## 4 Discussion  
Our study was focused only on mean platelet volume (MPV) in the population of patients with heart failure (HF). In the current medical literature, there are few related studies cited, including the study conducted by [PERSON] et al. [11], the study conducted by [PERSON] et al. [12], and the one conducted by [PERSON] et al. [14], all of which demonstrated that MPV could be a prognostic parameter in HF patients. The main objective of our research was to introduce new thinking to the current medical research regarding MPV as a prognostic parameter in HF. Knowing that a simple parameter such as MPV could provide us with information regarding the prognosis of HF patients is of importance because through it we could identify HF patients at risk and, therefore, treat them in advance to prevent negative events. Our statistical results, which revealed that patients with decompensated chronic HF (class IV NYHA HF and APE) had higher MPV values compared to patients with stable chronic HF (class II NYHA), support the results from the study conducted by [PERSON] et al. [12], which showed that patients with decompensated HF had higher values than patients with stable HF. However, the novelty of our study compared to the one conducted by [PERSON] was the use of regression model analysis by which we were able to determine the probability of an HF patient having decompensated or stable HF based on the MPV value. Regarding the negative event in HF represented by mortality, compared to the results from the study conducted by [PERSON] et al. [12], which showed that HF patients who died at 6 months or died in hospital had higher MPV values, the results from our study revealed that patients with HF who died at 1 year had higher MPV values compared to those who did not die at 1 year, but, regarding in-hospital death, our results were not promising. A possible explanation for this phenomenon, according to which we could not demonstrate a clear relationship between the MPV value and in-hospital death, is that the patients in our study sample who died in-hospital were of a lower number compared to those who did not die in-hospital, as can be seen in Figure 16, which shows very clearly that patients who died in hospital were of a very small number. Hence, compared to the  
Figure 17: The probability that HF patients will die in hospital based on the MPV value by applying the logistic regression model. study conducted by [PERSON] et al., the novel contribution of our study is represented by the identification of a significant relationship between an increased value of MPV and 3-month and 6-month hospitalization, 1-year mortality, and increased length of in-hospital stay. These findings were determined using regression model analysis through which we were able to estimate the probability of an HF patient having a negative prognosis (rehospitalization or 1-year mortality) based on the MPV value. Another study cited in the medical literature regarding the prognostic impact of MPV in HF patients was the one conducted by [PERSON] et al. [11], which focused on patients with stable HF in sinus rhythm and revealed that patients who had frequent hospitalizations had MPV values above 9.1 fl. Our study showed that HF patients who were rehospitalized at 3 or 6 months had MPV values above 9 fl, and, therefore, support the results obtained in the study conducted by [PERSON]. In contrast to [PERSON]'s study, the novel aspects of our study are represented by the following: (1) our study included, in addition, patients with decompensated HF; (2) our study revealed that patients with decompensated HF had higher MPV values compared to those with stable HF; (3) our study data demonstrated a statistically significant relationship between an increased MPV value and the probability of 3-month or 6-month rehospitalization, 1-year mortality and the probability of prolonged length of in-hospital stay.