The influence of time on the characteristics and risk factors for patients submitted to myocardial revascularization.

OBJECTIVE: To compare the clinical and surgical profile between two groups of patients submitted to Myocardial Revascularization (MCR) surgery at the Instituto de Cardiologia of Rio Grande do Sul with a ten year interval, to observe its influence upon MCR hospital mortality and to verify the predictability of this result using the risk score. METHODS: A retrospective cohort study involving 307 patients who underwent MCR surgery within a six month period during 1991/92 (INITIAL group, n=153) or 2001/02 (CURRENT group, n=154). Demographic characteristics, heart disease, comorbidities and surgical events were analyzed to compare the groups and to define the hospital mortality risk score (based on the Cleveland Clinic method). RESULTS: The CURRENT group was older, had more severe heart condition (functional class, incidence of heart failure and number of vessels with severe lesions) and a greater prevalence of comorbidities. The INITIAL group had a higher prevalence of nonelective surgery. Both groups had similar mean risk scores (2.8 +/- 3.1 for INITIAL and 2.2 +/- 2.5 for CURRENT) and hospital mortality rates (3.3% and 1.9% respectively). These figures are comparable to those for reported by Cleveland Clinic (for a risk score of 3 the predicted mortality range between 2.0 %; using a confidence level of 95% the predicted mortality is between 0 and 4.3%; and actual mortality confirmed by the study was 3.4%). CONCLUSION: Patients currently submitted to MCR are older and in worse clinical condition (heart and systemic) than those operated on ten years ago; however, the risk scores and hospital mortality rates were slightly higher in the INITIAL group. The higher number of nonelective surgical interventions could have contributed to this. A risk score can be used to identify patients that require a higher level of care and to predict surgical outcomes.

Influências temporais nas características e fatores de risco de pacientes submetidos a revascularização miocárdica / The influence of time on the characteristics and risk factors for patients submitted to myocardial revascularization / The influence of time on the characteristics and risk factors for patients submitted to myocardial revascularization

OBJETIVO: Comparar perfil clínico e cirúrgico entre dois grupos de pacientes submetidos a Cirurgia de Revascularização Miocárdica (CRM) no Instituto de Cardiologia do Rio Grande do Sul, com intervalo de 10 anos; observar sua influência na mortalidade hospitalar e verificar previsibilidade deste resultado mediante escore de risco. MÉTODOS: Estudo de coorte retrospectivo, envolvendo 307 pacientes submetidos a CRM isolada em período semestral de 1991/92 (grupo INICIAL, n=153) ou 2001/02 (grupo ATUAL, n=154). Foram analisados características demográficas, doenças cardíacas, co-morbidades e eventos operatórios, visando à comparação entre grupos e definição do escore de risco de morte hospitalar (conforme Cleveland Clinic). RESULTADOS: O grupo ATUAL tinha idade mais avançada, condição cardíaca mais grave (classe funcional, prevalência de insuficiência cardíaca e número de vasos com lesão severa) e maior prevalência de co-morbidades. Os pacientes iniciais mostraram maior prevalência na indicação cirúrgica de urgência. Não ocorreu diferença no escore médio de risco calculado para ambos os grupos (2,8 + 3,1 no INICIAL e 2,2 + 2,5 no ATUAL) ou na mortalidade hospitalar (respectivamente 3,3 por cento e 1,9 por cento), valores comparáveis com os comunicados pela Cleveland Clinic (para escore de risco 3, mortalidade prevista de 2,0 por cento, com limite de confiança 95 por cento de 0-4,3 por cento e mortalidade real em estudo de confirmação de 3,4 por cento). CONCLUSÃO: Pacientes atualmente submetidos a CRM são mais idosos e em pior condição clínica (cardíaca e sistêmica) que os operados há 10 anos, mas a pontuação no escore de risco e a mortalidade hospitalar foram discretamente aumentadas no grupo inicial. Para isto, pode ter contribuído maior prevalência de cirurgias de urgência. Um escore de risco pode ser utilizado para identificar pacientes que requerem maiores cuidados e predizer o resultado cirúrgico.

OBJECTIVE: To compare clinical and surgical and clinical profiles of two group of patients submitted to Coronary Artery Bypass Graft (CABG) at Instituto de Cardiologia do RGS within a decade interval, define related hospital mortality and to validate a severity risk score for this populations. METHODS: Retrospective cohort study, including 307 CABG patients operated during six months of 1991/92 (n=153) and 2001/02 (n=154). Demographic characteristics, heart disease severity, co-morbidities and pre-operative events were evaluated and compared between groups. Hospital mortality and severity risk scores for mortality according to Cleveland Clinic were also assessed. RESULTS: Patients operated in 2001/02 were older, had more severe cardiac disease (increased NYHA functional class, prevalence of heart failure, and distribution of coronary diseased) and presented more co-morbidities than those operated in 1991/92. This patients required urgent surgery more often. The mean Cleveland Clinic severity risk score wasn't different between groups (2.8 + 3.1 in 1991/92 and 2.2 + 2.5 in 2001/02) and hospital mortality didn't present significant difference (3.3 percent and 1.9 percent, respectively). For Cleveland Clinic score 3 the predicted mortality was estimated as 2.0 percent (with confidence limit 95 percent of 0- 4.3 percent) and observed mortality for surgical patients of this institution was 3.4 percent. CONCLUSION: Patients submitted to CABG currently are older and in worse clinical conditions than those operated 10 years ago, but severity risk scores and hospital mortality were discretely increased for initial series of patients. This may be a consequent of a higher prevalence of urgent surgical indication in those patients. A severity risk score for hospital mortality can be used to predict surgical result and identify patients requiring specific care.