Introduction : Heart failure with preserved ejection fraction (HFpEF) constitutes half of all heart failure (HF). Adverse outcomes in HFpEF individuals are primarily non-cardiac and there are no mortality modifying therapies available. Frailty represents a state of multiorgan system functional and reserve reduction predisposing to adverse outcomes when under physiologic stress; however, the prevalence and prognostic implications of frailty in HFpEF are not well known. Methods We included patients referred to the Johns Hopkins HFpEF Clinic with a clinical and hemodynamic diagnosis of HFpEF who completed the Johns Hopkins Frailty Assessment Instrument (JH-FAI), a validated frailty assessment tool. JH-FAI includes five phenotypic criteria: unintentional weight loss, exhaustion, low energy expenditure, low grip strength, and slowed waking speed to characterize individuals as non-frail (none of the criteria), pre-frail (1 or 2 of the criteria), or frail (3-5 of the criteria). Adverse outcome was defined as HF hospitalization or death within 3 years from index visit. Statistical analyses including multivariate Cox survival analysis were performed comparing pre-frail and frail using conventional methods. Results Of 187 individuals included, only 13 (7%) were classified as non-frail, 96 (51%) were pre-frail, and 75 (40%) were frail. Risk of adverse outcome was associated with presence of chronic obstructive pulmonary disease (HR 1.60, p=0.014), elevated right ventricular systolic pressures by echo (HR 1.02, p=0.006), and elevated filling pressures including right atrial pressure (HR 1.09, p<0.001), mean pulmonary artery pressure (HR 1.04, p=0.002), and pulmonary capillary wedge pressure (HR 1.06, p=0.008). Event free survival (Figure) was significantly reduced in frail versus pre-frail individuals (log rank test p<0.001); even after adjusting for age, gender, COPD, and filling pressures (unadjusted HR 1.67, p=0.007; adjusted HR 1.82, p=0.012). Conclusions The majority of HFpEF patients were classified as either frail or pre-frail by the JHU-FAI. Frailty score predicted adverse outcomes, independent of well-established prognostic factors including filling pressures. Frailty should be routinely assessed in HFpEF and further investigation is needed into therapeutic interventions targeting frailty in the management of HFpEF. : Heart failure with preserved ejection fraction (HFpEF) constitutes half of all heart failure (HF). Adverse outcomes in HFpEF individuals are primarily non-cardiac and there are no mortality modifying therapies available. Frailty represents a state of multiorgan system functional and reserve reduction predisposing to adverse outcomes when under physiologic stress; however, the prevalence and prognostic implications of frailty in HFpEF are not well known. We included patients referred to the Johns Hopkins HFpEF Clinic with a clinical and hemodynamic diagnosis of HFpEF who completed the Johns Hopkins Frailty Assessment Instrument (JH-FAI), a validated frailty assessment tool. JH-FAI includes five phenotypic criteria: unintentional weight loss, exhaustion, low energy expenditure, low grip strength, and slowed waking speed to characterize individuals as non-frail (none of the criteria), pre-frail (1 or 2 of the criteria), or frail (3-5 of the criteria). Adverse outcome was defined as HF hospitalization or death within 3 years from index visit. Statistical analyses including multivariate Cox survival analysis were performed comparing pre-frail and frail using conventional methods. Of 187 individuals included, only 13 (7%) were classified as non-frail, 96 (51%) were pre-frail, and 75 (40%) were frail. Risk of adverse outcome was associated with presence of chronic obstructive pulmonary disease (HR 1.60, p=0.014), elevated right ventricular systolic pressures by echo (HR 1.02, p=0.006), and elevated filling pressures including right atrial pressure (HR 1.09, p<0.001), mean pulmonary artery pressure (HR 1.04, p=0.002), and pulmonary capillary wedge pressure (HR 1.06, p=0.008). Event free survival (Figure) was significantly reduced in frail versus pre-frail individuals (log rank test p<0.001); even after adjusting for age, gender, COPD, and filling pressures (unadjusted HR 1.67, p=0.007; adjusted HR 1.82, p=0.012). The majority of HFpEF patients were classified as either frail or pre-frail by the JHU-FAI. Frailty score predicted adverse outcomes, independent of well-established prognostic factors including filling pressures. Frailty should be routinely assessed in HFpEF and further investigation is needed into therapeutic interventions targeting frailty in the management of HFpEF.