Comparison of Serum Prolactin Levels Between the Acute Phase of Heart Failure and After Guideline-Directed Medical Therapy

Background: Prolactin (PRL) has increasingly been recognized to play a stimulatory role in inflammatory response. Recently, studies have reported an increase in the PRL level among patients with chronic heart failure (HF); however, there are conflicting data about its role as a prognostic factor in these patients. We aimed to measure the PRL level in the acute phase of HF and the post guideline-directed medical therapy (GDMT) of HF to clarify whether PRL is an acute-phase reactant or more than an acute phase-reactant in patients with HF. Methods: The serum PRL level was assessed in 94 patients with HF in the acute phase of HF decompensation and post-GDMT of HF. Serum N-terminal pro-brain natriuretic peptide, high-sensitive C-reactive protein, 6-minute walk test, erythrocyte sedimentation rate, CRP, blood urea nitrogen, creatinine, serum sodium, and white blood cell count were also measured. Our secondary end points were mortality, transplantation, and hospitalization due to acute HF. All the patients were followed up for 6 months. Results: The mean serum PRL level in the acute phase was 31.3 ng/mL, which was significantly higher than the normal reference values (4.04–15 ng/mL) (P < 0.001). The mean serum PRL level before discharge was 34.84 ng/mL, which was significantly higher than the normal reference values and similar to the acute phase values. The mean PRL level in the patients with dilated cardiomyopathy was 33.61 ng/mL in the acute phase and 43.15 ng/mL after the GDMT of HF. The mean PRL level in the patients without dilated cardiomyopathy was 33.42 ng/mL in the acute phase and 29.92 ng/mL before discharge. The mean PRL level in the patients with re-admission was higher (27.7 ng/mL in the acute phase and 29.7 ng/mL before discharge in the patients with no re-admission and 37.4 ng/mL in the acute phase and 42.5 ng/mL before discharge in the patients with re-admission). Conclusions: In 57% of the patients, the mean level of PRL increased after treatment. The level remained unchanged in 3.5% of the patients and had a drop in 39.2%. Our findings suggest that PRL may be more than an acute-phase reactant alone. Larger studies are needed to further elucidate the role of PRL in patients with HF. Research regarding the treatment of patients suffering from HF with high levels of PRL post-GDMT of HF with bromocriptine may have consequences like those in peripartum cardiomyopathy.