Prevalence, Risk Factors and Cardiovascular Comorbidities of Resistant Hypertension among Treated Hypertensives in a Nigerian Population.

ABSTRACT

The true prevalence and cardiovascular comorbidities of resistant hypertension (RH) in Nigeria and Africa are not known. We sought to determine the prevalence and cardiovascular comorbidities of resistant hypertension in a treated Nigerian hypertensive population. We analyzed 1,378 patients with essential hypertension from a prospective clinical registry, the Federal Medical Centre Abuja Hypertension Registry. Resistant hypertension was defined as blood pressure ≥140/90 mmHg despite the use of ≥3 guideline-recommended antihypertensive medications including a diuretic, reninangiotensin system blocker and calcium-channel blocker at optimal or best-tolerated doses or blood pressure <140/90 mmHg on ≥4 antihypertensive medications. Resistant hypertension was confirmed with the use of home blood pressure monitoring while adherence was determined by monitoring prescription orders. The prevalence of resistant hypertension was 15.5%, with 12.3% as controlled resistant hypertension and 3.3% as uncontrolled resistant hypertension. Risk factors independently associated with the odds of resistant hypertension were male sex (adjusted odds ratio [AOR] 1.62, 95% confidence interval [CI] 1.19-2.21, p = 0.002), obesity, and diabetes mellitus. Furthermore, patients with resistant hypertension were more likely to have heart failure with preserved ejection fraction (AOR 3.36, 95% CI 1.25-9.07, p = 0.017), cerebrovascular disease, and chronic kidney disease. In our treated hypertensive cohort, resistant hypertension was associated with an increased risk of cerebrovascular disease, chronic kidney disease, and heart failure with preserved ejection fraction, and it appears this burden maybe 2-3 times more in those with resistant hypertension compared to those without. Concerted efforts to prevent or promptly treat resistant hypertension in our population will reduce cardiovascular comorbidities.