Nocturnal hypertension and cardiovascular events: risk analysis using propensity score matching.

Background: Nocturnal hypertension (NHT) is associated with major adverse cardiovascular events (MACE) and heart failure (HF), and remains an area of growing interest, with evidence suggesting a differential impact compared to daytime hypertension (DTH).

Objectives: To evaluate the relationship between NHT and the risk of cardiovascular events, independently of daytime blood pressure.

Methods: We conducted an observational study based on a continuous registry of patients who underwent ambulatory blood pressure monitoring at a tertiary care center. Propensity score matching (1:1) was applied using relevant clinical factors to ensure comparability between groups. The primary outcome was the composite of MACE and HF. Cox regression and cubic spline models were used to explore non-linear associations and identify critical thresholds.

Results: After matching, 1,392 patients were analyzed (691 per group). In adjusted models, nocturnal systolic blood pressure was significantly associated with increased risk of MACE/HF (HR 1.04; 95 % CI: 1.01-1.07), whereas daytime systolic pressure showed no association (HR 0.98; 95 % CI: 0.95-1.01). In the multivariable model, NHT maintained its adverse effect (HR 1.03; 95 % CI: 1.01-1.04), together with other established clinical predictors. Risk curves demonstrated a non-linear association, with a significant increase in risk above 148 mmHg of nocturnal systolic blood pressure.

Conclusions: NHT independently increases the risk of cardiovascular events and provides prognostic thresholds that may improve risk stratification.