Precipitating factors of acute heart failure-differences between new-onset and worsening heart failure: single-center experience

Background

Understanding the frequency of precipitating factors (PF) for acute heart failure (AHF), whether in new-onset heart failure (NOHF) or worsening heart failure (WHF), is clinically important. However, few studies have examined differences in the triggers leading to hospitalization for AHF, and data from the Balkan region remain particularly scarce.2

Purpose

To characterize precipitating factors of acute heart failure and to assess differences between heart failure phenotypes and clinical presentations.

Methods

This retrospective study included AHF patients, who referred to the coronary care unit at our University Clinical Hospital Centre between January 2025 and January 2026. We included as PF: acute coronary syndrome/myocardial ischemia, rapid atrial fibrillation (RAF), uncontrolled hypertension (TA > 160mmHg), anaemia (hemoglobin <10 g/dL), renal dysfunction (estimated glomerular filtration rate <50 mL/min/1.73 m²), acute exacerbation of chronic obstructive pulmonary disease, infection.

Results

A total of 168 patients were included (mean age 69 ± 12 years; 57% male), with a mean left ventricular ejection fraction (LVEF) of 39 ± 16%. A prior history of heart failure was present in 47% of patients. According to LVEF categories, 60% had HFrEF, 11% had HFmrEF, and 29% had HFpEF.

The most common precipitating factors for hospitalization due to acute heart failure (AHF) were PAF (34%), renal dysfunction 17%, infection (16%), acute coronary syndrome/myocardial ischemia (ACS/MI, 15%), anemia 8%, uncontrolled hypertension (8%), and acute exacerbation of chronic obstructive pulmonary disease (2%).

Patients with HFpEF had significantly higher rates of atrial fibrillation and uncontrolled hypertension as triggers of acute decompensation. ACS was the most frequent precipitating factor in patients with new-onset heart failure and was also significantly more common in those with HFmrEF. In contrast, patients with worsening heart failure had higher rates of infection and renal dysfunction, whereas those with new-onset heart failure more frequently presented with ACS/MI and atrial fibrillation.

Regarding clinical presentation, 13% of patients were admitted with cardiogenic shock, 19% with pulmonary oedema, 10% with isolated right ventricular failure, and 58% with acute decompensated heart failure. The median length of hospital stay was 10 days (interquartile range 5–15), and in-hospital mortality was 5.8%.

Conclusions

Precipitating factors of acute heart failure are common and have a substantial impact on outcomes after hospitalization. Identifying and addressing these triggers is essential both for preventing AHF admissions and for recognizing patients at highest risk of short-term mortality.