Abstract 17561: Higher Heart Rate is Associated With Increased Three-Year Mortality in Hospital Survivors of Acute Myocardial Infarction
Introduction: Although admission heart rate (HR) predicts higher mortality after acute myocardial infarction (AMI), little is known regarding discharge HR, a potentially modifiable means of risk stratification. We tested the hypothesis that higher discharge HR is related to increased 3-year mortality following AMI, and assessed whether β-blocker use modified this relationship.
Methods: Our study involved two prospective U.S., multicenter registries of AMI: TRIUMPH and PREMIER (N=6576). Patients’ discharge HR (median 72, range 42-130 bpm) was examined as a continuous variable and was also divided into 5 groups: G1 ≤60 bpm (N=989), G2 61-70 (N=2035), G3 71-80 (N=1958), G4 81-90 (N=1077) and (G5) >90 (N=517). We assessed the shape of the association between discharge HR and mortality using cubic splines. Cox models were used to calculate adjusted risks of death for discharge HR after inclusion of demographic, psychosocial, and clinical covariates, including admission HR.
Results: The mean age was 60 ± 13; women 33%; black 24%. Higher discharge HR was associated with higher initial HR (r=0.28), greater co morbidities, and higher infarct severity. Splines suggested a linear relationship with mortality. After full adjustment, both discharge HR (RR 1.13 per 10 bpm, 95% CI 1.07-1.20) and initial HR (RR 1.06 per 10 bpm, 1.02-1.10) were associated with increased risk of death. There was significant interaction between discharge HR and β-blocker use (p=0.003), wherein risk was markedly higher among those off (RR 1.35 per 10 bpm, 1.19-1.54) vs. on β-blockers at discharge (RR 1.09, 1.03-1.16). Across groups, this difference between β-blocker nonusers and users was most pronounced for G4 (RR [vs. G1] 2.3, 1.07-4.96 vs. RR 1.31, 1.00-1.72) and G5 (RR 3.63, 1.68-7.88 vs. RR 1.15, 0.83-1.59). This occurred after adjustment for covariates associated with nonuse of β-blockers, including older age, black race, lower SES and social support, h/o lung disease and heart failure, NSTEMI, lack of critical coronary stenosis, and lower use of other guideline-directed medical therapy at discharge.
Conclusions: In patients with AMI, a higher discharge HR is independently associated with increased 3-year mortality. β-blockers modify this association, particularly at HR>80 bpm.
Author Disclosures: V. Alapati: None. F. Tang: None. E. Charlap: None. P. Chan: None. P. Heidenreich: None. P. Jones: None. J.A. Spertus: None. V. Srinivas: None. J.R. Kizer: Ownership Interest; Significant; Gilead Sciences, Inc; Pfizer, Inc.
- © 2016 by American Heart Association, Inc.