Blood pressure control and left ventricular hypertrophy in hypertensive Nigerians

Abstract

Background : Hypertension is a disease characterized by end-organ complications, leading to high morbidity and mortality in many cases. People with untreated or uncontrolled hypertension often run the risk of developing complications directly associated with the disease. Left ventricular hypertrophy (LVH) has been shown to be a significant risk factor for adverse outcomes both in patients with hypertension and in the general population. We investigated the prevalence and pattern of LVH in a treated hypertensive population at the University College Hospital, Ibadan, Nigeria, using non-hypertensive subjects as control. Design and Setting : A prospective observational study performed at the University College Hospital, Ibadan, Nigeria. Methods : Patients had 6 visits, when at least one blood pressure measurement was recorded for each hypertensive subject and average calculated for systolic blood pressure (SBP) and diastolic blood pressure (DBP) separately. The values obtained were used for stratification of the subjects into controlled and uncontrolled hypertension. Subjects also had echocardiograms to determine their left ventricular mass. Results : LVH was found in 14 (18.2%) of the normotensive group, 40 (20.8%) of the uncontrolled hypertensive group and 14 (24.1%) of the controlled hypertensive group when left ventricular mass (LVM) was indexed to body surface area (BSA). When LVM was indexed to height, left ventricular hypertrophy was found in none of the subjects of the normotensive group, while it was found present in 43 (22.4%) and 14 (24.1%) subjects of the uncontrolled and controlled hypertensive groups, respectively. Significant difference in the prevalence of LVH was detected only when LVM was indexed to height alone. Conclusion : Clinic blood pressure is an ineffective way of assessing BP control. Thus in apparently controlled hypertensive subjects, based on office blood pressure, cardiac structural changes do remain despite antihypertensive therapy. This population is still at risk of cardiovascular events.