Effects of Short Daily versus Conventional Hemodialysis on Left Ventricular Hypertrophy and Inflammatory Markers

Abstract

Left ventricular hypertrophy (LVH) and inflammation independently increase risk for death in people who receive hemodialysis. A nonrandomized, controlled trial was conducted of the effect of short daily (6 sessions/wk of 3 h each) or conventional (three sessions/wk of 4 h each) hemodialysis on LVH and inflammatory factors. A total of 26 short daily hemodialysis and 51 matched conventional hemodialysis patients were enrolled, and baseline and 12-mo measures of echocardiographic left ventricular mass index (LVMI), serum C-reactive protein (CRP), serum calcium and phosphorus, and erythropoietin resistance index were collected. Baseline characteristics were similar between groups except that hemoglobin and serum calcium were lower and serum phosphorus was higher in the short daily hemodialysis group. At 12-mo follow-up, short daily hemodialysis patients experienced a 30% decrease in LVMI (154 ؎ 33 to 108 ؎ 25; P < 0.0001). After adjustment for potential confounders, short daily hemodialysis (␤ ‫؍‬ ؊41.63, P ‫؍‬ 0.03) and percentage decrease in serum phosphorus (␤ ‫؍‬ ؊0.12, P ‫؍‬ 0.04) predicted a 12-mo decrease in LVMI. Among short daily hemodialysis patients, there were significant reductions in median CRP levels [1.22 interquartile range (IQR) (0.37 to 3.70) to 0.05 IQR (0.05 to 1.17); P < 0.01] and erythropoietin resistance index [19.5 IQR (8.6 to 37.6) to 10.5 IQR (5.5 to 14.6); P < 0.001]. There were no significant changes in LVMI, CRP, or erythropoietin resistance index in the conventional hemodialysis group. Short daily hemodialysis is associated with improved fluid and phosphorus management and a reduction in LVH and inflammatory factors compared with conventional hemodialysis. Future trials are needed to determine whether short daily hemodialysis can reduce morbidity and mortality in this high-risk population.

Left Ventricular Hypertrophy

“…Our group recently published results that demonstrate that even with aggressive therapy for BP control (average systolic BP of 145 mmHg) and anemia, conventional hemodialysis is associated with significant LVH (mean LVMI of 155 g/m 2 ) (11), whereas short daily dialysis is associated with a significant reduction in LVMI (154 to 108 g/m 2 ) and control of serum phosphorus (mean serum phosphorus of 4.2 mg/dl) correlates with this reduction in LVMI. There findings suggest a novel mechanism for the deleterious effect of hyperphosphatemia on cardiovascular outcomes among hemodialysis patients (11). Previous investigators have noted the association of hyperphosphatemia and LVH (9,10), although our study is the first that we are aware of to show that improvement in serum phosphorus is associated with improvement in LVH.…”

“…Our findings show that in patients in whom phosphorus is improved, LVH improves (11). Decreased vascular compliance through vascular calcification that is induced by poor mineral metabolism is a very likely mechanism for the association of poor mineral metabolism and cardiovascular disease.…”

“…However, daily hemodialysis had mixed effects on serum phosphorus in previous studies (32-34). Our group was the first to report good control of serum phosphorus in a controlled study of daily in-center hemodialysis with reduction in use of phosphate binders (11). The prescription of more frequent dialysis sessions, using the same weekly total time, would be predicted to enhance phosphorus removal by maximizing the first-hour removal, which is greatest during the first hour of hemodialysis (48).…”

“…Daily hemodialysis with session length of 3 h is a modality that has been shown to reduce effectively serum phosphorus levels (11,31); increasing dialysis frequency currently is recommended only when the relative risk for death is increased by 43% (28). In addition, these guidelines suggest changing only the variable of dialysis frequency, without explicitly stating that total dialysis time also must be increased, because just altering frequency has not been shown to reduce effectively serum phosphorus levels (32)(33)(34).…”

“…Currently, the mechanistic link between hyperphosphatemia and cardiovascular mortality in dialysis patients is not known; however, recent data suggest that the deleterious effects of hyperphosphatemia may be related to left ventricular hypertrophy (LVH) (9 -11). Furthermore, our group recently published data that suggest that correction of hyperphosphatemia is associated with reduction in left ventricular mass index (LVMI) (11). This review focuses on the new evidence that suggests that hyperphosphatemia leads to LVH and highlights effective treatment options.…”