Association of calcium channel blocker use with intra-dialytic hypotension in maintenance hemodialysis.

Introduction Calcium channel blockers (CCBs) are common anti-hypertensive agents among patients receiving hemodialysis (HD). Despite this, the association of CCBs with intra-dialytic hypotension (IDH), an important adverse outcome that is associated with cardiovascular morbidity and mortality, remains largely unexplored. Methods Using kinetic modeling sessions data from the Hemodialysis Study, random-effects regression models were fit to assess the association of CCB use versus not with IDH (defined as systolic blood pressure (SBP)<90 mmHg if pre-HD SBP<160 mmHg or <100 mmHg if pre-HD SBP≥160 mmHg). Models were adjusted for age, sex, race, randomized Kt/V and flux assignments, heart failure, ischemic heart disease, peripheral vascular disease, diabetes mellitus, blood urea nitrogen, ultrafiltration rate, access type, pre-HD SBP, and other anti-hypertensives. Results Data was available for 1,838 patients and 64,538 sessions. At baseline, 49% of patients were prescribed CCBs. The overall frequency of IDH was 14% with a mean decline from pre-to nadir-SBP of 33±15 mmHg. CCB use was associated with lower adjusted risk of IDH, compared with no use (incidence rate ratio [IRR] 0.84; 95%CI 0.78, 0.89). The association was most pronounced for those in the pre-HD SBP lowest quartile (IRR 0.77;95%CI 0.70, 0.85), compared with the highest quartile (IRR 0.86; 95%CI 0.77, 0.97; P-interaction<0.001). Conclusion Among patients receiving HD, CCB use was associated with a lower risk of developing IDH, independent of pre-HD SBP and other anti-hypertensive use. Mechanistic studies are needed to better understand the effects of CCB and other anti-hypertensives on peri-dialytic blood pressure parameters among patients receiving HD.