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FRONTIERS IN MEDICAL CASE REPORTS - Volume 2; Issue 4, (Jul-Aug, 2021)

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One Year of Covid-19 Hospital at Croatia: Prevalence Cardio Comorbidities and Predictors of Health Outcomes - A Retrospective Study

Author: Hrvoje Jakic, Hrvoje Simic

Category: Medical Case Reports


Backround: During the pandemic 2020 many hospitals became so-called Covid-19 Hospital. In Croatia our General County Hospital Nasice was the very first one with declared Covid-19 status. Our objective was to determine the clinical features of patients with severe COVID-19 disease considering of different cardiovascular risk factors and their health outcomes.

Materials and Methods: A retrospective study was conducted by analysing the medical records of 541 hospitalized COVID-19 patients in Croatian General County Hospital Nasice during one year in the period from March 1st 2020 to March 1st 2021. We examined collected individual data as gender, age, presence or absence of comorbidity, type of comorbidity, laboratory data, number of days at hospital and outcomes (discharge home, transfer to another hospital and death).

Results: Patients mean age was 72 years with range of 22 do 95 years. There were 408 (77%) discharged from the hospital, 23 (4%) transferred to another hospital, and 94 (18%) died. Hypertension had 325 (61%) of patients, coronary heart disease had 58 (11%) patients, cardiomyopathy had 98 (19%), arrhythmic disease had 88 (17%), valve disease had 24 (5%). Diabetes as risk factor had 151 patients (29%). Patients without any comorbidity were only 55 (10%). Total range of hospitalized days was 33 with 8 days mean. We found statistically significant differences in disease outcomes according to the gender and age of patients and whether patients suffer from cardiomyopathy and arrhythmic diseases. Age over 65, cardiomyopathy and valve disease were independent predictors of poor outcome for male. For female risk factors were cardiomyopathy, obesity and body mass index.

Conclusions: The prevalence of cardio comorbidity in Croatian Covid-19 hospitalized patients was analyzed and gender-different predictors of health have been identified.

Keywords: COVID-19 Disease, Comorbidity, Coronary Disease, Hypertension, Heart Disease Risk Factors


Full Text:


The SARS-CoV-2 causing COVID-19 has reached pandemic levels since March 2020. The World Health Organisation on April 10th 2021 speaks of frightening 134 million persons infected with the SARS-COV-2 virus and nearly 3 million died worldwide. In Europe, slightly more than 47 million are infected, of which 1 million are dead. Citing World Health Organisation data in Croatia, on the day of writing the paper 290,899 people were infected, of which 6,269 died, the death rate is 54.67% of men versus 45.33% of women. Case fatality ratio were 1,3 on March 1 2021. According to WHO at date February 2 2020 at 91 countries hospitalized were 46520 corona patients and on March 1 2021 hospitalized corona patients were 169 354. (Source: World Health Organisation). All these numbers strongly argue for all scientific efforts against pandemic endanger humanity.

The scientific community has focused on the well-being of humanity, so since the beginning of the pandemic, according to WHO, all global research of corona virus disease counting almost 298 thousands of papers ( Today is well known that SARS-CoV-2 not only causes viral pneumonia but has major implications for the cardiovascular system. Patients with cardiovascular risk factors including male gender advanced age, diabetes, hypertension and obesity as well as patients with established cardiovascular and cerebrovascular disease have been identified as particularly vulnerable populations with increased morbidity and mortality when suffering from COVID-19. (Cumming et al., 2020; Du et al., 2020; Guo et al., 2020; Kumar et al., 2020; Phelan et al., 2020; Strozzi et al., 2020; Zheng et al., 2020; Zhou et al., 2020).

The European Society of Cardiology 2020 in June proclaimed very important document for clinicans in which is notify that patients with cardiovascular risk factors and established cardiovascular disease represent a vulnerable population when suffering from COVID-19. (

Around the world studies have shown the importance of comorbidities in coping with covid-19 disease (Alemu, 2020; Azevedo et al., 2020; Berenguer et al., 2020; Cen et al., 2020; Christensen et al., 2020; Cummings et al., 2020; Du et al., 2020; Emami et al., 2020; Galván-Tejada et al., 2020; Guo et al., 2020; Gupta et al., 2021; Guzik et al., 2020; Jordan et al., 2020; Kumar et al., 2020; Lang et al., 2020; Liu et al., 2020; Long et al., 2020; Ruan et al., 2020; Sun et al., 2020; Wang et al., 2020; Williamson et al., 2020; Wu et al., 2021; Zheng et al., 2020; Zhou et al., 2020). Most papers divided comorbidity factors into: diabetes mellitus, heart problems, obesity, high blood pressure, chronic kidney disease, COPD-asthma (Elezkurtaj et al., 2021; Koya et al., 2021; Phelps et al., 2020; Petrilli et al., 2020; Yang HJ et al., 2020).

During the pandemic 2020 many hospitals became so-called Covid-19 Hospital. General County Hospital Nasice in Croatia was the very first one with declared Covid-19 status. The focus of our research is therefore to gain insight into the composition of corona patients who have been hospitalized in General County Hospital Nasice and determination of different cardiovascular risk factors and their health outcomes.

Materials and Methods

We conducted a retrospective study after approval from the Etic committee of General hospital Nasice on 03/25/2021. The sample consisted of SARS-COV-2 positive patients hospitalized in General Hospital Nasice during 03/01/2020 to 03/01/2021. The sample included the total 530 had severe respiratory problems with pneumonia of total 541 hospitalized persons with COVID-19 disease during the declared period. A total of 11 pediatric and / or gynecological patients had asymptomatic COVID-19 and were excluded from the sample. All analyzed data had collected by manual extraction from the medical records of hospitalized patients with a confirmed diagnosis of COVID-19 disease. According to the researchs available to us (Alemu, 2020; Azevedo et al., 2021; Berenguer et al., 2020; Cen et al., 2020; Christensen et al., 2020; Cummings et al., 2020; Du et al., 2020; Emami et al., 2020; Galván-Tejada et al., 2020; Guo et al., 2020; Gupta et al., 2021; Guzik et al., 2020; Jordan et al., 2020; Kumar et al., 2020; Lang et al., 2020; Liu et al., 2020; Long et al., 2020; Ruan et al., 2020; Sun et al., 2020; Wang et al., 2020; Williamson et al., 2020; Wu et al., 2021; Zheng et al., 2020; Zhou et al., 2020), we decided to collect data about hospitalized patient: age, gender, laboratory characteristic CRP and D-dimer, presence or absence: coronary heart disease, cardiomyopathy, arrhythmic disease, valve disease, diabetes, psychiatry diagnoses, body mass index, number of hospitalized dvcays and health outcomes. Cardiovascular and other comorbidities were fully noted in the discharge letters we analyzed. Laboratory data (crp and d-dimers) and body mass index however were not been recorded at electronic form of medical records for each patients and the collected for these variables was less than the total numbers.

Statistical Analysis

Data analysis was performed using IBM SPSS Statistics for Windows (Version 25). Examination of the normality of the distribution showed that mostly the variables had asymmetric distributions, so we used the nonparametric Chi-square test or Fisher exact test when data are limited (p<0.05). Descriptive statistics for continuous variables as age, body mass index, days at hospital and laboratory dana are presented at Table 1. Categorical variables as gender and presence or absence of comorbidity are presented as number and percentage at Table 3.

The Pearson correlation coefficients were calculated to determine the association between characteristics of patients and health outcomes also with significant level p<0.05. In order to examine how much of outcome variance can be explained by characteristics of patients we conduct logistic regression model (Table 5 and 6).


The focus of our interest is one-year work with corona patients within the COVID-19 hospital with the aim of insight into patient characteristics and their health outcomes. During one year period total of 530 hospitalized with heavy COVID-19 illness participated in this study. Male hospitalized patients were 54.09% and female 45.91%. The mean patient age was 72 years (Table 1) with standard deviation 12 years. A majority of patients were in the range of 80 to 89 years (29.3%). The smallest number of patients (below 5%) were those younger than 49 years and over 90 years. We were found difference in mortality rates between male and female (Table 3). In our hospital during one year 14.08% (40/284) male and 22.41% (54/241) female died. Patients with 82+ years had twice more mortality (33.3%) from corona than patients 65 to 81 years old (15.1%).

Table 1: Descriptive statistics of patients observed characteristics

N-number, %-percentage, Min-minimum value, Max –maximum value, SD- standard deviation

Even 157 (29.6%) hospitalized had body mass index over 30. The mean of body mass index was 28.37 kg/m2 which is considered overweigh, but no correlation with health outcomes was found. Non one observed laboratory data showed significance differences in health outcomes.

The presence of comorbidities, especially cardiac comorbidities in corona patients was as follows: hypertension had 325 (61.3%) of patients, coronary heart disease 58 (10.9%) patients, cardiomyopathy had 98 (18.5%), arrhythmic disease had 88 (16.6%), valve disease had 24 (4.5%) (Table 4).

Diabetes as risk factor had 151 patients (28.5%). Patients without any comorbidity were only 55 (10.4%). We also examined the interrelationships of comorbidities (Table 3).

Table 2: Patients characteristics and health outcomes (univariate analysis)

Note: p= significance of hi2 tests *p<.05, ***p<.01

Table 3: Comorbidities and health outcomes (x2 test)

Note: H = hypertension, D=diabetes; *p<.05, ***p<.01

Table 4: Total burden of heart disease and outcomes of covid-19 patients

Note: *p<.05

Table 5: Pearsons correlation coefficients of comorbidity, gender and age with health outcomes

Legend: CHV- coronary heart disease, **. Correlation is significant at the 0.01 level (2-tailed), *. Correlation is significant at the 0.05 level (2-tailed)

As seen at Table 5, patient age correlated with all cardiac comorbidity except cardio heart disease.

We performed series of regression analyses in order to examine how much of health outcomes can be explained by independent variables such as sex, age and all type of comorbidity mainly cardiovascular diseases. At male gender hospitalized persons (Table 6), significant predictors of health outcomes were age of patient, absence of valve disease and/or cardiomyopathia (R2=0.146 with significance 0.018*). In women, however, cardiomyopathia, obesity and body mass index had a predictive value for the health outcome (R2=0.102 with significance 0.041* (Table 7).

Table 6: The results of logistic regression model for prediction of health outcomes of male gender

Note: *p<.05

Table 7: The results of logistic regression model for prediction of health outcomes of female gender

Note: *p<.05


In our paper, we wanted to view all comorbidities within the category of cardiac disease separately as comorbidities. All the research whose findings we analyzed treated cardiac diseases as one entity and so we have no comparative data to refer to. In our one-year pandemic patient sample, we found a distribution of different comorbidities: hypertension had 61%, coronary heart disease 11%, cardiomyopathy 19%, arrhythmic disease 17%, valve disease 5%. Diabetes mellitus had 29%, obesity almost 30%. Age has been confirmed as a risk factor for serious corona disease outcomes. However, elevated blood pressure and elevated body mass index also laboratory data CRP and d-dimers did not have statistical significance as risk factors which contradicts some of the researchers findings (Berenguer et al., 2020; Gupta et al., 2021; Yang J et al., 2020).

Heart disease and stroke statistics in 2020 declared a serious concern for the general state of health in the population (WHO). Unfortunately, the health status of the entire planet in 2020 received a new challenge: Covid-19 illness. The outcomes of the disease are related to the general physical and mental health of the person and the danger of the disease contributor. Almost at the beginning of the outbreak of pneumonia caused by coronavirus, scientists warned of comorbidities that significantly burden the carrying of SARS-COV-2 virus infection (Guo et al., 2020; Du et al., 2020; Petrilli et al., 2020; Yang HJ et al., 2020; Yang J et al., 2020; Zheng et al., 2020; Zhou et al., 2020; Kumar et al., 2020; Cummings et al., 2020; Ruan et al., 2020).

Comparing the presence of comorbidities in different parts of the world, we encounter different data in a series of papers. Unfortunately, we do not have comparative data for Eastern European countries and we compare the findings with large world nations. Chinese researchers find a range between 35% according to Guo, et al. 2020, 48% according to Zhou, et al. 2020 to 63% comorbidity for poor outcome according to Ruan, et al. 2020). Cardiac comorbidity at Chinese studies were from 8% (Zhou et al., 2020), 8,4% (Yang HJ et al., 2020) to 27,8% (Guo et al., 2020). Comorbidity range in European studies is bigger and ranges from 22% in Denmark (Phelps et al., 2021), 23,3% in Spain (Berenguer et al., 2020) to 29% in UK. In an Indian study, 18% of patients had coronary artery disease (Koya et al., 2021). Kumar, et al. (2020) in a meta-analysis of 79 studies cited 18.4% of patients with hypotension, 9.8% with diabetes, 8.8% with cardiovascular disease, 5.8% with endocrine disease, and 5% with gastrointestinal disease.

Various cardio comorbidities showed different outcomes in COVID-19 disease of which cardiomyopathies and arrhythmic disease had significantly more fatal outcomes.

There are several limitations to this research. The first relates to the incompleteness of laboratory data (CRP and D-dimer) and body mass index for each subject. The second objection relates to the retrospective study as a research method since all heart health indicators and others persons characteristics are not quantitatively equalized which limits the possibility of inference. We have not considered the contributions of partial correlations of some other data from the life habits of people that may contribute to the development of the disease (for example, high blood pressure if a person follows a doctor’s advice may be a less risk factor).


In our study, we analyzed covid-19 patients in a one-year pandemic period with special reference to the cardiac diseases underlying poor health. Cardiac conditions such as cardiomyopathy and vulvar disease with age over 65 in male patients are burdensome for health, while in women they are cardiomyopathies, body mass index and pathological obesity. All the efforts of cardiologists as well as other different professions that advocate for better cardiovascular health of people are invaluable for human society in general.


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