Pulmonary hypertension in peritoneal dialysis patients: prevalence and risk factors.

AIM

To investigate the prevalence of pulmonary arterial hypertension (PAH) and the possible contributing factors for PAH in patients receiving regular continuous ambulatory peritoneal dialysis (CAPD).

PATIENTS AND METHODS

The study included 135 CAPD patients and 15 disease-free controls. Patients that had chronic obstructive pulmonary disease, severe mitral or aortic valve disease, connective tissue disease, history of pulmonary embolism, left ventricular ejection fraction <50%, or chest wall or parenchymal lung disease were excluded. All patients and controls were examined using echocardiography and bioelectrical impedance analysis. PAH was defined as systolic pulmonary artery pressure (PAP) >35 mmHg at rest.

RESULTS

Mean systolic PAP was higher in the CAPD patients than in the controls (19.66 +/- 11.66 vs 14.27 +/- 4.55 mmHg, p = 0.001). PAH was detected in 17 (12.6%) of the 135 CAPD patients. Mean systolic PAP was significantly higher in patients with PAH than in those without PAH (42.00 +/- 9.13 vs 16.44 +/- 7.83 mmHg, p = 0.001). Serum albumin level and ejection fraction were lower in patients with PAH than in those without PAH (p = 0.001 and 0.003 respectively). The ratio of extracellular water/total body water (ECW/TBW), which can reflect hydration status, was significantly higher in patients with PAH than in those without PAH (p = 0.008). In the PD group, no patients were hypovolemic; 51 (37.8%) of the 135 PD patients were hypervolemic and 84 (62.2%) were normovolemic. Only 3 of the 17 patients with PAH were normovolemic; the rest were hypervolemic. Mean systolic PAP was significantly higher in hypervolemic PD patients (24.57 +/- 14.19 mmHg) than in normovolemic PD patients (16.68 +/- 7.61 mmHg) (p = 0.001). PAP correlated with ECW/TBW (r = 0.317, p = 0.001) and left ventricular mass index (LVMI; r = 0.286, p = 0.001). On the other hand, it inversely correlated with serum albumin level (r = -0.281, p = 0.001), hemoglobin level (r = -0.165, p = 0.044), and ejection fraction (r = -0.263, p = 0.001). Serum albumin level, ECW/TBW, and LVMI were found in multivariate analysis to be independent risk factors for PAP.

CONCLUSION

PAH is a frequent cardiovascular complication in CAPD patients. Serum albumin level, hypervolemia, and LVMI are major risk factors for PAH. Therefore, strategies for treatment of hypervolemia, left ventricular hypertrophy, and hypoalbuminemia should be enhanced to prevent the development of PAH in CAPD patients.