Systolic blood pressure-dependent association of baseline diastolic blood pressure with major adverse cardiovascular events in patients undergoing percutaneous coronary intervention: a retrospective cohort study

Current evidence demonstrates a J-shaped association between low diastolic blood pressure (DBP) and major adverse cardiac and cerebrovascular events (MACCE). However, the association pattern in patients after percutaneous coronary intervention (PCI) remains controversial, potentially due to myocardial reperfusion. Therefore, this study aimed to examine the relationship of baseline DBP with MACCE in coronary artery disease (CAD) patients undergoing PCI to enhance clinical risk stratification. This retrospective cohort study analysed publicly available data from the Dryad Digital Repository, comprising 2,444 patients who underwent PCI. Logistic regression, curve fitting, threshold effect analysis, and subgroup analyses were applied to examine the association of baseline DBP with MACCE. During a mean follow-up of 29.8 months, 296 patients (12.11%) developed MACCE. In fully adjusted models, DBP was associated with MACCE both as a continuous variable (OR: 1.16, 95% CI: 1.05–1.29) and when analyzed by quartile: participants in the highest DBP quartile (≥ 84 mm Hg) had greater MACCE risk than those in the lowest quartile (< 70 mm Hg) (OR: 1.53, 95% CI: 1.09–2.16). Curve-fitting and threshold-effect analyses demonstrated a nonlinear association ( P for non-linearity = 0.011) with an inflection point at approximately 73 mm Hg. Below this threshold, DBP showed no association with MACCE (OR: 0.76, 95% CI: 0.55–1.04); above it, each 10 mm Hg increment was associated with a 20% higher risk (OR: 1.20, 95% CI: 1.00–1.42). Furthermore, DBP exhibited a linear positive correlation with cardiac death (OR: 1.56, 95% CI: 1.25–1.94). In subgroup analyses, a linear positive association was evident among patients with SBP ≥ 130 mm Hg (OR: 1.41, 95% CI: 1.12–1.78) but not in those with SBP < 130 mm Hg (OR: 0.97, 95% CI: 0.85–1.12). This study revealed a nonlinear association between DBP and MACCE, with an inflection point at approximately 73 mm Hg. Notably, this pattern diverged from the classical J-shaped relationship: elevated MACCE risk was observed exclusively at higher DBP levels. DBP exhibited a linear positive correlation with cardiac death. Additionally, the association between DBP and MACCE risk varied depending on SBP control status, with patients exhibiting SBP ≥ 130 mm Hg demonstrating a significantly increased risk with elevated DBP. These exploratory findings may help identify high-risk patients and warrant confirmation in prospective studies.