Antiplatelet drug response status does not predict recurrent ischemic events in stable cardiovascular patients: results of the Antiplatelet Drug Resistances and Ischemic Events study.

BACKGROUND: The biological response to antiplatelet drugs has repeatedly been shown to predict the recurrence of major adverse cardiovascular events (MACEs). However, most studies involved coronary artery disease patients with recent vessel injury shortly after the initiation of antiplatelet therapy. Data on stable cardiovascular patients are scarce, and the added predictive value of specific assays (the vasodilator phosphoprotein assay for the clopidogrel response and serum thromboxane B2 for the aspirin response) and aggregation-based assays relative to common predictors has rarely been addressed. METHODS AND RESULTS: Stable cardiovascular outpatients participating in the Antiplatelet Drug Resistances and Ischemic Events (ADRIE) study (n=771) were tested twice, at 2 separate visits, with specific and aggregation-based assays. Follow-up lasted 3 years, and <1% of patients were lost to follow-up. MACEs were adjudicated by an independent committee. Multivariate survival analyses included relevant variables identified in univariate analysis and platelet function test results. The C-index was used to express the prognostic value of various multivariate models. MACEs, the primary end point, occurred in 16% of patients. Hypertension, smoking, older age, and elevated low-density lipoprotein cholesterol were predictive of MACE recurrence, with a C-index of 0.63 (P<0.001). Neither the specific nor the aggregation-based assays added significant predictive value for the primary end point. CONCLUSIONS: Biological antiplatelet drug responsiveness, measured with specific or aggregation-based assays, has no incremental predictive value over common cardiovascular risk factors for MACE recurrence in stable cardiovascular outpatients. These results do not support platelet function testing for MACE risk evaluation in stable cardiovascular patients. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00501423.

Admission NT-proBNP levels, renal insufficiency and age as predictors of mortality in elderly patients hospitalized for acute dyspnea.

BACKGROUND: Assay of baseline B-type peptide (BNP and NT-proBNP) is useful for heart failure (HF) prognostication. In contrast, the prognostic value of NT-proBNP assay performed on admission of elderly subjects for acute dyspnea is uncertain. The aim of this study was to determine the vital prognostic value of NT-proBNP assay and other relevant variables available on admission in elderly patients hospitalized for acute dyspnea. METHODS: 254 patients over 70 years of age who were initially hospitalized with acute dyspnea were prospectively studied. The log-rank test and Cox proportional-hazards regression models were used to determine the prognostic value of NT-proBNP and creatinine clearance, measured within 24 h of initial admission, as well as age, gender, vascular risk factors and other clinical variables. RESULTS: Mean age was 81+/-7 years, and 52% of the patients were women. During a median follow-up of 34 months, 134 patients (55%) died and 9 patients (4%) were lost to follow-up. The median survival time was 25 months, and almost half the deaths occurred during the first 6 months. In multivariate analysis the following three variables were independently associated with mortality (shown with their accompanying hazard ratios (HR)): NT-proBNP>2856 pg/mL (median), HR=1.6[95%CI:1.3-5.2]; creatinine clearance <30 mL/min, HR=1.7[95%CI:1.2-2.5]; and age>80 years, HR=1.7[95%CI:1.1-2.6]. The median survival time among patients with an admission NT-proBNP level of >2856 pg/mL (median) was 14 months, compared to >36 months in the rest of the population. CONCLUSION: The admission NT-proBNP level, age, and creatinine clearance are predictive of vital outcome in elderly patients hospitalized for acute dyspnea.

Prohormone brain natriuretic peptide (proBNP), BNP and N-terminal-proBNP circulating levels in chronic hemodialysis patients. Correlation with ventricular function, fluid removal and effect of hemodiafiltration.

BACKGROUND: Brain natriuretic peptide (BNP), N-terminal proBNP (NT-proBNP) and to a lesser extent prohormone proBNP are recognized as biochemical markers of left ventricular dysfunction. In renal failure, interpretation of natriuretic peptide remains unclear, as natriuretic peptide levels may be not only be dependent on cardiac function and dimensions but also on renal function, fluid volume and removal by dialysis procedure including hemodiafiltration (HDF). The purpose of this study was (i) to assess BNP, NT-proBNP and proBNP levels and their correlation with clinical and echocardiographic data in chronic hemodialysis patients, and (ii) to investigate basal level alteration following HDF. METHODS: Baseline clinical and echocardiographic parameters were collected in 31 dialysis patients without evidence of cardiac failure. Pre- and post-HDF BNP, NT-proBNP and proBNP concentrations were measured. Correlations between echocardiographic measurements and basal circulating peptides, between changes in peptide values and changes in fluid volume after HDF were investigated. RESULTS: Baseline plasmatic levels were elevated (BNP=517+/-840 pg/mL, NT-proBNP=5340+/-6132 pg/mL and proBNP=3569+/-4683 pg/mL) and correlated with left auricular diameter and left ventricular mass index. HDF session induced a significant decrease of 39%, 59% and 36% for BNP, NT-proBNP and proBNP levels, respectively. This decrease was not correlated to post-HDF fluid removal or weight decrease. Correlation between BNP and proBNP was stronger (r(2)=0.88) than between NT-proBNP and proBNP (r(2)=0.54). CONCLUSIONS: Despite their elimination, BNP, NT-proBNP and proBNP could be potential markers of left ventricular remodeling in chronic renal failure patients on hemodialysis. According to these results, their cut-off values, however, need to be re-evaluated.

Use of N-terminal prohormone brain natriuretic peptide assay for etiologic diagnosis of acute dyspnea in elderly patients.

BACKGROUND: B-type peptide assay (brain natriuretic peptide [BNP] and N-terminal prohormone brain natriuretic peptide [NT-proBNP]) is useful for the diagnosis of heart failure (HF), but few data are available on the use of these markers in elderly subjects. The aim of this study was to evaluate NT-proBNP assay for the diagnosis of acute left HF in patients older than 70 years hospitalized for acute dyspnea. METHODS: We prospectively enrolled 256 elderly patients with acute dyspnea. They were categorized by 2 cardiologists unaware of NT-proBNP values into a cardiac dyspnea subgroup (left HF) and a noncardiac dyspnea subgroup (all other causes). RESULTS: Mean age was 81 +/- 7 years, and 52% of the patients were women. The diagnoses made in the emergency setting were incorrect or uncertain in 45% of cases. The median NT-proBNP value was higher (P < .0001) in patients with cardiac dyspnea (n = 142; 7906 pg/mL) than in patients with noncardiac dyspnea (n = 112; 1066 pg/mL). The area under the receiver operating characteristic curve was 0.86 (95% CI 0.81-0.91). At a cutoff of 2000 pg/mL, NT-proBNP had a sensitivity of 86%, a specificity of 71%, and an overall accuracy of 80% for cardiac dyspnea. The use of 2 cutoffs (< 1200 and > 4500 pg/mL) resulted in an 8% error rate and a gray area englobing 32% of values. CONCLUSION: NT-proBNP appears to be a sensitive and specific means of distinguishing pulmonary from cardiac causes of dyspnea in elderly patients. An optimal diagnostic strategy requires the use of 2 cutoffs and further investigations of patients with values in the gray area.