Carlos Manuel de Almeida Brandão

Multivariate analysis of risk factors for hospital mortality in valvular reoperations for prosthetic valve dysfunction

OBJECTIVES The purpose of the study was to analyze risk factors for hospital mortality in patients undergoing valvular reoperations for prosthetic valve dysfunction. METHODS We performed a prospective analysis of 146 patients who underwent valvular reoperations for prosthetic valve dysfunction between July 1995 and June 1999 at the Heart Institute of the University of São Paulo Medical School. Multivariate statistical analysis with logistic regression was used to analyze preoperative and intraoperative variables to determine risk factors for hospital mortality. RESULTS The overall hospital mortality was 10.9% (16 patients). Univariate analysis showed that the following variables were associated with higher mortality rates: advanced New York Heart Association (NYHA) functional class, increased creatinine level, prolonged extracorporeal circulation time and treatment of annular abscess. Logistic multivariate analysis identified advanced NYHA functional class and a creatinine level higher than 1.5 mg/dl as independent predictors of hospital mortality. CONCLUSIONS Advanced NYHA functional class and higher creatinine levels were independent predictors of hospital mortality in patients submitted for valvular reoperations for prosthetic valve dysfunction.

Benefits of non-invasive ventilation after extubation in the postoperative period of heart surgery.

OBJECTIVE to show the benefits of the use of non-invasive positive pressure ventilation (NPPV) in the process of weaning from mechanical ventilation in the immediate postoperative period of heart surgery. METHODS A prospective, randomized and controlled study was performed involving 100 consecutive patients submitted to coronary artery bypass grafting or valve surgery. The subjects were admitted into the Intensive Care Unit (ICU) under mechanical ventilation and randomized in a study group (n=50), which used NPPV with bilevel pressure for 30 minutes after extubation, and a control group (n=50) which only used a nasal O2 catheter. Anthropometric variables and the times of the intra-operative periods corresponding to anesthesia, surgery and cardiopulmonary bypass, as well as the time required for weaning from invasive mechanical ventilation were analysed. The arterial blood gases and hemodynamic variables were also assessed before and after extubation. RESULTS The evolution was similar for the control and study groups without statistically significant differences of the variables analyzed except for the PaO2. On comparing the groups, the PaO2 improved significantly (p = 0.0009) with the use of NPPV for 30 minutes after extubation, but there was no statistically significant difference in the PaCO2 (p = 0.557). CONCLUSION The use of NPPV for 30 minutes after extubation improved oxygenation in the immediate postoperative period of heart surgery.OBJETIVO: Demonstrar os beneficios da utilizacao da ventilacao nao-invasiva (VNI) no processo de interrupcao da ventilacao mecânica, no pos-operatorio de cirurgia cardiaca. METODOS: Estudo prospectivo, randomizado e controlado, com 100 pacientes submetidos a cirurgia de revascularizacao do miocardio ou cirurgia valvar. Os pacientes foram admitidos na Unidade de Terapia Intensiva (UTI), sob ventilacao mecânica e randomizados posteriormente em grupo estudo (n= 50) que utilizou VNI com dois niveis pressoricos apos a extubacao por 30 minutos, e grupo controle (n= 50) que fez uso apenas de cateter nasal de O2. Foram analisadas as variaveis antropometricas, os tempos correspondentes a anestesia, cirurgia e circulacao extracorporea, bem como o tempo necessario para a supressao da ventilacao mecânica invasiva. As variaveis gasometricas e hemodinâmicas tambem foram avaliadas antes e apos a extubacao. RESULTADOS: Os grupos controle e estudo evoluiram de forma semelhante e nao apresentaram diferenca estatisticamente significante na analise das variaveis, exceto para a PaO2. A utilizacao da VNI por 30 minutos apos a extubacao promoveu melhora na PaO2 quando comparados os grupos, com p= 0,0009, mas nao apresentou diferenca estatisticamente significante na PaCO2 (p=0,557). CONCLUSAO: O uso da VNI por 30 minutos apos extubacao produziu melhora na oxigenacao do pacientes em posoperatorio imediato de cirurgia cardiaca.

Contrast-enhanced magnetic resonance imaging identifies focal regions of intramyocardial fibrosis in patients with severe aortic valve disease: Correlation with quantitative histopathology.

BACKGROUND Chronic aortic valve disease (AVD) is characterized by progressive accumulation of interstitial myocardial fibrosis (MF). However, assessment of MF accumulation has only been possible through histologic analyses of endomyocardial biopsies. We sought to evaluate contrast-enhanced magnetic resonance imaging (ce-MRI) as a noninvasive method to identify the presence of increased MF in patients with severe AVD. METHODS Seventy patients scheduled to undergo aortic valve replacement surgery were examined by cine and ce-MRI in a 1.5-T scanner. Cine images were used for the assessment of left ventricular (LV) volumes, mass, and function. Delayed-enhancement images were used to characterize the regions of MF. In addition, histologic analyses of myocardial samples obtained during aortic valve replacement surgery were used for direct quantification of interstitial MF. Ten additional subjects who died of noncardiac causes served as controls for the quantitative histologic analyses. RESULTS Interstitial MF determined by histopathologic analysis was higher in patients with AVD than in controls (2.7% +/- 2.0% vs 0.6% +/- 0.2%, P = .001). When compared with histopathologic results, ce-MRI demonstrated a sensitivity of 74%, a specificity of 81%, and an accuracy of 76% to identify AVD patients with increased interstitial MF. There was a significant inverse correlation between interstitial MF and LV ejection fraction (r = -0.67, P < .0001). Accordingly, patients with identifiable focal regions of MF by ce-MRI exhibited worse LV systolic function than those without MF (45% +/- 14% vs 65% +/- 14%, P < .0001). CONCLUSIONS Contrast-enhanced MRI allows for the noninvasive detection of focal regions of MF in patients with severe AVD. Moreover, patients with identifiable MF by ce-MRI exhibited worse LV functional parameters.

Aneurysm of the left atrial appendage

We present the case of a 33-year-old woman with atrial tachyarrhythmias and chest pain. The transthoracic echocardiography demonstrated an intrapericardial liquid mass confirmed as an aneurysm of the left atrial appendage by a nuclear magnetic imaging study. Aneurysmectomy was performed with the assistance of cardiopulmonary bypass with a bilateral submammary skin incision and subsequent median sternotomy. The patient had an uneventful postoperative course. We suggest aneurysmectomy aided by cardiopulmonary bypass as a safer method of treatment for this rare cardiac anomaly.

Fatores de risco pré-operatórios para mediastinite após cirurgia cardíaca: análise de 2768 pacientes

BACKGROUND Longitudinal median sternotomy is the most common surgical approach for access to heart disease treatment. The deep wound infections in postoperative period of cardiovascular surgery are a serious complication requiring high costs during treatment. Different studies have indicated some risk factors for the development of mediastinitis and preoperative variables are currently under investigation. OBJECTIVE The aim of this study is to identify the preoperative risk factors for postoperative development of mediastinitis in patients undergoing coronary artery bypass grafting and valve replacement. METHODS This observational study represents a cohort of 2768 consecutive operated patients. The period considered for analysis was from May 2007 to May 2009 and there were no exclusion criteria. Analysis was performed by univariate and multivariate logistic regression model of 38 preoperative variables. RESULTS Thirty-five (1.3%) patients developed mediastinitis and 19 (0.7%) associated with osteomyelitis. The patient age average was 59.9 ± 13.5 years and the EuroSCORE of 4.5 ± 3.6. Hospital mortality was 42.8%. The multivariate analysis identified three variables as independent predictors of postoperative mediastinitis: intra-aortic balloon pump (OR 5.41, 95% CI [1.83 -16.01], P = 0.002), hemodialysis (OR 4.87, 95% CI [1.41 to 16.86], P = 0.012) and extracardiac vascular intervention (OR 4.39, 95% CI [1.64 to 11.76], P = 0.003). CONCLUSION This study showed that necessity of preoperative hemodynamic support with intra-aortic balloon, hemodialysis, and extracardiac vascular intervention were risk factors for development of mediastinitis after cardiac surgery.INTRODUCAO: A esternotomia mediana longitudinal e a via de acesso mais utilizada no tratamento das doencas cardiacas. As infeccoes profundas da ferida operatoria no pos-operatorio das cirurgias cardiovasculares sao uma complicacao seria, com alto custo durante o tratamento. Diferentes estudos tem encontrado fatores de risco para o desenvolvimento de mediastinite e as variaveis pre-operatorias tem tido especial destaque. OBJETIVO: O objetivo deste estudo e identificar fatores de risco pre-operatorios para o desenvolvimento de mediastinite em pacientes submetidos a revascularizacao do miocardio e a substituicao valvar. METODOS: Este estudo observacional representa uma coorte de 2768 pacientes operados consecutivamente. O periodo considerado para analise foi de maio de 2007 a maio de 2009 e nao houve criterios de exclusao. Foi realizada analise univariada e multivariada pelo modelo de regressao logistica das 38 variaveis pre-operatorias eleitas. RESULTADOS: Nesta serie, 35 (1,3%) pacientes evoluiram com mediastinite e 19 (0,7%) com osteomielite associada. A idade media dos pacientes foi de 59,9 ± 13,5 anos e o EuroSCORE de 4,5 ± 3,6. A mortalidade hospitalar foi de 42,8%. Na analise multivariada, foram identificadas tres variaveis como preditoras independentes de mediastinite: balao intra-aortico (OR 5,41, 95% IC [1,83 -16,01], P=0,002), hemodialise (OR 4,87, 95% IC [1,41 - 16,86], P=0,012) e intervencao vascular extracardiaca (OR 4,39, 95% IC [1,64 - 11,76], P=0,003). CONCLUSAO: O presente estudo demonstrou que necessidade do suporte hemodinâmico pre-operatorio com balao intra-aortico, hemodialise e intervencao vascular extracardiaca sao fatores de risco para o desenvolvimento de mediastinite apos cirurgia cardiaca.

Comparison of Inhaled Nitric Oxide Versus Oxygen on Hemodynamics in Patients With Mitral Stenosis and Severe Pulmonary Hypertension After Mitral Valve Surgery

Pulmonary hypertension represents an important cause of morbidity and mortality in patients with mitral stenosis who undergo cardiac surgery, especially in the postoperative period. The aim of this study was to test the hypothesis that inhaled nitric oxide (iNO) would improve the hemodynamic effects and short-term clinical outcomes of patients with mitral stenosis and severe pulmonary hypertension who undergo cardiac surgery in a randomized, controlled study. Twenty-nine patients (4 men, 25 women; mean age 46 ± 2 years) were randomly allocated to receive iNO (n = 14) or oxygen (n = 15) for 48 hours immediately after surgery. Hemodynamic data, the use of vasoactive drugs, duration of stay, and short-term complications were assessed. No differences in baseline characteristics were observed between the groups. After 24 and 48 hours, patients receiving iNO had a significantly greater increase in cardiac index compared to patients receiving oxygen (p <0.0001). Pulmonary vascular resistance was also more significantly reduced in patients receiving iNO versus oxygen (-117 dyne/s/cm(5), 95% confidence interval -34 to -200, vs 40 dyne/s/cm(5), 95% confidence interval -34 to 100, p = 0.005) at 48 hours. Patients in the iNO group used fewer systemic vasoactive drugs (mean 2.1 ± 0.14 vs 2.6 ± 0.16, p = 0.046) and had a shorter intensive care unit stay (median 2 days, interquartile range 0.25, vs median 3 days, interquartile range 7, p = 0.02). In conclusion, iNO immediately after surgery in patients with mitral stenosis and severe pulmonary hypertension improves hemodynamics and may have short-term clinical benefits.

Plástica da valva mitral: resultados aos 17 anos de experiência

From March 1980 to December 1997, 545 patients underwent 560 mitral valve repairs at the Heart Institute of HCFMUSP. Ages ranged from 3 months to 86 years with mean age of 42.2 and standard deviation of 21.4 years. Two hundred and seventy four (50.3%) were male. Ethiology was rheumatic disease in 234 (42.9%) patients. The techniques used were: quadrangular resection of posterior leaflet in 204 (36.5%) patients, annuloplasty with posterior sling in 139 (24.5%), Carpentier ring annuloplasty in 102 (18.2%), segmentary posterior annuloplasty in 37 (6.6%) and others. Associated procedures were performed in 267 (35.6%) patients with the most frequent tricuspid valve repair in 95 (17%) patients. Immediate mortality was 3.7% (21 patients). The linearizated rates of reoperation, thromboembolism, endocarditis and hemolysis, were respectively 2.9%, 0.6%, 0.3% and 0.1% patient/ year. The actuarial survival rate at 17 years was 76.8 ± 10.8% and the actuarial freedom from endocarditis, thromboembolism, reoperation and hemolisis at 17 years was 98.9 ± 0.6%, 93.9 ± 3.7%, 61.0 ± 7.9% and 99.7 ± 0.2%, respectively. We conclude that patients submitted to mitral valve repair presented satisfactory evolution.

Mitral valve annuloplasty with a bovine pericardial strip - 18-year results

PURPOSE Prosthetic annuloplasty rings are currently used in mitral reconstruction. Posterior annuloplasty with a bovine pericardial strip is a technique largely used in the Heart Institute of University of São Paulo Medical School. The purpose of the study was to analyze the late results of mitral valve repair with posterior annuloplasty using a bovine pericardial strip. METHODS Between January 1984 and December 2002, 273 patients underwent mitral valve repair with posterior pericardial annuloplasty in the Heart Institute of University of São Paulo Medical School. One hundred and forty four (52.7%) were women and ages ranged between 1 and 76 years (38.3 +/- 21.1). Rheumatic fever was present in 52.0% of the patients. Associated techniques were employed in 26.0% of the patients, and the most frequent was chordal shortening (9.2%). RESULTS Hospital mortality was 3.3% (9 patients), with the major cause being low cardiac output (6 patients). Actuarial survival was 55.1% +/- 16.8% in 18 years. During the 18-year follow-up: patients were free from the following: reoperation (59.1% +/- 13.9%, (percent +/- Standard Error), thromboembolism (97.4% +/- 2.3%), hemolysis (99.2% +/- 0.2%), and endocarditis (99.6% +/- 1.0%). In the late follow-up period, 83.9% were classified as New York Heart Association functional class I. CONCLUSIONS Late results with mitral valve repair with posterior annuloplasty using a bovine pericardial strip were satisfactory. The technique is feasible, reproducible, and cost effective.

Substituição valvar com próteses mecânicas de duplo folheto

OBJECTIVE: The purpose of this study is to analyze the experience of the Heart Institute with the use of mechanical bileaflet prostheses. PATIENTS AND METHODS: Between June 1989 and August 1998, 323 mechanical bileaflet prostheses were implanted in 300 patients. Mean age was 38.7 ± 18.4 years. One hundred and ninety one (63.7%) patients were male. The ethiology was rheumatic fever in 161 (53.7%) patients. One hundred and eighty-six aortic valve replacements, 89 mitral replacements, 2 tricuspid replacements, 22 double mitral and aortic replacement and 1 mitral and tricuspid replacement were performed. Seventy -three (24.3%) patients were in NYHA functional class (FC) IV 165 (55.4%) in FC III and 61 (20.3%) in FC II. RESULTS: Hospital mortality was 9% (27 patients), 13.5% in the mitral group, 7.5% in the aortic group and 4.5% in double mitral and aortic. The linearized rates in the late postoperative period were: 0.3% patient-year for endocarditis, 0.3% patient-year for leak, 0.2% patient-year for hemorrhage and 1.0% patient-year for thromboembolism. In the late postoperative period 213 patients (91%) were in FC I, 16 (6.8%) in FC II, 4 (1.7%) in FC III and 1 (0.5%) in FC IV. The actuarial survival in 9 years was 68.1 ± 15.5% for the mitral group and 67.5 ± 10.8% for the aortic. CONCLUSIONS: In conclusion, the results of valve replacement with mechanical bileaflet prostheses were satisfactory.

Plástica da valva mitral em portadores de febre reumática

Purpose: To analyze the late results of mitral valve repair in rheumatic patients. Material and Methods: Between March 1980 and December 1997, 201 rheumatic patients underwent mitral valve repair in the Heart Institute of HCFMUSP. Average age was 26.9 ± 15.4 years and 59.6% were female. Other diagnoses were present in 67.7% of patients and the most common was tricuspid regurgitation (31.3%). The techniques of repair were: Carpentier ring annuloplasty in 75 (37.3%), posterior annuloplasty with pericardial sling in 68 (33.8%), posterior segmental annuloplasty in 16 (7.9%), quadrangular resection of the posterior leaflet in 11 (5.5%), partial resection of the anterior leaflet in 6 (3%), De Vega type annuloplasty in 6 (3%), Kay in 5 (2.5%), Reed in 4 (2%) and others in 10 patients. Associated techniques were employed in 94 patients (46.8%), the most frequent was chordal shortening (48 patients - 23.9%). Associated procedures were performed in 113 patients (56.2%). The actuarial curves (Kaplan-Meier) were compared through linear regression analysis. Results: Hospital mortality was 4 patients (2.0%) and the causes were multiorgan failure in 2 (50%) and low cardiac output in 2 (50%). In the late postoperative period, 83.9% of the patients were in functional class I (NYHA). The actuarial survival was 93.9 ± 1.9% in 125 months. Twenty three patients were reoperated in the post-operative period with a mean interval of 35.7 months. The actuarial freedom from reoperation was 43.3 ± 13.7% in 125 months. Comparing the patients according to age, in the group over 16 years (group 1), the actuarial survival was 91.3 ± 3.8%, against 95.6 ± 2.7% in the group with more than 16 years (group 2), with a statistic difference (p < 0.0001). Freedom from reoperation was 50.8 ± 16.9% in group 1 and 47.0 ± 14.9% in group 2 (p < 0.0001). Conclusions: Late results with mitral valve repair in rheumatic mitral insufficiency were satisfactory.