Association between DBP and major adverse cardiovascular events in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

In patients with stable coronary artery disease, low DBP is associated with an increased risk of myocardial infarction and cardiovascular death, but its association with clinical outcomes in patients with acute myocardial infarction undergoing percutaneous coronary intervention (PCI) is unknown.Consecutive patients with ST-segment elevation myocardial infarction (STEMI) undergoing PCI from January 2010 to June 2016 were enrolled. The patients were divided into five groups according to the quintiles of DBP at admission. The primary outcome was in-hospital major adverse cardiovascular events (MACE) including all-cause death, stroke, target vessel revascularization, and recurrent myocardial infarction.A total of 2198 patients were enrolled, of whom 157 (7.1%) developed in-hospital MACE. Patients with DBP lower than 60 mmHg was associated with a higher rate of in-hospital MACE (14.8, 7.8, 5.6, 6.1, and 3.8%, P < 0.001) and all-cause death (12.5, 6.4, 4.3, 3.9, and 1.9%, P < 0.001) compared with those with DBP 60-69, 70-79, 80-89, and at least 90 mmHg. Multivariate logistic regression analysis demonstrated that DBP higher than 90 mmHg was a significant predictor of lower risk of in-hospital MACE (OR = 0.16, 95% CI = 0.04-0.61, P = 0.007). Cubic spline models for the association between DBP and MACE did not demonstrate a U-type relationship after adjusting for potential risk factors. During the follow-up, lower DBP was associated with a higher risk of all-cause death (P < 0.0001).Lower DBP is independently associated with an elevated risk of in-hospital MACE and follow-up all-cause death.