Relationships between brain natriuretic peptide, troponin I and QT dispersion in asymptomatic dialysis patients

The relationships between increased wall stress, myocyte death, and ventricular repolarization instability in patients with heart failure were reported.

The relationships between brain natriuretic peptide (BNP), a predictor of increased wall stress of hearth; troponin I (cTnI), a predictor of myocyte death; and QT dispersion (QTd), a reflection of ventricular repolarization instability were evaluated in age- and sex-matched asymptomatic 29 hemodialysis (HD) patients and 26 peritoneal dialysis (PD) patients, and the finding were compared.

Serum BNP and cTnI levels in HD patients (722.9 +/- 907.9 pg/mL, 0.05 +/- 0.07 microg/L, respectively), just before HD, were significantly higher than those of PD patients (255.4 +/- 463.7 pg/mL, 0.02 +/- 0.02 microg/L, respectively; p < 0.05). There was no significant difference between groups with regard to corrected QTd and maximum and minimum QT intervals (p > 0.05). Serum cTnI levels were significantly and positively correlated with serum BNP levels in both dialysis groups (r = 0.447, p = 0.048). No relationship was found between plasma BNP and ECG parameters studied in both groups (p > 0.05).

Increased serum cTnI levels were associated with elevated BNP levels in both dialysis groups. The increases in BNP and troponin I are more likely to reflect hypervolemia. Although CAPD patients were receiving dialysis daily and HD patients were more hypervolemic, CAPD patients have similar QTdc and accordingly a similar tendency toward arrhythmias. This suggests that factors other than electromechanical interaction may be important in determining the QT interval length in patients on dialysis.