Association Between Admission Pulse Pressure and Long-Term Mortality in Elderly Patients With Type 2 Diabetes Mellitus Admitted for Acute Coronary Syndrome: An Observational Cohort Study

OBJECTIVE: The aim of this study was to assess the effect of pulse pressure (PP) at admission on long-term cardiac and all-cause mortality among elderly patients with type 2 diabetes mellitus (T2DM) admitted for acute coronary syndrome (ACS). METHODS: This is a retrospective observational study. The patients aged at least 65 years with T2DM and ACS from January 2013 to April 2018 were enrolled and divided into 4 groups according to admission PP: <50 mmHg; 50–59 mmHg; 60–69 mmHg, and ≥70 mmHg. Multivariate Cox proportional hazard regression analyses and restricted cubic spline were performed to determine the association between PP and outcomes (cardiac and all-cause death). RESULTS: A total of 2,587 consecutive patients were included in this cohort study. The mean follow-up time was 39.2 months. The incidences of cardiac death and all-cause death were 6.8% (n = 176) and 10.8% (n = 280), respectively. After multivariate adjustment in the whole cohort, cardiac and all-cause mortality were significantly higher in PP <50 mmHg group and PP ≥70 mmHg group, compared with PP 50–59 mmHg group. Further analysis in acute myocardial infarction (AMI) subgroup confirmed that PP <50 mmHg was associated with cardiac death [hazard ratios (HR) 2.92, 95% confidence interval (CI) 1.45–5.76, P = 0.002] and all-cause death (HR 2.08, 95% CI 1.20–3.58, P = 0.009). Meanwhile, PP ≥70 mmHg was associated with all-cause death (HR 1.78, 95% CI 1.05–3.00, P = 0.031). However, admission PP did not appear to be a significant independent predictor in unstable angina pectoris (UAP) subgroup. There is a U-shaped correlation between PP and cardiac and all-cause mortality in the whole cohort and UAP subgroup and a J-shaped correlation in the AMI subgroup, both with a nadir at 50–59 mmHg. CONCLUSION: In elderly patients with T2DM admitted for ACS, admission PP is an independent and strong predictor for long-term cardiac and all-cause mortality, especially in patients with AMI.