Cardio‐Oncologic Considerations in Heart Failure With Mildly Reduced Ejection Fraction: Prevalence and Prognostic Impact of Malignancies

Background Patients with malignancies were commonly excluded from prior heart failure (HF) trials resulting in limited data regarding the outcomes of patients with HF accompanied by concomitant malignancies. The study sought to assess the prevalence and prognostic impact of malignancies in patients with HF and HF with mildly reduced ejection fraction. Methods Consecutive patients hospitalized with HF with mildly reduced ejection fraction were retrospectively included at 1 institution from 2016 to 2022. The prognosis of patients with malignancies was investigated regarding the primary end point all‐cause mortality at 30 months (median follow‐up). The key secondary end point was rehospitalization for worsening HF. Results Among 2184 patients with HF with mildly reduced ejection fraction, 15.3% (n=335) suffered from concomitant malignancies. In patients with active malignancies (n=257), most patients had solid (n=175) followed by hematological malignancies (n=73) (both: n=9), whereas cancer‐therapy HF was observed in 3.9%. Patients with malignancies had lower rates of ischemic cardiomyopathy and were less commonly treated with beta blockers, renin‐angiotensin aldosterone antagonists, and statins. The presence of malignancies was associated with a higher risk of long‐term all‐cause mortality (59.4% versus 26.2%; P =0.001; adjusted hazard ratio, 2.568 [95% CI, 2.101–3.138]; P =0.001), which was already observed during index hospitalization (8.4% versus 2.5%; P =0.001) and mainly attributed to noncardiac mortality. In contrast, the risk of HF‐related rehospitalization did not significantly differ in both groups. Conclusions Malignancies were present in 15% of patients with HF with mildly reduced ejection fraction and independently associated with long‐term all‐cause mortality, mainly attributed to an increased risk of in‐hospital noncardiac mortality. The risk of HF‐related rehospitalization was not affected by the presence of concomitant malignancies.