Immunohistochemical quantification of inflammatory cells in endomyocardial biopsy fragments after heart transplantation: a new potential method to improve the diagnosis of rejection after heart transplantation.

Inconsistencies in cardiac rejection grading systems corroborate the concept that the evaluation of inflammatory intensity and myocyte damage seems to be subjective. We studied in 36 patients the potential role of the immunohistochemical (IHC) counting of inflammatory cells in endomyocardial biopsy (EMB) as an objective tool, testing the hypothesis of correlation between the International Society for Heart and Lung Transplantation 2004 rejection and IHC counting of inflammatory cells. We observed a progressive increment in CD68+ cells/mm(2) (P = .000) and CD3+ cells/mm(2) (P = .000) with higher rejection grade. A strong correlation between the grade of cellular rejection and both CD68+ cells/mm(2) and CD3+ cells/mm(2) was obtained (P = .000). One patient with CD3+ and CD68+ cells/mm(2) above the upper limit of the 95% confidence interval for cells/mm(2) found in rejection grade 1R evolved to rejection grade 2R without treatment. In patients with 2R that did not respond to treatment the values of CD68+ or CD3+ cells were higher than the overall median values for rejection grade 2R. For diagnosis of rejection needing treatment, the CD68+ and CD3+ cells/mm(2) areas under the receiver operating characteristic curves were 0.956 and 0.934, respectively. IHC counting of mononuclear inflammatory infiltrate in EMB seems to have additive potential role in evaluation of EMB for the diagnosis and prognosis of rejection episodes.

Rheumatic fever: how S. pyogenes-primed peripheral T cells trigger heart valve lesions.

The pathogenesis of rheumatic fever (RF) is related to autoimmune humoral and cellular responses against human tissues triggered by Streptococcus pyogenes. CD4(+) T cells are the ultimate effectors of chronic heart lesions in rheumatic heart disease (RHD). Heart-infiltrating CD4(+) T cell clones are able to recognize heart tissue and streptococcal antigens by molecular mimicry. The streptococcal M5(81-103) region, an immunodominant region, was recognized by both intralesional and peripheral T cell clones (62% and 38%, respectively). Peripheral T lymphocytes from Brazilian patients with severe RHD preferentially recognized the M5(81-96) peptide, in the context of HLA-DR7(+) and DR53(+) molecules. HLA-DR7 seems to be related to the development of multiple valvular lesions in RHD patients from different countries. In addition, the fact that peripheral and intralesional T cells recognized the M5(81-103) region points to this region as one of the streptococcal triggers of autoimmune reactions in RHD. T cell repertoire analysis from peripheral and intralesional T cell lines derived from RHD patients showed several oligoclonal expansions of BV families. Major expansions were found in the heart lesions, suggesting that such T cell populations preferentially migrate from the periphery to the heart. Some cross-reactive intralesional T cell clones displayed the same T cell receptor (TCR) BVBJ and CDR3 sequences, showing a degenerate pattern of antigen recognition. Heart tissue-infiltrating cells from myocardium and valvular tissue produced TNF-alpha, IFN-gamma, IL-10, and IL-4, whereas few cells from valvular tissue produced IL-4, showing that the lack of regulation in the valves could be responsible for the permanent and progressive valvular lesions.

Repeated echocardiographic examinations of patients with suspected infective endocarditis.

OBJECTIVE: To study the diagnostic contribution of repeated transthoracic (TTE) and transoesophageal echocardiography (TOE) among patients with suspected infective endocarditis. METHODS: 262 patients with 266 episodes of suspected infective endocarditis were referred for TTE and TOE over three years in a 423 bed university cardiology hospital. Patients were a mean (SD) of 47.6 (17.9) years old. 139 (52.3%) episodes occurred in men and 127 (47.7%) in women. The diagnostic information obtained from repeated TTE and TOE examinations was evaluated relative to the diagnosis of endocarditis. RESULTS: TTE examinations were repeated in 192 (72.2%) and TOE examinations were repeated in 49 (18.4%) of 266 episodes. A mean of 2.4 TTE and 1.2 TOE examinations were performed for each episode of suspected endocarditis. The second and third TTEs added diagnostic information in 34 (26.7%) and the second and third TOEs added diagnostic information in 25 (19.7%) of 127 episodes with definite endocarditis. After the third TTE or TOE no additional diagnostic information was obtained. CONCLUSIONS: The diagnostic contribution of repeated TTE or TOE for the diagnosis of endocarditis decreased as the number of repetitions increased. In this setting, the data do not substantiate more than three TTE or TOE examinations as an efficient strategy to increase the diagnostic yield for all but selected patients with suspected endocarditis.

T-cell reactivity against streptococcal antigens in the periphery mirrors reactivity of heart-infiltrating T lymphocytes in rheumatic heart disease patients.

T-cell molecular mimicry between streptococcal and heart proteins has been proposed as the triggering factor leading to autoimmunity in rheumatic heart disease (RHD). We searched for immunodominant T-cell M5 epitopes among RHD patients with defined clinical outcomes and compared the T-cell reactivities of peripheral blood and intralesional T cells from patients with severe RHD. The role of HLA class II molecules in the presentation of M5 peptides was also evaluated. We studied the T-cell reactivity against M5 peptides and heart proteins on peripheral blood mononuclear cells (PBMC) from 74 RHD patients grouped according to the severity of disease, along with intralesional and peripheral T-cell clones from RHD patients. Peptides encompassing residues 1 to 25, 81 to 103, 125 to 139, and 163 to 177 were more frequently recognized by PBMC from RHD patients than by those from controls. The M5 peptide encompassing residues 81 to 96 [M5(81-96) peptide] was most frequently recognized by PBMC from HLA-DR7+ DR53+ patients with severe RHD, and 46.9% (15 of 32) and 43% (3 of 7) of heart-infiltrating and PBMC-derived peptide-reactive T-cell clones, respectively, recognized the M5(81-103) region. Heart proteins were recognized more frequently by PBMC from patients with severe RHD than by those from patients with mild RHD. The similar pattern of T-cell reactivity found with both peripheral blood and heart-infiltrating T cells is consistent with the migration of M-protein-sensitized T cells to the heart tissue. Conversely, the presence of heart-reactive T cells in the PBMC of patients with severe RHD also suggests a spillover of sensitized T cells from the heart lesion.

Tricuspid dura mater bioprostheses: more than 20-year follow-up of 3 patients.

Replacement of the tricuspid valve is sometimes necessary. We report 3 consecutive patients with tricuspid insufficiency who underwent valve replacement with glycerol-preserved, homologous dura mater cardiac bioprostheses between 1971 and 1973. The first 2 patients are well 28 and 27 years later; the last patient was lost to follow-up after 20 years. We conclude that preservation of homologous dura mater bioprostheses in glycerol may reduce rates of thromboembolism, thrombosis, and structural dysfunction during the late postoperative period.

Relapses, recurrences, valve replacements, and mortality during the long-term follow-up after infective endocarditis.

BACKGROUND: Late prognosis after infective endocarditis has not been systematically studied in large series of patients with different underlying heart conditions in recent years. METHODS: We studied an inception cohort study of 420 patients discharged after treatment of endocarditis from a university tertiary care hospital. The patients were aged 34.2+/-17.2 years (mean +/- SD), ranging from 2 months to 83 years; 270 (64.3%) were men and 150 (35.7%) were women. Mean follow-up was 6.1+/-4.3 years for survivors and 3.7+/-3.7 years for the patients who died during the follow-up. We studied the frequency and risk factors for relapses and recurrences of endocarditis, cardiac valve replacements, and deaths during the follow-up. Statistical analysis was performed through comparison of groups, of event-free survival, and risk ratios. RESULTS: Relapses were observed in 14 (3.3%) patients. There was one recurrence of endocarditis in 48 (11.4%) patients, two (0.5%) in 2 patients, three in 1 patient (0.2%), and five (0.2%) in 1 patient. Valve replacement was performed in 83 (19.7%) patients. Ninety-eight (12.3%) patients died. Risk factors for recurrent endocarditis were increasing age (risk ratio 1.02) and male sex (risk ratio 1.61). Risk factors for valve replacement were recurrent endocarditis (risk ratio 1.62) and prosthetic valve endocarditis (risk ratio 1.61). Risk factors for death were increasing age (risk ratio 1.03) and recurrent endocarditis (risk ratio 2.06). CONCLUSIONS: The long-term event-free survival for patients who survived their first episode of endocarditis was low. Recurrent endocarditis, prosthetic valve endocarditis, and increasing age contributed to the high rate of events during the follow-up.

Molecular evidence for antigen-driven immune responses in cardiac lesions of rheumatic heart disease patients.

Rheumatic heart disease (RHD) is a sequel of post-streptococcal throat infection. Molecular mimicry between streptococcal and heart components has been proposed as the triggering factor of the disease, and CD4(+) T cells have been found predominantly at pathological sites in the heart of RHD patients. These infiltrating T cells are able to recognize streptococcal M protein peptides, involving mainly 1-25, 81-103 and 163-177 N-terminal amino acids residues. In the present work we focused on the TCR beta chain family (TCR BV) usage and the degree of clonality assessed by beta chain complementarity-determining region (CDR)-3 length analysis. We have shown that in chronic RHD patients, TCR BV usage in peripheral blood mononuclear cells (PBMC) paired with heart-infiltrating T cell lines (HIL) is not suggestive of a superantigen effect. Oligoclonal T cell expansions were more frequently observed in HIL than in PBMC. Some major BV expansions were shared between the mitral valve (Miv) and left atrium (LA) T cell lines, but an in-depth analysis of BJ segments usage in these shared expansions as well as nucleotide sequencing of the CDR3 regions suggested that different antigenic peptides could be predominantly recognized in the Miv and the myocardium. Since different antigenic proteins probably are constitutively represented in myocardium and valvular tissue, these findings could suggest a differential epitope recognition at the two lesional heart sites after a common initial bacterial challenge.

Mitral valve repair in rheumatic patients.

BACKGROUND: There is controversy regarding the role of reparative techniques for rheumatic-mitral valve disease. We have analyzed the late results of mitral valve repair in a group of patients with rheumatic mitral valve insufficiency. METHODS: From March 1980 to December 1997, 201 patients with rheumatic fever underwent mitral valve repair at the Heart Institute, Hospital das Clínicas, Medical School, University of São Paulo. The mean age of patients was 26.9 +/- 15.4 years, with 59.7% of the patients being female. Other diagnoses were present in 67.7% of patients; the most common was tricuspid regurgitation (31.3%). Mitral valve repair techniques included: 1) Carpentier ring annuloplasty in 75 patients (37.3%); 2) posterior annuloplasty with bovine patch in 68 patients (33.8%); 3) posterior segmental annuloplasty in 16 patients (7.9%); 4) quadrangular resection of the posterior leaflet with ring plication in 11 patients (5.5%); 5) partial resection of the anterior leaflet in 6 patients (3%); 6) De Vega's annuloplasty in 6 patients (3%); 7) Kay's annuloplasty in 5 patients (2.5%); 8) Reed's annuloplasty in 4 patients (2%); and 9) miscellaneous techniques in 10 patients (4.9%). Combined techniques were used in 94 patients (46.8%), the most frequent of which was chordal shortening (48 patients, 23.9%). Other non-mitral cardiac procedures were performed in 113 patients (56.2%). Actuarial survival and event-free curves (Kaplan-Meier method) were compared by linear regression analysis. RESULTS: The in-hospital mortality rate was 2.0% (four patients). The causes of death were multiorgan failure in two patients and low cardiac output in the other two patients. In the late postoperative period, 83.9% of the patients were in New York Heart Association (NYHA) functional class 1. The actuarial survival was 93.9% +/- 1.9% at a mean of 125 months. Twenty-three patients were reoperated in the postoperative period at a mean interval of 35.7 months. Survival free from reoperation was 43.3% +/- 13.7% at 125 months. When analyzing the patients according to age, actuarial survival was 91.3% +/- 3.8% in the group of patients younger than 16 years (Group 1), compared with 95.6% +/- 2.7% in the group older than 16 years (Group 2), with a statistically significant difference of p < 0.0001. Survival free from reoperation was 50.8% +/- 16.9% in Group 1 and 47.0% +/- 14.9% in Group 2 (p < 0.0001). CONCLUSIONS: Late results obtained with mitral valve repair for rheumatic mitral valve insufficiency were satisfactory and exceeded those reported for mitral valve replacement in the same population.

Mitral restenosis in the early postoperative period of a patient with systemic lupus erythematosus.

A forty-eight year old woman, who had undergone mitral comissurotomy and subsequently developed early restenosis, presented with major comissural fusion and verrucous lesions on the cuspid edges of the mitral valve, with normal subvalvar apparatus. Patient did well for the first six months after surgery when she began to present dyspnea on light exertion. A clinical diagnosis of restenosis was made, which was confirmed by an echocardiogram and cardiac catheterization. She underwent surgery, and a stenotic mitral valve with verrucous lesions suggesting Libman-Sacks' endocarditis was found. Because the diagnosis of systemic lupus erythematosus (SLE) had not been confirmed at that time, a bovine pericardium bioprosthesis (FISICS-INCOR) was implanted. The patient did well in the late follow-up and is now in NYHA Class I.

Mitral valve repair. Quadrangular resection of the posterior leaflet in patients with myxomatous degeneration.

OBJECTIVE: To analyze the immediate and late results of mitral valve repair with quadrangular resection of the posterior leaflet without the use of a prosthetic ring annuloplasty. METHODS: Using this technique, 118 patients with mitral valve prolapse who underwent mitral repair from January '84 through December '96 were studied. Age ranged from 30 to 86 (mean = 59.1 +/- 11.8) years and 62.7% were males. An associated surgery was performed in 22% of the patients, and coronary artery bypass graft was the most frequently performed surgery (15 patients--12.7%). In 20 (16.9%) patients other associated techniques of mitral valve repair were used and shortening of elongated chordae tendineae was the most frequent one (6 patients). RESULTS: Immediate mortality was 0.9% (one patient). Long-term rates for thromboembolism, endocarditis, reoperation and death in the late postoperative period were 0.4%, 0.4%, 1.7% and 2.2% patients/year, respectively. The actuarial curve of survival was 83.8 +/- 8.6% over 12 years; survival free from re-operation was 91.8 +/- 4.3%, free from endocarditis was 99.2 +/- 0.8% and free from thromboembolism was 99.2 +/- 0.8%. In the late postoperative period, 93.8% of the patients were in functional class 1 (NYHA), with a complete follow-up in 89.7% of the patients. CONCLUSION: Patients with mitral valve prolapse who undergo mitral valve repair using this technique have a satisfactory prognosis over 12 years.

Immediate and long term evolution of valve replacement in children less than 12 years old.

OBJECTIVE: The aim of this work was the follow-up and evaluation of valve replacement in children under 12 years of age. METHODS: Forty-four children less than 12 years old were underwent valve replacement at INCOR-HCFMUSP between January 1986 and December 1992. Forty (91%) were rheumatic, 39 (88.7%) were in functional classes II or IV, 19 (43.2%) were operated upon on an emergency basis, and 6 (13.6%) had atrial fibrillation. Biological prostheses (BP) were employed in 26 patients (59.1%), and mechanical prostheses (MP) in 18 (40.9%). Mitral valves were replaced in 30 (68.7%), aortic valves in 8 (18.2%), a tricuspid valve in 1 (2.3%), and double (aortic and mitral) valves in 5 (11.4) of the patients. RESULTS: Hospital mortality was of 4.5% (2 cases). The mean follow-up period was 5.8 years. Re-operations occurred in 63.3% of the patients with BP and in 12.5% of those with MP (p=0.002). Infectious endocarditis was present in 26.3% of the BP, but in none of the cases of MP (p=0.049). Thrombosis occurred in 2 (12.5%) and hemorrhage in one (6.5%) of the patients with a MP. Delayed mortality occurred in 5 (11.9%) of the patients over a mean period of 2.6 years; four had had BP and one had a MP (NS). Actuarial survival and re-operation-free curves after 10 years were respectively, 82.5+/-7.7 (SD)% and 20.6+/-15.9%. CONCLUSION: Patients with MP required fewer re-operation, had less infectious endocarditis and lower late mortality rates compared with patients with bioprostheses. The former, therefore, appear to be the best valve replacement for pediatric patients.

[Comparison between percutaneous balloon valvuloplasty and open commissurotomy for mitral stenosis]. / Avaliação comparative entre valvoplastia percutânea e comissurotomia a céu aberto na estenose mitral.

PURPOSE: To compare immediate and late (12 months) follow-up of clinical and Doppler echocardiographic results between percutaneous mitral balloon valvuloplasty and open commissurotomy in a prospective and randomized trial. METHODS: Eighty eight symptomatic patients with severe mitral stenosis and favorable anatomy were randomized in a prospective trial comparing the two procedures. All patients were submitted to clinical and Doppler echocardiographic evaluation before the procedures and immediate and twelve months thereafter. RESULTS: Mean mitral gradient (mmHg) decreased from 12.2 +/- 5.8 to 5.80 +/- 2.7 (p < 0.001) in commissurotomy group (CG) and from 11.7 +/- 6.1 to 5.0 +/- 2.4 (p < 0.001) in the balloon valvuloplasty group (VG). Mitral valve are (cm2) increased from 0.98 +/- 0.21 to 2.52 +/- 0.46 in CG and from 1.05 +/- 0.25 to 2.18 +/- 0.40 in VG (p < 0.001). In both groups there was a slight decrease in mitral valve area at 12 month follow-up. There was no death in either group. One patient in the VG had moderate mitral regurgitation and underwent surgery. At the 12 month follow-up, all patients in CG and 97.7% of patients in VG were in New York Heart Association functional class I or II. CONCLUSION: Both procedures were safe and showed similar immediate improvement in mitral gradient and functional class. Mitral valve area had a greater increase immediately after commissurotomy, however, there was a significantly greater reduction in the CG after 12 months of follow-up, when compared to balloon valvuloplasty. In both groups, mitral gradient remained reduced and most patients did not change functional class during the follow-up.

Fisics-Incor bovine pericardial bioprostheses: 15 year results.

BACKGROUND: From March 1982 to December 1995, 2,607 Fisics-Incor bovine pericardial bioprostheses were implanted in 2,259 patients. Mean age was 47.2 +/- 17.5 years, and 55% were male. Rheumatic fever was present in 1,301 (45.7%) patients. METHODS: One thousand and seventy-three aortic valve replacements, 1,085 mitral replacements, 27 tricuspid replacements, 195 mitral-aortic replacements, and 16 other combined valve replacements were carried out. Combined procedures were performed in 788 (32.9%) patients, the most frequent being tricuspid valve repair (9.2%) and coronary artery bypass grafting (7.7%). RESULTS: Hospital mortality was 8.6% (194 patients), 8.6% for the mitral group, 4.7% for the aortic group, and 12.8% for double-valve replacements. The linear rates for calcification, thromboembolism, rupture, leak and endocarditis were, respectively, 1.1%, 0.2%, 0.9%, 0.1% and 0.5% patient-year. The actuarial survival curve was 56.7 +/- 5.4% in 15 years. Survival free from endocarditis was 91.92%, survival free from thromboembolism was 95 +/- 1.7%, survival free from rupture was 43.7 +/- 9.8%, survival free from leak was 98.9 +/- 4.5%, and survival free from calcification was 48.8 +/- 7.9% in 15 years. In the late postoperative period, 1,614 (80.6%) patients were in New York Heart Association functional Class I. CONCLUSIONS: We conclude that the results with the Fisics-Incor bovine pericardial prostheses were satisfactory in our group of patients.

[Results of aortic stenosis surgery in patients with severe ventricular dysfunction]. / Resultados da cirurgia da estenose aórtica em pacientes com disfunção ventricular grave.

PURPOSE: To study the short and long term clinical course of patients with severe aortic stenosis after surgical treatment of the valvular lesion. METHODS: Thirty survivors among 31 consecutive patients with severe left ventricular dysfunction (LVD) due to aortic stenosis (AS) were submitted to clinical and echocardiographic follow-up during a mean of 30 months after surgical treatment of the valvular lesion. Twenty five (83.3%) patients were male with a mean age of 50 years (25 to 74). Before operation the following parameters were obtained: diastolic left ventricular diameter (DLVD), shortening fraction (SF), left ventricular ejection fraction (LVEF), aortic valve area (AVA), left ventricular-aortic pressure gradient (PG) and NYHA functional class (FC). During the follow up, after the surgical procedure, FC, DLVD, LVEF and SF could be analysed and compared with previous data. RESULTS: A significant rise in SF (p = 0.001) and LVEF (p = 0.0001), as well as a decrease in DLVD (p = 0.001) were observed in the follow up. Symptoms lessened in severity in the majority of patients. Three of our patients died with progressive LVD and heart failure, after at least 36 months of follow-up. These results indicate that when operation is carried out in patients with AS and left ventricular failure, a significant improvement in left ventricular function and in symptoms takes place. Although the risk of surgical treatment is increased in this group of patients, LVD should not be considered a contraindication to the procedure. CONCLUSION: The left ventricular dysfunction is not a contraindiction for the surgical treatment of the aortic stenosis.

[Mitral subvalvular aneurysm of the left ventricle]. / Aneurisma subvalvar mitral de ventrículo esquerdo.

A 21-year-old white man presented with cardiogenic shock and refractory pulmonary congestion. At the transthoracic echocardiogram a subvalvar left ventricular aneurysm of the inferior wall with severe mitral regurgitation was observed. The outcome was favorable after surgical correction of the mitral regurgitation and of the subvalvar aneurysm. We emphasize that, whenever possible, valvar repair is better than mitral replacement, since annulus tissue fragility causes suturing of the mitral prosthesis to be difficult.

Human heart-infiltrating T-cell clones from rheumatic heart disease patients recognize both streptococcal and cardiac proteins.

BACKGROUND: beta-Hemolytic streptococcal infection in developing countries still causes thousands of causes of rheumatic heart disease, demanding surgical valve correction. Antigenic mimicry between self and streptococcal components has been proposed as the triggering factor leading to autoimmunity in individuals with genetic susceptibility. Although heart streptococcal-M protein cross-reactive antibodies have been demonstrated, heart tissue damage seems to be T lymphocyte-dependent. We studied the infiltrating T lymphocytes in rheumatic heart lesions with the aim of understanding the role of cellular immune response at the site of the lesions. METHODS AND RESULTS: We obtained 107 T-cell clones from surgical fragments of cardiac tissue from four rheumatic heart disease patients. We tested their capacity to recognize streptococcal M protein-derived synthetic peptides and heart proteins. We found eight infiltrating T-cell clones from all four patients that simultaneously recognize streptococcal M and heart proteins. Among the M-protein sequences tested, only synthetic peptides corresponding to regions 1 through 25, 81 through 103, and 163 through 177 were simultaneously recognized with heart protein fractions. Interestingly, regions 81 through 103 and 163 through 177 have been known to bear heart cross-reactive epitopes at the antibody level. Five of these clones are CD4+, and one is CD8+. CONCLUSIONS: The presence of heart-M protein cross-reactive T-cell clones in rheumatic heart lesions suggests their direct involvement in the pathogenesis of this disease. The dissection of protective and pathogenic epitopes of streptococcal M protein is an important step in allowing the development of a safe anti-streptococcal synthetic vaccine.

[Chronic rheumatic cardiopathy in a patient with of hemophilia successfully treated with surgery]. / Cardiopatia reumática crônica em portador de hemofilia submetido com sucesso a tratamento cirúrgico.

A 52 year-old man, with rheumatic cardiopathy and hemophilia was admitted to the hospital for aortic valve replacement and mitral valve commisurotomy. He had a history of allergic reaction to cryoprecipitate, and to undergo to the cardiac surgery, the ideal level of factor VIII was estimated to be 100%. To reach this level he first received 2,500UI of the factor VIII:C increasing the factor VIII:C level from 20 to 58%. During the surgery he received an additional dose of 1,500UI of factor VIII plus 3,500,000UI of aprotinin (Trasylol), which was started at the beginning of the anaesthesia and maintained during the surgical procedure, increasing the factor VIII level to 220%. The patient was discharged 11 days after the surgery without any hemorrhagic complication.

[Randomized study comparing mitral valve replacement with and without preservation of mitral ring chordae tendinae papillary continuity]. / Estudo randomizado comparando-se a substituição valvar mitral com e sem preservação da continuidade anel-cordas tendíneas-papilares.

PURPOSE: To demonstrate the importance of the preservation of mitral annulus-chordae tendineae-papillary muscles continuity in mitral valve replacement. METHODS: We studied 21 patients who were submitted to mitral valve replacement, divided in two randomized groups: group 1, 12 cases who undergone mitral valve replacement, with preservation of the posterior leaflet and correspondent chordae tendineae; and group 2-9 cases who undergone conventional mitral valve replacement, excising the mitral valve apparatus. The left ventricular function was studied both, in the pre and post operative period, by echocardiography, cardiac catheterization, and radioisotopic study. The statistical analysis was done by the Wilcoxson's test. RESULTS: There were no early post operative deaths. Analyzing the results of the ejection fraction by the radioisotopic study we found a significant difference (p = 0.03) between the percentual decrease of the two groups. The results of the fractional shortening were higher in group 1 than in group 2, however not significant. The left ventricular diastolic diameters average was lower in group 1 than in group 2, so as the left atrium diameter. We found a decrease in left ventricular end-diastolic pressure in group 1, however there was an increase in group 2, by the cardiac catheterization. There was a proportional increase in group 1 both in lung artery and lung capillary pressures. There was a significant difference (p = 0.05) between the average values of right ventricular diastolic pressure. CONCLUSION: There is better preservation of left ventricular function in group 1.

A non-conventional reniform heart valve bioprosthesis with improved performance.

Conventional bioprosthetic heart valves have been designed with circular mounting rings. This article describes a mitral bioprosthetic valve consisting of three bovine pericardial leaflets with a "reniform" base. Its shape resembles that of the mitral anulus, and therefore, it provides a better anatomic fit. Hydrodynamic comparisons were made between conventional valves (CV) and equivalent sized reniform valves (ERV) that would adapt to the same anulus. Under steady flow of 30 L/min, pressure drops were compared in CVs and ERVs. For CV sizes 27, 29, and 31mm, the ratios of pressure drops compared with ERVs were 2, 1.49, and 1.30, respectively. With the same flow rate, the ratios of effective orifice areas (EOA) for CVs and ERVs in sizes 27, 29, and 31mm were 1.41, 1.21, and 1.14, respectively. Under pulsatile flow (mean flow, 5 L/min, 100 beats/min [bpm]), the pressure drop across CVs was averaged for sizes 27, 29, and 31mm, and found to be 1.51-fold the averaged pressure drops for ERVs. In addition, ERV sizes 27, 29, and 31mm had EOAs averaging 1.24-fold those of CVs. Similarly, for an 80 bpm frequency, the pressure drops across CVs for the three sizes averaged 1.48-fold that of ERVs. The EOAs of ERVs were 1.22-fold those of CVs averaged for the three sizes.