Traditional risk factors—such as diabetes, hypertension, dyslipidemia—and those specific to dialysis patients (anemia and mineral metabolism abnormalities) require regular assessment and treatment as per current recommendations. The relative importance and weight of each of these risk factors in the dialysis population is not known and, in the absence of controlled trials in this population, current recommendations from existing organizations should be followed, with special consideration given to potential risks.
Furthermore, lifestyle issues such as smoking, physical activity, depression, and anxiety are the cornerstones of therapy as in the general population. The treatment options are often similar, but the impact of these factors is potentially more profound in dialysis patients. These factors are all discussed in this section. Special attention will be paid to the difference between the usual recommendations and those for dialysis patients.
Guideline 15: Anemia
The impact of anemia on CVD (specifically, LVH) and exacerbation of CAD is well described in the dialysis population. Given the prevalence of anemia in the dialysis population, and its association with poor outcomes, anemia is considered a “uremia-specific” CVD risk factor.
15.1 All dialysis patients with anemia should follow the KDOQI Guidelines for Treatment of Anemia.52
Anemia results in decreased peripheral vascular resistance and plasma viscosity, and increased venous return. A reduced hemoglobin level lowers oxygen delivery, resulting in increased heart rate and venous tone. These factors cause increased cardiac output, which increases arterial volume and LV wall tension. The cumulative effect is LVH, arterial hypertrophy, and arteriosclerosis. Guidelines have been previously developed by the KDOQI Anemia Work Group.52
Observational studies have demonstrated an association between anemia and adverse cardiovascular outcomes in CKD patients. One such study demonstrated that a hemoglobin level <8.8 g/dL was independently associated with LV dilation, cardiac failure, and total mortality.331 Other studies have supported these findings, and are reviewed in the previous anemia guidelines.52
It is not known if treatment of anemia prevents cardiovascular events in CKD patients. The Normal Hematocrit Trial randomized 1,200 patients with heart failure or ischemic heart disease to a target hematocrit of 30% or 42%, and assessed time to first myocardial infarction or death.332 Although there was no significant difference in outcome between groups, the trial was stopped early due to a trend suggesting poorer outcomes among those with higher hematocrit levels.
The Canadian Normalization of Hemoglobin Trial randomized 146 CKD patients with either concentric LV hypertrophy or LV dilation333 to receive doses of erythropoietin to achieve a hemoglobin of either 10 or 13 g/dL (100 or 130 g/L). In the patients with concentric LVH, changes in LV mass index were similar between groups. In the patients with LV dilation, changes in volume index were also similar between groups. However, those with concentric LVH were less likely to develop progressive LV dilation if they were assigned to the high hemoglobin group.