Background Extracorporeal circulation with circuits coated with surface-bound heparin has allowed reduced levels of systemic heparinization. Clinical benefits have included reduced postoperative bleeding and less homologous blood usage. However, the effects on the hemostatic and fibrinolytic systems have remained in part unknown. Methods and Results Indications of thrombin generation, platelet activation, and fibrinolytic activity were investigated in patients undergoing coronary artery bypass surgery. Two groups were perfused with cardiopulmonary bypass (CPB) circuits completely coated with surface-bound heparin: one group with low systemic heparin dose (activated clotting time [ACT] >250 seconds; n=17) and a second group having a full heparin dose (ACT >480 seconds; n=18). A third control group was perfused with ordinary uncoated circuits and full heparin dose (n=17). The plasma level of thrombin-antithrombin complex and prothrombin fragment 1.2 increased in all groups during bypass, and somewhat more in both the heparin-coated groups toward the end of CPB, compared with the control group ( P <.01). However, the increase during CPB was minimal compared with the major elevation observed 2 hours after surgery in all groups. Platelet release of β-thromboglobulin increased in all groups ( P <.01) during CPB and significantly more in the high-dose group compared with the other two groups ( P =.03). Fibrinolytic activities were similar in all groups, and there were no indications of major consumption of coagulation factors. Conclusions Reduced systemic heparinization (ACT >250 seconds) in patients having extracorporeal circulation with completely heparin-coated circuits did not lead to increased thrombogenicity. Thrombin formation remained within low ranges during CPB compared with patients receiving a full heparin dose and with the major elevations observed after surgery.
An alternative approach to the study of the follow-up of patients with heart prostheses is the use of the reliability theory (hazard function) and proportional hazard model (Cox's model). In a population of 480 patients who underwent AVR in the period from June 1977 to January 1983, with a mean follow-up time of 2.8 years, 16 preoperative variables were considered. From this pool of variables, six entered the regression model in a time-independent mode. These were age at operation, sex, preoperative NYHA classification, presence of AI, presence of endocarditis and presence of atrial fibrillation on ECG, none of which entered the model in the time-related mode. Another multifactorial approach, using a stepwise regression analysis to examine primary predictive factors that independently correlate with survival, while simultaneously accounting for the other previous variables, showed that the variables with additive prognostic value were age at operation, presence of AI and presence of endocarditis. Based on this model, a forecast five-year survival rate ranging from 88 to 14 per cent was found at the end of the fifth year. For the most favourable and the worst combinations of these prognostic variables, a patient-specific forecast five-year survival rate was drawn up. Our results were compared, using univariate and multivariate methods, with the results found in the literature, and the implications of this comparison were discussed.
To determine survival and the risk factors of death in primary biliary cirrhosis, data from 52 symptomatic and 13 asymptomatic patients were analyzed. The mean follow-up time was 6.3 years (range, 0.4-23 years). The average length of survival was 18 years for the symptomatic and 8.4 years for the asymptomatic patients. By a univariate analysis, ascites, presence of esophageal varices, gastrointestinal bleeding, jaundice, hepatomegaly and the logarithms of albumin and bilirubin were all associated with a poor prognosis. A multivariate analysis of the clinical features showed that the presence of bleeding from esophageal varices and the logarithm of bilirubin were the only predictors for poor prognosis. The survival of the symptomatic patients is longer than reported previously, while the life expectancy for the asymptomatic patients seems no better than for the symptomatic group.
Serious pulmonary failure may be treated with extracorporeal membrane oxygenation (ECMO) when other treatment has failed. The aim of this study was to analyze pre-operative risk factors of early mortality in patients who underwent either veno-arterial (VA) ECMO or veno-venous (VV) ECMO for pulmonary failure. We studied a total of 26 risk factors in 72 patients with severe pulmonary insufficiency treated with ECMO. All consecutive cases treated at our institution between Sept 1990 and Aug 2007 were included. Univariate analysis and multiple logistic regression analysis were performed on 26 risk factors. The end point was early mortality (any death within 30 days of ECMO treatment). Thirty-six (50%) of the patients died within 30 days of treatment. Age, gender, body mass index(BMI)(adults), cause of pulmonary failure, pre-ECMO treatment with nitric oxide(NO), intra-aortic balloon pump(IABP), and type of ventilation did not significantly influence early mortality. Neither pre-operative blood gas results, oxygenation index or pre-operative PaO 2 /FiO 2 ratio, nor mean ventilator days prior to ECMO gave any indications on early mortality. Liver function did not predict early mortality, but pre-ECMO serum creatinine levels were significantly lower in patients who survived. Treatment with ECMO in patients with severe pulmonary failure may save lives. It is, however, difficult to predict outcome when initiating ECMO. In this analysis, only pre-operative serum creatinine levels correlated with survival. None of the other parameters, including those which were used to select patients for ECMO treatment, could significantly predict the outcome.
Long-term results after prosthetic heart valve replacement are usually presented in actuarial terms, which do not take into account the background mortality of the general population. The calculations of the relative survival, which is the ratio between the observed survival in a group of patients during a specified time interval and the survival expected from the general population experience, permit correction for important demographic variables. We have analysed the long-term relative survival rates in a consecutive series of 841 Norwegian patients who, on the basis of clinical symptoms, underwent aortic (AVR, n = 617), mitral (MVR, n = 146), and double (AVR + MVR, n = 78) valve replacement between June 1977 and January 1985. The follow-up was closed on May 1st 1986, was 100% complete and included 2056 patient-years. The actuarial survival data for the total cohort was 75.1%, and for AVR, MVR and DVR, 77.9, 69.7 and 63.0%, respectively. The corresponding figures for the relative survival were 83.5, 87.0, 76.6 and 69.1%, respectively. Within the subgroup undergoing AVR, our analysis demonstrated a poor prognosis in those who were operated for pure aortic regurgitation or endocarditis, as well as in those who received the smallest valve size prosthesis due to a narrow aortic root. In this analysis, as in the analysis of the total material, we observed that the differences between survival in the patients and in the general population were of smaller magnitude when based on relative survival rates than when analysed in the standard (actuarial) way.(ABSTRACT TRUNCATED AT 250 WORDS)
To study the pre-operative level of left ventricular ejection fraction that may be indicative of an increased risk of early and late mortality and of recurrent angina pectoris and late non-fatal myocardial infarction.A total of 934 patients with known left ventricular ejection fraction, 80 women and 854 men, were submitted to coronary artery bypass grafting at the Cardiovascular Unit of Rikshospitalet, Oslo, between August 1982 and December 1986. The closing date was the 1st of January 1993, with a mean follow-up of time of 7.4 years. The patients were divided in to four subgroups according to their level of left ventricular ejection fraction: < or = 40%, 41-60%, 61-80% and > 80%. The left ventricular ejection fraction varied from 13-98%. A chi-square test of linear trend was used to calculate the relative risk between the different subgroups. Cumulative survival was determined using survival curves.Early mortality. Twenty-five patients (2.7%) died within 30 days of operation. Patients with left ventricular ejection fraction < or = 40% had a relative risk of 10.2 (1.9-17.2), for left ventricular ejection fraction 41-60% the relative risk was 0.9 (0.1-8.9) and for left ventricular ejection fraction 61-80% the relative risk was 2.8 (0.6-17.2). Left ventricular ejection fraction > 80% was defined as relative risk = 1. Late mortality. Altogether, 174 patients died in the late phase (18.6%). For patients with left ventricular ejection fraction < or = 40% the relative risk was 3.6 (2.8-10.9), for left ventricular ejection fraction 41-60% the relative risk was 1.8 (1.1-3.6), and for left ventricular ejection fraction 61-80% the relative risk was 1.5 (0.9-2.8). Recurrent angina pectoris. A total of 138 patients developed recurrent angina pectoris during the follow-up period, giving an incidence of 14.8%. Here, for left ventricular ejection fraction < or = 40% the relative risk was 0.5 (0.2-1.3), for left ventricular ejection fraction 41-60% the relative risk was 1.0 (0.5-1.8) and for left ventricular ejection fraction 61-80% the relative risk was 1.2 (0.7-2.0). Late non-fatal myocardial infarction. Altogether, 90 patients (9.6%) experienced non-fatal myocardial infarction in the late phase. For left ventricular ejection fraction < or = 40% the relative risk was 0.6 (1.2-1.8), for left ventricular ejection fraction 41-60% the relative risk was 1.0 (0.5-2.0) and for left ventricular ejection fraction 61-80% the relative risk was 0.7 (0.41-1.3). Cumulative survival. When pooled together, the cumulative survival for patients with left ventricular ejection fraction > 40% was 95.9, 91.9 and 79% after 1, 5 and 10 years, respectively. For the patients with left ventricular ejection fraction < or = 40% cumulative survival was 87.5, 73.1 and 55.2%, respectively.When the left ventricular ejection fraction was 40% or lower, there was a substantial increase in the risk of early mortality in patients submitted to coronary artery bypass grafting. As for the risk of late mortality, there was a practically linear increase in risk with falling values of left ventricular ejection fraction. We found no difference in risk of developing recurrent angina pectoris or of late non-fatal myocardial infarction related to values of left ventricular ejection fraction.
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