RELATIONSHIP BETWEEN CLINIC AND AMBULATORY BLOOD PRESSURE AND MORTALITY IN PATIENTS WITH PREVIOUS STROKE

Abstract

Objective: The aim of this study was to evaluate the association between clinic and ambulatory BP and mortality in patients with a previous stroke Design and method: Observational cohort study from the Spanish Ambulatory Blood Pressure Registry. Mortality data (date and cause) were ascertained by a computerized search of the vital registry of the Spanish National Institute of Statistics. For each study participant, follow-up was from the date of his or her recruitment to the date of death, or December 31st, 2019, whichever occurred first. Cox models were used to estimate associations between clinic and ambulatory BP and mortality, adjusted for clinical confounders (age, sex, BMI, smoking, diabetes, and dyslipidemia), and additionally for alternative measures of BP. Results: From the 59 124 individuals included in the Registry, we selected 2,183 with a previous stroke. Mean age was 67.5 ± 11.8 years, 43.6% were female. During a median follow-up of 9.7 years (IQR 7.7–11.3), 632 (29.5%) participants died, including 236 from cardiovascular causes (62 ischemic heart disease deaths, 83 stroke deaths, and 28 heart failure deaths). In the confounder-adjusted model, clinic systolic BP was not associated with the risk of all-cause or cardiovascular mortality. In contrast, systolic BP indices obtained through ABPM (24h, day and night) were all associated with all-cause and cardiovascular mortality. In the simultaneous adjustment of daytime and night-time systolic BP, only night-time systolic BP remained significantly associated with all cause and cardiovascular death: OR 1.36 (1.21-1.52) and 1.45 (1.21-1.73), respectively. For diastolic BP, only night-time BP was associated with all-cause and cardiovascular mortality: OR 1.33 (1.18-1.49) and 1.58 (1.32-1.89), respectively. Reverse dipper pattern (risers) was also associated with all-cause mortality: OR 1.56 (1.18-1.86) and cardiovascular mortality: OR 1.81 (1.27-2.57). Conclusions: In patients who have suffered a previous stroke, night-time blood pressure is the BP estimate most closely associated with all-cause and cardiovascular mortality.