Background: Recent US guidelines recommend lower blood pressure (BP) targets in hypertension, but aggressive lowering of diastolic BP (DBP) can occur at the expense of myocardial perfusion, particularly in the presence of coronary artery disease. We sought to establish the long-term impact of low DBP on mortality among patients undergoing percutaneous coronary intervention with well-controlled systolic BP.
Methods: We analyzed data from 12 965 patients undergoing percutaneous coronary intervention between 2009 and 2018 from the Melbourne Interventional Group registry who had a preprocedural systolic BP of ≤140 mm Hg. Patients with ST-elevation myocardial infarction, cardiogenic shock, and out-of-hospital arrest were excluded. Patients were stratified into 5 groups according to preprocedural DBP: <50, 50 to 59, 60 to 69, 70 to 79, and ≥80 mm Hg. The primary outcome was long-term, all-cause mortality. Mortality data were derived from the Australian National Death Index.
Results: Patients with DBP<50 mm Hg were older with higher rates of diabetes, renal impairment, prior myocardial infarction, left ventricular dysfunction, peripheral and cerebrovascular disease (all P<0.001). Patients with DBP<50 mm Hg had higher 30-day (2.5% versus 0.7% for the other 4 quintiles; P<0.0001) and long-term mortality (median, 3.6 years; follow-up, 29% versus 11%; P<0.0001). Cox-regression analysis revealed that DBP<50 mm Hg was an independent predictor of long-term mortality (hazard ratio [HR], 1.55 [95% CI, 1.20-2.00]; P=0.001).
Conclusions: In patients with well-controlled systolic BP undergoing percutaneous coronary intervention, low DBP (<50 mm Hg) is an independent predictor of long-term mortality.
Keywords: coronary artery disease; diastolic blood pressure; long-term outcomes; perfusion; registries.