Relation between red blood cell distribution width (RDW) and all-cause mortality at two years in an unselected population referred for coronary angiography.

BACKGROUND: Red blood cell distribution width (RDW), a numerical measure of the variability in size of circulating erythrocytes, has recently been shown to be a strong predictor of adverse outcomes in patients with heart failure and in patients with prior myocardial infarction but no symptomatic heart failure at baseline, even after adjustment for hematocrit. However, there are no data in other cardiac populations, including patients with acute coronary syndromes (ACS). METHODS: The present study investigated the long-term prognostic significance of baseline RDW in a well-characterized cohort of 389 male patients who were referred to coronary angiography for a variety of indications. All patients were followed prospectively for all-cause mortality, and data regarding this endpoint was available for 97% of the population at 24 months. RESULTS: After controlling for a variety of baseline variables (including hemoglobin and the presence of heart failure), RDW (analyzed as a categorical variable comparing the upper tertile of baseline values to the lower two levels combined) was a strong and independent predictor of all-cause mortality using a Cox proportional hazards model [hazard ratio (HR) 2.69, 95% confidence interval (CI) 1.50-4.84, p=0.0008]. In addition, baseline RDW was also an independent predictor of all-cause mortality in the non-anemic (HR 4.73, 95% CI 2.06-10.86, p=0.0003) and ACS (HR 2.90, 95% CI 1.32-6.38, p=0.0082) subpopulations of patients. CONCLUSIONS: These data demonstrate that elevated RDW is a strong and independent predictor of all-cause mortality in an unselected population of male patients across a broad spectrum of risk (including ACS) referred for coronary angiography.

Activated clotting time (ACT)-guided intravenous dalteparin dosing during percutaneous coronary intervention.

BACKGROUND: The activated clotting time (ACT) has been reported to be sensitive to the anticoagulant activity of the low-molecular weight heparin dalteparin following intravenous (IV) administration. OBJECTIVE: To evaluate the feasibility of an ACT-guided dalteparin dose adjustment strategy during percutaneous coronary intervention (PCI). METHODS: This was a retrospective study of 104 consecutive patients who underwent PCI using an ACT-guided strategy of IV dalteparin. All patients received an initial IV bolus of 50 IU/kg of dalteparin. The minimum target ACT was 175 seconds for patients who received glycoprotein IIb/IIIa inhibitors and 200 seconds for patients who did not. Patients who did not achieve the target ACT after the initial 50 IU/kg were given supplemental boluses of dalteparin based on the assumption that for every additional 10 IU/kg of dalteparin, the ACT will rise by approximately 10 seconds. RESULTS: After the initial bolus of dalteparin, the mean baseline ACT rose from 138 +/- 41 seconds to 235 +/- 78 seconds. In the 36 patients (35% of the study population) who required a mean supplemental dose of 14 +/- 6 IU/kg/kg, the mean ACT after the supplemental dose was 239 +/- 79 seconds. The composite endpoint of in-hospital death, target vessel revascularization (TVR) and myocardial infarction (MI) was 5.8%. Major and minor bleeding rates were 1% each. The composite incidence of death/MI/TVR was comparable to, and the bleeding complications were lower than, those achieved in the SYNERGY and STEEPLE trials. CONCLUSION: ACT-guided dose adjustment of intravenously administered dalteparin during PCI appears to constitute a feasible strategy.