Sex Differences in Heart Failure

This single-study briefing examines reported sex- and NYHA-stage-specific differences in in-hospital outcomes among people admitted with a primary diagnosis of left ventricular heart failure (LVHF) in Germany. It describes associations in hospital data; it does not establish that sex or NYHA stage caused the observed outcomes, nor does it address outcomes beyond the hospitalization captured in the analysis. pmid:41729245

Evidence

The investigators reported a retrospective nationwide inpatient cohort study using anonymized DESTATIS hospital data covering 2014 to 2022. The dataset included inpatient cases treated in German hospitals, excluding psychiatric or psychosomatic admissions, and the analysis focused on cases with a primary diagnosis of LVHF. The reported study population comprised 2,616,462 hospital admissions. pmid:41729245

Cases were stratified by sex and NYHA stage. The researchers assessed baseline characteristics, comorbidities, in-hospital outcomes, and healthcare costs, and used multivariable logistic regression to evaluate in-hospital survival. DESTATIS conducted analyses using pre-approved scripts because direct access to the anonymized dataset was not permitted; the reported statistical software included SAS 9.3 and R version 4.3.2. pmid:41729245

Overall in-hospital mortality was reported as higher among women than men: 8.34% (108,461) versus 7.90% (103,883). The authors also reported that stratified analyses showed higher mortality rates for men across most age and NYHA groups, with specified exceptions for men aged 80–89 in NYHA I, younger than 40 in NYHA III, and aged 40–59 in NYHA IV. Thus, the overall comparison and the reported subgroup pattern were not identical. pmid:41729245

In the regression models, NYHA stage was reported as the strongest predictor of in-hospital mortality: NYHA II had an OR of 1.596, NYHA III an OR of 5.290, and NYHA IV an OR of 22.533; all reported p-values were less than 0.001. Confidence intervals were not located in the supplied packet. The packet reports these as statistical associations and does not provide an assessment of their clinical significance. pmid:41729245

The study also reported sex-specific healthcare-cost differences in more advanced NYHA categories, with men incurring higher costs in NYHA III and NYHA IV. This is a reported hospital-data comparison and should be read alongside the study’s inpatient setting and the way NYHA class may have been recorded during an acute admission. pmid:41729245

Analysis — Interpretation of In-Hospital Associations

The central result is not simply an overall sex contrast. Women had higher reported overall in-hospital mortality, whereas men had higher reported mortality across most age- and NYHA-stratified groups. Those findings can coexist because stratification changes which patients are being compared; the supplied evidence does not establish why the patterns differ. The analysis therefore supports a careful description of heterogeneity in the reported inpatient data, rather than a universal conclusion that one sex has worse LVHF outcomes. pmid:41729245

NYHA stage had the strongest reported association with in-hospital mortality in the regression models, with progressively larger reported odds ratios for NYHA II through IV and p-values below 0.001. Statistical significance indicates that these model results met the study’s reported threshold, but it does not by itself show clinical significance. Because the study evaluates hospital admissions and in-hospital survival, its findings are most directly relevant to severity and outcomes during the recorded admission. pmid:41729245

The design is well suited to describing a large national inpatient experience and comparing recorded characteristics and outcomes across strata. At the same time, a retrospective observational analysis cannot by itself distinguish causal effects from differences in case mix, documentation, admission circumstances, or other factors not resolved by the supplied evidence. The reported associations should consequently be interpreted as population-level findings within this dataset and outcome window. pmid:41729245

Limitations

The available data could not distinguish heart failure with preserved ejection fraction from heart failure with reduced ejection fraction because the dataset lacked ICD coding that separated those conditions. This limits phenotype-specific interpretation of the reported LVHF results. pmid:41729245

The authors noted that the observed NYHA-class pattern may reflect differences in assessment and recording across data sources. In routine hospital documentation, NYHA may capture transient functional limitation during acute decompensation rather than habitual functional capacity in a stable outpatient setting. pmid:41729245

Accordingly, the authors advised viewing NYHA in this analysis primarily as a marker of clinical severity at hospital presentation, rather than as a surrogate for long-term disease stage. They further stated that the regression models predominantly account for short-term severity of illness at admission rather than baseline heart-failure severity. pmid:41729245