NITRATE-CIN Study: Protocol of a Randomized (1:1) Single-Center, UK, Double-Blind Placebo-Controlled Trial Testing the Effect of Inorganic Nitrate on Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography for Acute Coronary Syndromes.

BACKGROUND: Contrast-induced nephropathy (CIN), an acute kidney injury resulting from the administration of intravascular iodinated contrast media, is a significant cause of morbidity/mortality following coronary angiographic procedures in high-risk patients. Despite preventative measures intended to mitigate the risk of CIN, there remains a need for novel effective treatments. Evidence suggests that delivery of nitric oxide (NO) through chemical reduction of inorganic nitrate to NO may offer a novel therapeutic strategy to reduce CIN and thus preserve long term renal function. DESIGN: The NITRATE-CIN trial is a single-center, randomized, double-blind placebo-controlled trial, which plans to recruit 640 patients presenting with acute coronary syndromes (ACS) who are at risk of CIN. Patients will be randomized to either inorganic nitrate therapy (capsules containing 12 mmol KNO3) or placebo capsules containing potassium chloride (KCl) daily for 5 days. The primary endpoint is development of CIN using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. A key secondary endpoint is renal function over a 3-month follow-up period. Additional secondary endpoints include serum renal biomarkers (e.g. neutrophil gelatinase-associated lipocalin) at 6 h, 48 h and 3 months following administration of contrast. Cost-effectiveness of inorganic nitrate therapy will also be evaluated. SUMMARY: This study is designed to investigate the hypothesis that inorganic nitrate treatment decreases the rate of CIN as part of semi-emergent coronary angiography for ACS. Inorganic nitrate is a simple and easy to administer intervention that may prove useful in prevention of CIN in at-risk patients undergoing coronary angiographic procedures.

The relationship of ethnicity to the prevalence and management of hypertension and associated chronic kidney disease.

BACKGROUND: The effect of ethnicity on the prevalence and management of hypertension and associated chronic kidney (CKD) disease in the UK is unknown. METHODS: We performed a cross sectional study of 49,203 adults with hypertension to establish the prevalence and management of hypertension and associated CKD by ethnicity. Routinely collected data from general practice hypertension registers in 148 practices in London between 1/1/07 and 31/3/08 were analysed. RESULTS: The crude prevalence of hypertension was 9.5%, and by ethnicity was 8.2% for White, 11.3% for South Asian and 11.1% for Black groups. The prevalence of CKD stages 3-5 among those with hypertension was 22%. Stage 3 CKD was less prevalent in South Asian groups (OR 0.77, 95% CI 0.67 - 0.88) compared to Whites (reference population) with Black groups having similar rates to Whites. The prevalence of severe CKD (stages 4-5) was higher in the South Asian group (OR 1.53, 95% CI 1.17 - 2.0) compared to Whites, but did not differ between Black and White groups. In the whole hypertension cohort, achievement of target blood pressure (< 140/90 mmHg) was better in South Asian (OR 1.43, 95% CI 1.28 - 1.60) and worse in Black groups (OR 0.79, 95% CI 0.74 - 0.84) compared to White patients. Hypertensive medication was prescribed unequally among ethnic groups for any degree of blood pressure control. CONCLUSIONS: Significant variations exist in the prevalence of hypertension and associated CKD and its management between the major ethnic groups. Among those with CKD less than 50% were treated to a target BP of ≤ 130/80 mmHg. Rates of ACE-I/ARB prescribing for those with CKD were less than optimal, with the lowest rates (58.5%) among Black groups.