IJCS | Volume 33, Nº2, March / April 2020

179 Cont. Table 1 - Univariable predictors of rehospitalization within 30 days after discharge Variable Overall cohort (n = 312) No readmission (n = 241) Readmission (n = 71) OR univariate 95% CI p-value Betablockers in hospital 237 (76.9%) 179 (75.5%) 58 (81.7%) 1.45 (0.74 – 2.83) 0.279 ACEI/ARB in hospital 239 (77.3%) 187 (78.6%) 52 (73.2%) 0.75 (0.41 – 1.37) 0.342 LVEF < 40%(+) 126 (43.0%) 85 (38.3%) 41 (57.7%) 2.20 (1.28 – 3.79) 0.004* Hyponatremia on admission 24 (7.7%) 14 (5.8%) 10 (14.1%) 2.65 (1.12 – 6.25) 0.022* Abnormal blood urea nitrogen on admission 47 (15.2%) 36 (15.1%) 11 (15.5%) 1.03 (0.49 – 2.14) 0.940 Abnormal creatinine on admission 126 (40.5%) 97 (40.4%) 29 (40.8%) 1.29 (0.76 – 2.22) 0.948 Anemia on admission 163 (52.8%) 122 (51.3%) 41 (57.7%) 1.02 (0.59 – 1.75) 0.337 Complication during hospitalization 81 (25.9%) 61 (25.3%) 20 (28.2%) 1.18 (0.65 – 2.14) 0.597 Hospitalization period > 7 days 198 (63.5%) 150 (62.2%) 48 (67.6%) 1.27 (0.72 – 2.21) 0.409 OR: odds ratio; 95%CI: 95% confidence interval 95%; ACS: acute coronary syndrome; COPP: chronic obstructive pulmonary disease; BP: blood pressure; ACEI: angiotensin-converting enzyme inhibitors; ARB: angiotensin receptor blockers; LVEF: left ventricular ejection fraction; (+) = sample of 293 patients who underwent echocardiography; (*) = p-value < 0.05. Sarteschi et al. Predictors of post-discharge 30-day readmission Int J Cardiovasc Sci. 2020; 33(2):175-184 Original Article ventricular ejection fraction < 40% (OR = 2.11; 95% CI 1.21 – 3.69), hyponatremia on admission (OR = 2.87; 95% CI 1.16 – 7.07) andACS as a cause of decompensation (OR = 1.89; 95% CI 1.08 – 3.31). The final model with these three variables presented a reasonable discrimination capability (C-statistic = 0.655 – 95% CI: 0.582 – 0.728) and good calibration (Hosmer-Lemeshow: χ 2 = 0.892, p = 0.925). Figure 2 shows the graphic representation of those variables and their respective odds ratio and 95% CI. Discussion This study contributed to the comprehension of the dynamics of hospital readmission of patients with HF, which has becomemore prevalent among the population, due to increase of population and life expectancy. Therefore, the concern with the improvement of clinical conditions and survival rate is justified, contributing to better planning of health actions. The main characteristic of the studied population is the profile of high severity and complexity and advanced age: more than 70% were elderly (over 65) with many comorbidities. This configuration can be explained by the fact that the studied hospital is a reference in cardiology in the North and Northeast of Brazil. The profile is similar to the population on international records, such as ADHERE done in multiple health centers in the USA with more than 118,000 patients between 2001 and 2004, whose average age was 73 and 50% were men. 9 On the other hand, the 1st Brazilian Registry of Heart Failure — BREATHE — done in 51 hospitals (public and private) from different parts of Brazil, reported younger age on average (64 ± 16 years), majority of women and infection as the main causes of decompensation. 4 Considering the etiology of HF, the most frequent one found in our population was ischemic etiology (58%), followed by hypertensive (17%), corroborating most of the studies. 10-12 When we looked at the northeastern states only, in the BREATHE registry, the percentage of hypertensive and valvar etiology were greater than the ones observed in that population. 4 The average time of hospitalization for compensation, among our patients, was 13 days, which superior to that in the literature, with an average time of 9 days for the most critical cases. 12 Despite the technological progress achieved in the last decades, such as new drugs, pacemaker and resynchronizer use, the length of stay and in-hospital mortality of the patients with HF is increasing in Brazil, and, automatically, the average cost of hospitalization has increased significantly from