BACKGROUND: Black patients have been shown to have different baseline characteristics and outcomes compared with nonblack patients in cohort studies. However, few studies have focused on heart failure (HF) with preserved ejection fraction (HFpEF) patients. We aimed to determine the difference in cardiovascular outcomes in black and nonblack patients with HFpEF and to determine the relative efficacy and safety of spironolactone in black and nonblack patients. METHODS AND RESULTS: Patients with HFpEF, randomized to spironolactone versus placebo in the TOPCAT trial (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist) in North and South America, were grouped according to self-described black and nonblack race. Black HFpEF patients (n=302) were younger and were more likely to have diabetes mellitus and hypertension than nonblack patients but had similar HFpEF severity. Black patients had higher risk for the primary outcome (hazard ratio [HR], 1.34; 95% confidence interval, 1.06-1.71; P=0.02) and first HF hospitalization (HR, 1.51; 95% confidence interval, 1.167-1.97; P=0.002)], but no significant difference in cardiovascular mortality risk (HR, 0.78; 95% confidence interval, 0.51-1.20; P=0.326). In black and nonblack patients, randomization to spironolactone conferred similar efficacy in the primary outcome (HR, 0.83 versus 0.79; P for interaction=0.49), HF hospitalization (HR, 0.67 versus 0.82; P for interaction=0.76), and cardiovascular mortality (P for interaction=0.19). The risk of hyperkalemia and worsening renal function with spironolactone and study drug adherence were also similar. CONCLUSIONS: Black patients with HFpEF have a higher HF hospitalization risk than nonblack patients, but spironolactone is similarly effective and safe in both groups. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00094302.