Drug utilization and blood pressure control in ambulatory hypertensive patients: focus on those with compelling indications.

OBJECTIVE: Compelling indications require the use of specific antihypertensive drug classes and often two or more antihypertensive medications for blood pressure (BP) control. This study assessed drug utilization patterns among hypertensive patients with compelling indications, conformity with recommended guidelines, and the effect on BP control. MATERIALS AND METHODS: A prospective, cross-sectional study of hypertensive patients attending three subspecialty hospital clinics. Data on demographics, prescriptions, and BP were collected. BP control was defined as BP less than 140/90 mmHg in nondiabetic subjects and less than 130/80 for those with diabetes. Analysis was done with SPSS version 17. RESULTS: Of the 1,926 patients with hypertension, 877 (45.5%) had compelling indications. Patients were aged 59.3 ± 11.5 years. The most frequently-encountered compelling indications were hypertensive heart disease (35.8%), diabetic mellitus (31.9%), and renal diseases (11.5%). The most prescribed drug was angiotensin-converting enzyme inhibitor (ACEIs), which was present in 22.6% of all prescriptions. Only 23.1% of patients had fully controlled BP. Poor BP control significantly correlated with the number of antihypertensive drugs r = 0.205, p < 0.001, but negatively correlated with age and duration of hypertension, r = -0.071, p = 0.038 and r = -0.448, p = 0.042, respectively. CONCLUSION: BP control was very poor in this study, and there was a high prevalence of compelling indications. Poor control was negatively correlated with increasing age and duration of hypertension. The most common compelling indications were hypertensive heart disease, diabetes mellitus, and renal disease.

Prevalence and severity of atherosclerosis in extra cranial carotid arteries in Nigeria: an autopsy study.

BACKGROUND: There has been a paucity of autopsy studies on atherosclerotic lesions in Nigerians, the last one conducted at our centre being more than four decades ago. There has also been considerable epidemiological transition. The objective of the study was to determine the frequency, severity, pattern and distribution of atherosclerotic lesions in extra cranial carotid arteries (ECCA) in Nigerians at autopsy. METHODS: ECCA of 30 consecutive Nigerian patients undergoing autopsy at a University teaching hospital were examined using the American Heart Association (AHA) histological grading and classification of atherosclerosis. RESULTS: Atherosclerotic lesions of ECCA were present in 73.3% of the subjects with the right and the left carotid bifurcations (28.3%) being the most frequently affected sites. Using the AHA classification of atherosclerosis, a total of 176(73.3%) lesions were found in the 240 histological sections of blood vessels examined. Of these, 22.5% were types I, 22.5% were types II, 15.4% were type V, and 7.5% were type III. The VII to type IX lesions were rare. When these atherosclerotic lesions were grouped into mild, moderate and severe, 52.5% were mild lesions (types I-III); 18.3% were moderate lesions (types IV and V); and 2.5% were severe lesions (types VI to IX). The severe lesions were most frequently observed in the left carotid bifurcation (50%) and they first appeared in the age group 45-49 years. Age, hypertension and diabetes mellitus were strong risk factors for atherosclerosis. CONCLUSIONS: Compared with four decades ago there has been an apparent increase in severity and extent of ECCA atherosclerosis especially after the age of 45 years in autopsies from our centre. This change in the amount of atherosclerosis over time is possibly due to the epidemiologic transition. This may worsen the rise in stoke incidence within this community and as such, great effort should be made to follow-up and manage CVD risk factors within the community.

Blood pressure control and left ventricular hypertrophy in hypertensive Nigerians.

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.

Characterisation of heart failure with normal ejection fraction in a tertiary hospital in Nigeria.

BACKGROUND: The study aimed to determine the frequency and characteristics of heart failure with normal EF in a native African population with heart failure. METHODS: It was a hospital cohort study. Subjects were 177 consecutive individuals with heart failure and ninety apparently normal control subjects. All the subjects underwent transthoracic echocardiography. The group with heart failure was further subdivided into heart failure with normal EF (EF > or = 50) (HFNEF) and heart failure with low EF(EF <50)(HFLEF). RESULTS: The subjects with heart failure have a mean age of 52.3 +/- 16.64 years vs 52.1 +/- 11.84 years in the control subjects; p = 0.914. Other baseline characteristics except blood pressure parameters and height were comparable between the group with heart failure and the control subjects. The frequency of HFNEF was 39.5%. Compared with the HFLEF group, the HFNEF group have a smaller left ventricular diameter (in diastole and systole): (5.2 +/- 1.22 cm vs 6.2 +/- 1.39 cm; p < 0.0001 and 3.6 +/- 1.24 cm vs 5.4 +/- 1.35 cm;p < 0.0001) respectively, a higher relative wall thickness and deceleration time of the early mitral inflow velocity: (0.4 +/- 0.12 vs 0.3 +/- 0.14 p < 0.0001 and 149.6 +/- 72.35 vs 110.9 +/- 63.40 p = 0.001) respectively. The two groups with heart failure differed significantly from the control subjects in virtually all echocardiographic measurements except aortic root diameter, LV posterior wall thickness(HFLEF), and late mitral inflow velocity(HFNEF). HFNEF accounted for 70(39.5%) of cases of heart failure in this study. Hypertension is the underlying cardiovascular disease in 134(75.7%) of the combined heart failure population, 58 (82.9%) of the subjects with HFNEF group and 76(71%) of the HFLEF group. Females accounted for 44 (62.9%) of the subjects with HFNEF against 42(39.3%) in the HFLEF group (p = 0.002). CONCLUSION: The frequency of heart failure with normal EF in this native African cohort with heart failure is comparable with the frequency in other populations. These groups of patients are more likely female, hypertensive with concentric pattern of left ventricular hypertrophy.

Left ventricular geometric patterns in normotensive type 2 diabetic patients in Nigeria: an echocardiographic study.

Left ventricular hypertrophy has been linked with diabetes mellitus and abnormal glucose tolerance in several studies. Most previous studies have been carried out in the western world with dearth of data in native Africans. A total of 122 type 2 diabetic patients with a mean age of 55.0+/-8.5 years and another 90 normal patients with a mean age of 55.4+/-8.7 years were recruited for the study. Two-dimensional guided M-mode echocardiography was performed on each patient. In the diabetic patients, 49.2% had normal geometry, 23.0% had concentric hypertrophy, 13.0% had concentric remodeling, and 14.8% had eccentric hypertrophy. In the control group, 72.2% had normal geometry, 4.4% had concentric hypertrophy, 11.2% had concentric remodeling, and 12.2% had eccentric hypertrophy. In a multiple regression analysis, there was significant difference in the geometric pattern of the diabetics and controls (chi(2)=11.09, P<.001). Diabetes mellitus is independently associated with left ventricular structural changes in Nigerian diabetics.

Characterisation of left ventricular function by tissue Doppler imaging technique in newly diagnosed, untreated hypertensive subjects.

BACKGROUND: Hypertension results in structural and functional changes in the heart. Early detection of abnormalities of cardiac structure and function is important in the assessment and treatment of hypertensive subjects. The aim of this study was to evaluate the utility of the tissue Doppler echocardiographic technique in characterising diastolic and systolic functions in untreated native black African hypertensive subjects. MATERIALS AND METHODS: Forty consecutive, newly diagnosed, untreated hypertensives with adequate conventional echocardiographic (2-D, M-mode, transmitral and pulmonary Doppler flow velocities) and tissue Doppler echocardiographic images were recruited into the study. The control subjects were apparently normal individuals. Each arm of the study consisted of 21 male and 19 female subjects. RESULTS: The two groups were comparable by age (48.6 +/- 11.35 years in the hypertensives vs 48.1 +/- 11.33 years in the controls; p = 0.844) and gender distribution (M/F: 21/19 in both groups). Other baseline characteristics, except for blood pressure parameters, which were predictably higher in the hypertensive subjects, were comparable between the two groups. The hypertensive subjects had a lower systolic myocardial velocity (Sm) and early diastolic myocardial velocity (Em) in comparison with the controls (p = 0.033 and p = 0.018, respectively). The late diastolic myocardial velocity (Am) was comparable in the two groups (p = 0.430). CONCLUSIONS: Tissue Doppler echocardiography demonstrates diastolic dysfunction relatively early in native African hypertensives and may be useful for detecting subtle deterioration in systolic function.

Changes in left atrial dimension and function and left ventricular geometry in newly diagnosed untreated hypertensive subjects.

BACKGROUND: It is known that a spectrum of changes in structure, size and function of the different chambers of the heart occur in individuals with hypertension. The earliest changes and the sequence of these changes are still being studied. AIMS: The present study aimed to assess early changes in the left atrial size and function in hypertension, and its relationship with left ventricular geometry and other factors that may influence left atrial size. METHODS: One hundred consecutive subjects who were newly diagnosed with hypertension and 50 apparently normal individuals were recruited into the study. Standard M-mode, two-dimensional and Doppler echocardiography were performed. The endocardial border of the left atrium was traced to obtain the atrial area and left atrial volumes and emptying fractions were derived from measured areas. RESULTS: The hypertensive patients and the controls were comparable by age, sex and body mass index. Thirty-seven (37%) of the hypertensive subject had increased left ventricular mass versus eight subjects (16%) in the normal controls. The patients with hypertension had a higher linear left atrial dimension (3.5 +/- 0.48 cm versus 3.1 +/- 0.47 cm, P < 0.0001), longer pre-atrial contraction length (3.8 +/- 0.56 cm versus 3.6 +/- 0.45 cm; P = 0.02) and higher peak late mitral inflow velocity (0.64 +/- 0.19 m/s versus 0.56 +/- 0.15 m/s; P = 0.010). CONCLUSIONS: Changes in the geometry of the left ventricle occur early in hypertension and precede deterioration in left ventricular systolic function. The corresponding left atrial changes are marginal and are indicative of increased left atrial length and accentuated atrial systolic function.

Characterisation of left ventricular function by tissue Doppler imaging technique in newly diagnosed, untreated hypertensive subjects

BACKGROUND:Hypertension results in structural and functional changes in the heart. Early detection of abnormalities of cardiac structure and function is important in the assessment and treatment of hypertensive subjects. The aim of this study was to evaluate the utility of the tissue Doppler echocardiographic technique in characterising diastolic and systolic functions in untreated native black African hypertensive subjects.MATERIALS AND METHODS:Forty consecutive, newly diagnosed, untreated hypertensives with adequate conventional echocardiographic (2-D, M-mode, transmitral and pulmonary Doppler flow velocities) and tissue Doppler echocardiographic images were recruited into the study. The control subjects were apparently normal individuals. Each arm of the study consisted of 21 male and 19 female subjects.RESULTS:The two groups were comparable by age (48.6 +/- 11.35 years in the hypertensives vs 48.1 +/- 11.33 years in the controls; p = 0.844) and gender distribution (M/F: 21/19 in both groups). Other baseline characteristics, except for blood pressure parameters, which were predictably higher in the hypertensive subjects, were comparable between the two groups. The hypertensive subjects had a lower systolic myocardial velocity (Sm) and early diastolic myocardial velocity (Em) in comparison with the controls (p = 0.033 and p = 0.018, respectively). The late diastolic myocardial velocity (Am) was comparable in the two groups (p = 0.430). CONCLUSIONS:Tissue Doppler echocardiography demonstrates diastolic dysfunction relatively early in native African hypertensives and may be useful for detecting subtle deterioration in systolic function

Echocardiographic partition values and prevalence of left ventricular hypertrophy in hypertensive Nigerians.

BACKGROUND: Left ventricular hypertrophy (LVH) is a well known independent risk factor for cardiovascular events. It has been shown that combination of left ventricular mass (LVM) and relative wall thickness (RWT) can be used to identify different forms of left ventricular (LV) geometry. Prospective studies have shown that LV geometric patterns have prognostic implications, with the worst prognosis associated with concentric hypertrophy. The methods for the normalization or indexation of LVM have also recently been shown to confer some prognostic value especially in obese population. We sought to determine the prevalence of echocardiographic lLVH using eight different and published cut-off or threshold values in hypertensive subjects seen in a developing country's tertiary centre. METHODS: Echocardiography was performed in four hundred and eighty consecutive hypertensive subjects attending the cardiology clinic of the University college Hospital Ibadan, Nigeria over a two-year period. RESULTS: Complete data was obtained in 457 (95.2%) of the 480 subjects (48.6% women). The prevalence of LVH ranged between 30.9-56.0%. The highest prevalence was when LVM was indexed to the power of 2.7 with a partition value of 49.2 g/ht2.7 in men and 46.7 g/ht2.7 in women. The lowest prevalence was observed when LVM was indexed to body surface area (BSA) and a partition value of 125 g/m2 was used for both sexes. Abnormal LV geometry was present in 61.1%-74.0% of our subjects and commoner in women. CONCLUSION: The prevalence of LVH hypertensive patients is strongly dependent on the cut-off value used to define it. Large-scale prospective study will be needed to determine the prognostic implications of the different LV geometry in native Africans.

Left ventricular geometric patterns in newly presenting Nigerian hypertensives: an echocardiographic study.

BACKGROUND: Hypertension is a global problem and it is prevalent in Nigeria. Left ventricular hypertrophy is a major complication of hypertension with risk of sudden death and arrhythmias among others. Abnormal left ventricular geometric patterns also increase the burden of morbidity and mortality. It is therefore important to know the different left ventricular geometric patterns in Nigerian hypertensives because of their prognostic significance. METHODS: One hundred (100) newly presenting hypertensives (53 males and 47 females) and 100 controls (53 males and 47 females) were recruited for the study. All were subjected to clinical evaluation and full echocardiographic examination was performed according to the ASE recommendation. The relative wall thickness and the presence or absence of echocardiographic left ventricular hypertrophy were used to determine the various geometric patterns. RESULTS: The mean age of the hypertensive subjects was 56.06 (+/- 7.68) years while that of the control subjects was 56.10 (+/- 7.68) years. There was no significant difference in the mean ages of the two groups. In the hypertensive subjects 28% had normal geometry, 26% had concentric remodeling, 28% had concentric hypertrophy and 18% had eccentric hypertrophy. In the control group, 86% had normal geometry, 11% had concentric remodeling, 3% had eccentric hypertrophy and none had concentric hypertrophy. There was statistical significance when the geometric patterns of the hypertensive and controls were compared (chi2 = 74.30, p value < 0.0001). CONCLUSION: The study showed that only 28% of the hypertensive subjects had normal LV geometric pattern while 86% of the normal subjects had normal geometry. There is need for longitudinal studies in order to prognosticate the various geometric patterns.

Standard electrocardiographic criteria for left ventricular hypertrophy in Nigerian hypertensives.

OBJECTIVES: Left ventricular hypertrophy (LVH) is a major risk factor for cardiovascular morbidity and mortality. Various electrocardiographic criteria for LVH have differing sensitivities and specificities. Most of the available electrocardiographic criteria for LVH have not been evaluated in the African populace. METHODS: Electrocardiograms (ECGs) and echocardiograms were obtained from 100 hypertensive subjects and 60 controls. Electrocardiogram (ECG) LVH was determined by the Sokolow-Lyon, Sokolow-Lyon-Rappaport, Cornell voltage, Romhilt-Estes point score, and the Perugia score criteria. Echocardiographic LVH was defined by LV mass indexed for height at 97.5 percentile of the controls (126 g/m and 130 g/m in females and males respectively). RESULTS: The prevalence of echocardiographic LVH indexed for height was 34% and 1.67% in the hypertensive patients and controls respectively. The prevalence of ECG LVH obtained in the hypertensive patients with the various ECG criteria were 56% for Sokolow-Lyon-Rappaport voltage, 48% for Sokolow-Lyon voltage, 41% for Perugia score, 22% for Cornell sex specific voltage, and 18% for Romhilt-Estes score. Sokolow-Lyon-Rappaport voltage criteria had the best sensitivity (80%) and area under the receiver operating characteristic (ROC) curve while the Romhilt-Estes score had the best specificity (93%). CONCLUSION: Sokolow-Lyon and Sokolow-Lyon-Rappaport voltage criteria combine the best sensitivity and specificity values and would seem better suited for the diagnosis of ECG LVH in Nigerians.

Correlates of left atrial size in Nigerian hypertensives.

AIM: Left atrial (LA) enlargement is a common finding in systemic hypertension and is a risk factor for the development of atrial fibrillation and stroke. We determined the correlates of LA enlargement in a Nigerian hypertensive population. METHODS: A total of 361 hypertensives were recruited for echocardiography. Enlarged left atrium was defined as LA diameter > 4.2 cm in men or > 3.8 cm in women. RESULTS: Enlarged LA was found in 15.8% of the hypertensives (19.2% in females and 12.5% males). Compared with those without dilated LA, subjects with dilated LA had higher age, body mass index, left ventricular end diastolic diameter, left ventricular wall thickness, lower ejection fraction and fractional shortening. In multivariate analysis, body mass index and left ventricular (LV) mass were the major predictors of LA size, whereas dilated LA was related to age, female gender and LV mass or the presence of left ventricular hypertrophy in logistic regression analysis. CONCLUSION: Left atrial size in Nigerian hypertensives is influenced by age, female gender, left ventricular mass and body mass index.

Left ventricular diastolic function parameters in hypertensives.

BACKGROUND: Hypertension is associated with left ventricular diastolic function abnormalities. There have been few studies evaluating left ventricular diastolic function in an African populace. MATERIALS AND METHODS: Ninety-eight hypertensives (52 females, 46 males) and 99 normal controls (49 females, 50 males) were recruited for echocardiography. M-mode measurements and Doppler measurements of Mitral inflow and pulmonary venous flow were taken. RESULTS: The hypertensives had significantly larger left ventricular wall thicknesses than the controls PWT: 0.93 (0.214) vs. 0.88 (0.130), p=0.039: septum: 0.93 (0.255) vs. 0.87 (0.131), p=0.039. The left ventricular mass indexed to the allometric power of height was larger in the hypertensives than in the controls. The Doppler parameters of peak A-wave velocity, E/A ratio, deceleration time, peak pulmonary venous S-wave, peak pulmonary venous D-wave, S/D ratio and peak pulmonary reverse flow velocity were significantly different between the hypertensives and the controls. The major determinant of left ventricular diastolic function parameters were age and the duration of hypertension. The level of the systolic blood pressure, left atrial size and ejection fraction are less important determinants. CONCLUSION: Nigerian hypertensives have significantly different diastolic function indices when compared with normal controls.