Impact of Metabolically Healthy Obesity on Cardiovascular Outcomes in Older Adults with HFpEF: Insights from a Nationwide Sample

Background: Clinical outcomes among older adults hospitalized with heart failure with preserved ejection fraction (HFpEF) in the setting of metabolically healthy obesity (MHO) remain insufficiently explored. This study aimed to evaluate whether MHO status is associated with different rates of major adverse cardiac and cerebrovascular events (MACCEs) during HFpEF-related hospitalizations compared to patients without MHO. Methods: Data from the 2019 National Inpatient Sample (NIS) database was analyzed using relevant ICD-10 codes to identify HFpEF admissions in older adults. Propensity score matching (1:1) was applied to generate balanced cohorts of patients with and without MHO. Multivariable adjustments were performed to assess primary outcomes, including MACCEs, all-cause mortality (ACM), acute myocardial infarction (AMI), dysrhythmia, cardiac arrest (CA), and stroke. Statistical significance was set at p < 0.05. Results: Each MHO cohort included 22,405 patients with a median age of 75 years. The MHO+ group demonstrated a significantly higher risk of dysrhythmia (OR 1.32, 95% CI 1.21–1.43, p < 0.001). Interestingly, an “obesity paradox” was observed, as the MHO+ cohort had lower odds of MACCEs (OR 0.70, 95% CI 0.61–0.81, p < 0.001), ACM (OR 0.66, 95% CI 0.54–0.82, p < 0.001), and AMI (OR 0.71, 95% CI 0.59–0.86, p = 0.001) compared to MHO−. No significant differences were found for CA or stroke between the groups. Conclusions: Although the MHO+ group had an elevated risk of dysrhythmia, they exhibited more favorable outcomes in terms of MACCEs, ACM, and AMI—supporting the concept of an “obesity paradox.” Further research is needed to better understand the role of MHO as a comorbid condition in patients with HFpEF.