Low Diastolic Blood Pressure Is Associated With Angina in Patients With Chronic Coronary Artery Disease

Background In patients with coronary artery disease (CAD), low diastolic blood pressure (DBP) is associated with increased risk of myocardial infarction, but its association with angina is unknown. Objectives The goal of this study was to examine the association of low DBP and angina in patients with CAD. Methods The study assessed the frequency of angina (measured by using the Seattle Angina Questionnaire–Angina Frequency score) according to DBP in patients with known CAD from 25 U.S. cardiology clinics. Hierarchical logistic regression was used to test the association between DBP and angina, with a spline term for DBP to assess nonlinearity. Results Among 1,259 outpatients with CAD, 411 (33%) reported angina in the prior month, with higher rates in the lowest DBP quartile (40 to 64 mm Hg: 37%). In the unadjusted model, DBP was associated with angina with a J-shaped relationship (p = 0.017, p for nonlinearity = 0.027), with a progressive increase in odds of angina as DBP decreased below ∼70 to 80 mm Hg. This association remained significant after sequential adjustment for demographic characteristics (p = 0.002), comorbidities (p = 0.002), heart rate (p = 0.002), systolic blood pressure (p = 0.046), and antihypertensive antianginal medications (p = 0.045). Conclusions In patients with chronic CAD, there seemed to be an association between lower DBP and increased odds of angina. If validated, these findings suggest that clinicians should consider less aggressive blood pressure control in patients with CAD and angina.