Abstract 2487: Relationship Between Heart Rate, Blood Pressure and In-hospital Mortality in Patients with Non-ST-segment Elevation Acute Coronary Syndromes: Results in 139,194 Patients
Background: There is a “J-shaped” relationship between blood pressure and cardiovascular outcomes in patients with coronary artery disease, with higher event rates at very low and very high BP. However, the role of heart rate (HR) and systolic blood pressure (SBP) as a predictor of in-hospital mortality in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) is not well defined.
Methods: We evaluated 139,194 patients with NSTE ACS in the CRUSADE quality improvement initiative. The admission HR and SBP were recorded and summarized as 10-unit increments. Patients with SBP<90 mm Hg (4030 patients) were excluded from the HR portion of the analysis to avoid the confounding effect of cardiogenic shock. An adjusted odds ratio (OR) was calculated using a reference OR for HR of 60 – 69 bpm and a SBP of 120 –129 mm Hg.
Results: The relationship between unadjusted and adjusted in-hospital mortality and HR followed a “J-shaped” curve with an increased mortality at very low and very high HR with a nadir at 61 bpm (Figure⇓). In contrast, SBP appeared to have an inverse association with mortality, with a very high risk of mortality at lower SBP and lower risk at higher SBP (e.g., OR for SBP 70 –79=3.23; 95% CI=2.60 – 4.01, p<0.001 and OR for SBP 170 –179, OR=0.46, 95% CI=0.39 – 0.55, p<0.001).
Conclusions: Studying a very large community cohort of patients with NSTE ACS, we found that the relationship of admission HR and SBP and in-hospital mortality are complex. While mortality tends to decline with rising blood pressure, there is a J-shaped curve relationship between HR and mortality,with a nadir at 61 bpm (60 – 69 bpm). These associations should be considered in ACS prognostic models.