Valor prognóstico do fragmento N-terminal do peptídeo natriurético tipo B em cirurgia não-cardíaca / Prognostic value of perioperative N-terminal pro-B-type natriuretic peptide in noncardiac surgery

FUNDAMENTO: Já foi demonstrado o uso do NT-proBNP pré-operatório para prever resultado cardíaco adverso, embora estudos recentes tenham sugerido que a determinação do NT-proBNP pós-operatório possa fornecer um valor adicional em pacientes submetidos à cirurgia não cardíaca. OBJETIVO: Avaliar o valor prognóstico perioperatório do NT-proBNP em pacientes de intermediário e alto risco cardiovascular submetidos à cirurgia não cardíaca. MÉTODOS: Este estudo incluiu prospectivamente 145 pacientes com idade > 45 anos, com pelo menos um fator de risco do Índice de Risco Cardíaco Revisado e submetidos à cirurgia de médio ou alto risco não-cardíaca. Os níveis de NTproBNP foram medidos no pré e pós-operatório. Preditores cardíacos de curto prazo foram avaliados por modelos de regressão logística. RESULTADOS: Durante uma mediana de acompanhamento de 29 dias, 17 pacientes (11,7%) apresentaram eventos cardíacos adversos importantes (MACE - 14 infartos do miocárdio não fatais, 2 paradas cardíacas não-fatais e 3 mortes cardíacas). Os níveis ótimos de limiar discriminatório para o NT-proBNP pré e pós-operatório foram 917 e 2962 pg/ mL, respectivamente. O NT-proBNP pré e pós-operatório (OR = 4,7, IC 95%: 1,62-13,73, p = 0,005 e OR 4,5, IC 95%: 1,53-13,16, p = 0,006) foram associados de forma significativa com MACE (eventos cardíacos adversos maiores). O NTproBNP pré-operatório foi significativa e independentemente associado com eventos cardíacos adversos em análise de regressão multivariada (OR ajustado 4,2, IC 95%: 1,38-12,62, p = 0,011). CONCLUSÃO: O NT-proBNP é um importante marcador de curto prazo de eventos cardiovasculares perioperatórios em pacientes de alto risco. Os níveis pós-operatórios foram menos informativos do que os níveis pré-operatórios. Uma única medição de NT-proBNP pré-operatório deve ser considerada na avaliação de risco pré-operatório.

BACKGROUND: Preoperative NT-proBNP has been shown to predict adverse cardiac outcomes, although recent studies suggested that postoperative NT-proBNP determination could provide additional information in patients submitted to noncardiac surgery. OBJECTIVE: To evaluate the prognostic value of perioperative NT-proBNP in intermediate and high risk cardiovascular patients undergoing noncardiac surgery. METHODS: This study prospectively enrolled 145 patients aged >45 years, with at least one Revised Cardiac Risk Index risk factor and submitted to intermediate or high risk noncardiac surgery. NT-proBNP levels were measured pre- and postoperatively. Short-term cardiac outcome predictors were evaluated by logistic regression models. RESULTS: During a median follow-up of 29 days, 17 patients (11.7%) experienced major adverse cardiac events (MACE- 14 nonfatal myocardial infarctions, 2 nonfatal cardiac arrests and 3 cardiac deaths). The optimum discriminatory threshold levels for pre- and postoperative NT-proBNP were 917 and 2962 pg/mL, respectively. Pre- and postoperative NT-proBNP (OR 4.7; 95% CI 1.62-13.73; p=0.005 and OR 4.5; 95% CI 1.53-13.16; p=0.006) were significantly associated with MACE. Preoperative NT-proBNP was significantly and independently associated with adverse cardiac events in multivariate regression analysis (adjusted OR 4.2; 95% CI 1.38-12.62; p=0.011). CONCLUSION: NT-proBNP is a powerful short-term marker of perioperative cardiovascular events in high risk patients. Postoperative levels were less informative than preoperative levels. A single preoperative NT-proBNP measurement should be considered in the preoperative risk assessment.

Prognostic value of perioperative N-terminal pro-B-type natriuretic peptide in noncardiac surgery.

BACKGROUND: Preoperative NT-proBNP has been shown to predict adverse cardiac outcomes, although recent studies suggested that postoperative NT-proBNP determination could provide additional information in patients submitted to noncardiac surgery. OBJECTIVE: To evaluate the prognostic value of perioperative NT-proBNP in intermediate and high risk cardiovascular patients undergoing noncardiac surgery. METHODS: This study prospectively enrolled 145 patients aged ≥ 45 years, with at least one Revised Cardiac Risk Index risk factor and submitted to intermediate or high risk noncardiac surgery. NT-proBNP levels were measured pre- and postoperatively. Short-term cardiac outcome predictors were evaluated by logistic regression models. RESULTS: During a median follow-up of 29 days, 17 patients (11.7%) experienced major adverse cardiac events (MACE- 14 nonfatal myocardial infarctions, 2 nonfatal cardiac arrests and 3 cardiac deaths). The optimum discriminatory threshold levels for pre- and postoperative NT-proBNP were 917 and 2962 pg/mL, respectively. Pre- and postoperative NT-proBNP (OR 4.7; 95% CI 1.62-13.73; p=0.005 and OR 4.5; 95% CI 1.53-13.16; p=0.006) were significantly associated with MACE. Preoperative NT-proBNP was significantly and independently associated with adverse cardiac events in multivariate regression analysis (adjusted OR 4.2; 95% CI 1.38-12.62; p=0.011). CONCLUSION: NT-proBNP is a powerful short-term marker of perioperative cardiovascular events in high risk patients. Postoperative levels were less informative than preoperative levels. A single preoperative NT-proBNP measurement should be considered in the preoperative risk assessment.

Clinical use of ultrasensitive cardiac troponin I assay in intermediate- and high-risk surgery patients.

BACKGROUND: Cardiac troponin levels have been reported to add value in the detection of cardiovascular complications in noncardiac surgery. A sensitive cardiac troponin I (cTnI) assay could provide more accurate prognostic information. METHODS: This study prospectively enrolled 142 patients with at least one Revised Cardiac Risk Index risk factor who underwent noncardiac surgery. cTnI levels were measured postoperatively. Short-term cardiac outcome predictors were evaluated. RESULTS: cTnI elevation was observed in 47 patients, among whom 14 were diagnosed as having myocardial infarction (MI). After 30 days, 16 patients had major adverse cardiac events (MACE). Excluding patients with a final diagnosis of MI, predictors of cTnI elevation included dialysis, history of heart failure, transoperative major bleeding, and elevated levels of pre- and postoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP). Maximal cTnI values showed the highest sensitivity (94%), specificity (75%), and overall accuracy (AUC 0.89; 95% CI 0.80-0.98) for postoperative MACE. Postoperative cTnI peak level (OR 9.4; 95% CI 2.3-39.2) and a preoperative NT-proBNP level ≥917 pg/mL (OR 3.47; 95% CI 1.05-11.6) were independent risk factors for MACE. CONCLUSIONS: cTnI was shown to be an independent prognostic factor for cardiac outcomes and should be considered as a component of perioperative risk assessment.

Influence of implementation of a chest pain unit on acute coronary syndrome outcomes.

BACKGROUND: Different strategies have been described to increase promptness and efficiency in the assessment and management of patients with acute chest pain and acute coronary syndrome (ACS) in the emergency department (ED). OBJECTIVE: The objective of this study is to evaluate the results of implementing a Chest Pain Unit (CPU) to assist patients with ACS, and to determine its impact on quality of health care indexes and clinical outcomes. METHODS: A study was conducted with a prospective cohort of patients admitted to the ED with a chief complaint of acute chest pain or suspected ACS at two different time periods: before (n = 663) and after (n = 450) introducing a CPU as part of the ED. Quality-of-care indexes analyzed in this study were adherence to a critical pathway, length of hospital stay, and hospital mortality. RESULTS: There was increased adherence to a critical pathway during the CPU period compared to the period with no designated CPU area, including compliance with prescribing aspirin, beta-blockers, and angiotensin-converting enzyme inhibitor, and performing coronary angiography in high-risk patients. After adjustment to baseline characteristics, admissions to a CPU resulted in a 65% reduction in mortality (odds ratio 0.35; 95% confidence interval 0.14-0.88; p = 0.03). There was no difference in median length of hospital stay, 7 days (interquartile range [IQR] 4-12) before CPU and 6 days (IQR 4-11) after introducing the CPU (p = 0.10). CONCLUSION: In the scenario of a crowded ED, implementation of a CPU was associated with greater adherence to a critical pathway for patients with ACS, with a concomitant reduction in mortality rates.

Prognostic value of myeloperoxidase in coronary artery disease: comparison of unstable and stable angina patients.

BACKGROUND: Atherosclerosis is a chronic inflammatory process, and myeloperoxidase (MPO) seems to contribute directly to the pathogenesis of acute coronary syndrome (ACS). OBJECTIVE: To compare MPO levels among the patients with stable and unstable ischemic heart disease and to evaluate their independent prognostic value for cardiovascular events. METHODS: MPO and C-reactive protein (CRP) were assessed in two cohorts of coronary artery disease patients, including 178 patients with stable angina and 130 patients with ACS evaluated at the emergency department. RESULTS: MPO and CRP levels were significantly higher among patients with ACS [MPO 93 (54-127) vs. 9.9 pmol/l (5-21) and high sensitivity-CRP 11 (3-27) vs. 2.6 mg/l (1-5)]. Among patients with stable angina, high sensitivity-CRP levels greater than 3 mg/l were associated with a three-fold risk of further cardiovascular events during a mean follow-up period of 13+/-4 months, although there was no significant association between MPO levels and outcomes. Among patients with ACS, baseline MPO level was an independent predictor of major adverse cardiac events during hospitalization, odds ratio of 3.8 (95% confidence interval: 1.2-12) for the combined endpoint (death, recurrent angina, heart failure, and arrhythmia). CRP levels were associated with hospital mortality in patients with ACS, but were not independently related to cardiovascular events. CONCLUSION: Elevated MPO levels among the ACS patients suggest that this marker may participate in plaque vulnerability and instability process, whereas higher CRP levels were predictive of cardiac events only among the stable angina patients. These findings suggest distinct role of the inflammatory markers studied in the pathophysiology of coronary artery disease.

Interleukin-18: an independent predictor of cardiovascular events in patients with acute coronary syndrome after 6 months of follow-up.

BACKGROUND: Interleukin-18 (IL-18), a proinflammatory cytokine, has been associated with atherogenesis and plaque rupture in acute coronary syndrome (ACS). Recent studies suggest that IL-18 may have a long-term prognostic value. The aim of this study was to evaluate the relationship between IL-18 levels and major adverse cardiovascular events within 6 months of follow-up in post-ACS patients. METHODS: One hundred and twelve consecutive patients admitted to a university hospital with ACS were included in the study. IL-18 and C-reactive protein were measured within the first 24 h of admission. Six months after hospital discharge, the incidence of major adverse cardiovascular events (cardiovascular death, new episode of ACS, and need for unplanned revascularization) was assessed. RESULTS: Mean age of patients was 64 +/- 11 years, and 58 (52%) were male. During the 6 months of follow-up, 33 patients (31.4%) experienced major adverse cardiovascular events. Median IL-18 serum levels were higher among patients who had events than among those who did not: 271.7 pg/ml (interquartile range: 172.9-389.6) and 139.7 pg/ml (interquartile range: 99.9-265.7), respectively (P < 0.01). In the Cox multivariate analysis, after adjustment for clinical risk factors and serum troponin, elevated levels of IL-18 were associated with higher incidence of events (hazard ratio: 2.5; 95% confidence interval: 1.14-5.52; P = 0.023). In this population, C-reactive protein was of borderline significance for events. CONCLUSION: Serum IL-18 levels in ACS patients were independent predictors of long-term cardiovascular events. These findings support the association between inflammation and prognosis of ACS patients, as well as the clinical impact of this biomarker.

Association of anemia with clinical outcomes in stable coronary artery disease.

BACKGROUND: Although anemia is pathophysiologically associated with myocardial ischemia, there are scarce data on its clinical impact in patients with stable coronary artery disease on contemporary treatment. This study aims to describe the prevalence of anemia, and its association with symptoms and outcomes in this population. METHODS: We conducted a prospective cohort study in stable documented coronary artery disease patients. Anemia criteria was hemoglobin (Hb) <12 g/dl in women and <13 g/dl in men. Hemoglobin levels were divided in quartiles (Q) adjusted for sex. Major events included acute coronary syndromes, stroke and cardiovascular deaths. Secondary outcomes were presence of angina and chronic use of nitrates. Cox regression models were used to evaluate the independent effect of anemia on clinical outcomes. RESULTS: Among 310 patients, 71 (23%) met criteria for anemia. After a mean follow-up of 44+/-23 months, hemoglobin levels had a marked association with occurrence of major events (27% in Q1, 7% in Q2, 8% in Q3 and 12% in Q4; P<0.01). In multivariate analysis, anemia was independently associated with an increased risk of death [hazard ratio (HR) 6.5, 95% confidence interval (1.7-24.2)], major events [HR 3.3 (1.7-6.5)] and revascularization procedures [HR 2.3 (1.3-4.1)]. Persistent of angina symptoms (32 vs. 18%, P=0.01) and chronic use of nitrates (35 vs. 21%, P=0.02) were also more frequent among patients with anemia at baseline. CONCLUSIONS: In patients with stable ischemic heart disease, presence of anemia, even mild, is associated with a worse prognosis. Strategies aiming at identifying reversible causes of anemia or new treatments should be evaluated in prospective clinical trials.