Background: High visit-to-visit variability of blood pressure (VVV-BP) is associated with adverse cardiovascular events and premature death in essential hypertension. It is unknown if this effect is replicated in patients with malignant hypertension (MHT), the most severe form of hypertension. We compared VVV-BP and mean diastolic and systolic blood Pressures (ie. VVV-DBP, VVV-SBP, Mean-DBP and Mean-SBP) as predictors of “death or dialysis” in our cohort of patients with MHT from the West Birmingham MHT Registry.
Methods: Mean-SBP, mean-DBP, VVV-SBP, and VVV-DBP were computed, and their relationship with 'death or dialysis' established in a 10-year follow-up period of 460 patients to May 2015.
Results: Patients in the highest Mean-SBP and Mean-DBP quartiles demonstrated a significantly greater risk of “death or dialysis” than patients in the lowest mean BP quartiles (Q4 vs Q1), while those in the highest quartiles for VVV-DBP and VVV-SBP (Q4 vs Q1) did not (Fig 1, Table 1). These findings persisted after controlling for risk factors known to independently affect death and dialysis in multivariate analyses.
Conclusion: Mean SBP and DBP independently predict “all-cause mortality or dialysis” in patients with MHT. Contrary to prior studies in non-MHT essential hypertension, MHT patients with the highest VVV-BPs (i.e. changes in BP) are actually “moving away” from the extremely high baseline BPs and towards cardiovascular protection. Patients with high mean BPs are therefore those with more sustained clinical risk and poorer outcomes.