Mean Platelet Volume as a Predictor of Heart Failure-Related Hospitalizations in Stable Heart Failure Outpatients with Sinus Rhythm

Background: In this study, we investigated the relationship between the mean platelet volume (MPV) with mortality and heart failure (HF)-related hospitalization in stable chronic HF outpatients with reduced ejection fraction (HFrEF) and with sinus rhythm (SR). Methods: This retrospective cohort study included 197 consecutive stable chronic HFrEF outpatients with SR, who were admitted to our cardiology outpatient clinics for examination between January 2014 and January 2015. According to the receiver-operating characteristic curve analysis, the optimal cut-off value of MPV to predict HF-related hospitalization was ＞ 9.1 fL. Patients were classified into two categories according to threshold MPV levels, as group I with MPV≦9.1 fL and group II with MPV ＞ 9.1 fL. Results: The mean age of patients was 65 ± 13 years. The mean follow-up duration was 10 ± 3 months, and 44 patients (22%) succumbed to cardiovascular (CV) death. The rate of CV mortality was similar between the two groups (21% vs. 24%, p = 0.649). However, the rate of patients who experienced HF-related hospitalization was lower in group I compared with group II (41% vs. 87%, p ＜ 0.001, respectively). Univariate analysis demonstrated associations of many clinical factors in addition to increased MPV ＞ 9.1 fL with HF-related hospitalization; however, In the multivariate Cox proportional-hazards model, only increased MPV ＞ 9.1 fL (HR: 2.895, 95% CI: 1.774-4.724, p ＜ 0.001), systolic pulmonary artery pressure level (HR: 1.018, 95% CI: 1.001-1.036, p = 0.048) and pre-admission beta blocker use (HR: 0.517, 95% CI: 0.305-0.877, p = 0.014) remained associated with a risk of HF-related hospitalization. Conclusions: The mean platelet volume might be a useful parameter for risk stratification with regard to HF-related hospitalization in HFrEF outpatients with SR.