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.

Keywords: acute myocardial infarction; hypertension; mortality; pulse pressure; systolic blood pressure..