Ps-c18-6: the impact of antihypertensive drug use on intradialytic blood pressure decline considering seasonal variation: a retrospective cohort study

Objective: Risk factors of intradialytic systolic blood pressure decline remain less understood. We aimed to identify clinical and laboratory predictors of intradialytic systolic blood pressure decline, considering its seasonal variation. Design and method: In a retrospective cohort of 47,219 hemodialysis sessions from 307 patients undergoing hemodialysis for 1 year in three dialysis clinics, seasonal variation and intradialytic systolic blood pressure decline predictors (predialysis systolic blood pressure - nadir intradialytic systolic blood pressure) were assessed using cosinor analysis and linear mixed models adjusted for baseline/monthly hemodialysis-related variables, respectively. Results: Intradialytic systolic blood pressure decline was highest and lowest in the winter and summer, respectively, following a clear seasonal pattern. In both models adjusted for baseline and monthly hemodialysis-related parameters, calcium channel blocker use was associated with a smaller decline (-4.58 [95% confidence interval (CI), -5.84 to -3.34], P < 0.001; -3.66 [95% CI, -5.69 to -1.64], P < 0.001) and alfa blocker use, with a greater decline (3.25 [95% CI, 1.53–4.97], P < 0.001; 3.57 [95% CI, 1.08–6.06], P = 0.005). Baseline and monthly serum phosphorus levels were positively correlated with a decline (1.55 [95% CI, 0.30–2.80], P = 0.02; 0.59 [95% CI, 0.16–1.00], P = 0.007) and baseline and monthly normalized protein catabolic rate, inversely correlated (-22.41 [95% CI, -33.53 to -11.28], P < 0.001; 9.65 [95% CI, 4.60–14.70], P < 0.001) Conclusions: Calcium channel blocker use, alfa blocker avoidance, and serum phosphorus-lowering therapy may attenuate intradialytic systolic blood pressure decline and should be investigated in prospective trials.