Septicemia, access and cardiovascular disease in dialysis patients: The USRDS Wave 2 Study

Background. Microinflammation is linked to cardiovascular disease, and is highly prevalent in dialysis patients. It is logical to postulate that septicemia, a common macroinflammatory occurrence in dialysis patients, contributes to their large burden of cardiovascular disease. Methods. The Dialysis Morbidity and Mortality Wave 2 was a randomly selected prospective cohort of incident dialysis patients. Admission claims data were used to define and calculate rates of septicemia or bacteremia and cardiovascular events in those with Medicare as the primary payer. Utilizing Cox proportional hazard models we determined the association between baseline access and the development of bacteremia or sepsis, and also the association between bacteremia or sepsis episodes and subsequent cardiovascular events. Results. The 2358 (59%) patients with Medicare as primary payer were older and more likely to have heart failure than those with other payers, but had similar comorbidity-adjusted mortality hazards. Rates of first septicemia, bacteremia, or either condition, were 7.0, 5.9 and 10.4 events per 100-patient years, respectively. Cox regression identified initial dialysis access as the main antecedent of septicemia or bacteremia. Hazards ratios for hemodialysis with permanent catheters, temporary catheters, and grafts were 1.95 (95% CI 1.47-2.57), 1.76 (95% CI 1.29-2.41), and 1.05 (95% CI 0.82-1.35), respectively, while that for peritoneal dialysis was 0.96 (95% CI 0.75-1.23) (reference arteriovenous fistula). After adjustment for baseline factors, septicemia or bacteremia, as a time-dependent covariate, was associated with subsequent death [hazards ratio (HR) 2.33, 95% CI 1.38-2.28], myocardial infarction (HR 1.78, 95% CI 1.38-2.28), heart failure (HR 1.64, 95% CI 1.39-1.95), peripheral vascular disease (HR 1.64, 95% CI 1.34-2.0), and stroke (HR 2.04, 95% CI 1.27-3.28). Conclusion. Septicemia appears to be an important, potentially preventable, cardiovascular risk factor in dialysis patients.