Echocardiographic Predictors of Chronotropic Incompetence to Exercise in Patients with Heart Failure with Preserved Ejection Fraction

Abstract

Objective: Exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF) is most often attributed to diastolic dysfunction (DD); however, chronotropic incompetence (CI) could also play an important role. We intended to examine whether there are predictive echocardiographic parameters of DD for impaired chronotropic response to exercise. Methods and Results: Patients (n = 143) with unexplained dyspnea and/or exercise intolerance who fulfilled clinical and echocardiographic criteria of HFpEF presence underwent a symptom-limited exercise test using a treadmill (ETT) according to the Bruce protocol. CI was defined as an achieved heart rate reserve (HRR) of ≤ 80%. Comparison of the groups with (n = 98) and without CI (n = 45) did not show any statistically significant difference regarding demographic and clinical characterristics except for use of beta blockers (BB) that were more frequently present (p = 0.012) in patients with CI in comparison with those without. Patients with CI had a higher mean E-wave velocity, E/A ratio, increased E/E' septal, lateral as well as average ratio and abnormal IVRT/T E-e' index all consistent with elevated LV filling pressures. E/E' average ratio > 15 was statistically insignificantly more frequently present in patients with CI. In addition, by multivariate stepwise regression analysis value of E' septal (β = 3.697, 95%CI 0.921-6.473, p = 0.009) along with use of BB, current smoking and basal heart rate appeared as statistically significant independent predictors of lower HRR %. Conclusion: Patients with HFpEF frequently have chronotropic incompetence to graded exercise which may partly be predicted with echocardiographic parameters that are consistent with elevated LV filling pressures.