<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">WJCD</journal-id><journal-title-group><journal-title>World Journal of Cardiovascular Diseases</journal-title></journal-title-group><issn pub-type="epub">2164-5329</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/wjcd.2023.136031</article-id><article-id pub-id-type="publisher-id">WJCD-126105</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Medicine&amp;Healthcare</subject></subj-group></article-categories><title-group><article-title>
 
 
  Prevalence of Re-Hospitalization for Heart Failure in a Cameroonian Tertiary Hospital: A Cross-Sectional Study
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Amalia</surname><given-names>Owona</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ning</surname><given-names>Lom Bryan-Bill</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ahmadou</surname><given-names>Musa Jingi</given-names></name><xref ref-type="aff" rid="aff2"><sup>2</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Dieudonne</surname><given-names>Danwe</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Alain</surname><given-names>Patrick Menanga</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib></contrib-group><aff id="aff2"><addr-line>Faculty of Health Sciences, University of Bamenda, Bamenda, Cameroon</addr-line></aff><aff id="aff1"><addr-line>Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon</addr-line></aff><pub-date pub-type="epub"><day>08</day><month>06</month><year>2023</year></pub-date><volume>13</volume><issue>06</issue><fpage>333</fpage><lpage>340</lpage><history><date date-type="received"><day>20,</day>	<month>February</month>	<year>2023</year></date><date date-type="rev-recd"><day>27,</day>	<month>June</month>	<year>2023</year>	</date><date date-type="accepted"><day>30,</day>	<month>June</month>	<year>2023</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
  Aim:
   To determine the prevalence of re-hospitalization for heart failure in the cardiology unit of the Yaound&#233; General Hospital. <b>Study Design:</b> This was a retrospective cross-sectional study from January 2015 to December 2020. <b>Patients and Methods:</b> Patients aged at least 18 years who were hospitalized for heart failure during the study period were included. Data were collected using a predesigned form and were analyzed using Epi Info<sup>TM </sup>version 7.2.2. <b>Results:</b> We included a total of 160 patients. The prevalence of re-hospital
  ization was 30.6%. Re-hospitalized patients had a mean age of 71.0 &#177; 13.9 years and a sex ratio of 1.6. The most common etiologies of HF were hypertensive heart disease (36.7%), followed by dilated cardiomyopathy (22.5%), and atrial fibrillation (16.3%). More than two third had class IV NYHA disease (77.6%). Most of them also had HFrEF (71.4%) and anemia (77.6%). <b>Conclusion:</b> There is a high rate of re-hospitalization in the cardiology unit of the Yaound&#233; General Hospital with most of these patients having old age and severe HF.
 
</p></abstract><kwd-group><kwd>Re-Hospitalization</kwd><kwd> Heart Failure</kwd><kwd> Yaound&#233;</kwd><kwd> Cameroon</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction</title><p>Heart failure (HF) is a worldwide public health problem. Hospitalization for HF accounts for 6.5 million hospital days spent annually in the United States with nearly 50% of patients requiring readmission in the 6 months following initial hospitalization [<xref ref-type="bibr" rid="scirp.126105-ref1">1</xref>] [<xref ref-type="bibr" rid="scirp.126105-ref2">2</xref>] . In addition to its high prevalence, hospitalization for decompensated HF is associated with extraordinarily high rates of morbidity and mortality. Aranda et al. analyzed Medicare data and found that in the 6 to 9 months following initial hospitalization for HF, 60% of the patients had readmission from any cause with HF accounting for 28% of readmissions [<xref ref-type="bibr" rid="scirp.126105-ref3">3</xref>] . In a recent meta-analysis, Lan et al. reported an all-cause readmission rate of 53% and 36% for HF [<xref ref-type="bibr" rid="scirp.126105-ref4">4</xref>] . The high prevalence and morbidity associated with decompensated HF combine to create a substantial economic burden on the healthcare system. The total yearly cost of HF reported in the United States in 2009 was estimated to be $37.2 billion of which $20 billion were related to hospitalization [<xref ref-type="bibr" rid="scirp.126105-ref5">5</xref>] . This social and economic burden of HF hospitalization is certainly greater in Africa where the disease affects men and women in their most productive years of life, at a median age of 55 years, and where many countries lack universal health care [<xref ref-type="bibr" rid="scirp.126105-ref6">6</xref>] . There is also a scarcity of updated data, especially related to heart failure readmissions. This study aimed to determine the prevalence of re-hospitalization for HF and to describe the clinical and paraclinical presentation of patients in the Yaound&#233; General Hospital.</p></sec><sec id="s2"><title>2. Methods</title><sec id="s2_1"><title>2.1. Study Design and Setting</title><p>This was a cross-sectional retrospective study conducted in the cardiology unit of the Yaound&#233; General Hospital (YGH). The study involved the period spanning from January 2015 to December 2020. The YGH is a tertiary health institution in the political capital of Cameroon, sub-Saharan Africa. It has a catchment population of about 3 million inhabitants.</p></sec><sec id="s2_2"><title>2.2. Participants</title><p>We included patients aged 18 years and above, followed up in the study setting during the study period. All those who had at least one readmission for HF were classified as re-hospitalized. Patients with incomplete charts were excluded.</p></sec><sec id="s2_3"><title>2.3. Sampling</title><p>The sampling was random. The minimal sample size of 118 was calculated using Lorentz’s formula with an error threshold of 5% and an estimated the prevalence of readmissions at the Yaound&#233; General Hospital of Yaound&#233;.</p></sec><sec id="s2_4"><title>2.4. Data Collection</title><p>Files of patients who met inclusion criteria were reviewed. We used a predesigned data collection form. Socio-demographic parameters and Comorbidities including hypertension, diabetes, chronic kidney disease, COPD/asthma, HIV, alcohol consumption, smoking, and other chronic diseases were collected. Antecedents and clinical details of the last hospitalization were also collected. These included the stage of HF at the most recent admission for HF, symptoms and physical signs of HF, associated diagnosis, and paraclinical workup including hemoglobin value, leucocyte count, sodium and potassium concentrations, creatinine values along with alanine and aspartate aminotransferase values. Chest X-ray, electrocardiogram, and echocardiographic results were also assessed.</p></sec><sec id="s2_5"><title>2.5. Statistical Analysis</title><p>We used the software Epi Info<sup>TM</sup> version 7.2.2.6 for Windows&#174;. Descriptive analysis was used to generate means and standard deviations for quantitative data and frequency distributions for categorical data.</p></sec><sec id="s2_6"><title>2.6. Ethical Considerations</title><p>The study was carried out in full consideration of the ethical principles of the Helsinki declaration and strict compliance with the fundamental principles for human health research in Cameroon. Ethical approval was obtained from the Institutional Review Board of the Faculty of Medicine and Biomedical Sciences of the University of Bamenda. We also obtained administrative approval from the General Director of the YGH.</p></sec></sec><sec id="s3"><title>3. Results</title><p>A total of 160 patients were included in the study. Forty-nine (30.6%) were readmitted for HF. The sex ratio was 1.6 with a mean age of 71.0 &#177; 13.9 years, and almost two-thirds had &gt; 70 years. Most of them (81.6) lived in urban areas. The most common etiologies (<xref ref-type="fig" rid="fig1">Figure 1</xref>) of HF in re-hospitalized patients were hypertensive heart disease (36.7%) followed by dilated cardiomyopathy (22.5%) and atrial fibrillation (16.3%). Associated comorbidities (<xref ref-type="fig" rid="fig2">Figure 2</xref>) were mainly hypertension (51.1%), alcohol consumption (51.0%), and atrial fibrillation (34.7%).</p><p><xref ref-type="table" rid="table1">Table 1</xref> shows the clinical presentation of re-hospitalized patients. More than two third had New York Heart Association class IV disease. Laboratory studies revealed anemia in 77.6% of re-hospitalized patients, altered glomerular filtration rate &lt; 60 ml/kg/m<sup>2</sup> body surface area in 32.7% and hyponatremia in 44.9%. Twenty-four (49.0%) patients had pleural effusion on chest X-ray and atrial fibrillation was the most common (46.9%) anomaly on electrocardiography. Evaluation of left ventricular ejection fraction on cardiac ultrasound showed that more than two third (71.4%) of the patients re-hospitalized had reduced ejection fraction (HFrEF). <xref ref-type="table" rid="table2">Table 2</xref> shows the overall results from the paraclinical workup. The patients were treated using diuretics (93.4%), angiotensin-converting enzyme inhibitors (ACEI)/angiotensin II receptor blockers (ARB) (81.6%), beta-blockers (77.6%) and digoxin (48.9%).</p></sec><sec id="s4"><title>4. Discussion</title><p>We found in this study a prevalence of re-hospitalization for decompensated HF of 30.6%. This prevalence was determined out of any timeframe since all readmissions during our study period were considered. Thus, it may be overestimated compared to other studies that often report the prevalence of re-hospitalizations within a certain timeframe. Some authors have reported a high readmission rate for HF in Africa. Okello et al. in Uganda reported a prevalence of readmissions of 31.4% within a 12-month study period, while Akpa and Iheji found 35.6% after 6 months in Nigeria [<xref ref-type="bibr" rid="scirp.126105-ref7">7</xref>] [<xref ref-type="bibr" rid="scirp.126105-ref8">8</xref>] . This prevalence in sub-Saharan Africa is higher than that reported in the United States of America where Aranda, J.M. et al. [<xref ref-type="bibr" rid="scirp.126105-ref3">3</xref>] found 16.8% of readmission for HF in the 6 to 9 months following initial HF hospitalization. One reason why we had a higher rate of readmission may be because not all our patients were receiving the evidence-based medications recommended for</p><table-wrap id="table1" ><label><xref ref-type="table" rid="table1">Table 1</xref></label><caption><title> Clinical presentation of re-hospitalized patients</title></caption><table><tbody><thead><tr><th align="center" valign="middle" >Variables</th><th align="center" valign="middle" >Re-hospitalized (N = 49)</th></tr></thead><tr><td align="center" valign="middle" >Mean Duration of Heart Failure (SD), Years</td><td align="center" valign="middle" >6.0 (5.7)</td></tr><tr><td align="center" valign="middle" >Age range, n (%), Years</td><td align="center" valign="middle" ></td></tr><tr><td align="center" valign="middle" >&lt;40</td><td align="center" valign="middle" >2 (4.1)</td></tr><tr><td align="center" valign="middle" >40 - 49</td><td align="center" valign="middle" >1 (2.0)</td></tr><tr><td align="center" valign="middle" >50 - 59</td><td align="center" valign="middle" >8 (16.3)</td></tr><tr><td align="center" valign="middle" >60 - 69</td><td align="center" valign="middle" >8 (16.3)</td></tr><tr><td align="center" valign="middle" >70 - 79</td><td align="center" valign="middle" >16 (32.7)</td></tr><tr><td align="center" valign="middle" >≥80</td><td align="center" valign="middle" >14 (28.6)</td></tr><tr><td align="center" valign="middle" >Symptoms, n (%)</td><td align="center" valign="middle" ></td></tr><tr><td align="center" valign="middle" >NYHA II</td><td align="center" valign="middle" >1 (2.0)</td></tr><tr><td align="center" valign="middle" >NYHA III</td><td align="center" valign="middle" >10 (20.4)</td></tr><tr><td align="center" valign="middle" >NYHA IV</td><td align="center" valign="middle" >38 (77.6)</td></tr><tr><td align="center" valign="middle" >Dyspnea</td><td align="center" valign="middle" >49.0 (100)</td></tr><tr><td align="center" valign="middle" >Orthopnea</td><td align="center" valign="middle" >45.0 (91.8)</td></tr><tr><td align="center" valign="middle" >Paroxysmal nocturnal dyspnea</td><td align="center" valign="middle" >28.0 (57.1)</td></tr><tr><td align="center" valign="middle" >Cough</td><td align="center" valign="middle" >33.0 (67.4)</td></tr><tr><td align="center" valign="middle" >Pedal edema</td><td align="center" valign="middle" >43.0 (87.8)</td></tr><tr><td align="center" valign="middle" >Signs</td><td align="center" valign="middle" ></td></tr><tr><td align="center" valign="middle" >Mean Temperature (SD), ˚C</td><td align="center" valign="middle" >37.6 (0.8)</td></tr><tr><td align="center" valign="middle" >Mean Heart Rate (SD), bpm</td><td align="center" valign="middle" >107.6 (11.5)</td></tr><tr><td align="center" valign="middle" >Mean Respiratory Rate (SD), cpm</td><td align="center" valign="middle" >28.2 (4.4)</td></tr><tr><td align="center" valign="middle" >Mean SBP (SD), mmHg</td><td align="center" valign="middle" >12.5 (38.3)</td></tr><tr><td align="center" valign="middle" >Mean DBP (SD), mmHg</td><td align="center" valign="middle" >80.8 (22.3)</td></tr><tr><td align="center" valign="middle" >Mean Pulse Pressure (SD), mmHg</td><td align="center" valign="middle" >45.7 (20.4)</td></tr><tr><td align="center" valign="middle" >Mean Oxygen Saturation (SD), (%)</td><td align="center" valign="middle" >93.2 (3.1)</td></tr><tr><td align="center" valign="middle" >Distended Neck Veins, n (%)</td><td align="center" valign="middle" >40 (81.6)</td></tr><tr><td align="center" valign="middle" >Hepato-jugular Reflux, n (%)</td><td align="center" valign="middle" >37 (75.5)</td></tr><tr><td align="center" valign="middle" >Smooth Hepatomegaly, n (%)</td><td align="center" valign="middle" >24 (49.0)</td></tr><tr><td align="center" valign="middle" >Ascites, n (%)</td><td align="center" valign="middle" >15 (30.6)</td></tr><tr><td align="center" valign="middle" >Crackles, n (%)</td><td align="center" valign="middle" >44 (89.8)</td></tr><tr><td align="center" valign="middle" >Arrhythmia, n (%)</td><td align="center" valign="middle" >24 (50.0)</td></tr><tr><td align="center" valign="middle" >Murmur, n (%)</td><td align="center" valign="middle" >19 (38.8)</td></tr></tbody></table></table-wrap><p>Bpm: beat per minute, Cpm: beat per minute, SD: standard deviation, NYHA: New York Heart Association.</p><table-wrap id="table2" ><label><xref ref-type="table" rid="table2">Table 2</xref></label><caption><title> Results of paraclinical workup in re-hospitalized patients</title></caption><table><tbody><thead><tr><th align="center" valign="middle" >Variable</th><th align="center" valign="middle" >Re-hospitalized (N = 49)</th></tr></thead><tr><td align="center" valign="middle" >Biology</td><td align="center" valign="middle" ></td></tr><tr><td align="center" valign="middle" >Mean Hemoglobin Conc. (SD), g/dl</td><td align="center" valign="middle" >10.8 (2.2)</td></tr><tr><td align="center" valign="middle" >Anemia n (%)</td><td align="center" valign="middle" >38 (77.6)</td></tr><tr><td align="center" valign="middle" >Mean WBC Count (SD), &#215;10<sup>3</sup>/mm<sup>3</sup></td><td align="center" valign="middle" >11.5 (14.0)</td></tr><tr><td align="center" valign="middle" >Mean Serum Creatinine (SD), mg/dl</td><td align="center" valign="middle" >13.8 (7.6)</td></tr><tr><td align="center" valign="middle" >Mean eGFR (SD), ml/min/1.73m<sup>2</sup></td><td align="center" valign="middle" >67.9 (22.7)</td></tr><tr><td align="center" valign="middle" >eGFR &lt; 60, n (%)</td><td align="center" valign="middle" >16 (32.7)</td></tr><tr><td align="center" valign="middle" >Mean Sodium Conc. (SD), mmol/1</td><td align="center" valign="middle" >133.6 (6.4)</td></tr><tr><td align="center" valign="middle" >Hyponatremia, n (%)</td><td align="center" valign="middle" >22 (44.9)</td></tr><tr><td align="center" valign="middle" >Radiology (Chest X-ray)</td><td align="center" valign="middle" ></td></tr><tr><td align="center" valign="middle" >Cardiothoracic Index (SD)</td><td align="center" valign="middle" >0.69 (0.08)</td></tr><tr><td align="center" valign="middle" >Pleural Effusion, n (%)</td><td align="center" valign="middle" >24 (49.0)</td></tr><tr><td align="center" valign="middle" >Cardiac Ultrasound</td><td align="center" valign="middle" ></td></tr><tr><td align="center" valign="middle" >HFpEF, n (%)</td><td align="center" valign="middle" >5 (10.2)</td></tr><tr><td align="center" valign="middle" >HFmrEF, n (%)</td><td align="center" valign="middle" >9 (18.4)</td></tr><tr><td align="center" valign="middle" >HFrEF, n (%)</td><td align="center" valign="middle" >35 (71.4)</td></tr><tr><td align="center" valign="middle" >Left Ventricular Hypertrophy, n (%)</td><td align="center" valign="middle" >25 (51.0)</td></tr><tr><td align="center" valign="middle" >Left Ventricular Dilatation, n (%)</td><td align="center" valign="middle" >19 (38.8)</td></tr><tr><td align="center" valign="middle" >Left Atrial Dilatation, n (%)</td><td align="center" valign="middle" >31 (63.3)</td></tr><tr><td align="center" valign="middle" >Elevated Post Capillary Pressure, n (%)</td><td align="center" valign="middle" >30 (61.2)</td></tr><tr><td align="center" valign="middle" >Valvopathy, n (%)</td><td align="center" valign="middle" >34 (69.4)</td></tr><tr><td align="center" valign="middle" >Electrocardiogram</td><td align="center" valign="middle" ></td></tr><tr><td align="center" valign="middle" >Mean Heart Rate (SD), bpm</td><td align="center" valign="middle" >108.0 (14.1)</td></tr><tr><td align="center" valign="middle" >Atrial fibrillation/flutter, n (%)</td><td align="center" valign="middle" >23 (46.9)</td></tr><tr><td align="center" valign="middle" >Signs of Myocardial Ischemia, n (%)</td><td align="center" valign="middle" >10 (20.4)</td></tr><tr><td align="center" valign="middle" >Atrioventricular blocks, n (%)</td><td align="center" valign="middle" >6 (12.2)</td></tr></tbody></table></table-wrap><p>SD: standard deviation, WBC: white blood cells, GFR: glomerular filtration rate, HFpEF: heart failure with preserved ejection fraction, HFmrEF: heart failure with mildly reduced ejection fraction, HFrEF: heart failure with reduced ejection fraction.</p><p>the reduction of hospitalization and death, even though most of them had HFrEF. In our study, we had 81.6% treated with ACEI/ARB, 77.6% with beta-blockers and none of them were treated with mineralocorticoid receptor antagonists or ivabradine. Similarly in the study of Okello, S. et al., [<xref ref-type="bibr" rid="scirp.126105-ref7">7</xref>] only 32.9% and 27.0% of the patients were treated respectively with ACEI/ARB and beta-blockers. Most of our re-hospitalized patients were male, had old age, class IV NYHA disease, HFrEF, and anemia. Whether these characteristics are associated with readmissions needs to be determined in further studies.</p></sec><sec id="s5"><title>5. Conclusion</title><p>There was a high rate of re-hospitalization for HF in the cardiology unit of the Yaound&#233; General Hospital during our study period. Re-hospitalized patients had mostly old age, class IV NYHA disease, HFrEF, and anemia. Further studies are needed to assess the determiners of re-hospitalization in these patients.</p></sec><sec id="s6"><title>Authors’ Contributions</title><p>Amalia Owona, Ning Lom Bryan-Bill, Ahmadou Musa Jingiand Alain Patrick Menanga designed the study. Ning Lom Bryan-Bill collected the data. Ning Lom Bryan-Bill and Dieudonne Danwe performed the statistical analysis. Amalia Owona and Dieudonne Danwe drafted the manuscript. Alain Patrick Menanga did the overall supervision.</p></sec><sec id="s7"><title>Conflicts of Interest</title><p>The authors declare no conflicts of interest regarding the publication of this paper.</p></sec><sec id="s8"><title>Cite this paper</title><p>Owona, A., Bryan-Bill, N.L., Jingi, A.M., Danwe, D. and Menanga, A.P. (2023) Prevalence of Re-Hospitalization for Heart Failure in a Cameroonian Tertiary Hospital: A Cross-Sectional Study. World Journal of Cardiovascular Diseases, 13, 333-340. https://doi.org/10.4236/wjcd.2023.136031</p></sec></body><back><ref-list><title>References</title><ref id="scirp.126105-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">Akpa, M.R. and Iheji, O. (2018) Short-Term Rehospitalization or Death and Determinants after Admission for Acute Heart Failure in a Cohort of African Patients in Port Harcourt, Southern Nigeria. Cardiovascular Journal of Africa, 29, 46-50.  
https://doi.org/10.5830/CVJA-2017-038%</mixed-citation></ref><ref id="scirp.126105-ref2"><label>2</label><mixed-citation publication-type="other" xlink:type="simple">Okello, S., Rogers, O., Byamugisha, A., Rwebembera, J. and Buda, A.J. (2014) Characteristics of Acute Heart Failure Hospitalizations in a General Medical Ward in Southwestern Uganda. International Journal of Cardiology, 176, 1233-1234.  
https://doi.org/10.1016/j.ijcard.2014.07.212</mixed-citation></ref><ref id="scirp.126105-ref3"><label>3</label><mixed-citation publication-type="other" xlink:type="simple">Sliwa, K., Davison, B.A., Mayosi, B.M., Damasceno, A., Sani, M., Ogah, O.S., et al. (2013) Readmission and Death after an Acute Heart Failure Event: Predictors and Outcomes in Sub-Saharan Africa: Results from the THESUS-HF Registry. European Heart Journal, 34, 3151-3159. https://doi.org/10.1093/eurheartj/eht393</mixed-citation></ref><ref id="scirp.126105-ref4"><label>4</label><mixed-citation publication-type="other" xlink:type="simple">WRITING GROUP MEMBERS, Lloyd-Jones, D., Adams, R., Carnethon, M., De Simone, G., Ferguson, T.B., et al. (2009) Heart Disease and Stroke Statistics—2009 Update: A Report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation, 119, e21-e181.  
https://doi.org/10.1161/CIRCULATIONAHA.108.191261</mixed-citation></ref><ref id="scirp.126105-ref5"><label>5</label><mixed-citation publication-type="other" xlink:type="simple">Lan, T., Liao, Y.-H., Zhang, J., Yang, Z.-P., Xu, G.-S., Zhu, L., et al. (2021) Mortality and Readmission Rates after Heart Failure: A Systematic Review and Meta-Analysis. Therapeutics and Clinical Risk Management, 17, 1307-1320.  
https://doi.org/10.2147/TCRM.S340587</mixed-citation></ref><ref id="scirp.126105-ref6"><label>6</label><mixed-citation publication-type="other" xlink:type="simple">Aranda, J.M., Johnson, J.W. and Conti, J.B. (2009) Current Trends in Heart Failure Readmission Rates: Analysis of Medicare Data. Clinical Cardiology, 32, 47-52.  
https://doi.org/10.1002/clc.20453</mixed-citation></ref><ref id="scirp.126105-ref7"><label>7</label><mixed-citation publication-type="other" xlink:type="simple">Krumholz, H.M., Parent, E.M., Tu, N., Vaccarino, V., Wang, Y., Radford, M.J., et al. (1997) Readmission after Hospitalization for Congestive Heart Failure among Medicare Beneficiaries. Archives of Internal Medicine, 157, 99-104.</mixed-citation></ref><ref id="scirp.126105-ref8"><label>8</label><mixed-citation publication-type="other" xlink:type="simple">Hunt, S.A., Abraham, W.T., Chin, M.H., Feldman, A.M., Francis, G.S., Ganiats, T.G., et al. (2005) ACC/AHA 2005 Guideline Update for the Diagnosis and Management of Chronic Heart Failure in the Adult: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Update the 2001 Guidelines for the Evaluation and Management of Heart Failure): Developed in Collaboration with the American College of Chest Physicians and the International Society for Heart and Lung Transplantation: Endorsed by the Heart Rhythm Society. Circulation, 112, e154-235.  
https://doi.org/10.1161/CIRCULATIONAHA.105.167586</mixed-citation></ref></ref-list></back></article>