Resistant hypertension: demography and clinical characteristics in 6,292 patients in a primary health care setting.

INTRODUCTION AND OBJECTIVES

The prevalence of resistant hypertension has recently been reported, but there are no studies on its demography. This study aimed to examine the demography and clinical characteristics of resistant hypertension in a large sample of primary care patients.

METHODS

A cross-sectional study was performed of all computerized medical records of hypertensive patients in Health Area 6 of Madrid (Spain). Of 63 167 hypertensive patients, we selected 48 744 with prescription of antihypertensive medication; of these, we selected those who met the American Heart Association criteria for resistant hypertension.

RESULTS

A total of 6292 patients had resistant hypertension, representing 9.9% of all hypertensive patients and 12.9% of those treated. A total of 5.5% were < 50 years (8.5% men and 3.2% women) and 24.7% were > 80 years (15.8% men and 31.4% women) (P < .001). In patients < 50 years, resistant hypertension was associated with male sex (odds ratio female/male = 0.006; 95% confidence interval, 0.000-0.042; P < .001), systolic blood pressure, obesity, stroke, and chronic kidney disease (P < .001). In those > 80 years, resistant hypertension was associated with female sex (odds ratio female/male = 1.27; 95% confidence interval, 1.08-1,10; P = .004), systolic blood pressure, diabetes mellitus, obesity, chronic kidney disease, coronary heart disease, and atrial fibrillation (P < .001). More than 50% of patients > 80 years with resistant hypertension had cardiovascular disease.

CONCLUSIONS

One in 4 patients with resistant hypertension is > 80 years. Resistant hypertension is associated with cardiovascular disease, age < 50 years in men and age > 80 years in women. There is a high proportion of cardiovascular disease in elderly patients with resistant hypertension.