Abstract Introduction: This study examines early- and long-term outcomes of mitral valve repairs in a low-volume cardiac surgery centre in the Caribbean. Methods: Ninety-six consecutive patients underwent mitral valve repair from April 2009 to December 2018. Patients were divided into two groups: functional mitral regurgitation requiring simple mitral annuloplasty (FMR, n=63) or structural degenerative mitral regurgitation requiring more complex repair (DMR, n=33). Data collected prospectively were retrospectively analysed from the unit-maintained cardiac surgery database. Results: Thirty-day mortality in the whole series was 2.1%, with 3% in the FMR group and 0% in the DMR group. Early post-operative echocardiography in the FMR group demonstrated 51 patients (83.6%) without mitral regurgitation, 8 patients (13.1%) with trivial to mild regurgitation, and 2 patients (3.3%) with moderate regurgitation. However, at a mean follow-up of 98.2±50.8, only 21 patients (42.8%) were in NYHA class I, with 7 (14.2%) in class II, 16 (32.6%) in class III, and 5 (10.2%) in class IV. There were 9 cardiac-related deaths at final follow-up, with freedom from re-operation and survival of 98% and 75.6%, respectively. In the DMR group, early post-operative echocardiography demonstrated 29 patients (87.9%) without mitral regurgitation, 3 patients (9.1%) with trivial regurgitation and 1 patient (3.0%) with mild regurgitation. At a mean follow-up of 114.1±25.4 months, there was a good functional post-operative status in this group with 93.3% in NYHA class I, and 6.7% in class II. No patient required reintervention, 96.3% of patients had mild or no mitral regurgitation and survival was 90.9%. Conclusion: Despite challenges of maintaining skills in a low-volume centre, mitral valve repair can be performed safely with good early- and long-term results.

ABSTRACT Introduction: The second best conduit for coronary artery bypass grafting is uncertain. The objective of this study is to determine the second best conduit according to graft patency results from randomized controlled trials using a network meta-analysis. Methods: A systematic literature search was conducted for randomized controlled trials comparing the angiographic patency rate of the no-touch saphenous vein (NT-SV), the radial artery (RA), the right internal thoracic artery (RITA), and the gastroepiploic artery (GEA) in reference to the conventionally harvested saphenous vein (CON-SV). The primary outcome was graft occlusion, and the secondary outcome was all-cause mortality. Results: A total of 859 studies were retrieved, of which 18 were included. A total of 6,543 patients and 8,272 grafts were analyzed. The weighted mean angiographic follow-up time was 3.5 years. Compared with CON-SV, RA (incidence rate ratio [IRR] 0.56; 95% confidence interval [CI], 0.43-0.74) and NT-SV (IRR 0.56; 95% CI, 0.44-0.70) demonstrated lower graft occlusion. NT-SV and RA were ranked as the best conduits (rank score for NT-SV 0.88 vs. 0.87 for RA, 0.29 for GEA, 0.27 for CON-SV, and 0.20 for RITA). There was no significant difference in late mortality between different conduit types. Conclusion: RA and NT-SV are associated with significantly lower graft occlusion rates and are comparably ranked as the best conduit for patency.

ABSTRACT Introduction: Coronary artery bypass grafting remains one of the best therapies for advanced coronary artery disease. The most used conduit remains the great saphenous vein, which is susceptible to short-term and long-term failure, the result of acute thrombosis, intimal hyperplasia, and late superimposed atheroma. In this review, we present the current findings related to the pathophysiology of vein graft failure. Methods: A search of three databases - MEDLINE®, Web of Science™, and Cochrane Library - was undertaken for the terms “pathophysiology”, “prevention”, and “treatment” plus the term “vein graft failure”. Results: The pathophysiology of saphenous graft failure can be classified in three distinct phases - acute thrombosis, intimal hyperplasia, and accelerated atherosclerosis. All these processes start with an underlying histological predisposition of the vein and at the time of harvesting and preparation for grafting. These mechanisms are a result of localized inflammatory and prothrombotic cascades that obey different causes, but ultimately result in the stenosis or occlusion of the vein graft. Conclusion: The interaction between the different parts of the pathophysiology of vein graft failure is extremely complex and variable. Recent improvements in surgical techniques and secondary pharmaceutical prevention like early aspirin administration and long-term statin treatment have significantly reduced early and late saphenous vein graft failure. However, this continues to be a fascinating area of research with the potential for further improvement for patients and health service provision.

OBJETIVO: A população do Caribe constitui uma sociedade multiétnica, incluindo caucasianos, afro-caribenhos, indianos, asiáticos, hispânicos, europeus e nativos, com uma grande variabilidade de padrões socioeconômicos. A incidência e os tipos de doenças cardíacas também variam significativamente entre essas etnias. Relatamos aqui a experiência (em pacientes adultos e pediátricos) em um serviço de cirurgia cardíaca de baixo volume em Trinidad e Tobago, no Caribe. MÉTODO: O programa de cirurgia cardíaca de adultos começou em novembro de 1993, são reportados os dados de 878 pacientes (629 homens, idade entre 18 e 88 anos, com média de 67 anos). Destes, 39,4% eram diabéticos e 46,5% hipertensos. Os procedimentos incluíram cirurgia de revascularização miocárdica (CRM), reparo e substituição de valvas e cirurgias da aorta. O programa de cirurgia cardíaca pediátrica (idades entre duas semanas e 21 anos) começou em setembro de 1998, tendo sido realizado um total de 279 operações. RESULTADOS: Adultos - a mortalidade total foi de 3,8%. A maioria dos procedimentos foi CRM (82,3%) com mortalidade total de 2,8% (0% em 2004). A técnica sem circulação extracorpórea foi empregada em 43% dos procedimentos de CRM (71,2% em 2004). A cirurgia de valva aórtica foi feita em 49 pacientes, e a substituição/reparo da valva mitral em 96 doentes. Pediátricos - a maioria dos procedimentos foi correção de comunicação interventricular (111), comunicação interatrial (57), tetralogia de Fallot (23), e 88 outros (com mortalidade de 1,5%). CONCLUSÃO: Cirurgia cardíaca em um serviço multiétnico de baixo volume pode ser realizada com excelentes resultados, comparáveis com padrões internacionais de qualidade.

INTRODUCTION: The Caribbean is a multi-ethnic society, including Caucasian, Afro-Caribbean, East Indians, Asians, Hispanics, European and natives, which has a broad range of living standards. The incidence and types of heart diseases vary significantly amongst these races. We report the surgical experience (adult and paediatric) of a low volume multiethnic population service based on Trinidad and Tobago. METHODS: The Adult Heart Surgery program started in November 1993. The data on a total of 878 cases (629 male, median age 67, range 18-88 years old) is reported. Of these 39.4% were diabetics and 46.5% hypertensive. The procedures performed include coronary artery bypass grafting, valve repair and replacement, and major aortic surgery including emergency dissection. The paediatric heart surgery program started in Sept 1998 and a total of 279 operations have been performed (Age range, 2 weeks to 21 years) RESULTS: Adult - Overall mortality was 3.8%. The majority of procedures were CABG (82.3%) with an overall mortality of 2.8% (0% in 2004). Off pump CABG accounts for 43% of the total procedures (71.2% in 2004). Aortic valve surgery was carried out in 49 patients and mitral valve replacement/ repair in 96 either with or without CABG. Paediatric - The majority of the procedures were VSD 111, ASD 57, TOF 23, and 88 others (including A-V canal, BT shunt, aorta coarctation) with an overall mortality of 1.5%. CONCLUSION: Heart surgery in a multiethnic low volume service can be performed with excellent results comparable to international standards for adults and paediatrics.

Rupture of the left ventricle following mitral valve replacement is a catastrophic complication with deadly consequences. We report here the case of a 75-year-old man who underwent elective mitral valve replacement for severe mitral regurgitation. Delayed type 1 rupture of the left ventricle developed 3 hours postoperatively in the intensive care unit. A salvaging maneuver was used, which gained time, allowing reoperation and successful intraventricular repair.

OBJETIVOS: As cardioplegias sangüíneas normotérmica e hipotérmica, administradas de maneira anterógrada e intermitente, têm demonstrado serem eficientes na proteção miocárdica em cirurgias de revascularização miocárdica. Entretanto, pouco se conhece da eficiência dessas técnicas em corações hipertróficos. Dessa maneira, foram estudados seus efeitos nos substratos intracelulares miocárdicos em pacientes portadores de estenose aórtica, submetidos a cirurgia de troca valvar aórtica. CASUÍSTICA E MÉTODOS: A concentração intracelular miocárdica dos substratos (ATP, lactato, glutamato, aspartato e alanina) foi medida em biópsias de ventrículo esquerdo de 20 pacientes submetidos a troca valvar aórtica, usando, como método de proteção miocárdica, cardioplegia sangüínea normotérmica (n=10) ou hipotérmica (n=10), administradas de forma anterógrada e intermitente. As biópsias foram retiradas 5 minutos após o início da circulação extracorpórea (controle), 30 minutos após o pinçamento aórtico (isquemia) e 20 minutos após o despinçamento (reperfusão). RESULTADOS: Não houve alterações significantes na concentração intracelular dos substratos nas amostras coletadas durante o período isquêmico, em comparação ao controle. Na reperfusão, entretanto, houve significante queda nos valores de ATP e aminoácidos em ambos os grupos, em relação ao grupo controle. CONCLUSÃO: Os dados sugerem que ambos os protocolos de proteção miocárdica empregados não foram eficientes na proteção miocárdica de corações hipertróficos.

OBJECTIVE: Warm intermittent blood cardioplegia has been shown to prevent the reperfusion damage seen when cold blood cardioplegia is used in patients undergoing coronary revascularization. Little is known on the effects of these two cardioplegic techniques on hypertrophic hearts. The aim of this study was to investigate the comparative effects of cold and warm antegrade blood cardioplegia in patients with aortic stenosis who underwent aortic valve replacement. MATERIAL AND METHODS: The intracellular concentration of substrates (ATP, lactate and amino acids) was measured in left ventricular biopsies taken from 20 patients undergoing aortic valve replacement in whom myocardial protection was achieved by hyperkalaemic intermittent warm (n=10) or cold (n=10) blood cardioplegia. Biopsies were taken 5 minutes after institution of cardiopulmonary bypass (control), after 30 minutes of ischaemic arrest and 20 minutes after reperfusion. RESULTS: There were no significant changes in the intracellular concentration of substrates in the samples collected during the time of ischaemic arrest when compared to control. Upon reperfusion however there was a significant fall in the ATP and amino acids regardless of the cardioplegia technique used. CONCLUSION: The data suggest that both cardioplegia techniques do not confer adequate myocardial protection in hypertrophic hearts.