Fernando Miranda

Prognostic impact of admission blood glucose for all-cause mortality in patients with acute coronary syndromes: added value on top of GRACE risk score

Background: Abnormal glucose metabolism is a predictor of worse outcome after acute coronary syndrome (ACS). However, this parameter is not included in risk prediction scores, including GRACE risk score. We sought to evaluate whether the inclusion of blood glucose at admission in a model with GRACE risk score improves risk stratification. Methods: Study of consecutive patients included in a single centre registry of ACS. Our primary endpoint was the occurrence of all-cause mortality at one-year follow-up. The ability of the two logistic regression models (GRACE risk score alone and in combination with blood glucose) to predict death was analysed. Continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI), with corresponding 95% confidence intervals (CIs), were also calculated. Results: We included 2099 patients, with a mean age of 64 (SD=13) years, 69% males. In our sample, 55.1% presented with ST-segment elevation ACS and 13.1% in Killip class ≥ 2. Only 25% were known diabetic at admission. In-hospital mortality was 5.8% and 9.7% at one-year follow-up. The best cut-point for blood glucose was 160 mg/dl (sensitivity 62% and specificity 68%), and 35.2% of the patients had increased levels. This group was elderly, had more prevalence of cardiovascular risk factors, worse renal function and GRACE score as well as more frequently Killip class ≥2. Treatment was similar in both groups besides less frequent use of clopidogrel in high glycaemic patients. The hyperglycaemia group had higher one-year mortality (17.2% vs. 5.6%, p<0.001). Moreover, binary blood glucose remained a predictor of death independently of the GRACE risk score and the presence of diabetes (odds ratio (OR) 1.99, 95% CI 1.40–2.84, p<0.001). The inclusion of blood glucose, as a continuous variable, in a logistic regression model with GRACE score, increased the area under the ROC curve from 0.80 to 0.82 (p=0.018) as well as the goodness-of-fit and was associated with an improvement in both the NRI (37%) and the IDI (0.021), suggesting effective reclassification. Conclusions: A blood glucose level on admission ≥ 160 mg/dl is an independent predictor of mortality in medium-term follow-up. It offers an incremental predictive value when added to the GRACE risk score, although with a modest magnitude of improvement, probably due to the high predictive performance of the GRACE risk score alone.

Serum uric acid: a forgotten prognostic marker in acute coronary syndromes?

Background: Serum uric acid (UA) has been shown to be an independent predictor of outcome in the general population and in patients with heart failure. There are, however, limited data regarding the prognostic value of UA in the context of acute coronary syndromes (ACS) particularly in medium-term follow up and the available results are contradictory. Materials and methods: Study of consecutive patients admitted with an ACS (with and without ST-segment elevation) at a single-centre coronary care unit. Primary endpoint was all-cause mortality at 1-year follow up. We evaluated if serum UA is an independent predictor of outcome and if it has any added value on top of GRACE risk score for risk prediction. Results: We included 683 patients, mean age 64±13 years, 69% males. In-hospital and 1-year mortality were 4.5 and 7.6% respectively. The best cut-off of UA to predict 1-year mortality was 6.25 mg/dl (sensitivity 59%, specificity 72%) and 30.2% of the patients had an increased UA according to this cut off. Independent predictors of UA were male gender (β= 0.078), body mass index (β=0.163), diuretics before admission (β=0.142), and admission serum creatinine (β=0.403). One-year mortality was significantly higher in patients with increased UA (15.5 vs. 4.2%, p<0.001; log rank, p<0.001). After adjustment, both increased UA as a categorical variable (HR 2.25, 95% CI 1.23–4.13, p=0.008) and as a continuous variable (HR 1.26, 95% CI 1.13–1.41, p<0.001) are independent predictors of mortality. The AUC increases only slightly after inclusion of UA in the model with GRACE risk score (from 0.78 to 0.79, p=0.350). Both models had a good fit; however, model fit worsened after inclusion of UA. Overall, the inclusion of UA in the original was associated with an improvement in both the net reclassification improvement (continuous NRI=44%), and the integrated discrimination improvement (IDI=0.052) suggesting effective reclassification. Conclusions: Serum UA is an independent predictor of all-cause mortality in medium-term after the whole spectrum of ACS and has an added value for risk stratification.

Does admission NT-proBNP increase the prognostic accuracy of GRACE risk score in the prediction of short-term mortality after acute coronary syndromes?

Background: NT-proBNP has prognostic implications in heart failure. In acute coronary syndromes (ACS) setting, the prognostic significance of NT-proBNP is being sought. We studied short-term prognostic impact of admission NT-proBNP in patients admitted for ACS and in association with GRACE risk score (GRS). Methods and Results: We studied 1035 patients admitted with ACS. Patients were divided in quartiles according to NT-proBNP levels on admission: Q1 <180 pg/ml; Q2 180–691 pg/ml; Q3 696–2664 pg/ml; Q4 2698–35 000 pg/ml. Groups were compared in terms of short-term all-cause mortality. Patients with higher NT-proBNP had worst GRS on admission. They also received less aggressive treatment. In-hospital mortality was 0.8%, 3.0%, 5.8% and 12.8% (P<0.001) and 30-day mortality 1.6%, 4.6%, 6.5% and 16.7% (P<0.001) respectively. In multivariate logistic regression analysis, NT-proBNP is an independent predictor of in-hospital (OR 2.35; 95% CI: 1.12–4.93, P=0.022) and 30-day mortality (OR 2.20; 95% CI: 1.17–4.12, P=0.014). However, NT-proBNP does not add any incremental benefit to GRS for prediction of outcome by ROC curve analysis. Conclusions: NT-proBNP is an independent predictor of in-hospital and 30-day mortality after ACS, independently of left ventricular function, but does not increase the prognostic accuracy of GRS.

Predictive impact on medium-term mortality of hematological parameters in Acute Coronary Syndromes: added value on top of GRACE risk score.

Background: Red Cell Distribution Width (RDW) prognostic value in patients with Acute Coronary Syndrome (ACS) has been well validated whereas that of Platelet Distribution Width (PDW) is less well known. Objectives: Investigate the incremental prognostic value, on top of GRACE risk score, of a new variable resulting from the combination of RDW and PDW. Methods: Consecutive patients with ACS. Complete blood count, with RDW and PDW, was obtained. Primary endpoint was one-year all-cause mortality and Cox regression models were used to measure the influence of RDW and PDW on patients’ survival time. A new combination categorical variable (RDW/PDW) was created with both discretized RDW and PDW and logistic regression models were used. Predictive value and discriminative ability of the model with GRACE risk score alone and of the model with inclusion of RDW/PDW was assessed. Results: We included 787 patients. Hospital and one-year mortality rates were 5.1% and 7.8%, respectively. Both continuous RDW and PDW were independent predictors of death. The best cut-off for RDW was 13.9%, and 14.5% for PDW. Inclusion of RDW/PDW in a model with GRACE risk score improved the AUC from 0.81 (95% CI 0.75–0.86) to 0.84 (95% CI 0.79–0.90) (p=0.024) with an improvement in total NRI (56%) and IDI (0.048). Conclusions: Simple markers such as RDW and PDW can be useful in risk stratification of death after ACS. Combining both markers with GRACE risk score improved the predictive value for all-cause mortality and reduced the estimated risk of those who did not die.

Pode a presenca de anemia na admissão melhorar a capacidade preditiva do score GRACE para mortalidade a curto e médio prazo após síndrome coronária aguda

Introduction: In patients admitted for acute coronary syndrome (ACS), the presence of anemia is a predictor of prognosis. However, risk scores used for prognostic stratification do not include this variable. Objectives: To evaluate whether the presence of anemia on admission in patients with ACS has additional value over the GRACE risk score in the prediction of short-and medium-term mortality. Methods: Between January 2005 and December 2008, we assessed consecutive patients admitted to our intensive care unit for ACS and included in our single-center ACS registry. In all patients information was collected on demographic and anthropometric variables, risk factors for coronary artery disease, and clinical and laboratorial data on admission, including hemoglobin. Patients with anemia were identified (hemoglobin <12 g/dl for women and <13 g/dl for men). Patients were classified as low, intermediate or high risk on the GRACE risk score (<126, 126-154 and >154, respectively). In-hospital, 30-day and one-year mortality were analyzed. Results: The study population included 1423 patients with a mean age of 64 ± 13 years, 69% male, anemia on admission being present in 27.7%. These patients were older and more often female, with a higher proportion of hypertensives and diabetics, and more often had a history of myocardial infarction, worse Killip class on admission and higher GRACE risk score. On the other hand, fewer were smokers, fewer presented ST-segment elevation myocardial infarction and they were less often treated with beta-blockers, statins and coronary angioplasty. They had more bleeding complications during hospital stay. In-hospital (10% vs. 4%), 30-day (12% vs. 5%) and one-year mortality (15% vs. 6%) were higher in the anemia group (p < 0.001). In bivariate analysis, the presence of anemia was a predictor of in-hospital ଝ Please cite this article as: Timóteo, AT. Pode a presença de anemia na admissão melhorar a capacidade preditiva do score GRACE para mortalidade a curto e médio-prazo após síndrome coronária aguda? Any transmission of this document by any media or format is strictly prohibited. 280 A.T. Timóteo et al. no longer significant. When we analyzed the presence or absence of anemia for each GRACE risk score group, there was only a difference in one-year mortality, which was higher in both the intermediate-and high-risk GRACE score groups (6.7% vs. 2.3%, p = 0.024; 23.4% vs. 15.6%, p = 0.022, respectively), with a trend for higher 30-day mortality in the high-risk group (19.6% vs. 13.5%, p = 0.056). Conclusions: Our data …