A006: Resistant hypertension in a tertiary care clinic: revisited

Resistant hypertension (RHTN) is probably the most common reason for referral to hypertension specialist clinics. Study Objective: To determine the prevalence and evaluate the etiologies of RHTN, as well as evaluate the impact of the HTN specialist to achieve goals set forth by JNC VI. Design: Review of clinic records of all patients seen for the first time between 1/1/93 and 3/31/98 using similar criteria and methods to our earlier study (Yakovlevitch & Black, 1991). Methods: Records of all patients who met inclusion criteria for RHTN (≥3 antihypertensive medications and a BP ≥ 140/90 mmHg) were evaluated. Demographic data, medical history, physical exam findings, and lab results were recorded. Specific attention was given to the HTN history including anti-hypertensive regimen prior to and after being seen at the clinic, side effects, compliance, and other factors that may be considered to be responsible for their RHTN. Results: Of the 568 charts reviewed, 65 (11%) met our study criteria for RHTN. As in our prior study, the most common cause was a suboptimal regimen (23 patients). Unexpected secondary hypertension accounted for 11%, similar to our previous study. Obesity (BMI ≥ 27) was a significant factor in this cohort and was found in 51 (78%) of patients. BP control, defined as BP ≤ 140/90 mmHg, on 2 consecutive visits, was achieved in 34 (52%) of patients. Another 11 (17%) had significant improvement in their blood pressure (≥15% decrease in DBP). The most common change made in the antihypertensive regimen involved switching to fixed-dose combinations. Most patients were already on diuretics, ACE inhibitors and/or calcium antagonists. Conclusions: A suboptimal medication regimen is the most common cause of RHTN. Hypertension specialists were successfully able to control or induce significant improvement in BP in approximately 70% of those referred to a specialist clinic. This supports the recommendations of JNC VI and BHS to refer to the HTN specialist.