Accuracy of Spectral Doppler in evaluation of diastolic dysfunction in hypertensive patients in Mulago Hospital Complex

Abstract

ABSTRACT Background: Hypertension is major risk factor for heart failure, coronary artery disease, kidney injury and stroke worldwide. Uncontrolled hypertension leads to structural changes in the heart which eventually results into interstitial fibrosis, myocardial wall thickness and alteration of function when diastolic dysfunction develops. Hypertension has been observed to be the most predisposing factor for cardiac failure worldwide and a common cause of heart failure on the cardiology ward of Mulago Hospital, accounting for about 40% of all causes of heart failure. Early detection of diastolic dysfunction is likely to halt its progression into overt diastolic heart failure. Spectral Doppler and Tissue Doppler Imaging (TDI) is considered as the most practical and reproducible method for either confirming or excluding diastolic dysfunction in Heart Failure with preserved Ejection Fraction (HFpEF). In Mulago hospital, only spectral Doppler is used to diagnose diastolic dysfunction. Objective: To determine the accuracy of spectral Doppler in diagnosing diastolic dysfunction among hypertensive patients in Mulago Hospital complex. Methods: This was a cross sectional study done in Mulago Hospital Complex. The study was conducted between April 2017 and May 2017. A total of 229 hypertensive patients were enrolled excluding the elderly, those with diabetes mellitus, documented evidence of other heart diseases like pericardial effusion, peripartum cardiomyopathy, valvular heart disease and atrial fibrillation, diabetes mellitus. Data on demographic, clinical characteristics and echocardiographic findings for both systolic and diastolic function was collected using a pretested questionnaire. Spectral Doppler imaging was compared to both spectral and tissue Doppler imaging (gold standard). Sensitivity, specificity, positive and negative predictive values were calculated in comparison to the both spectral and tissue Doppler imaging (gold standard). Results: Of the 229 patients, 146 (63.8%) were females and most of the patients were above 45 years of age. 87 (72.5%) were on antihypertensive treatment with majority of patients on calcium channel blockers and angiotensin converting enzyme inhibitors. Of the 229 enrolled patients, 172 (75%) had diastolic dysfunction using both spectral and tissue Doppler imaging (gold standard). The sensitivity and specificity of spectral Doppler was 60.44% and 51.1% respectively. The negative and positive predictive values were 25% and 82.71% respectively. The accuracy of spectral Doppler in diagnosing diastolic dysfunction was 59%. Conclusions: There was a low level of accuracy in using spectral Doppler to diagnose diastolic dysfunction. The prevalence of diastolic dysfunction was high using the both spectral and tissue Doppler imaging (gold standard). Recommendations: Therefore, it very important for us to emphasize the use the spectral and tissue Doppler imaging (gold standard) in hypertensive patients between 18 and 65 years of age so that we don’t miss out on patients with diastolic dysfunction.