Author + information
Background: Diagnosis of Heart Failure with Preserved Ejection Fraction (HFpEF) is challenging. Invasive hemodynamic exercise testing represents the gold standard but is limited by cost and risk. Cardiopulmonary exercise testing (CPET) is commonly used to noninvasively establish the diagnosis but has never been compared to the invasive gold standard.
Methods: We retrospectively examined patients with normal EF (>50%) undergoing invasive hemodynamic exercise testing and maximal upright CPET for evaluation of exertional dyspnea over a 15-year period. HFpEF was defined by the presence of exercise pulmonary wedge pressure ≥25mmHg at catheterization.
Results: Compared to controls (n=72), HFpEF patients (n=134) displayed lower peak O2 consumption (VO2, 14.5±4.3 vs 20.5±5.6 ml/kg/min, p<0.0001). In a multivariable model, low peak VO2 (<14 ml/kg/min) identified HFpEF independent of other predictors (c-statistic 0.71, p<0.0001) with excellent specificity (91%) and positive predictive value (92%) but poor sensitivity (50%). Using percent-predicted peak VO2 based upon age/sex normative values (<50% or <80% predicted) was inferior to absolute peak VO2 (c-statistics lower by -0.186 and -0.127 vs absolute peak VO2, both p<0.001). Approximately half of patients with invasively-proven HFpEF displayed relatively preserved VO2 (50% with ≥14ml/kg/min and 40% with peak VO2≥70% predicted). Compared to HFpEF patients with low peak VO2, those with preserved VO2 had better cardiac output reserve assessed at catheterization, but no difference in pulmonary wedge pressure on exercise. Low peak VO2 was independently associated with increased mortality in HFpEF (HR 7.7, 95% CI [1.1-51.4]) (p=0.04).
Conclusions: Reduced peak VO2 is highly specific for HFpEF and predicts mortality. However, many patients with invasively-proven HFpEF display relatively preserved peak VO2 coupled to greater cardiac output reserve on exercise, despite high cardiac filling pressures. We conclude that low peak VO2 is useful prognostically and to identify the presence of HFpEF, but preserved peak VO2 does not exclude HFpEF and should not be used to rule this diagnosis out among patients presenting with exertional dyspnea.
Poster Hall, Hall C
Saturday, March 18, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Emerging Developments in HFpEF and Arryhthmias
Abstract Category: 13. Heart Failure and Cardiomyopathies: Clinical
Presentation Number: 1250-268
- 2017 American College of Cardiology Foundation