Prevalence, types and clinical presentation of heart failure among hypertensive patients referred for echocardiogram examination at Muhas academic medical center, Dar es salaam, Tanzania

Abstract

Background:Heart failure (HF) is a common complication in patients with hypertension who may present as HF with preserved ejection fraction (HFpEF) or HF with reduced ejection fraction (HFrEF). These categories have different clinical presentationsand may require special attention to diagnose, especially when the presentation is HFpEF. Still, data is lacking on the magnitude and clinical presentation of HF among known hypertensive patients on regular hypertension follow-up in Tanzania. Aims:To assess the prevalence, types and clinical presentation of HF among known hypertensive patients referred for echocardiogram examination at Muhimbili University of Health and Allied Sciences (MUHAS) Academic Medical Centre (MAMC). Methods: This was a cross sectional prospective study among adult (≥ 18 years) hypertensive patients referred for echocardiogram examination at MAMC from June 2019 to December 2019. A structured questionnaire was used togather patients’ socio-demographiccharacteristics, clinical information, cardiovascular risk profile, as well as symptoms and signs of HF. Patient’s symptoms in combination with signs were used to identify patients with HF using the Framingham criteria. Blood was collected and analyzed for hemoglobin level, random blood glucose, creatinine, and cholesterol panel. All patients were then subjected to detailed echocardiogram examination, and patients were then categorized as HFpEF (EF ≥50%) or HFrEF(EF < 50%) depending on their symptoms, signs and echocardiographic findings. Data Handling and Analysis:Data entry and analysis was done using SPSS for Windows version 23 (IBM SPSS, Chicago, IL). Data ispresented as mean ± standard deviation for continuous variables and percentages for categorical variables. The χ² or Fisher's exact test (when the expected frequency was <5) was used to compare categorical variables. Student's t test was used to compare the mean values. A p-value of less than 0.05 was considered to indicate a statistically significant difference.

Results:In total, 346 hypertensive patients fulfilled the inclusion criteria and were enrolled.Their mean ± SD age was 58.3±12.4 years, and 60.4% were females. The mean ± SD systolic and diastolic BP in the total population was 152±23 and 91±15, respectively. In the total population, 102 (29.5%) patients were found to have HF. Among patients with HF, 26 (25.5%) had HFrEF, while 76 (74.5%) had HFpEF in echocardiogram. Patients with HFpEF were more likely to be outpatients, showed a trend of being older, were more likely to be overweight and obese, and were more likely to have echocardiographic features of LV hypertrophy, all p <0.05. On the other hand, patients with HFrEF were more likely to present withparoxysmal nocturnal dyspnea, shifted apex beat, gallop rhythm and basal crepitations, all p < 0.05. Patients with HFrEFwere also more likely to have had significantly higher left atrial volume index and left ventricular internal diameter when compared with HFpEF, all p < 0.05. Conclusion: The prevalence of HF among hypertensive patients referred for echocardiogram examination at a tertiary hospital in Tanzania is high at 29.5%, and a majority of patients with HF present as HFpEF. HFpEF differs from the commonly known HFrEF in terms of blood pressure level, obesity status and some echocardiographic parameters, which need to be carefully examined when HF is suspected. Recommendations Due to the high prevalence of HF found in this study that was done among hypertensive patients, it is recommended that there should be active screening for HF especially in the obese and uncontrolled HT patients, as they may present with HFpEF which can pass unnoticed.