Abstract 12508: Tuning the Heart Rate Recovery For Age
Introduction: Exercise parameters such as peak heart rate (HR) are generally adjusted for age, whereas HR recovery is generally given as an absolute value: < 13 bpm at 1 minute post-peak exercise being abnormal.
Hypothesis: We analyzed a large cohort of patients to determine the impact of age on HR recovery (HRRec) and if the prognostic performance of HRRec is improved by adjustment for age.
Methods: Non-imaging exercise tests performed on patients aged 30-79 years from 1993 to 2010 were included. Patients with known cardiovascular diseases were excluded. Patients were assigned to 5 groups according to age: 30-39, 40-49, 50-59, 60-69, and 70-79. Mortality was reported according to HRRec during the first minute of active recovery using Cox regression analysis. Mortality was determined from Minnesota and National Death Indices.
Results: 22,643 patients (64 % male) were included. The median HRRec in the age groups with IQR were as follows: 30-39: 20 [15-26]; 40-49: 19 [14-25]; 50-59: 18 [13-23]; 60-69: 15 [10-20]; and 70-79: 11 [6-16]. There were 1566 deaths (6.9%) over a mean follow-up of 11.8 ± 5.0 years. HRRec of 13 would fall at the 17th percentile for patients 30-39 years old, but this increased to the 20th, 27th, 40th, and 60th percentiles with increasing age group. The mortality in age groups according to HRRec is shown in the Figure. For age groups 30-39 and 40-49, the hazard ratio for mortality at a HRRec of 11-12 bpm (i.e. just below the standard of 13) versus patients with a HRRec of ≥ 20 bpm was > 2.0. For age 50-59 and 60-69, however, a HRRec of < 11 bpm is necessary to obtain a doubling of risk, and for age 70-79 a HRRec of < 9 bpm is necessary.
Conclusions: HRRec decreases significantly with age. The performance of abnormal HRRec defined as < 13 bpm is inconsistent across age groups. To standardize the ability of HRRec to identify at least a 2.0-fold increased risk, lowering the cup-point to < 11 bpm for ages 50-59 and 60-69 and < 9 bpm for age 70-79 is required.
Author Disclosures: N. Sydó: None. T. Sydó: None. K.A. Gonzalez Carta: None. J.G. Murphy: None. B. Merkely: None. T.G. Allison: None.
- © 2015 by American Heart Association, Inc.