Comparison of 4 Admission Blood Pressure Indexes for Predicting 30-Day Mortality in Patients With ST-Segment Elevation Myocardial Infarction

Abstract

BACKGROUND We compared admission systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP) in predicting 30-day all-cause mortality in patients with ST-segment elevation myocardial infarction (STEMI) without cardiogenic shock. METHODS A retrospective study was performed in 7,033 consecutive STEMI patients. Multivariate-adjusted hazard ratios (HRs) with a 10mm Hg increment and quartiles of each blood pressure were determined by Cox proportional hazard analyses; Wald χ 2 tests were used to compare the strength of relationships. RESULTS Totally 593 (8.4%) patients died during follow-up. Of 4 indexes, only SBP (HR 0.94 per 10mm Hg, 95% confidence interval (CI) 0.91 to 0.98; P = 0.001) and PP (HR 0.89 per 10 mmHg, 95% CI 0.85 to 0.94; P < 0.001) were significantly associated with 30-day all-cause mortality; these in the highest vs. lowest quartiles of SBP (≥140 vs. <110mm Hg) and PP (≥60 vs. <40mm Hg) had HRs of mortality of 0.70 (95% CI 0.55 to 0.87; P = 0.003) and 0.60 (95% CI 0.47 to 0.75; P < 0.001), respectively. Compared with SBP, PP was a better predictor for mortality no matter in men (χ 2 = 5.9 for per 10mm Hg, χ 2 = 10.8 for quartiles) or women (χ 2 = 15.1 for per 10mm Hg, χ 2 = 19.5 for quartiles), and the relationship remained significant after adjustment of SBP. There was a pattern of declining risk with increasing blood pressures for mortality, and this trend was mainly observed in age groups of more than 70 years. CONCLUSIONS Pulse pressure was an independent predictor of mortality in patients with STEMI, and low admission blood pressure should serve as a warning sign.