Outcomes Research in the Global Environment

Risk-Factor Profile and Comorbidities in 2398 Patients With Newly Diagnosed Hypertension From the Abuja Heart Study

Risk factors, comorbidities, and end-organ damage in newly diagnosed hypertension (HT) are poorly described in larger cohorts of urban African patients undergoing epidemiological transition. We therefore decided to characterize a large cohort of hypertensive subjects presenting to a tertiary health center in sub-Saharan Africa. It is an observational cross-sectional study. We prospectively collected detailed clinical, biochemical, electrocardiography, and echocardiography data of all subjects with HT as the primary diagnosis in patients presenting at the Cardiology Unit of the University of Abuja Teaching Hospital over an 8-year period. Of 2398 subjects, 1187 patients (49.4%) were female with a mean age of 51 ± 12.8 years. Presenting symptoms and signs were most commonly palpitation in 691 (28.8%) followed by dyspnoea on exertion in 541 (22.6%), orthopnea in 532 (22.2%), pedal oedema in 468 (19.5%), paroxysmal nocturnal dyspnoea in 332 (13.8%), whereas only 31 (1.3%) presented with chest pain. Risk factors were obesity in 671 (28%); 523 (21.8%) had total cholesterol >5.2 mmol/L, diabetes mellitus was present in 201 (8.4%) and 187 (7.8%) were smokers. End-organ damage was present in form of echocardiographic left ventricular hypertrophy in 1336 (55.7%) followed by heart failure in 542 (22.6%). Arrhythmias occurred in 110 (4.6%) of cases, cerebrovascular accident in 103 (4.3%), chronic kidney disease in 26 (1.1%), hypertensive encephalopathy in 10 (0.4%), and coronary artery disease in 6 (0.26%). There were marked differences in sex as women were more obese and men presented with more advanced disease. The burden of HT and its complications in this carefully characterized African cohort is quite enormous with more than three-fourth having one form of complication. The need of effective primary and secondary preventive measures to be mapped out to tackle this problem cannot be overemphasized.

A predominance of hypertensive heart failure in the Abuja Heart Study cohort of urban Nigerians: a prospective clinical registry of 1515 de novo cases

AIMS

Even though cardiovascular disease is gradually becoming the major cause of morbidity and mortality in sub-Saharan Africa, there are very few data on the pattern of heart disease in this part of the world. We therefore decided to determine the pattern of heart disease in Abuja, which is one of the fastest growing and most westernized cities in Nigeria, and compare our findings with those of the Heart of Soweto Study in South Africa.

METHODS AND RESULTS

Detailed clinical data were consecutively captured from 1515 subjects of African descent, residing in Abuja, and equivalent Soweto data from 4626 subjects were available for comparison. In Abuja, male subjects were on average, ∼2 years older than female subjects. Hypertension was the primary diagnosis in 45.8% of the cohort, comprising more women than men [odds ratio (OR) 1.96, 95% confidence interval (CI) 1.26-2.65], and hypertensive heart failure (HF) was the most common form of HF in 61% of cases. On an age- and sex-adjusted basis, compared with the Soweto cohort, the Abuja cohort were more likely to present with a primary diagnosis of hypertension (adjusted OR 2.10, 95% CI 1.85-2.42) or hypertensive heart disease/failure (OR 2.48, 95% CI 2.18-2.83); P < 0.001 for both. They were, however, far less likely to present with CAD (OR 0.04, 95% CI 0.02-0.11) and right heart failure (2.5% vs. 27%).

CONCLUSION

As in Soweto, but more so, hypertension is the most common cause of de novo HF presentations in Abuja, Nigeria.