Association of Post-Treatment Blood Pressure Levels with Incident Stroke in Patients with Primary Aldosteronism: A Retrospective Cohort Study

OBJECTIVES The optimal blood pressure (BP) target for stroke prevention in patients with primary aldosteronism (PA) remains to be determined. This cohort study examined the association between mean BP levels during follow-up and stroke incidence in this population. METHODS The study retrospectively enrolled patients with PA aged ≥30 years who were hospitalized at our hypertension center between January 2008 and December 2019. The exposure variable was the mean BP from ≥3 follow-up visits per patient. The primary outcome was incident stroke during follow-up. The association of mean follow-up BP with risk of stroke was assessed using Cox proportional hazard models and restricted cubic splines. RESULTS The cohort comprised 3138 patients with PA (median age 49 years, 55% male). During a median follow-up of 6 years, 101 patients experienced incident stroke (ischemic, n=79; hemorrhagic, n=22). After adjusting for age, sex,pretreatment BP, and other relevant confounders, the mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) during follow-up showed significant positive associations with the risk of incident stroke (HR 1.04, 95% CI 1.02-1.06, P<0.001 and HR 1.05, 95% CI 1.01-1.08, P=0.005, respectively). In multivariable survival analysis, compared with the SBP ≥140 mmHg group, the risk of stroke was decreased by 54% in the SBP <130 mmHg group (HR 0.46, 95% CI 0.26-0.80, P=0.006) and by 47% in the SBP 130-139 mmHg group (HR 0.53, 95% CI 0.33-0.84, P=0.007). No association was observed when DBP was analyzed categorically. When variables were modeled using restricted cubic splines, the risk of stroke increased linearly with SBP and DBP. The risk of stroke began to increase rapidly at a BP of around 133/83 mmHg. In subgroup and sensitivity analyses, the association between mean follow-up SBP and stroke incidence remained consistent. CONCLUSIONS A target BP of <130/80 mmHg might be associated with a reduced risk of stroke in patients with primary aldosteronism. Nevertheless, additional validation remains necessary through prospective, randomized controlled trials.