Echocardiographic Partition Values and Prevalence of Left Ventricular Hypertrophy in Hypertensive Jamaicans

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1 HYPERTENSION ORIGINAL RESEARCH Echocardiographic Partition Values and Prevalence of Left Ventricular Hypertrophy in Hypertensive Jamaicans Chiranjivi Potu MD 1,2, Edwin Tulloch-Reid, MD, FACC 1,2, Dainia Baugh, MD 1,2, Olusegun A Ismail, FRSS 3 & Ernest C. Madu, MD, FACC, FRCP (Edin) 1,2 Received 3/1/2012, Reviewed 20/1/2012, Accepted 27/1/2012 Key words: Echocardiography, Partition values, Left ventricular hypertrophy DOI: /ejcm ABSTRACT Background: Left ventricular hypertrophy (LVH) detected by either electrocardiography or echocardiography has been shown to be an extremely strong predictor of morbidity and mortality in patients with essential hypertension and in members of the general population. Alternative to LVH, left ventricular geometrical patterns offer incremental prognostic value beyond that provided by the other cardiovascular risk factors including left ventricular mass (LVM). Combination of LVM and relative wall thickness (RWT) can be used to identify different left ventricular geometrical patterns. Various indexation methods normalised for LVM have been shown to offer prognostic significance. There was no prior study on the prevalence of LVH and geometric patterns in hypertensive patients in Jamaica using multiple partition values. Our study was designed to estimate the prevalence of LVH and geometrical patterns in a hypertensive Caribbean population in Jamaica using 10 different published cut-off values. Methods: Clinical and echocardiographic data were collected from 525 consecutive hypertensive patients attending the cardiology clinic of the Heart Institute of the Caribbean over a period of 24 months who met the inclusion criteria for the study. LVM was calculated using different methods of indexation for body size and different partition values (PV) to identify LVH as described below: LVM/ BSA (g/m 2 ) PVs for men/women 116/104, 125/110, 125/125, 131/100; LVM/height (g/m) PVs 143/102, 126/105; LVM/height 2.0 PV 77.5/58.0; LVM/height 2.13 PV 68/61 and LVM/height 2.7 (g/m 2.7 ) PVs 51/51 and 49.2/46.7. RWT was calculated using the formula 2 X Posterior Wall Thickness (PWT)/ Left Ventricular Internal Diameter in diastole (LVIDd). Left ventricular geometrical patterns were categorised utilising the RWT and LVM. The impact of selected indexation methods and PVs on the prevalence of LVH and geometrical patterns were analysed. 1. Department of Medicine, Division of Cardiovascular Medicine, Heart Institute of the Caribbean, Jamaica. 2. Center of Excellence for Cardiovascular Medicine and Sports Physiology, University of Technology, Jamaica. 3. Division of Statistics and Research Methodology, School of Mathematics and Statistics, Faculty of Science and Sports, University of Technology, Jamaica CORRESPONDENCE Ernest C. Madu, MD, FACC, FRCP (Edin). Division of Cardiovascular Medicine, Heart Institute of the Caribbean 23 Balmoral Avenue, Kingston 10, Jamaica Phone: (-08) Fax: Results: Complete data was obtained in 501(95.5%) of the 525 subjects (40.5% men & 59.5% women). The prevalence of LVH ranged between %. The highest prevalence of LVH was found when the LVM was indexed to the height with a partition value of 126 g/ht in men and 105 g/ht in women and height raised to the power of 2.7 with a partition value of 49.2 g/ht 2.7 in men and 46.7 g/ht 2.7 in women. Abnormal LV geometry ranged between %. Concentric remodelling was the most common type of abnormal geometry ( %) while the eccentric hypertrophy was the least common type ( %) found for all indexation methods and partition values. Concentric hypertrophy ( %) was the second most common type of abnormal geometry found in our patients. Conclusion: Concentric remodelling was the most common type of abnormal geometry in our Jamaican hypertensive population. Height-based indexation methods and partition values demonstrated the highest prevalence of LVH compared to other methods in our population. ISSN EUROPEAN JOURNAL OF CARDIOVASCULAR MEDICINE VOL II ISSUE I

2 ECHOCARDIOGRAPHIC PARTITION VALUES AND PREVALENCE OF LEFT VENTRICULAR HYPERTROPHY IN HYPERTENSIVE JAMAICANS INTRODUCTION Hypertension is a global health problem causing significant disability and premature death with its major impact on cardiovascular disease. 1,2 It is estimated that the current burden of hypertension would escalate to more than 1.56 billion by the year 2025 with nearly two-thirds of them living in low- and middle-income countries, resulting in a huge economic burden. 3 Population-based studies have shown the prevalence of hypertension in the range of 20-30% in persons years old in Jamaica. 4,5 Left ventricular hypertrophy (LVH) that occurs as an adaptation to chronic pressure overload in patients with hypertension is a strong marker of adverse cardiovascular prognosis independent of other conventional risk factors. 6-8 Echocardiography is the most commonly used non-invasive imaging method for the diagnosis of LVH. Echocardiographic LVH can be diagnosed by indexing the LVM for body size (Body surface area, height, height raised to power of 2.7 etc) using cut-off values derived from the population based studies. Recent studies have shown that these methods of indexation or normalisation offer prognostic value in specific populations. 9,10 Furthermore combination of left ventricular mass index (LVMI) and relative wall thickness (RWT) can be used to identify different left ventricular geometric patterns. 7 These left ventricular geometric patterns confer useful prognostic information (with the worst prognosis associated with concentric hypertrophy) and can be used for risk stratification of hypertensive patients Moreover several studies have shown that risk stratification by abnormal left ventricular geometry is a stronger independent predictor of cardiovascular risk than blood pressure or other conventional cardiovascular risk factors. 9,11 The objective of this study was to assess the influence of various published partition values for LVM in the diagnosis of LVH and LV geometry in a native Caribbean hypertensive population. METHODS The study was carried out at the Cardiology Clinic of the Heart Institute of the Caribbean, Kingston, Jamaica. It was a cross-sectional study, which was conducted over a period of 24 months. Clinical data was collected at the time of patient visit and retrieved from our electronic medical records platform. Of the 525 hypertensive patients recruited for the study, 501 participants had adequate data for analysis. Subjects with diabetes mellitus, ischemic heart disease, valvular heart disease, congestive heart failure, sickle cell disease and renal failure were excluded from the study. Patients who have undergone coronary artery bypass surgery were also excluded. Both treated and untreated hypertensive subjects were recruited. All subjects gave informed consent before they were enrolled into the study. The study was approved by the institutional review board of the Heart Institute of the Caribbean. Clinical Evaluation Baseline clinical and demographic characteristics were obtained from all the subjects as shown in Table 1. Blood pressure (BP) was measured in the outpatient clinic by a research nurse using standard protocol (1st and 5th phases of Koroktoff sounds taken as SBP and DBP, respectively). Measurements were performed after 5 10 min of quiet rest in the sitting position using a mercury sphygmomanometer. Three measurements were taken at 3 min intervals, and the average used to define clinic systolic and diastolic BP. Blood pressure 140/90 was taken as hypertension using joint national committee (JNC-VII) guidelines. 15 Height was measured to the nearest centimetre using anthropometrical plane with subjects not putting on shoes or headgear. Each subject was asked to remove his or her shoes and stand with his/her back to the rule. The back of head, back, buttocks, calves and heels touched the upright. The head was positioned so that the top of the external auditory meatus was level with the inferior margin of the bony orbit. Subjects were weighed without shoes and in light clothing on a standard beam balance. Body mass index (BMI) was calculated using the formula: BMI = Weight in (kg) / (height in m 2 ). Body surface area (BSA) was calculated using the formula of Dubois. 16 Echocardiography M-mode, two-dimensional and Doppler echocardiographic examinations were performed with subjects in the partial left lateral position, using a commercially available instrument (Vivid 3 & Vivid 7) equipped with a 2-5 MHz imaging transducer. Two dimensional guided M-mode measurements were made according to the recommendations of the American Society of Echocardiography (ASE) 17 as represented in Table 2. LV internal dimension (LVID), posterior wall thickness (PWT) and interventricular septal thickness (IVST) were measured at end-diastole and end-systole. Left atrial end systolic diameter was obtained from the trailing edge of the posterior aortic-anterior left atrial complex. Measurements were obtained in up to 3 cardiac cycles according to the ASE convention.17 Left ventricular mass was calculated using the formula derived from Devereux et al 18 validated in necropsy studies. The relative wall thickness (RWT) was obtained using the standardised formula: RWT = (2 PWT)/LVIDd. Increased RWT was considered to be present when RWT exceeded This represents the 97.5th percentile in normal subjects. 19 LVH was assessed using the various published partition values as represented below. Partition values for LVM indexed for height were: 126 g/m for men and 105 g/m for women g/m for men and 102 g/m for women 21 Partition values for LVM indexed for height raised to the allometric growth rate of g/m2 in men and 58.0 g/m 2 in women 22 Partition values for LVM indexed for height raised to the allometric growth rate of g/m 2.13 for men and 61 g /m 2.13 for women 23 Partition values for LVM indexed for height raised to the allometric growth rate of g/m 2.7 for both men and women g/m 2.7 for men and 46.7 g/m2.7 for women 20 Partition values for LVM indexed for body surface area (BSA) 125 g/m 2 for both men and women g/m 2 for men and 104 g/m2 for women g/m 2 for men and 110 g/m2 for women g/m 2 for men and 100 g/m2 for women 27 EUROPEAN JOURNAL OF CARDIOVASCULAR MEDICINE VOL II ISSUE I 71

3 HEALTHCARE BULLETIN HYPERTENSION Four different mutually exclusive left ventricular geometric patterns were calculated according to criteria described by Ganau et al. 28 Normal geometry, when LVMI and RWT were normal (<0.45); concentric remodelling, when LVMI was normal and RWT increased (>0.45); eccentric hypertrophy, when LVMI was increased but normal RWT (<0.45); and concentric hypertrophy, when both LVMI and RWT (>0.45) were increased. STATISTICAL ANALYSIS Statistical analysis was performed using SPSS software version The median were calculated for the continuous variables while the categorical variables were expressed as percentages. Median test was performed as a result of the fact that the continuous variables were not normally distributed. The Chi-Square test of proportions was applied to the categorical variables. A 2-tailed p-value of 0.05 was assumed statistically significant. RESULTS The clinical characteristics of our study subjects are as shown in Table 1. A total of 525 hypertensive subjects who met the inclusion criteria were recruited for the study. 24 subjects were dropped from the final analysis because of inadequate echocardiograhic images or incomplete data. 501 subjects were included in the final analysis (95.4%); of these 501 subjects, 203 were men and 298 were women constituting 40.5% and 59.4%, respectively. The median ages for men and women were similar (63 vs 62, p-value, ). The men were taller (171 cm vs 160 cm, p-value, ) and have a greater body surface area (1.94 vs 1.83, p-value, ) than the women. Men weighed more than women (80.5 kg vs 75 kg, p- value, ). The median systolic blood pressure (154 mmhg vs mmhg, p-value, ), median diastolic blood pressure (90 mmhg vs 90 mmhg, p-value, ) and median pulse pressure (67 mmhg vs 70 mmhg, p-value, ) were similar in both sexes. Echocardiographic Measurements Echocardiographic measurements are presented according to the sex in Table 2. The dimensions of the aorta, left ventricle in diastole and systole, left ventricular mass and left ventricular mass index were significantly higher in men than women. The dimensions of the left atrium, PW thickness, IVS thickness although higher in males, the difference did not achieve statistical significance. LV systolic function, relative wall thickness and fractional shortening were similar in both sexes. Statistically significant differences were noted in absolute LV mass and when corrected for body surface area, height, height raised 2.0, 2.13, between males and females. Distribution of left ventricular hypertrophy and abnormal geometric patterns were presented in Table 3. Depending on the method of LVM indexation and the criteria selected, left ventricular hypertrophy was present in % of the patients. The lowest prevalence was found when LVM was indexed to BSA and a partition value of 125 g/m 2 was used for both sexes. Table 1: Baseline clinical and demographic characteristics. Median Parameters Total N=501 Male N=203 Female N=298 p-value Median Test Age(yrs) Weight (Kg) Height (cm) BMI(kg/m 2 ) BSA(m 2 ) Heart rate(beats/min) SBP(mm of Hg) DBP(mm of Hg) PP(mm of Hg) MAP (mm of Hg) BMI = body mass index, BSA = body surface area, SBP = systolic blood pressure, DBP = diastolic blood pressure, PP = pulse pressure, MAP = mean arterial pressure 72 EUROPEAN JOURNAL OF CARDIOVASCULAR MEDICINE VOL II ISSUE I

4 ECHOCARDIOGRAPHIC PARTITION VALUES AND PREVALENCE OF LEFT VENTRICULAR HYPERTROPHY IN HYPERTENSIVE JAMAICANS Table 2: Echocardiographic measurements. Median Parameters Total N=501 Male N=203 Female N=298 p-value Median Test LAD Aorta IVSTd PWTd LVIDd LVIDs RWT EF FS LVM LVM/BSA LVM/Ht LVM/Ht LVM/Ht LVM/Ht LAD = left atrial diameter, IVSTd = interventricular septal thickness in diastole, PWTd = posterior wall thickness in diastole, LVIDd & LVIDs = left ventricular internal diameter in diastole and systole respectively, RWT = relative wall thickness, EF = ejection fraction, FS = fractional shortening The highest prevalence of LVH was found when the LVM was indexed to height with a partition value of 126 g/ht in men and 105 g/ ht in women and height raised to the power of 2.7 with a partition value of 49.2 g/ht 2.7 in men and 46.7 g/ht 2.7 in women. Abnormal LV geometry ranged between %. Concentric remodelling was the most common type of abnormal geometry ( %) while the eccentric hypertrophy was the least common type of abnormal geometry ( %) found for all indexation methods and partition values. Concentric hypertrophy ( %) was the second most common type of abnormal geometry found in our patients. Table 4 represents the distribution of the LV geometric patterns according to the gender. All abnormal geometric patterns were in general higher in women compared with men except for one PV (LVM/BSA PV 125/125) for eccentric hypertrophy, which is more common in men. Statistically significant differences between males and females for abnormal geometry were noted only for some partition values as shown below (LVM/Ht PV of 143/102, LVM/Ht 2.0 PV of 77.5/58 and LVM/BSA PV of 131/110). Although the females have more prevalence of abnormal geometry than men for the remaining partition values (LVM/Ht PV 126/105, LVM/Ht 2.13 PV68/61, LVM/ Ht 2.7 PVs 51/51, 49.2/46.7, LVM/BSA PVs 116/104, 125/125, 125/110, the difference didn t achieve statistical significance. EUROPEAN JOURNAL OF CARDIOVASCULAR MEDICINE VOL II ISSUE I 73

5 HEALTHCARE BULLETIN HYPERTENSION Table 3: LV geometric patterns according to partition value. Partition value- LVH Normal Geometry (a) Concentric Remodeling(b) Eccentric Hypertrophy (c) Concentric Hypertrophy(d) Abnormal Geometry (b+c+d) LVM/HT-143/ (35.7%) 117(23.3%) 205(40.9%) 46(10.3%) 133(26.5%) 384(76.6%) LVM/HT-126/ (38.5%) 111(22.1%) 197(39.3%) 52(9.2%) 141(28.1%) 390(77.8%) LVM/HT /58 131(26.1%) 133(26.5%) 237(47.3%) 30(6.0%) 101(20.1%) 368(73.4%) LVM/HT /61 120(23.9%) 137(27.3%) 244(48.7%) 26(5.2%) 94(18.7%) 364(72.6%) LVM/HT / (38.5%) 115(22.9%) 193(38.5%) 48(9.6%) 145(28.9%) 386(77.04%) LVM/HT /51 167(33.3%) 119(23.7%) 215(42.9%) 44(8.8%) 123(24.5%) 382(76.2%) LVM/BSA-116/ (28.9%) 127(25.3%) 229(45.7%) 36(7.2%) 109(21.7%) 374(74.6%) LVM/BSA-125/125 97(19.3%) 143(28.5%) 261(52.1%) 20(4.0%) 77(15.3%) 358(71.4%) LVM/BSA-125/ (23.5%) 138(27.5%) 245(48.9%) 25(5.0%) 93(18.5%) 363(72.4%) LVM/BSA-131/ (27.2%) 129(25.7%) 235(46.9%) 34(6.8%) 103(20.5%) 372(74.2%) LVH = left ventricular hypertrophy, LVM = left ventricular mass, BSA = body surface area Table 4: Distribution of LV mass according to the gender. Partition value- LVH Normal Geometry Concentric Remodelling Concentric Hypertrophy Eccentric Hypertrophy p-value LVM/HT-143/102 50/129 54/63 99/106 39/94 11/35 < LVM/HT-126/105 71/122 46/65 86/111 52/89 19/33 NS LVM/HT /58 39/92 57/76 107/130 31/70 8/22 <0.001 LVM/HT /61 47/73 54/83 102/142 36/59 11/15 NS LVM/HT / /117 44/71 83/110 55/90 21/27 NS LVM/HT /51 67/100 46/73 90/125 48/75 19/25 NS LVM/BSA-116/104 56/89 49/78 98/131 40/69 16/20 NS LVM/BSA-125/125 43/54 54/89 106/155 32/45 11/9 NS LVM/BSA-125/110 43/75 54/84 106/139 32/61 11/14 NS LVM/BSA-131/110 37/100 55/74 111/124 27/76 10/24 < LVM = left ventricular mass, LV = left ventricular, BSA = body surface area, Ht = height, = male/female, NS = non significant 74 EUROPEAN JOURNAL OF CARDIOVASCULAR MEDICINE VOL II ISSUE I

6 ECHOCARDIOGRAPHIC PARTITION VALUES AND PREVALENCE OF LEFT VENTRICULAR HYPERTROPHY IN HYPERTENSIVE JAMAICANS DISCUSSION Left ventricular hypertrophy (LVH) detected by either electrocardiography or echocardiography has been shown to be an extremely strong predictor of morbidity and mortality in patients with essential hypertension and in members of the general population. 29, 30 Alternative to left ventricular hypertrophy, left ventricular geometrical patterns offer incremental prognostic value beyond that provided by the other cardiovascular risk factors including left ventricular mass. Based on echocardiographically derived left ventricular mass and relative wall thickness (RWT), left ventricular geometry can be classified into four mutually exclusive groups (concentric hypertrophy, eccentric hypertrophy, concentric remodelling and normal geometry). Several studies have shown the association of incremental risk with abnormal geometric patterns, with the highest risk associated with concentric hypertrophy (increased LVM & RWT), followed by eccentric hypertrophy (increase in LVM & normal RWT) and concentric remodelling (normal LVM & increase in RWT). 28,31-33 Adaptive response to hypertension may differ across ethnic groups and geographic locations and the impact of these ethnic and geographic differences on the prognostic significance of different geometric patterns has been very well established in patients with hypertension. 34,35 Several factors have been shown repeatedly in epidemiological studies to be associated with LVH and geometrical patterns. Factors such as age 36, gender and body size can adversely impact the echocardiographically derived LVM. Several indexation methods such as body weight, BSA, BSA rose to the power of 1.5, height and height raised to allometric growth exponents (2.0, 2.13, and 2.7) have been employed to reduce the impact of body size on left ventricular mass. Adjustment of LVM for BSA has been the most commonly used indexation method shown to reduce the variability due to body size and gender, but it underestimates the prevalence of LVH in patients with obesity. Height-based corrections have shown more an appropriate assessment of LVH in patients with obesity than BSA. Height-based indexation methods do not adjust for obesity and allow the evaluation of independent role of obesity in LVH. Numerous partition values have been proposed, most of which have been defined in normal population. The impact of these partition values on the estimated prevalence of LVH has been very well established. Our study is the first to look at the impact of various published cut-off values for LVM on the prevalence of LVH and abnormal LV geometry in Caribbean hypertensive patients. The prevalence of LVH in our study ranged between %. The highest prevalence of LVH was found when the LVM was indexed to the height with a partition value of 126 g/ht in men and 105 g/ht in women and height raised to the power of 2.7 with a partition value of 49.2 g/ht 2.7 in men and 46.7 g/ht 2.7 in women. The lowest prevalence was observed when LVM was indexed to BSA and a partition value of 125 g/m 2 was used for both sexes. Abnormal LV geometry was present in ( %) of our subjects. Concentric remodelling was the commonest abnormal geometry in our hypertensive population ( %) while concentric LVH was present in % of the subjects representing the second most common type. Eccentric hypertrophy ( %) was the least common type of abnormal geometry. Normal geometry was seen in %. Abnormal geometry was more common in women for all the partition values except for when indexed to BSA with PV 125 for both men and women. Findings in our study differ significantly from other studies in many respects. The prevalence of hypertrophy in our hypertensive population is low compared to the prevalence in several other studies33, and concentric remodelling was the most common type of abnormal geometry as opposed to eccentric hypertrophy in other studies. We presume this might be due to the effect of factors such as ethnicity and environment on the left ventricular mass. Although concentric remodelling was the most common type of abnormal geometry found, a significant proportion of the patients have concentric hypertrophy, increasing the risk for future adverse cardiovascular events. Adebiyi et al 40 have compared the impact of eight partition values on the prevalence of LVH in native African hypertensive population (Nigerians). According to their study, % of the subjects had LVH and % of the subjects had abnormal LV geometry. Highest prevalence of LVH was diagnosed when LVM was indexed to height to the power of 2.7 with a partition value of 49.2 g/ht 2.7 in men and 46.7 g/ht 2.7 in women. Lowest prevalence was observed when LVM was indexed to BSA and a partition value of 125 g/m 2 was used for both sexes. Eccentric hypertrophy was the commonest abnormal geometry found in their hypertensive population. Cuspidi et al 41 used six different echocardiographic criteria to define the LVH in their study population involving 611 hypertensive subjects. They found LVH in % of the subjects. Eccentric hypertrophy was the most common abnormal LV geometry by any criteria used and more frequent in women than in men. LVM was positively correlated with BSA, height and height raised to allometric growth exponent 2.7 and the prevalence of LVH varied depending on the partition value used. Wachtell et al 42 studied 941 patients with stage I to III hypertension and LVH by electrocardiogram enrolled in the Losartan Intervention For Endpoint reduction (LIFE) in Hypertension Study. The prevalence of LVH, according to eight different partition values, ranged from 42-77%. Abnormal LV geometry was present in 63-86% of the subjects and 15-40% of the subjects had normal geometry. Eccentric hypertrophy was the most common abnormal geometry found by any indexation method and partition value. In a study of left ventricular geometric adaptation to hypertension in 165 untreated hypertensive patients, Ganau et al28 reported normal geometry in 52% of their subjects with 13% showing concentric remodelling and 27% with eccentric hypertrophy. Only 8% had the typical hypertensive left ventricular hypertrophy. Gosse et al 43 studied 363 untreated hypertensive patients using three partition values and showed that indexation of LVM to height 2.7 gave rise to a more sensitive definition of LVH by compensating for the influence of growth. The authors concluded that a cut-off value of 53 g/m 2.7 in men and 47 g/m 2.7 in women corresponded to a cardiovascular risk linked to daytime systolic BP 135 mmhg. Prognostic implications of different normalisation methods for LVM were published recently in the Strong Heart Study 10 and Mavi study 9. The Strong Heart Study 10 - conducted in an American Indian population with high prevalence of obesity (56%) and hypertension - showed a higher prevalence of LVH for LVM/m 2.7 compared to other methods of indexation. Indexation of LVM for height was also associated with higher proportion of incident cardiovascular events compared to LVM raised to the body surface area and thus can be used for the identification of high-risk individuals especially in populations with high prevalence of obesity. Allometric power methods have been found to be superior in detecting the prognostically adverse obesity-related LVH which is unidentified using body surface area. EUROPEAN JOURNAL OF CARDIOVASCULAR MEDICINE VOL II ISSUE I 75

7 HEALTHCARE BULLETIN HYPERTENSION The data from the Strong Heart Study suggest that intervention to normalise LVM indexed for height raised to allometric powers could reduce the incidence of cardiovascular events significantly more than targeting the regression of LVH based on LVM/BSA criteria. The Mavi study 9 was conducted in a large clinical population of hypertensive subjects with low prevalence of obesity (22%). In that study, the prevalence of LVH ranged between 28-56% with slightly higher values for height-based normalisation. No meaningful advantage was obtained for any one method of LVM normalisation in terms of identifiable risk attributable to LVH. The population risk attributable to LVH was not significantly different (47% and 56%) among different methods of normalisation of LVM. CONCLUSIONS Echocardiographic LVH is present in % of hypertensive Caribbean population. Abnormal LV geometry was found in % of the subjects studied. Concentric remodelling was the most common type of abnormal LV geometry in our patient population. Prevalence of LVH and abnormal geometry varied depending upon the type of indexation methods and partition values used. Heightbased corrections (LVM/Ht PV 126/105 & LVM/Ht 2.7 PV 49.7/49.2) yielded highest prevalence of LVH in our population and can be used as a reference standard until further validation of our findings would require large scale prospective studies targeting the Caribbean population. These large-scale prospective studies should aim to determine the prognostic implications of the different types of abnormal LV geometry and to define the most reliable method of indexation for the Caribbean population. REFERENCES 1 2 WHO Global Report: Preventing chronic diseases: A vital investment. World Health Organization; Geneva: Whelton PK. Epidemiology of hypertension. 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