Cause-specific death in heart failure across the ejection fraction spectrum: A comprehensive assessment of over 100 000 patients in the Swedish Heart Failure Registry.

AIM: To assess cause-specific death in patients with heart failure with preserved, mildly reduced, and reduced ejection fraction (HFpEF, HFmrEF, and HFrEF). METHODS AND RESULTS: Data were analysed from the Swedish Heart Failure Registry (SwedeHF) and the National Patient Register of patients enrolled in SwedeHF 2000-2021. Cox proportional hazards regression models were performed and adjusted for age, sex and time period. Among 100 584 patients (23% HFpEF, 23% HFmrEF, 53% HFrEF), median age (interquartile range) was 75 (66-82) and 36% were female. Of those who died within 5 years, most deaths were ascribed to cardiovascular (CV) causes across all ejection fraction (EF) categories. Within 5 years, HFpEF had higher adjusted risk of non-CV death (hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.28-1.38, p < 0.001) and lower adjusted risk of CV death (HR 0.85, 95% CI 0.82-0.88, p < 0.001) compared to HFrEF. Ischaemic heart disease (IHD) and cancer were the most common causes of CV and non-CV death regardless of EF category. The incidence rate of CV death due to IHD was highest in HFrEF while incidence rates of CV death due to pulmonary vascular disease, stroke, valvular heart disease and atrial fibrillation increased with increasing EF. The incidence rates of non-CV deaths due to cancer, respiratory disease, and infections increased with increasing EF. CONCLUSION: Cardiovascular death was more common than non-CV death across all EF categories although the risk of non-CV death within 5 years was higher with increasing EF. IHD and cancer were the most common causes of CV and non-CV deaths, respectively, regardless of EF category.

Comorbidities and cause-specific outcomes in heart failure across the ejection fraction spectrum: A blueprint for clinical trial design.

BACKGROUND: Comorbidities may differently affect treatment response and cause-specific outcomes in heart failure (HF) with preserved (HFpEF) vs. mid-range/mildly-reduced (HFmrEF) vs. reduced (HFrEF) ejection fraction (EF), complicating trial design. In patients with HF, we performed a comprehensive analysis of type 2 diabetes (T2DM), atrial fibrillation (AF) chronic kidney disease (CKD), and cause-specific outcomes. METHODS AND RESULTS: Of 42,583 patients from the Swedish HF registry (23% HFpEF, 21% HFmrEF, 56% HFrEF), 24% had T2DM, 51% CKD, 56% AF, and 8% all three comorbidities. HFpEF had higher prevalence of CKD and AF, HFmrEF had intermediate prevalence of AF, and prevalence of T2DM was similar across the EF spectrum. Patients with T2DM, AF and/or CKD were more likely to have also other comorbidities and more severe HF. Risk of cardiovascular (CV) events was highest in HFrEF vs. HFpEF and HFmrEF; non-CV risk was highest in HFpEF vs. HFmrEF vs. HFrEF. T2DM increased CV and non-CV events similarly but less so in HFpEF. CKD increased CV events somewhat more than non-CV events and less so in HFpEF. AF increased CV events considerably more than non-CV events and more so in HFpEF and HFmrEF. CONCLUSION: HFpEF is distinguished from HFmrEF and HFrEF by more comorbidities, non-CV events, but lower effect of T2DM and CKD on events. CV events are most frequent in HFrEF. To enrich for CV vs. non-CV events, trialists should not exclude patients with lower EF, AF and/or CKD, who report higher CV risk.