Haemodialysis is associated with a pronounced fall in myocardial perfusion

Background. Whereas haemodialysis (HD) is lifesaving by replacement of renal function, there are data to suggest that the HD procedure itself may contribute to the high cardiac risk in dialysis patients. The HD procedure is associated with an increased risk of sudden death, and there is accumulating evidence that HD can elicit myocardial ischaemia. In this study, we evaluated the effect of HD on global and regional myocardial blood flow (MBF) and left ventricular (LV) function in non-diabetic, non-cardiac compromised patients.

Methods. N-13-NH3 positron emission tomography (PET) was used to quantify changes in MBF, LV wall motion, cardiac output (CO), LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) in seven non-diabetic patients with uneventful cardiac histories. PET scans were performed before and at 30 and 220 min of HD.

Results. In all patients global MBF fell during HD. At 30 min of HD without ultrafiltration (UF), global MBF had fallen 13.5 +/- 11.5% (P <0.05) while CO, LVEDV and LVESV were 4.6 +/- 5.3% (NS), 5.6 +/- 4.2% (P <0.05) and 6.9 +/- 7.2% (P <0.05) lower, respectively. At 220 min of HD, after UF of 2.5 +/- 0.9 l, global MBF had fallen 26.6 +/- 13.9% (P <0.05) from baseline while CO, LVEDV and LVESV were 21.0 +/- 19.7%, 31.1 +/- 12.7% and 36.4 +/- 17.5% (all P <0.05) lower, respectively. In two patients, new LV regional wall motion abnormalities (RWMA) developed at 220 min of HD. MBF was reduced to a greater extent in regions that developed LV RWMA compared to those that did not.

Conclusions. Haemodialysis induced a pronounced fall in MBF. Since MBF fell already early during HD not only hypovolaemia but also acute dialysis-associated factors seem to play a role. Haemodialysis-associated reductions in MBF may contribute to the high cardiac event rate of dialysis patients.