[Hemodialysis and cardiovascular outcome]

Hemodialysis patients often present multiple comorbidities and have a high mortality rate (15-20% per year), mostly due to cardiovascular events. Besides predisposing pathological conditions related to uremia (heart failure, coronary heart disease, left ventricular hypertrophy, arrhythmias), they also have specific risk factors linked to the hemodialysis (HD) treatment in itself: chronic inflammation, fluid overload, autonomic nervous system dysfunction, arterovenous fistula. These factors may affect the hemodynamic compensatory systems (vascular refilling, arteriolar and venous tone, autonomic nervous system response) to fluid removal, with high risk of intra-dialysis hypotension (IDH) episodes or arrhythmic events. IDH is recognized as associated to a negative long term outcome, due to the repeated episodes of organ hypoperfusion with ischemic damage to heart, brain and gut. Over the years, dialysis technology has greatly improved, with the development of continuous and noninvasive monitoring systems, able to control some hemodynamic parameters affecting blood pressure (mainly blood volume and body temperature), with positive results in terms of hemodynamic instability during HD. Furthermore, recent studies suggest that hemodiafiltration may reduce the risk of IDH and cardiovascular mortality, compared with conventional HD. Diabetic and/or old patients, as well as those with a previous cardiovascular event, are the first patients who should receive the new treatment options. Overall, the HD prescription needs to be tailored to each patient's need, to improve the hemodynamic tolerance to treatment and the cardiovascular outcome.