Oxidative stress in renal dysfunction: mechanisms, clinical sequelae and therapeutic options.

Oxidative stress has been increasingly linked to the high incidence of cardiovascular events in patients with chronic kidney disease (CKD), especially as traditional cardiovascular risk factors seem to not be able to account for the huge cardiovascular morbidity and mortality in this population group. Oxidative stress is increased in patients with renal impairment as a result of increased oxidant activity and reduced antioxidant capacity, and this is increased in a graded manner with increasing renal dysfunction. Inflammation, which is also present in CKD, further amplifies the oxidant generation process. The two clinical sequelae of oxidative stress are endothelial dysfunction and left ventricular hypertrophy, which have adverse cardiovascular consequences. With our new understanding of oxidative stress, it is now important to assess treatment options that reduce it in the hope that they reverse endothelial dysfunction and left ventricular hypertrophy and the clinical sequelae of these abnormalities.

A comparison between B-type natriuretic peptide, global registry of acute coronary events (GRACE) score and their combination in ACS risk stratification.

BACKGROUND: In acute coronary syndrome (ACS), both the Global Registry of Acute Coronary Events (GRACE) score and B-type natriuretic peptide (BNP) predict cardiovascular events. However, it is unknown how BNP compares with GRACE and how their combination performs in ACS. METHODS: The authors recruited 449 consecutive ACS patients and measured admission GRACE score and bedside BNP levels. The main outcome measure was all-cause mortality, readmission with ACS or congestive heart failure (defined as a cardiovascular event) at 10 months from presentation. RESULTS: Of the 449 patients, 120 patients presented with ST-elevation myocardial infarction (MI) (27%). There were 90 cardiovascular events at 10 months. Both higher GRACE terciles and higher BNP terciles predicted cardiovascular events. There was a significant but only partial correlation between the GRACE score and log BNP (R = 0.552, p<0.001). On multivariate analyses, after adjusting for the GRACE score itself, increasing BNP terciles independently predicted cardiovascular events (second BNP tercile adjusted RR 2.28 (95% CI 1.15 to 4.51) and third BNP tercile adjusted RR 4.91 (95% CI 2.62 to 9.22)). Patients with high GRACE score-high BNP were more likely to experience cardiovascular events at 10 months (RR 6.00 (95% CI 2.40 to 14.83)) compared to those with high GRACE score-low BNP (RR 2.40 (95% CI 0.76 to 7.56)). CONCLUSION: In ACS, most but not all of our analyses suggest that BNP can predict cardiovascular events over and above the GRACE score. The combined use of both the GRACE score and BNP can identify a subset of ACS patients at particularly high risk. This implies that both the GRACE score and BNP reflect somewhat different risk attributes when predicting adverse prognosis in ACS and their synergistic use can enhance risk stratification in ACS to a small but potentially useful extent.