation 91 +/- 3%. The Medtronic Intact, zero-pressure glutaraldehyde fixed prosthesis requires continued long term assessment to determine if the low incidence of structural valve deterioration is maintained.

Adult↗

PubMed1994

Carpentier-Edwards standard and supra-annular porcine bioprostheses: 10 year comparison of structural valve deterioration.

From 1975 to 1986 the Carpentier-Edwards standard (CE-S) and supra-annular (CE-SAV) porcine bioprostheses were implanted in 1213 and 1000 patients, respectively. The mean age of the standard group was 57.6 years (range 8 to 85 years) while in the supra-annular group it was 60.7 years (range 13 to 85 years). The freedom from structural valve deterioration (SVD) at 10 years for the entire patient population was 79.4% +/- 3.1% with CE-SAV and 76.1% +/- 1.6% with CE-S (p < 0.05). The overall freedom from SVD for those patients undergoing mitral valve replacement (MVR) was 74.5% +/- 4.6% for CE-SAV and 68.7% +/- 2.8% for CE-S (p = NS), while for those undergoing aortic valve replacement (AVR) it was 86.5% +/- 4.3% for CE-SAV and 84.1% +/- 2.0% for CE-S (p = NS). In those patients under 35 years of age undergoing MVR, the freedom from SVD for CE-SAV and CE-S was 94.4% +/- 5.4% and 62.9% +/- 8.6%, respectively (p < 0.05 at 8 years); for those aged 36-50 years, it was 75.6% +/- 7.4% and 61.7% +/- 6.0%; for those aged 51-65 years, it was 76.2% +/- 7.4% and 69.6% +/- 4.2%; for those over 65 years, it was 74.1% +/- 7.1% and 82.2% +/- 5.2%; for those aged 65-69 years, it was 70.2% +/- 8.7% and 63.7% +/- 8.1%; and for those over 70 years of age, it was 79.2% +/- 8.7% and 95.3% +/- 3.2%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Additive effect of allopurinol and deferoxamine in the prevention of spinal cord injury caused by aortic crossclamping.

Fourteen domestic swine were divided into two groups. Group A (n = 7) was the control group, in which no pharmacologic intervention was applied. In group B (n = 7), the ischemic-reperfused spinal cord was treated with the combination of allopurinol (50 mg/kg/day for 3 days before the day of operation) and deferoxamine (Desferal, 50 mg/kg administered intravenously over 3 to 4 hours). The administration of deferoxamine was completed 1 hour before crossclamping. The crossclamp was placed on the descending aorta just distal to the left subclavian artery for 30 minutes. Proximal hypertension was controlled with sodium nitroprusside and volume depletion. Methods of assessment included an evaluation of the neurologic status of the animals by quantitative Tarlov criteria, blood flow by radiolabeled microspheres, and histologic examination of the spinal cord. All animals in the control group, group A, were completely paraplegic with 0% recovery by Tarlov criteria at 24 hours after the removal of the crossclamp. In contrast, all animals in group B, in which the combination of allopurinol and deferoxamine was used, completely recovered (100% recovery by Tarlov criteria), and at 24 hours after the ischemic episode they were able to walk with no difficulty and had intact sensation. Functional parameters of these animals fully correlated with the morphologic findings. Widespread acute neuronal injury and vacuolation of neuropil were observed in the control group of animals. In contrast, animals in group B showed much less pronounced morphologic changes after the same period of ischemia. In summary, the combined use of these agents significantly (p < 0.001) reduced the incidence of paraplegia induced by aortic crossclamping with 82% additivity.

Allopurinol↗