Etiology, Management, and Outcomes of Hospitalized Heart Failure Patients: A Single-Center Study

Summary

Objectives:

To describe the clinical characteristics, etiologies, management patterns, and outcomes of hospitalized heart failure patients in a tertiary care military hospital in United Arab Emirates (UAE), and to benchmark guideline directed medical therapy (GDMT) uptake and care models against regional and international registries.

Methods:

We retrospectively reviewed all consecutive patients admitted with a primary diagnosis of heart failure between January and December 2024, at Zayed Military Hospital, UAE. Clinical data were extracted from electronic medical records. The GDMT adherence was assessed according to the 2022 American Heart Association (AHA)/ American College of Cardiology (ACC) and 2023 European Society of Cardiology (ESC) heart failure guidelines, and outcomes were compared between cardiology-led and non-cardiology services.

Results:

Among 152 patients (69% male; mean age 68.5 years), 57% had heart failure with reduced ejection fraction (HFrEF), 24% mildly reduced, and 19% preserved ejection fraction. Ischemic heart disease was the most common etiology (58.6%). Compared with published Gulf registries, GDMT uptake in HFrEF was high: angiotensin converting enzyme inhibitors (ACEi)/ angiotensin receptor blocker (ARB)/ angiotensin receptor-neprilysin inhibitors (ARNI) (82.8%), beta-blockers (94.3%), and sodium-glucose co-transporter 2 (SGLT2) inhibitors (74.7%). In contrast, mineralocorticoid receptor antagonists were markedly underused (21.8%). HFpEF patients had the highest 180-day readmission rate (41.4%). Cardiology-led care was associated with higher GDMT uptake, shorter length of stay, and improved follow-up and readmission outcomes.

Conclusion:

This cohort demonstrates improved adoption of evidence-based heart failure therapies compared with regional data, but highlights a persistent mineralocorticoid receptor antagonists (MRA) treatment gap. Cardiology-led inpatient management is associated with superior GDMT implementation and clinical outcomes, underscoring the importance of specialist-driven care pathways.

Introduction

Heart failure (HF) is a complex clinical syndrome caused by structural or functional myocardial impairment, leading to inadequate cardiac output and elevated filling pressures. The most common cause in the west is ischemic heart disease, although hypertension, valvular heart disease and hereditary cardiomyopathy contribute signicantly to the burden [1]. It is classified into 4 subtypes based on the left ventricular ejection fraction (LVEF): i) heart failure with reduced ejection fraction (HFrEF; LVEF≤40%); ii) mildly reduced ejection fraction (HFmrEF; LVEF 41–49%); iii) preserved ejection fraction (HFpEF; LVEF ≥50%), iv) and improved ejection fraction (HFimpEF; initial LVEF ≤40% then a signicant improvement in their LVEF, specifically an increase of at least 10 percentage to a value above 40%).

Despite substantial advances in pharmacological and device-based therapies, management of heart failure remains challenging for patients and physicians due to polypharmacy, side effects and socioeconomic factors. A systematic review evaluating interventions to enhance adherence to medications revealed that even after targeted strategies, only about 10% of patients consistently adhered to their medications [3]. Consequently, rehospitalization remains a significant problem in heart failure management. Approximately 25% of patients are re-admitted within 30 days of discharge, and nearly 50% return within 6 months of discharge [4]. These readmissions are often multifactorial, involving both HF-related and non-HF-related causes. Moreover, in-hospital mortality can reach up to 30% in certain high-risk subgroups, such as those with advanced HF or multiple comorbid conditions [5].

While evidence strongly recommends initiation of guideline-directed medical therapy (GDMT), data suggest significant gaps in its implementation. Data from the clinical heart failure management program CHAMP-HF registry, which studied GDMT among diabetic patients with HFrEF, showed that 39% were not receiving angiotensin converting enzyme inhibitors (ACEi)/ angiotensin receptor blocker (ARB), 20% were not on beta-blockers, 84% were not receiving angiotensin receptor-neprilysin inhibitors (ARNI), and 67% were not receiving mineralocorticoid receptor antagonists (MRAs), despite meeting eligibility criteria [6].

Regional data on heart failure in the Gulf remain limited, and adherence to GDMT in real-world hospital settings is not well characterized. This study aims to describe the contemporary clinical characteristics, underlying etiologies, treatment patterns, and readmission rates at days 30 and 180 post-discharge of hospitalized patients with heart failure and the extent to which in-hospital management aligns with current guideline recommendations.

Method

A retrospective observational study was conducted, including all consecutive adult patients admitted with a primary diagnosis of heart failure between January and December 2024, at Zayed Military Hospital, Abu Dhabi, United Arab Emirates (UAE). Eligible patients were identified using electronic medical records based on admission diagnosis codes related to heart failure. Medical records were reviewed to collect data on demographics, etiology of heart failure, previous medications prescribed, inpatient management (including drug class and device therapy), clinical outcomes, and readmission rates at 30 and 180 day post-discharge. Primary outcomes included GDMT utilization and follow up adherence. Secondary outcomes included 30 and 180 day readmission rates and in hospital mortality rates.

Guideline-directed medical therapy was assessed based on the 2022 American Heart Association (AHA)/ American College of Cardiology (ACC) and 2023 European Society of Cardiology (ESC) Heart Failure guidelines. Ethical approval for the study was obtained from the Research and Ethics Committee at Zayed Military Hospital, Abu Dhabi, UAE.

Result

A total of 152 patients hospitalized with heart failure were included in the analysis, of whom 105 (69%) were males and 47 (31%) were females. Most admissions occurred under cardiology service (n = 89), followed by internal medicine (n = 57) and intensive care (n = 6). Overall, 43% of admissions were due to acute decompensated heart failure, while the remainder presented with worsening chronic symptoms. These data represent all consecutive admissions during the study period without exclusions, reflecting real-world hospital practice.

Patients were categorized by ejection fraction (EF) into 3 groups: i) HFrEF <40% (n = 87), ii) HFmrEF 40–49% (n = 36) iii) and HFpEF ≥50% (n = 29). Patients with HFrEF were younger (mean age 66.3 years) and predominantly male (79.3%), whereas HFpEF patients were older (mean age 79.2 years) and more commonly female (58.6%). Ischemic heart disease (IHD) was the leading etiology of heart failure, accounting for 50% of all cases. It was identified in 58.6% of HFrEF, 41.6% of HFmrEF, and 34.4% of HFpEF patients.

The GDMT prescription in the HFrEF group was optimal for most drug classes, with 82.8% receiving ARNI/ACEi/ARB, 94.3% on beta-blockers, and 74.7% on (SGLT2i). Among HFpEF patients, 51.7% received ACEi/ARB/ARNI, 89.7% beta blockers, and 48.3% SGLT2i. The MRAs were underutilized across all EF categories, prescribed in only 21.8% of patients with reduced EF and 37.9% of those with preserved EF.

When comparing GDMT use by gender, prescription patterns in HFrEF patients were similar for ACEi/ARB/ARNI (83.3% in men vs. 82.6% in women), beta blockers (92.8% in men vs. 100% in women) and SGLT2i (72.2% in men vs. 75.3% in women). However, prescription of MRA was notably higher in men (58.5%) compared to women (27.7%). In both HFmrEF and HFpEF groups, SGLT2i prescriptions were also higher among males compared to females; 79.1% vs. 50% in the HFmrEF group, and 50% vs. 41% in the HFpEF group.

Both HFrEF and HFpEF patients admitted under the cardiology service had higher rates of GDMT utilization compared to those under internal medicine or the intensive care unit (ICU). Among HFrEF patients, ACEi/ARB/ARNI use was highest in cardiology (86.5%), followed by internal medicine (66.7%), and ICU (50%). Beta blocker use was comparable across services (91% cardiology vs. 94.7% internal medicine vs. 100% in ICU), while SGLT2i use was significantly higher under cardiology care (79.8%) than internal medicine (52.6%). Interestingly, MRA use was higher among patients admitted under internal medicine (31.6%) compared to cardiology (15.7%). Regarding non-pharmacological management, invasive coronary angiography was performed in 48% of HFrEF, 30% of HFmrEF, and 24% of HFpEF patients.

Device therapy was utilized in 41% of HFrEF patients, particularly in those with underlying ischemic etiology (57.5%). Across the entire cohort, 76.3% underwent coronary angiography, 21.1% had cardiac magnetic resonance imaging (MRI), and 8.6% had computed tomography (CT) coronary angiography.

Length of stay varied by service, being shortest among cardiology patients (mean 5.4 days), longer under internal medicine (13.6 days), and longest in ICU admissions (52 days). By EF category, HFpEF patients had longer admissions (mean 7 days) than those with HFrEF (4 days) or HFmrEF (3 days). HFpEF also had the highest 180-day readmission rate (41.4%) compared to HFrEF (19.5%) and HFmrEF (22.2%).

Early post-discharge follow-up within 2 weeks was achieved in 41.4% of patients, with the highest rates among those admitted under cardiology (50.6%), compared to internal medicine (29.8%) and ICU (16.7%). Across all EF categories, an average of 20% of patients followed up within four weeks of discharge. Overall, in-hospital mortality was 5.2%, and post-discharge mortality was 4%, resulting in a combined known mortality of 9.2%.

Clinical characteristics, etiologies, in-hospital course, and follow up outcomes of heart failure patients has been summarized in Table 1.

Table 1.

Summary of clinical characteristics, etiologies, in-hospital course, and follow up outcomes of heart failure patients.

	HFrEF (EF < 40%)	HFmrEF (EF 40–49%)	HFpEF (EF >50%)
Total patients	87 (57.2%)	36 (23.7%)	29 (19.1%)
Clinical characteristics
Male	69 (79.3%)	24 (66.7%)	12 (41.4%)
Female	18 (20.7%)	12 (33.3%)	17 (58.6%)
Mean Age (years)	66.3	65.2	79.2
Mean BMI (kg/m2)	27.3	29.5	28.4
Mean LOS (days)	9	3	10.6
Comorbidities
CKD	23 (26.4%)	8 (22.2%)	9 (31.1%)
DM	54 (62.1%)	17 (47.2%)	21 (72.4%)
HTN	68 (78.2%)	28 (77.8%)	29 (100%)
DLP	78 (89.7%)	29 (80.6%)	28 (96.6%)
AF	31 (35.6%)	10 (27.8%)	12 (41.4%)
Etiologies
IHD	51 (58.6%)	15 (41.7%)	10 (34.5%)
DCM	22 (25.3%)	6 (16.7%)	0
HTN	3 (3.4%)	8 (22.2%)	14 (48.3%)
Others (valvular, arrhythmias, etc.)	11 (12.7%)	7 (19.4%)	5 (17.2%)
Medications
ACEi/ARB/ARNI	72 (82.8%)	31 (86.1%)	15 (51.7%)
Beta-blockers	82 (94.3%)	33 (91.7%)	26 (89.7%)
MRA	19 (21.8%)	3 (8.3%)	11 (37.9%)
SGLT-2i	65 (74.7%)	24 (66.7%)	14 (48.3%)
Diuretics	44 (50.6%)	11 (30.6%)	4 (13.8%)
Aspirin	61 (70.1%)	17 (47.2%)	21 (72.4%)
Statins	81 (93.1%)	32 (88.9%)	27 (93.1%)
Device therapy
CRT/ICD	36 (41.4%)	4 (11.1%)	0
Follow up
2 weeks	40 (46%)	17 (47.2%)	9 (31%)
4 weeks	20 (23%)	7 (19.4%)	6 (20.9%)
Readmission
30-days	7 (8%)	1 (2.8%)	2 (7%)
180-days	17 (19.5%)	8 (22.2%)	12 (41.4%)
Mortality	7 (8%)	2 (5.6%)	5 (17.2%)

HFrEF: heart failure with reduced ejection fraction, HFmrEF: heart failure with mildly reduced ejection fraction, HFpEF: heart failure with preserved ejection fraction, BMI: body mass index, LOS: Length of stay, CKD: chronic kidney disease, DM: diabetes mellitus, HTN: hypertension, DLP: dyslipidemia, AF: atrial fibrillation, IHD: ischemic heart disease, DCM: dilated cardiomyopathy, ACEi: angiotensin-converting enzyme inhibitor, ARB: angiotensin receptor blocker, MRA: Mineralocorticoid receptor antagonist, SGLT2i: sodium glucose transporter 2 inhibitor, CRT: cardiac resynchronization therapy, ICD: implantable cardioverter-defibrillator.

Discussion

This study provides insights into the clinical characteristics, etiologies, management patterns, and outcomes of patients hospitalized with heart failure at Zayed Military Hospital in the United Arab Emirates (UAE). The findings highlight both the challenges and opportunities in optimizing acute and long-term heart failure management within our population.

Our cohort consisted of 152 consecutive heart failure patients, predominantly male (69%), with a mean age of 68.5 years. These demographics align with findings from regional registries, including Sultanate of Oman (57% male), Kingdom of Saudi Arabia (70.1% male) and the United Kingdom (UK) National Heart Failure Audit (NFHA) (57% male) [7,8,9]. Patients in our cohort were slightly older than those in the Omani registry (mean age 63 ±12 years), but younger than those in the UK cohort (mean age 75.9 years in males, 80 years in females).

IHD was the leading cause of heart failure, particularly among the HFrEF and HFmrEF groups, accounting for 53.6% of all causes. This is consistent with both regional (Sultanate of Oman: 59.6%) and international (UK audit: 57.7% in men, 42.7% in women) data. Hypertensive heart disease was the predominant etiology among HFpEF patients (48.2%) and was present across all EF categories (16.4% overall).

Similar trends have been reported in multinational heart failure registries, where hypertension accounted for approximately 20% of heart failure cases [11]. Hypertensive heart disease accounts for approximately 14-25% of heart failure cases in the Western population and about 16–20% of cases in Gulf countries [7,11,12,13]. The high burden in our cohort likely reflects a combination of an ageing population, rising prevalence of hypertension, obesity, and diabetes mellitus [14]. Suboptimal blood pressure control remains a key driver, as cumulative exposure to elevated blood pressure over decades leads to progressive cardiac remodelling and dysfunction [15,16]. In the UAE, only 38% of hypertensive patients achieve target blood pressure control (<140/90 mmHg), with similar trends across the Middle East and North Africa (MENA) region, where control rates are as low as 19% [17,18]. Moreover, over 40% of hypertensive patients remain undiagnosed, and nearly one in five patients with hypertension are untreated [19]. These findings highlight the crucial role of primary care physicians in screening, early diagnosis, timely initiation, and titration of antihypertensive therapy supported by effective patient education.

In terms of adherence to GDMT among HFrEF patients, we observe high prescription rates of ACEi/ARB/ARNI (82.8%), beta blockers (94.3%), and SGLT2i use (74.7%). The SGLT2i use in our cohort was relatively high, reflecting positive uptake following their integration in the 2022 AHA/ACC/ Heart Failure Society of America (HFSA) guidelines. However, MRAs were markedly underused (21.8%), lower than reported in the UK (62.9%), Kingdom of Saudi Arabia (43.6% in 2016), and Sultanate of Oman (31% in 2015) registries. Data regarding SGLT2i utilization was not reported in the Saudi and Omani registries, likely due to earlier data collection [7,8].

Gender based differences in GDMT utilization were also observed, with higher MRA use among males in the HFrEF group and higher SGLT2i prescription in men across both HFmrEF and HFpEF groups. Similar gender based disparities have been reported in previous studies, where women had a 23% lower probability of achieving optimal GDMT after a diagnosis of HFrEF, were more likely to be on single therapy and were less likely to be prescribed SGLT2i [20,21]. However, given the relatively small number of female patients in our cohort, these observations should be interpreted cautiously and cannot be generalized to the broader population.

MRAs are often withheld due to concerns over hyperkalemia and worsening renal function, particularly in patients with underlying chronic kidney disease and diabetes mellitus. Clinician-related barriers, such as limited experience with dose titration, have also been reported [22]. Similarly, concerns about volume depletion, hypotension and worsening renal function continue to limit SGLT2i use, despite evidence suggesting these risks are minimal [23]. Addressing these barriers requires structured, follow-up protocols, enhanced patient education, and multidisciplinary collaboration, particularly with nephrologists, to support safe initiation and monitoring as recommended by the current heart failure guidelines. HFpEF accounted for 19% of cases, higher than reported in the Saudi registry (12.3%) but similar to rates observed in the program for the evaluation and management of cardiac events (PEACE MENA) study (HFpEF: 19%) [8,24]. This remains lower than rates in Western populations (31.3% in the UK PULSE study) [25]. It is worth noting that both the Saudi registry and the PULSE study recruited chronic heart failure patients, while patients in the PEACE MENA study were inpatients. The rising burden of HFpEF is likely driven by increased longevity, obesity, and multiple comorbidities. Diagnostic challenges persist, as preserved systolic function on echocardiography can delay recognition, highlighting the importance of clinical context rather than relying on echocardiographic findings alone.

Patients with reduced and mildly reduced ejection fraction had higher prescription rates of guideline-recommended interventions compared to the HFpEF group, reflecting the long-established evidence base for HFrEF therapies. In contrast, HFpEF treatments, including SGLT2 inhibitors and ARNI, have only recently been integrated into guidelines, which may explain the lower uptake observed.

Hospital stay was shortest among patients admitted under the cardiology team (mean 5.4 days), and longest in internal medicine and ICU (mean 13.6 days and 52 days, respectively). Furthermore, patients with HFpEF stayed longer (mean 10.6 days) than those with HFrEF (mean 9.0 days), highlighting the considerable clinical burden of HFpEF, once under-appreciated by physicians but now increasingly recognized for its severity and hospitalization costs. Early post-discharge follow-up within 2 weeks was achieved in 41.4% overall, with the highest rates among cardiology-managed patients (50.6%) and those with HFrEF and HFmrEF (46% and 47.2% respectively). HFpEF patients had the lowest follow-up rate (17.9%). While these follow-up rates exceed the UK audit figure (32%), patients in the UK are more likely to be followed up by primary care, which may not be captured in hospital data [9].

Readmission rates at 30 days were similar between HFrEF (8%) and HFpEF (7.1%) groups. However, at 180 days, HFpEF patients had significantly higher readmissions (41.4% versus 19% for the HFrEF group). This is likely due to the absence of targeted therapies and a higher comorbidity burden. It also reinforces the evolving understanding that HFpEF is a more complex condition than previously appreciated. Globally, 30-day and 1 year heart failure readmission rates have been reported at 13.2% and 35.7% [26]. In contrast, regional data show substantially higher readmission rates. The Oman registry reported a 30-day and 12-month readmission rate of 30% and 52.7% respectively, while the Saudi registry reported a 1 year readmission rate of 39% [7,8]. The total mortality rate in our cohort (in-hospital and post-discharge) was 9.2% (n = 14), which is lower than the rate reported in the UK (9% in hospital and 14% post-discharge). Most deaths occurred in the HFrEF group, (64%) (n = 9).

Patients admitted under cardiology care had higher prescription rates of GDMT, shorter hospital stay, higher follow-up rates and lower mortality. This aligns with the NHFA finding, which shows lower mortality rates among patients managed by cardiology teams. However, it is important to consider that patients admitted under internal medicine and ICU services are older patients with higher comorbidity burden, which may have contributed to their poorer outcomes. Nevertheless, these findings point to the need for early cardiology input, ideally a heart failure specialist, to ensure optimal heart failure care. Moreover, strengthening the role of primary care in managing comorbidities such as hypertension remains essential to reducing the burden of heart failure in the population.

Limitations of the study

The are number of limitations to this study: i) single-center data with a relatively small sample size limits generalizability; ii) small number of females; iii) retrospective design was used, thus the study relies on documentation accuracy; iv) lack of long-term outcomes, data was limited to follow-up at 180 days only; v) and no assessment of medication doses to assess for optimization.

In conclusion, study highlights the clinical characteristics, underlying etiologies, treatment patterns, and outcomes of patients hospitalized with heart failure. Although most patients received appropriate GDMT, MRA use was suboptimal, highlighting the need for important structured, multidisciplinary heart failure programs to ensure uniform, evidence-based care.

The high readmission rates, particularly among HFpEF patients, emphasize the need for early post-discharge follow-up and optimization of comorbid conditions, particularly hypertension. Strengthening coordination between cardiology and primary care, improving physician education, and implementing standardized treatment protocols could substantially improve outcomes and reduce hospital burden in the UAE's growing heart failure population.

Acknowledgement

The authors acknowledge Grammarly for English language editing.

Disclosure statement

The authors declare that this manuscript, or its essential content, has not been previously published in whole or in part in any language, in print or online, and is not under consideration elsewhere. Artificial intelligence tools were used for grammar and language refinement.

Disclosure

The authors declare no conflict of interest, and the work was not supported or funded by any pharmaceutical or drug company. Ethics approval was given by the Zayed Military Hospital Ethics Committee for this study.