Operação de Ross: Resultados a Médio Prazo

The Ross procedure has been used in children and young adults for aortic valve replacement and the correction of complex obstruction syndromes of the left ventricular outflow tract. We report the mid-term results of the Ross procedure in a single institution and performed by the same surgical team. Population: Between March 1999 and December 2005, 18 patients were operated on using the Ross procedure. The mean age at the time of surgery was 12 years, being 12 patients male (67%). The primary indication for surgery was isolated aortic valve disease, being the predominant abnormality in 58% of cases aortic regurgitation and in 42% left ventricular outflow tract obstruction. Associated lesions included sub-aortic membrane in 3 patients (16%), small VSD in 2 patients (11%), bicuspid aortic valve in 4 patients (22%) and severe left ventricular dysfunction and mitral valve regurgitation in 1 patient (6%). Ten of the 18 patients (56%) had been submitted to previous surgical procedures or percutaneous interventions. Results: Early post-operative mortality was not seen, but two patients (11%), had late deaths, one due to endocarditis, a year after the Ross procedure, and the other due to dilated cardiomiopathy and mitral regurgitation. The shortest time of follow-up is 6 months and the longest 72 months (median 38 months). Of the 16 survivors, 14 patients are in class I of the NYHA and 2 in class II, without significant residual lesions or need for re-intervention. The 12 patients with more than a year of follow up revealed normal coronary perfusion in all patients and no segmental wall motion abnormalities. Nevertheless, two of the 12 patients developed residual dynamic obstruction of LVOT and in three patients aortic regurgitation of a mild to moderate degree was evident. Significant gradients were not verified in the RVOT. Conclusions: The Ross procedure, despite its complexity, can be undertaken with excellent immediate results. Aspects such as the dilation of the neo aortic root and homograft evolution can not be considered in a study of this nature, seeing that the mean follow up time does not exceed 5 years.

Endocardite a Nocardia após Cirurgia de Substituição Valvular Mitral: Caso Clínico e Revisão da Literatura

A Nocardia é responsável por diversos tipos de infecção quer em receptores imunocompetentes, quer imunocomprometidos e pode afectar qualquer órgão. A endocardite a Nocardia spp é muito rara e tem mau prognóstico. Segundo o nosso conhecimento e após revisão da literatura, foram reportados apenas 12 casos de endocardite a Nocardia, a maioria tratada com substituição valvular. Reportamos o primeiro caso descrito em Portugal de endocardite protésica a Nocardia, tratado com sucesso apenas com terapêutica antimicrobiana (trimetoprimsulfametoxazol), sem necessidade de substituição valvular.

Intervenção Percutânea Urgente no Enfarte Agudo do Miocárdio por Lesão do Tronco Comum

BACKGROUND: ST-elevation myocardial infarction (STEMI) with the culprit lesion in the left main artery is a rare cardiac emergency with a poor prognosis. OBJECTIVE: Review and prognosis evaluation of primary percutaneous coronary intervention (PCI) performed in the setting of STEMI with left main occlusion in a single high-volume center. METHODS: Of the 483 primary or rescue PCIs performed and followed in our hospital during a 24-month period (August 2004 to July 2006), we retrospectively evaluated those involving left main procedures and analyzed in-hospital mortality and major cardiac events (MACE) in a 12-month follow-up. We found nine patients, age 68 +/- 9 years, five male, seven with multivessel disease and two with isolated left main disease. Rescue PCI was performed in three patients and primary PCI in the others. RESULTS: Seven patients presented in cardiogenic shock and two were classified in Killip class II on admission. Inotropic drugs, intra-aortic balloon pump and abciximab were used in eight patients. Drug-eluting stents were used in six patients, bare-metal stents in two, and isolated balloon angioplasty in one. Five patients (55%) died in the hospital and the four discharged home (two of them aged 81 and 82 years) were still alive and free from MACE at 12-month follow-up. CONCLUSIONS: Clinical presentation of STEMI with the culprit lesion in the left main artery was very severe. During PCI, drug-eluting stents, intra-aortic balloon pump and abciximab were used in almost all patients. This entity had a high mortality rate even though primary PCI was performed. Those who survived had a good mid-term prognosis.

Mitral Valve Myxomas: an Unusual Entity

Primary tumours of the heart are uncommon entities, cardiac myxomas being the most frequent. However, mitral valve myxomas are exceptionally rare. In the last 12 years, there have been 25 myxomas diagnosed at our institution, with only two of them originating from the mitral valve. Both patients were female, the first, 25, and the second, 72 years old. The younger patient was very symptomatic with a large mass, 4 cm long, which involved both leaflets causing significant obstruction to the left ventricular inflow. The second one had a smaller mass located at the atrial side of the posterior leaflet that only produced some flow divergence. Neither of them had constitutional nor embolic symptoms. Both patients were submitted to emergent surgical resection that in the first case involved the mitral valve and replacement with mechanical prosthesis. The macroscopic appearance of these tumours suggested a malignant aetiology which may represent somewhat different features of the myxomas when originating from the cardiac valves. Both patients are well reflecting the good prognosis of this illness after resection, although the younger patient was re-operated because of prosthetic valve obstruction and suspicion of recurrence that was not confirmed. Because of the illustrative images and different presentations, we found it interesting to report and discuss them together.

Iatrogenic Aortic Pseudoaneurysm: a Forgotten Complication

Pseudoaneurysms of the ascending aorta are a rare complication of cardiac surgery. However, the poor prognosis associated with this condition if untreated makes early diagnosis and treatment important. We present the case of a 66-year-old woman who had undergone mitral valvuloplasty 12 days previously, who was admitted with a diagnosis of new-onset atrial fibrillation. The transthoracic echocardiogram showed a clot in the right atrium and anticoagulation was initiated, followed by antibiotic therapy. After further investigation, the patient was diagnosed with a pseudoaneurysm of the ascending aorta and underwent surgical repair, followed by six weeks of antibiotic therapy. She was readmitted six months later for an abscess of the lower sternum and mediastinum. After a conservative approach with antibiotics and local drainage failed, recurrence of a large pseudoaneurysm compressing the superior vena cava was documented. A third operation was performed to debride the infected tissue and to place an aortic allograft. There were no postoperative complications.

Prognostic Value of VEGF in Patients Submitted to Percutaneous Coronary Intervention

We examined the longitudinal changes of VEGF levels after percutaneous coronary intervention for predicting major adverse cardiac events (MACE) in coronary artery disease (CAD) patients. VEGF was measured in 94 CAD patients' serum before revascularization, 1-month and 1-year after. Independently of clinical presentation, patients had lower VEGF concentration than a cohort of healthy subjects (median, IQ: 15.9, 9.0-264 pg/mL versus 419, 212-758 pg/mL; P < 0.001) at baseline. VEGF increased to 1-month (median, IQ: 276, 167-498 pg/mL; P < 0.001) and remained steady to 1-year (median, IQ: 320, 173-497 pg/mL; P < 0.001) approaching control levels. Drug eluting stent apposition and previous medication intake produced a less steep VEGF evolution after intervention (P < 0.05). Baseline VEGF concentration <40.8 pg/mL conveyed increased risk for MACE in a 5-year follow-up. Results reflect a positive role of VEGF in recovery and support its importance in CAD prognosis.

Prosthetic Mitral Valve Thrombosis in Pregnancy: From Thrombolysis to Anticoagulation

INTRODUCTION: Pregnant women with mechanical prosthetic heart valves are at increased risk for valve thrombosis. Management decisions for this life-threatening complication are complex. Open-heart surgery has a very high risk of maternal mortality and fetal loss. Bleeding and embolic risks associated with thrombolytic agents, the limited efficacy of thrombolysis in certain subgroups, and a lack of experience in the setting of pregnancy raise important concerns. CASE REPORT: We report a case of mitral prosthetic valve thrombosis in early pregnancy, which was successfully treated with streptokinase. Ten years later, the same patient had an uneventful pregnancy, throughout which acenocoumarol was maintained. CONCLUSION: With this case we review the prevention (with oral anticoagulant therapy) and treatment of prosthetic valve thrombosis during pregnancy, which is important for both obstetrician and cardiologist.

Validation of Two US Risk Scores for Percutaneous Coronary Intervention in a Single-Center Portuguese Population of Patients with Acute Coronary Syndrome

INTRODUCTION: New scores have been developed and validated in the US for in-hospital mortality risk stratification in patients undergoing coronary angioplasty: the National Cardiovascular Data Registry (NCDR) risk score and the Mayo Clinic Risk Score (MCRS). We sought to validate these scores in a European population with acute coronary syndrome (ACS) and to compare their predictive accuracy with that of the GRACE risk score. METHODS: In a single-center ACS registry of patients undergoing coronary angioplasty, we used the area under the receiver operating characteristic curve (AUC), a graphical representation of observed vs. expected mortality, and net reclassification improvement (NRI)/integrated discrimination improvement (IDI) analysis to compare the scores. RESULTS: A total of 2148 consecutive patients were included, mean age 63 years (SD 13), 74% male and 71% with ST-segment elevation ACS. In-hospital mortality was 4.5%. The GRACE score showed the best AUC (0.94, 95% CI 0.91-0.96) compared with NCDR (0.87, 95% CI 0.83-0.91, p=0.0003) and MCRS (0.85, 95% CI 0.81-0.90, p=0.0003). In model calibration analysis, GRACE showed the best predictive power. With GRACE, patients were more often correctly classified than with MCRS (NRI 78.7, 95% CI 59.6-97.7; IDI 0.136, 95% CI 0.073-0.199) or NCDR (NRI 79.2, 95% CI 60.2-98.2; IDI 0.148, 95% CI 0.087-0.209). CONCLUSION: The NCDR and Mayo Clinic risk scores are useful for risk stratification of in-hospital mortality in a European population of patients with ACS undergoing coronary angioplasty. However, the GRACE score is still to be preferred.

Dura mater mitral and tricuspid bioprostheses: 30 years of follow-up

PURPOSE: The dura mater bioprosthesis was developed in the Department of Cardiopneumology of the Hospital das Clínicas of the University of São Paulo Medical School in 1971. Here, we present the clinical results of the dura mater bioprosthesis over 30 years of follow-up. METHODS: We studied 70 consecutive patients who underwent mitral or tricuspid valve replacement with a dura mater bioprosthesis between January 1971 and August 1972. RESULTS: The early mortality was 10% (7 patients). The follow-up was 87% complete (9 patients were lost to follow-up). Two patients were alive and asymptomatic 30 years after valve replacement; 33 patients underwent reoperations due to valve dysfunction, and 19 died during the follow-up period. At 30 years, the actuarial survival was 49.2 ± 8.6%; freedom from rupture, 27.0 ± 10.2%; freedom from calcification, 78.8 ± 8.6%; and freedom from reoperation, 18.8 ± 7.5%. CONCLUSIONS: The dura mater bioprosthesis played an important role in the treatment of patients with mitral and tricuspid valve disease. The low rate of thromboembolism and the long period of follow-up without evidence of valve dysfunction, which occurred for several of our patients, are important characteristics of these bioprosthesis.

Valvoplastia mitral percutânea de urgência em gestante

Gestante com 33 anos na 28ª semana e sinais de óbito fetal foi admitida em caráter de urgência com quadro de edema pulmonar agudo secundário à estenose mitral grave. Com o insucesso do tratamento medicamentoso intensivo, a paciente foi submetida à valvoplastia mitral percutânea de emergência com melhora imediata. O agravamento subseqüente do quadro, atribuído ao óbito fetal, foi tratado através parto cesáreo com melhora clínica considerável. A paciente teve alta hospitalar no 10º dia, e 11 meses após o procedimento, encontra-se em classe funcional I, sem uso de medicação e com sinais ecocardiográficos de estenose mitral leve (área valvar: 2,0 cm²).

Estudo mesoscópico da valva mitral e do seu anel fibroso

OBJETIVO: Estudar o arranjo espacial dos elementos fibrosos que constituem os folhetos da valva mitral e do seu anel fibroso. MÉTODOS: Foram utilizados 20 corações adultos, de ambos os sexos, fixados em formol a 10%. Isolaram-se a valva mitral, juntamente com o anel fibroso, e uma pequena quantidade de tecido muscular ao seu redor. Parte desse material foi incluído em parafina, submetido a cortes seriados de 40µm de espessura e corados pelo tricrômio de Azan e pela resorcina-fucsina, e o restante das peças dissecadas sob lupa estereoscópica, com ajuda de delicadas pinças e agulhas, para se observar a disposição dos feixes miocárdicos ao nível do anel mitral. RESULTADOS: Observou-se que o anel fibroso mitral era constituído por feixes colágenos de trajetória semicircular, envolvendo de forma incompleta o óstio atrioventricular, uma vez que era ausente na região ântero-medial do óstio. Verificou-se que os feixes miocárdicos ventriculares inseriam-se de forma oblíqua, na borda externa do anel, sendo que na região ântero-medial assumiam uma trajetória semicircular. Os folhetos da valva mitral eram constituídos de feixes colágenos dispostos, paralelamente, no sentido do maior eixo da válvula, recobertos pelo endocárdio atrial e ventricular. Os feixes colágenos, presentes na base dos folhetos valvares, praticamente se continuavam com os do anel fibroso. Observou-se, em alguns casos, a existência de delgados feixes miocárdios atriais no folheto valvar anterior, que praticamente eram restritos à região central das válvulas. CONCLUSÃO: Os folhetos da valva mitral e seu anel fibroso possuem uma continuidade estrutural, que demonstra que estes elementos funcionam de forma integrada no fechamento do óstio atrioventricular esquerdo durante a sístole ventricular, no que seria auxiliado pela redução do diâmetro do anel fibroso, através da contração dos feixes miocárdicos semicirculares que nele se inserem.

Adaptações fisiológicas precoces e tardias após valvotomia mitral por cateter balão

OBJETIVO: Avaliação não invasiva das respostas cardiopulmonares ao exercício a curto e longo prazo após valvotomia mitral por cateter balão. MÉTODOS: Estudaram-se 9 pacientes do sexo feminino, 35±9 anos, com estenose mitral, tipo funcional II ou III, em uso de digitálicos e diuréticos, através de teste ergoespirométrico, eletrocardiograma e ecocardiograma, antes e após valvotomia em fase precoce (3 a 5 dias) e tardia (8 a 12 meses). RESULTADOS: Os pacientes evoluíram para tipo funcional II (44%) ou I (56%), na fase tardia. Houve redução da freqüência cardíaca de repouso (87±11bpm vs 85±7bpm vs 75±9bpm) e elevação do número de estágios (4±1 estágios vs 5±2 estágios vs 6±1 estágios); a capacidade aeróbia máxima aumentou apenas na fase tardia (16±3mL/kg/min vs 18±4mL/kg/min vs 22±7mL/kg/min). O limiar anaeróbio, a ventilação pulmonar e o equivalente ventilatório do O2 permaneceram inalterados. Nas cargas submáximas de exercício ocorreu redução da freqüência cardíaca (estágio I: 124±18bpm vs 112±13bpm vs 87±15bpm), consumo de O2 (estágio I: 10±2mL/kg/min vs 8±2mL/kg/min vs 8±mL/kg/min) e ventilação pulmonar, nas fases precoce e tardia. A área valvar mitral mostrou reduções na fase tardia (0,94cm² vs 1,66cm² vs 1,20cm² ). CONCLUSÃO: Apesar da tendência à reestenose parcial, houve melhora no tipo funcional e no desempenho cardiopulmonar com diminuição da sobrecarga circulatória no exercício submáximo.

Avaliação comparativa entre valvoplastia percutânea e comissurotomia a céu aberto na estenose mitral

OBJETIVO: Comparar resultados imediatos e após 12 meses de seguimento entre valvoplastia por balão e comissurotomia na estenose mitral. MÉTODOS: Oitenta e oito portadores de estenose mitral sintomáticos com anatomia favorável foram randomizados nos dois grupos. Todos os pacientes submeteram-se a avaliação clínica e Doppler ecocardiográfica antes, imediatamente após e 12 meses depois do procedimento. RESULTADOS: Gradiente médio mitral (mmHg) diminuiu (p<0,001) de 12,18±5,84 para 5,80±2,66 no grupo comissurotomia (GC) e de 11,66±6,13 para 4,98±2,40 (p<0,001) no grupo valvuloplastia (GV). Área valvar mitral (cm²) aumentou de 0,98±0,21 para 2,52±0,46 no GC e de 1,05±0,25 para 2,18±0,40 no GV (p<0,001). Em ambos os grupos ocorreu uma diminuição discreta na área valvar mitral ao final do acompanhamento. Não ocorreram óbitos. Um paciente do GV apresentou insuficiência mitral significativa e necessitou tratamento cirúrgico. Aos 12 meses de acompanhamento todos os pacientes do GC e 97,7% dos pacientes do GV estavam em classe funcional I ou II (NYHA). CONCLUSÃO: Os procedimentos foram seguros e mostraram melhora semelhante no gradiente mitral e classe funcional. A área valvar mitral aumentou expressivamente mais no GC, e apresentou, também, uma redução mais significativa após 12 meses. A maioria dos pacientes não alterou a classe funcional no acompanhamento.