AGE-RELATED MAXIMUM HEART RATE AMONG ISCHEMIC AND NON-ISCHEMIC HEART FAILURE PATIENTS RECEIVING BETA-BLOCKADE THERAPY

Abstract

Background At the setting of evaluation of functional capacity, heart failure (HF) patients must be evaluated under optimised clinical therapy, including beta-adrenergic blockade (BB). Predicted maximum heart rate (HRmax) based on 220 – age is widespread used, but it is not applicable to patients receiving BB therapy. Few studies suggest other equations which estimate HRmax in patients receiving BB therapy with and without heart failure. However, these studies do not consider the etiology in HF. The purpose of this study was to determine an equation to predict HRmax in patients with ischemic and non ischemic HF who are receiving BB therapy. Methods We included patients with heart failure who were being considered for heart transplantation and underwent treadmill cardiopulmonary exercise testing between 1999 and 2010, using Naughton protocol. All patients were taking BB at maximum tolerated dose at the discretion of the treating physician. We excluded patients with pacemaker and/or implantable defibrillator, ejection fraction greater than 0.50 or peak respiratory exchange ratio (RER) less than 1.00 and chagas disease. We used linear regression to develop the equation that predict HR max, based on age in ischemic and non-ischemic patients. Results We analysed 278 patients, age 47±10, ischemic (n=75) and non-ischemic (n=203). The left ventricle ejection fraction was 30.8±9.4 and 28.6±8.2% (p = 0.04), peak VO2 was 16.9±4.7 and 16.9±5.2 ml/kg/min (p = NS) and the HRmax was 130.8±23.3 and 125.3±25.3 bpm (p = 0.051) in ischemic and non-ischemic respectively. We have found the equation HRmax = 168 − 0.76 × age for ischemic and HRmax = 134 − 0.18 × age for non-ischemic HF patients. Conclusion Our results suggest that equations to estimate HR max should consider the etiology in heart failure patients. ACC Moderated Poster Contributions McCormick Place South, Hall A Sunday, March 25, 2012, 9:30 a.m.-10:30 a.m. Session Title: Does the Exercise ECG Have a Role in 2012? Abstract Category: 25. Diagnostic Testing: ECG Exercise Presentation Number: 1155-455