Abstract 12116: Exercise Parameters and Risk of Coronary Heart Disease and Mortality Among Obstructive Lung Disease Patients: The Henry Ford Exercise Testing Project [FIT

Abstract

Background: In the general population, the exercise treadmill testing (ETT) variables of lower resting heart rate (HR) and higher peak HR, maximal age predicted HR (MPHR), and exercise capacity (METS) have favorable prognosis for mortality. Patients with obstructive lung disease have increased mortality risk. Furthermore, some pulmonary medications (i.e. beta agonists) can influence HR. We determined whether ETT parameters carry the same prognostic value in patients with lung disease on treatment compared to those without lung disease. Methods: We analyzed data on 69,855 patients (mean age 55 yrs) who completed a clinically indicated ETT. Patients were defined as “lung disease” if taking medications routinely used to treat obstructive lung disease (n=6145, 8.8%). ICD9 codes regarding type of lung disease were not available. Cox hazard models were used to determine risk of all-cause mortality, major adverse cardiac events (MACE) and myocardial infarction (MI) over a mean of 11 yrs follow-up. Results: Higher resting HR was associated with increased risk of all-cause mortality, while peak HR, achieving ≥85% MPHR, and higher METS were associated with decreased risk ( Table ). No significant interaction for lung disease status was seen for the HR variables, but slightly stronger protective effect for higher METS among lung patients (p-interaction 0.032). Similar results between lung and non-lung disease patients were observed for MACE and MI. Among lung patients stratified by the presence/absence of coronary artery disease (CAD), the prognostic significance for peak HR, MPHR, and METS was stronger among those without CAD (p-interaction <0.05). Conclusion: HR-related parameters achieved on ETT are equally prognostic among patients with and without lung disease. Higher fitness (METS) was associated with improved clinical outcomes in both groups. However, the relative benefit of fitness on survival was even greater in patients with (versus without) lung disease.