NT-proBNP na estratificação de risco no tromboembolismo pulmonar

Introduction: Pulmonary embolism (PE) is an entity with high mortality and morbidity, in which risk stratification for adverse events is essential. N-terminal brain natriuretic peptide (NT-proBNP), a right ventricular dysfunction marker, may be useful in assessing the short-term prognosis of patients with PE. Aims: To characterize a sample of patients hospitalized with PE according to NT-proBNP level at hospital admission and to assess the impact of this biomarker on short-term evolution. Methods: We performed a retrospective analysis of consecutive patients admitted with PE over a period of 3.5 years. Based on the median NT-proBNP at hospital admission, patients were divided into two groups (Group 1: NT-proBNP < median and Group 2: NT-proBNP ≥ median). The two groups were compared in terms of demographic characteristics, personal history, clinical presentation, laboratory, electrocardiographic and echocardiographic data, drug therapy, in-hospital course (catecholamine support, invasive ventilation and in-hospital death and the combined endpoint of these events) and 30-day all-cause mortality. A receiver operating characteristic (ROC) curve was constructed to determine the discriminatory power and cut-off value of NT-proBNP for 30-day all-cause mortality. Results: Ninety-one patients, mean age 69 ± 16.4 years (51.6% aged ≥75 years), 53.8% male, were analyzed. Of the total sample, 41.8% had no etiological or predisposing factors for PE and most (84.6%) were stratified as intermediate-risk PE. Median NT-proBNP was 2440 pg/ml. Patients in Group 2 were significantly older (74.8 ± 13.2 vs. 62.8 ± 17.2 years, p = 0.003) and more had a history of heart failure (35.5% vs. 3.3%, p = 0.002) and chronic kidney disease (32.3% vs. 6.7%, p = 0.012). They had more tachypnea on initial clinical evaluation (74.2% vs. 44.8, p = 0.02), less chest pain (16.1% vs. 46.7%, p = 0.01) and higher creatininemia (1.7 ± 0.9 vs. 1.1 ± 0.5 mg/dl, p = 0.004). Group 2 also more frequently had right chamber dilatation (85.7% vs. 56.7%, p = 0.015) and lower left ventricular ejection fraction (56.4 ± 17.6% vs. 66.2 ± 13.5%, p = 0.036) on echocardiography. There were no significant differences in drug therapy between the two groups. Regarding the studied endpoints, Group 2 patients needed more catecholamine support (25.8% vs. 6.7%, p = 0.044), had higher in-hospital mortality (16.1% vs. 0.0%, p = 0.022) and more frequently had the combined endpoint (32.3% vs. 10.0%, p = 0.034). All-cause mortality at 30 days was seen only in Group 2 patients (24.1% vs. 0.0%, p = 0.034). By ROC curve analysis, NT-proBNP had excellent discriminatory power for this event, with an area under the curve of 0.848. The best NT-proBNP cut-off value was 4740 pg/ml. Conclusion: Elevated NT-proBNP levels identified PE patients with worse short-term prognosis, and showed excellent power to predict 30-day all-cause mortality. The results of this study may have important clinical implications. The inclusion of NT-proBNP measurement in the initial evaluation of patients with PE can add valuable prognostic information.