Frequency of Various Causes of Hospitalization and Its Other Related Factors in Patients with Heart Failure

Background: Heart failure has the highest rate of Rehospitalization with 20-33% readmissions within 1 to 3 months of discharge from the hospital. we decided to find out the frequency of different causes of hospitalization in patients with heart failure during 2017 to 2019. Methods: This study was a cross-sectional descriptive study. A total of 120 patients with heart failure who were referred to Afshar Hospital of Yazd during 2017 to 2019 were enrolled. The random sampling method was used.The required information was collected from heart failure patients’ registry project. datum were collected and were analyzed by statistical tests and SPSS version 18. Results: The mean age of patients was 53.53±12.36 years. Of the 120 patients under study,41.7% were women and 58.3% were male. The results showed that, 14.2% did not follow the recommended diet,14.2% had not regular use of drugs,14.2% had renal dysfunction,9.2% had Original Research Article Jafarie et al.; JPRI, 33(14): 30-36, 2021; Article no.JPRI.65968 31 miscellaneous causes,8.3% had pulmonary disease and 40% had idiopathic cause(where the cause of the condition is not known). There was no significant difference among the distribution of various causes of hospitalization in terms of the variables in the study. Conclusions: It can be concluded that the most common reason for hospitalization of patients with heart failure is idiopathic cause.


INTRODUCTION
Cardiovascular disorders are among the most common conditions ultimately resulting into hospitalization. Among these diseases, heart failure has attracted much attention in the healthcare system [1,2]. It is one of the most prevalent cardiovascular conditions considered as a chronic, progressive, and debilitating disorder [3]. In this condition, the heart is unable to adequately pump blood to tissues to provide oxygen and nutrients. Impaired blood pumping by myocardium leads to increased afterload, dilatation of cavities, and increased intraventricular pressure. As a result, regurgitation of blood from left ventricle to the left atrium causes pulmonary congestion while regurgitation of blood from the right ventricle results in venous congestion and, finally leads to peripheral edema [4]. The onset and incidence of heart failure is enhanced by increasing age so that about 1-10% of Americans aged 50-80 years are affected with heart failure [5]. The increasing trend of heart failure due to infectious, inflammatory, vascular, and valvular complications serves as a major health problem and an epidemic condition in the USA. Annually, 5,000,000 Americans are affected with heart failure and an extra 500,000 new cases are added each year. These figures and statistics are expected to double by the next 30 years to come [6]. In Iran, the 2001 report by Center for Diseases Management has announced that 3337 per 100,000 people are affected with cardiac failure in 18 provinces [7]. Numerous factors contribute to lack of compensation for heart failure and patient hospitalization. These include: lack of adherence to drug and food regimen, uncontrolled hypertension, arrhythmia, inappropriate environmental conditions, inadequate treatment, pulmonary infections, psychological stress, inappropriate drug prescription and administration, myocardial ischemia, endocrine disorders like thyrotoxicosis, cardiac diseases, anemia, pregnancy, pulmonary embolism, infectious endocarditis, and myocarditis [8].It appears that unawareness of heart failure patients about the factors that influence their hospitalization plays a role in the incidence of this condition. Therefore, identifying the factors affecting hospitalization of patients with heart failure can reduce the hospitalization of these patients by 33%. [9]. Consequently, this study investigated the frequency of various causes of hospitalization and its other related factors in patients with heart failure to Afshar Hospital in Yazd, central Iran, during 2017 to 2019.

METHODS
A total of 120 heart failure patients presenting to Afshar Hospital in Yazd, central Iran, during 2017 to 2019 participated in this randomized descriptive cross-sectional study. They were hospitalized for clinical complaints and cardiac failure symptoms and were diagnosed with heart failure by the related cardiologist. They were selected randomly. Inclusion Criteria: Diagnosis of heart failure recorded in the patient's file, passage of at least 6 months after diagnosis of the disorder, age of 18+ years, and Ejection Fraction(EF)< 40%. Patients with incomplete information who were inaccessible were excluded from the study. The required data were gleaned using information from heart failure patients' registry project. The information included: cause of hospitalization, age, gender, frequency of hospitalization, chief complaint of patient's at admission, history of smoking, patient's signs, history of chronic diseases (diabetes, hypertension, and dyslipidemia), patient's vital signs (systolic pressure, diastolic pressure, heart rate),Electrocardiogram(ECG), echocardiographic findings (left ventricle hypertrophy(LVH),mitral valve regurgitation (MR), Ejection Fraction (EF), laboratory findings included: creatinine, urea, sodium, potassium, Brain Natriuretic Peptides (BNP), hemoglobin, troponin level, etiology of heart failure, and whether having a cardiac device included: Cardiac Resynchronization Therapy (CRT), implantable cardioverter-defibrillator(ICD), pacemaker. This information was recorded on a prepared form. Causes of hospitalization included: 1. nutritional diet (example: do not avoid salt), 2. Lack of adherence of drug regimen (patients who have discontinued their heart failure medication or taken them irregularly and), 3. Disturbance in renal function (on the basis of creatinine level), 4. Pulmonary causes such as pneumonia, and aggravation of chronic obstructive pulmonary disease (COPD), 5. Idiopathic conditions, 6. Miscellaneous conditions including: arrhythmia, stress, other infections except pneumonia, anemia, and myocardial infarction (MI).The gleaned data were imported to SPSS18 and analyzed with descriptive statistics including: mean, Standard deviation, frequency distribution tables, T-test, low significant difference (LSD) and Chi-square tests.

RESULTS
A total of 120 heart failure patients presenting to Afshar Hospital in Yazd, central Iran, were investigated in this analytic cross-sectional study during 2017 to 2019. Of these, 50 (41.7 percentage) were females and 70 (58.3 percentage) were males. The results of means of variables of age, systolic pressure, diastolic pressure, heart rate, EF, creatinine levels on admission and discharge, urea, sodium, potassium, brain natriuretic peptide (BNP), and hemoglobin are displayed in Table 1.
Also, the results of frequency distribution of the variables of subjective symptoms, presence of a cardiac device, patient's signs, etiology , history of smoking, hypertension, dyslipidemia, diabetes, ECG rhythm, Left ventricular hypertrophy (LVH) , MR ,troponin level level, and frequency of previous hospitalizations are presented in Table 2.
The results of frequency distribution of various causes of hospitalization of patients are given in Table 3. Table 4 presents the results of the correlations among age, systolic pressure, diastolic pressure, heart rate, EF, creatinine on admission and discharge, urea, sodium, potassium, BNP, hemoglobin, and also frequency distribution of gender, cardiac device, etiology of disease, smoking, hypertension, dyslipidemia, diabetes, ECG rhythm, left ventricle hypertrophy, troponin level, frequency of previous hospitalizations, Mitral valve regurgitation, and cause of hospitalization. T-test showed a significant difference between the mean diastolic pressures of the patients with hospitalization due to cause of hospitalization. Repeated analysis with LSD test indicated a significant difference in the mean diastolic pressure between patients with hospitalization due to pulmonary disease and patients with other causes of hospitalization. Also, the mean systolic pressure was significantly higher in patients with hospitalization due to pulmonary disease compared to other patients.
Moreover, Chi-square test demonstrated no significant correlation between cause of hospitalization and frequency distribution of any of the variables under study.

DISCUSSION
The highest rate of hospitalization in heart disease is related to heart failure so that 20-33% of cases are hospitalized during 1-3 months after discharge. The rate of rehospitalization due to heart failure during 30-60 days after discharge is about 30% and the mortality rate varies from 4% to 20% [10]. The rate of hospitalization of heart failure patients has been explored in other studies as well. The study by O'Connor reported 5239 cases of hospitalization while Kang reported a 36% rate [11,12]. Also, the qualitative study by Hekmatpou [13] enumerated the barriers to control rehospitalization as the following: insensitivity to causes of rehospitalization, patients' wrong hygienic/health beliefs and expectations, incomplete training, poor compliance with nutritional and pharmacological diet, wrong life style, lack of a proper follow-up system, lack of confidence in the physician, lack of rapport with the patient, patient's psychological problems, and patient's familial challenges [13].The results of Christopher's study revealed that 39.2% of causes of patient hospitalization are noncardiovascular, 46.3% are due to aggravated heart failure, and the rest are due to other miscellaneous causes like MI, stroke, etc. (22). Although that study used a different taxonomy of causes of hospitalization compared to our study, given that it reported non-cardiovascular causes like infections, pulmonary conditions, lack of dietary observance, lack of drug regimen observance, etc. as the most common causes of hospitalization. It was consistent with our study in which the non-cardiovascular causes such as idiopathic cases, followed by lack of adherence to dietary and pharmacological regimens and impaired renal function were the most common causes of patient hospitalization. Kang's study [12] reported poor health status, presence of severe pain and presence of skin problems as risk factors of hospitalization of heart failure patients [12].    Although our study did not investigate the mentioned factors in Kang study, none of our variables affected frequency of hospitalization. This is consistent with the results of the study above. A study carried out in 2016 on 387 heart failure patients with a mean hospitalization time of 11 days (8-18 days) suggested that 11.6% of patients sustained aggravation of heart failure symptoms or death during the first 7 days of hospitalization and 23.3% sustained aggravation of heart failure symptoms or death at any time of hospitalization. This latter group had more symptoms, lower systolic pressure, weaker renal function, and higher baseline troponin level [14]. The results of this study are not consistent with our finding that there was no significant difference among in the means of systolic pressure, creatinine on admission and discharge, and urea, sodium, and potassium as indices of renal assessment in terms of various causes of hospitalization. It seems that small sample volume in our study is the cause of insignificance of these factors in the patients under study. Also, our study assessed troponin level qualitatively (positive/negative) and found no significant difference in frequency distribution of causes of patient hospitalization in terms of troponin level. However, our study found a significant difference in mean diastolic pressure in terms of causes of patient hospitalization so that the diastolic pressure was significantly higher in patients with pulmonary causes of hospitalization compared to other causes. The results of another study by Ural demonstrated that the use of nitrate was associated with increased risk of mortality in patients that had used nitrate compared to patients that had not used it. Nevertheless, nitrate had not increased the risk of hospitalization. Moreover, coronary artery disease (CAD), age, gender, and underlying diseases had no significant effect on mortality rate and hospitalization [15]. The results of this study are consistent with our study that found no significant difference in the frequency distribution of causes of patient hospitalization in terms of age, gender, and underlying diseases. In other words, the mentioned variables had no effect on frequency of patient hospitalization in our study as well.

CONCLUSION
It may be postulated on the basis of our results that the most common causes of hospitalization of heart failure patients are idiopathic with ischemic heart disease being the most common etiologic cause of heart failure. Additionally, considering absence of any statistically significant correlation between frequency distribution of causes of hospitalization of heart failure patients in terms of variables, it may be said that none of the mentioned factors have influenced frequency distribution of hospitalization of heart failure patients.

CONSENT AND ETHICAL APPROVAL
In this study, except for maintaining the secrets of the patient in accordance with the Helsinki Treaty, it is assured to patients that their information will be confidential and will be used only for the purposes of the research. In addition, no additional costs were imposed on patients. The proposal is approved by ethics committee of Yazd Shahid Sadoughi University of Medical Sciences.