10 resultados para Modèle de Cox pondéré
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Cardiopulmonary exercise testing (CPET) is an objective method for assessment of functional capacity and for prognostic stratification of patients with chronic heart failure (CHF). In this study, we analyzed the prognostic value of a recently described CPET-derived parameter, the minute ventilation to carbon dioxide production slope normalized for peak oxygen consumption (VE/VCO2 slope/pVO2). METHODS: We prospectively studied 157 patients with stable CHF and dilated cardiomyopathy who performed maximal CPET using the modified Bruce protocol. The prognostic value of VE/VCO2 slope/pVO2 was determined and compared with traditional CPET parameters. RESULTS: During follow-up 37 patients died and 12 were transplanted. Mean follow-up in surviving patients was 29.7 months (12-36). Cox multivariate analysis revealed that VE/VCO2 slope/pVO2 had the greatest prognostic power of all the parameters studied. A VE/VCO2 slope/pVO2 of > or = 2.2 signaled cases at higher risk. CONCLUSION: Normalization of the ventilatory response to exercise for peak oxygen consumption appears to increase the prognostic value of CPET in patients with CHF.
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INTRODUCTION: A growing body of evidence shows the prognostic value of oxygen uptake efficiency slope (OUES), a cardiopulmonary exercise test (CPET) parameter derived from the logarithmic relationship between O(2) consumption (VO(2)) and minute ventilation (VE) in patients with chronic heart failure (CHF). OBJECTIVE: To evaluate the prognostic value of a new CPET parameter - peak oxygen uptake efficiency (POUE) - and to compare it with OUES in patients with CHF. METHODS: We prospectively studied 206 consecutive patients with stable CHF due to dilated cardiomyopathy - 153 male, aged 53.3±13.0 years, 35.4% of ischemic etiology, left ventricular ejection fraction 27.7±8.0%, 81.1% in sinus rhythm, 97.1% receiving ACE-Is or ARBs, 78.2% beta-blockers and 60.2% spironolactone - who performed a first maximal symptom-limited treadmill CPET, using the modified Bruce protocol. In 33% of patients an cardioverter-defibrillator (ICD) or cardiac resynchronization therapy device (CRT-D) was implanted during follow-up. Peak VO(2), percentage of predicted peak VO(2), VE/VCO(2) slope, OUES and POUE were analyzed. OUES was calculated using the formula VO(2) (l/min) = OUES (log(10)VE) + b. POUE was calculated as pVO(2) (l/min) / log(10)peakVE (l/min). Correlation coefficients between the studied parameters were obtained. The prognosis of each variable adjusted for age was evaluated through Cox proportional hazard models and R2 percent (R2%) and V index (V6) were used as measures of the predictive accuracy of events of each of these variables. Receiver operating characteristic (ROC) curves from logistic regression models were used to determine the cut-offs for OUES and POUE. RESULTS: pVO(2): 20.5±5.9; percentage of predicted peak VO(2): 68.6±18.2; VE/VCO(2) slope: 30.6±8.3; OUES: 1.85±0.61; POUE: 0.88±0.27. During a mean follow-up of 33.1±14.8 months, 45 (21.8%) patients died, 10 (4.9%) underwent urgent heart transplantation and in three patients (1.5%) a left ventricular assist device was implanted. All variables proved to be independent predictors of this combined event; however, VE/VCO2 slope was most strongly associated with events (HR 11.14). In this population, POUE was associated with a higher risk of events than OUES (HR 9.61 vs. 7.01), and was also a better predictor of events (R2: 28.91 vs. 22.37). CONCLUSION: POUE was more strongly associated with death, urgent heart transplantation and implantation of a left ventricular assist device and proved to be a better predictor of events than OUES. These results suggest that this new parameter can increase the prognostic value of CPET in patients with CHF.
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BACKGROUND: The major causes of renal transplant loss are death and chronic allograft dysfunction (CAD). The aims of this study were to determine the incidence of CAD in our population and the relation between allograft survival and immunosuppressive regimens. METHODS: We studied retrospectively 473 patients who received deceased donor kidney transplants with at least 1 allograft biopsy between January 1990 and May 2007. Clinical data included age, gender, biopsy data, and immunosuppression before and after kidney biopsy. Mean age was 45.4 +/- 12.7 years including 65% males with a mean follow-up of 6.7 +/- 4.5 years. CAD was observed in 177 of 473 biopsies: 48 patients showed interstitial fibrosis (IF); 101 chronic rejection (CR); 16 transplant glomerulopathy (TG); and 12, CR and TG. Mean follow-up since the discovery of the histologic feature was 60.5 +/- 50.5 months for IF; 38.3 +/- 40.8 for CR, and 18.2 +/- 19.2 for TG. RESULTS: CAD, which was more common in younger patients (P = .03), correlated upon univariate and multivariate analysis with CKD stage 5d development (P < .001). Deposition of C4d in peritubular capillaries was more frequent among CAD patients (P = .004), an association with particular relevance to recipients with CR (P = .02) and TG (P < .001). When we analyzed CAD subpopulation, we observed a positive correlation between allograft survival and immunosuppression modification after biopsy. Substitution of sirolimus (40/177) was shown in univariate, multivariate and Cox regression analyses to be a renal protector (P < .002). Allograft survival was also correlated with initial mycophenolate mofetil versus azathioprine, (62/177) immunosuppression (P < .001). CONCLUSION: CAD, a frequent histologic feature, may benefit from sirolimus conversion.
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OBJECTIVE: Long-term follow-up after endovascular aneurysm repair (EVAR) is very scarce, and doubt remains regarding the durability of these procedures. We designed a retrospective cohort study to assess long-term clinical outcome and morphologic changes in patients with abdominal aortic aneurysms (AAAs) treated by EVAR using the Excluder endoprosthesis (W. L. Gore and Associates, Flagstaff, Ariz). METHODS: From 2000 to 2007, 179 patients underwent EVAR in a tertiary institution. Clinical data were retrieved from a prospective database. All patients treated with the Excluder endoprosthesis were included. Computed tomography angiography (CTA) scans were retrospectively analyzed preoperatively, at 30 days, and at the last follow-up using dedicated tridimensional reconstruction software. For patients with complications, all remaining CTAs were also analyzed. The primary end point was clinical success. Secondary end points were freedom from reintervention, sac growth, types I and III endoleak, migration, conversion to open repair, and AAA-related death or rupture. Neck dilatation, renal function, and overall survival were also analyzed. RESULTS: Included were 144 patients (88.2% men; mean age, 71.6 years). Aneurysms were ruptured in 4.9%. American Society of Anesthesiologists classification was III/IV in 61.8%. No patients were lost during a median follow-up of 5.0 years (interquartile range, 3.1-6.4; maximum, 11.2 years). Two patients died of medical complications ≤ 30 days after EVAR. The estimated primary clinical success rates at 5 and 10 years were 63.5% and 41.1%, and secondary clinical success rates were 78.3% and 58.3%, respectively. Sac growth was observed in 37 of 142 patients (26.1%). Cox regression showed type I endoleak during follow-up (hazard ratio, 3.74; P = .008), original design model (hazard ratio, 3.85; P = .001), and preoperative neck diameter (1.27 per mm increase, P = .006) were determinants of sac growth. Secondary interventions were required in 32 patients (22.5%). The estimated 10-year rate of AAA-related death or rupture was 2.1%. Overall life expectancy after AAA repair was 6.8 years. CONCLUSIONS: EVAR using the Excluder endoprosthesis provides a safe and lasting treatment for AAA, despite the need for maintained surveillance and secondary interventions. At up to 11 years, the risk of AAA-related death or postimplantation rupture is remarkably low. The incidences of postimplantation sac growth and secondary intervention were greatly reduced after the introduction of the low-permeability design in 2004.
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OBJECTIVE: The objective of the study was to develop a model for estimating patient 28-day in-hospital mortality using 2 different statistical approaches. DESIGN: The study was designed to develop an outcome prediction model for 28-day in-hospital mortality using (a) logistic regression with random effects and (b) a multilevel Cox proportional hazards model. SETTING: The study involved 305 intensive care units (ICUs) from the basic Simplified Acute Physiology Score (SAPS) 3 cohort. PATIENTS AND PARTICIPANTS: Patients (n = 17138) were from the SAPS 3 database with follow-up data pertaining to the first 28 days in hospital after ICU admission. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The database was divided randomly into 5 roughly equal-sized parts (at the ICU level). It was thus possible to run the model-building procedure 5 times, each time taking four fifths of the sample as a development set and the remaining fifth as the validation set. At 28 days after ICU admission, 19.98% of the patients were still in the hospital. Because of the different sampling space and outcome variables, both models presented a better fit in this sample than did the SAPS 3 admission score calibrated to vital status at hospital discharge, both on the general population and in major subgroups. CONCLUSIONS: Both statistical methods can be used to model the 28-day in-hospital mortality better than the SAPS 3 admission model. However, because the logistic regression approach is specifically designed to forecast 28-day mortality, and given the high uncertainty associated with the assumption of the proportionality of risks in the Cox model, the logistic regression approach proved to be superior.
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Introduction & Objectives: Several factors may influence the decision to pursue nonsurgical modalities for the treatment of non-melanoma skin cancer. Topical photodynamic therapy (PDT) is a non-invasive alternative treatment reported to have a high efficacy when using standardized protocols in Bowen’s disease (BD), superficial basal cell carcinoma (BCC) and in thin nodular BCC. However, long-term recurrence studies are lacking. The aim of this study was to evaluate the long-term efficacy of PDT with topical methylaminolevulinate (MAL) for the treatment of BD and BCC in a dermato-oncology department. Materials & Methods: All patients with the diagnosis of BD or BCC, treated with MAL-PDT from the years 2004 to 2008, were enrolled. Treatment protocol included two MAL-PDT sessions one week apart repeated at three months when incomplete response, using a red light dose of 37-40 J/cm2 and an exposure time of 8’20’’. Clinical records were retrospectively reviewed, and data regarding age, sex, tumour location, size, treatment outcomes and recurrence were registered. Descriptive analysis was performed using chi square tests, followed by survival analysis with the Kaplan-Meier and Cox regression models. Results: Sixty-eight patients (median age 71.0 years, P25;P75=30;92) with a total of 78 tumours (31 BD, 45 superficial BCC, 2 nodular BCC) and a median tumour size of 5 cm2 were treated. Overall, the median follow-up period was 43.5 months (P25;P75=0;100), and a total recurrence rate of 33.8% was observed (24.4 % for BCC vs. 45.2% for BD). Estimated recurrence rates for BCC and BD were 5.0% vs. 7.4% at 6 months, 23.4% vs. 27.9% at 12 months, and 30.0% vs. 72.4% at 60 months. Both age and diagnosis were independent prognostic factors for recurrence, with significantly higher estimated recurrence rates in patients with BD (p=0.0036) or younger than 58 years old (p=0.039). The risk of recurrence (hazard ratio) was 2.4 times higher in patients with BD compared to superficial BCC (95% CI:1.1-5.3; p=0.033), and 2.8 times higher in patients younger than 58 years old (95% CI:1.2-6.5; p=0.02). Conclusions: In the studied population, estimated recurrence rates are higher than those expected from available literature, possibly due to a longer follow-up period. To the authors’ knowledge there is only one other study with a similar follow-up period, regarding BCC solely. BD, as an in situ squamous cell carcinoma, has a higher tendency to recur than superficial BCC. Despite greater cosmesis, PDT might no be the best treatment option for young patients considering their higher risk of recurrence.
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Introdução: O aumento da aurícula esquerda (AE) é um marcador de mortalidade na população geral. Os doentes com miocardiopatia dilatada (MCD) têm um amplo espetro de tamanhos deAE, mas a importância clínica desta observação tem sido pouco estudada. Objectivo: Avaliar a importância prognóstica a longo prazo do volume da AE (VAE) em doentes com MCD. Métodos: Estudo prospetivo de doentes admitidos durante o ano de 2004 com o diagnóstico deMCD, em ritmo sinusal. Foi realizado estudo ecocardiográfico completo em repouso e após stress farmacológico. O endpoint composto considerou a assistência ventricular mecânica (AVM), a transplantação cardíaca ou a morte. Resultados: Foram incluídos 35 doentes (68,6% sexo masculino, idade média 52,0), 82,9% etiologia não isquémica. Fração ejeção em repouso 31,1 ± 9,4%.Durante o seguimento, oito doentes morreram, um foi colocado em AVM e um foi transplantado. A análise de Cox univariável revelou potenciais marcadores ecocardiográficos de prognóstico na amostra tais como a dimensão da AE em modo M (HR-1,12; IC: 0,99-1,26;p = 0,067); VAE (HR-1,02; IC: 1,00-1,04; p = 0,046); VAE ajustado à superfície corporal (HR-1,03;IC: 1,00-1,07; p = 0,049); E/A (HR-0,99; IC: 0,99-1,81; p = 0,060); E/A > 2 (HR-7,00; IC:1,48-32,43; p = 0,014) e E/E’ mitral (HR-1,04; IC: 1,00-1,09; p = 0,074). Na análise multivariável a única variável que permaneceu no modelo foi o VAE com o ponto de corte de 63 ml (HR-7,7, IC:0,97-60,61, p = 0,05).Conclusão: Nesta amostra, o VAE foi o único parâmetro ecocardiográfico determinante de AVM,transplantação cardíaca ou morte. Os parâmetros ecocardiográficos habitualmente utilizadospara estratificação de risco, tais como a fração ejeção do ventrículo esquerdo, a dimensão do ventrículo esquerdo e a reserva contrátil não tiveram valor prognóstico na nossa amostra.
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Introdução: São escassos os estudos de eficácia a longo prazo da terapêutica fotodinâmica(TFD) no tratamento da doença de Bowen (DB) e do carcinoma basocelular (CBC). Objectivos: Determinar a eficácia a longo prazo da TFD com metilaminolevulinato (MAL) no tratamento da DB e do CBC pela análise de recidiva. Material e método: Foram analisados retrospectivamente os processos clínicos de doentes com o diagnóstico de DB ou CBC tratados com TFD-MAL num serviço de Dermato- Oncologia entre 2004 e 2008. Foi efectuada a análise descritiva dos dados pelo teste do chiquadrado, seguida da análise de sobrevivência pelos métodos de Kaplan-Meier e regressão de Cox. Resultados: Foram tratados 68 doentes (mediana etária 71 anos, P25;P75=30;92) com um total de 78 tumores (31 DB, 45 CBC superficiais, 2 CBC nodulares finos). No período de seguimento efectuado (mediana 43,5 meses, P25;P75=0;100) observou-se uma taxa de recidiva de 25% no CBC e 45,2% na DB. As taxas de recidiva estimadas para os CBC e DB foram de 5,0% vs. 7,4% aos 6 meses, 23,4% vs. 27,9% aos 12 meses e de 30,0% vs. 72,4% aos 60 meses. Idade e diagnóstico constituíram factores independentes de prognóstico, com taxas de recidiva significativamente maiores nos doentes com DB (p=0,0036) ou com menos de 58 anos (p=0,039). De modo semelhante, o risco de recidiva foi 2,4 vezes superior nos doentes com DB face àqueles com CBC (p=0,033) e 2,8 vezes maior em doentes com menos de 58 anos (p=0,02). Conclusões: Na população estudada, a taxa de recidiva foi superior àquela encontrada na literatura. A TFD pode não ser a melhor opção para o tratamento do cancro cutâneo nãomelanoma em doentes mais jovens, em particular na doença de Bowen. Apesar do melhor resultado cosmético, o risco de recidiva deve ser equacionado e a escolha terapêutica deve ser ponderada caso a caso.
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OBJECTIVE: Intensive image surveillance after endovascular aneurysm repair is generally recommended due to continued risk of complications. However, patients at lower risk may not benefit from this strategy. We evaluated the predictive value of the first postoperative computed tomography angiography (CTA) characteristics for aneurysm-related adverse events as a means of patient selection for risk-adapted surveillance. METHODS: All patients treated with the Low-Permeability Excluder Endoprosthesis (W. L. Gore & Assoc, Flagstaff, Ariz) at a tertiary institution from 2004 to 2011 were included. First postoperative CTAs were analyzed for the presence of endoleaks, endograft kinking, distance from the lowermost renal artery to the start of the endograft, and for proximal and distal sealing length using center lumen line reconstructions. The primary end point was freedom from aneurysm-related adverse events. Multivariable Cox regression was used to test postoperative CTA characteristics as independent risk factors, which were subsequently used as selection criteria for low-risk and high-risk groups. Estimates for freedom from adverse events were obtained using Kaplan-Meier survival curves. RESULTS: Included were 131 patients. The median follow-up was 4.1 years (interquartile range, 2.1-6.1). During this period, 30 patients (23%) sustained aneurysm-related adverse events. Seal length <10 mm and presence of endoleak were significant risk factors for this end point. Patients were subsequently categorized as low-risk (proximal and distal seal length ≥10 mm and no endoleak, n = 62) or high-risk (seal length <10 mm or presence of endoleak, or both; n = 69). During follow-up, four low-risk patients (3%) and 26 high-risk patients (19%) sustained events (P < .001). Four secondary interventions were required in three low-risk patients, and 31 secondary interventions in 23 high-risk patients. Sac growth was observed in two low-risk patients and in 15 high-risk patients. The 5-year estimates for freedom from aneurysm-related adverse events were 98% for the low-risk group and 52% for the high-risk group. For each diagnosis, 81.7 image examinations were necessary in the low-risk group and 8.2 in the high-risk group. CONCLUSIONS: Our results suggest that the first postoperative CTA provides important information for risk stratification after endovascular aneurysm repair when the Excluder endoprosthesis is used. In patients with adequate seal and no endoleaks, the risk of aneurysm-related adverse events was significantly reduced, resulting in a large number of unnecessary image examinations. Adjusting the imaging protocol beyond 30 days and up to 5 years, based on individual patients' risk, may result in a more efficient and rational postoperative surveillance.
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OBJECTIVE: A familial predisposition to abdominal aortic aneurysms (AAAs) is present in approximately one-fifth of patients. Nevertheless, the clinical implications of a positive family history are not known. We investigated the risk of aneurysm-related complications after endovascular aneurysm repair (EVAR) for patients with and without a positive family history of AAA. METHODS: Patients treated with EVAR for intact AAAs in the Erasmus University Medical Center between 2000 and 2012 were included in the study. Family history was obtained by written questionnaire. Familial AAA (fAAA) was defined as patients having at least one first-degree relative affected with aortic aneurysm. The remaining patients were considered sporadic AAA. Cardiovascular risk factors, aneurysm morphology (aneurysm neck, aneurysm sac, and iliac measurements), and follow-up were obtained prospectively. The primary end point was complications after EVAR, a composite of endoleaks, need for secondary interventions, aneurysm sac growth, acute limb ischemia, and postimplantation rupture. Secondary end points were specific components of the primary end point (presence of endoleak, need for secondary intervention, and aneurysm sac growth), aneurysm neck growth, and overall survival. Kaplan-Meier estimates for the primary end point were calculated and compared using log-rank (Mantel-Cox) test of equality. A Cox-regression model was used to calculate the independent risk of complications associated with fAAA. RESULTS: A total of 255 patients were included in the study (88.6% men; age 72 ± 7 years, median follow-up 3.3 years; interquartile range, 2.2-6.1). A total of 51 patients (20.0%) were classified as fAAA. Patients with fAAA were younger (69 vs 72 years; P = .015) and were less likely to have ever smoked (58.8% vs 73.5%; P = .039). Preoperative aneurysm morphology was similar in both groups. Patients with fAAA had significantly more complications after EVAR (35.3% vs 19.1%; P = .013), with a twofold increased risk (adjusted hazard ratio, 2.1; 95% confidence interval, 1.2-3.7). Secondary interventions (39.2% vs 20.1%; P = .004) and aneurysm sac growth (20.8% vs 9.5%; P = .030) were the most important elements accounting for the difference. Furthermore, a trend toward more type I endoleaks during follow-up was observed (15.6% vs 7.4%; P = .063) and no difference in overall survival. CONCLUSIONS: The current study shows that patients with a familial form of AAA develop more aneurysm-related complications after EVAR, despite similar AAA morphology at baseline. These findings suggest that patients with fAAA form a specific subpopulation and create awareness for a possible increase in the risk of complications after EVAR.