Long-term CAPD patients are volume expanded and display more severe left ventricular hypertrophy than haemodialysis patients

Background. Whether hypertension and left ventricular hypertrophy (LVH) are more prevalent in CAPD than in haemodialysis (HD) patients is still under discussion. Methods. To examine this problem we compared a group of 51 CAPD patients, with a group of 201 HD patients. The evaluation included the measurement of atrial natriuretic peptide (atrial natriuretic factor (ANF)), taken as indicator of volume status, and echocardiographic measurements. Results. CAPD patients were older, had been treated for a shorter time, and had lower serum albumin and phosphate than HD patients. Plasma ANF was higher (P<0.01) in CAPD (median 33.8 pmol/l (interquartile range 18.2-63.0)) than in HD patients (22.7 pmol/l (14.9-38.7)). Similarly, the left atrial volume was substantially higher (P<0.0001) in CAPD patients (49±22 ml) than in HD patients (37±17 ml), while the left ventricular end-diastolic diameter was similar in the two groups (CAPD 51 ± 7 mm; HD 50 ± 7 mm). Furthermore, left ventricular hypertrophy was more severe (P<0.0001) in CAPD (157 ± 37 g/m) than in HD patients (133 ± 39 g/m). The proportion of CAPD patients requiring antihypertensive drugs was markedly higher than that of HD patients (65 vs 38% P<0.001). Multivariate modelling showed that volume expansion and pressure load as well as serum albumin were independent predictors of left ventricular mass. Conclusions. Left ventricular hypertrophy is more severe in long-term CAPD patients than in HD patients. This finding is associated with evidence of more pronounced volume expansion, hypertension, and hypoalbuminaemia. Volume and pressure load along with factors associated with hypoalbuminaemia may aggravate LVH in uraemic patients on CAPD.