Heart Failure with Mid-Range or Mildly Reduced Ejection Fraction in the Era of Sodium-Glucose Co-Transporter 2 Inhibitors: Do We Now Provide Better Care for the "Middle Child of HF"? Real-World Experience from a Single Clinical Centre.

Heart failure (HF) with mid-range or mildly reduced ejection fraction (HFmrEF) is a separate clinical entity in the HF spectrum, with a left ventricular ejection fraction ranging from 40 to 49%. While sodium glucose co-transporter 2 inhibitors have become the cornerstone therapy for the entire HF spectrum, there are a few clinical trials of HFmrEF. This prospective observational study was conducted at Dubrava University Hospital, Zagreb, Croatia, from May 2021 to October 2023. We recruited 137 participants diagnosed with HFmrEF at admission. The majority were male, with a median age of 72 and overweight. A total of 110 participants were followed for 6 months and LVEF remained the same in the majority of patients ( n = 62, 56.4%), improved in 32 patients (29.1%), and decreased in 3 patients (2.73%). A total of 64 participants were followed for 12 months: 39 remained the same (60.94%) and 25 improved. There were 13 deaths in (9.5%). While the empagliflozin group had a lower BMI at 6-month- and lower HbA1c at 12-month follow-up, there were no differences in death, HF hospitalizations, ER visits, or urinary tract infections in between groups. Despite recent and daily advances in the treatment of all HF phenotypes, HFmrEF still represents a challenge in everyday clinical practice.