Impact of patient compliance on the outcomes in hypertensive patients receiving hydrochlorothiazide based combination therapy with spironolactone or captopril

OBJECTIVE: To explore the impact of patient compliance on the long-term outcomes in hypertensive patients receiving hydrochlorothiazide (HCTZ) based combination therapy with spironolactone or captopril. METHODS: A total of 853 patients with mild to moderate hypertension were recruited and randomly divided into HCTZ group (HCTZ 12.5 mg q.d), spironolactone group (HCTZ 12.5 mg q.d and spironolactone 20 mg q.d), and captopril group (HCTZ 12.5 mg q.d and captopril 25 mg bid) after 2-week placebo washout period and 6-week loading period for HCTZ. Since the efficacy of combination therapy was proven to be better than monotherapy 1 year after therapy beginning, patients in HCTZ group were randomly assigned to spironolactone group or captopril group. The patients were followed up for 4 years. Patients were divided to compliance (n = 424) or non-compliance group (n = 429) according test drug taking questionnaire. During the follow-up time, the blood pressure and the outcomes were recorded monthly, and blood biochemical parameters were determined once a year. RESULTS: At the end of follow up, incidence of cardio-cerebral vascular events was significantly lower in compliance group (2 fatal, 8 non-fatal) than that in noncompliance group (7 fatal, 21 non-fatal, P 0.05 vs. baseline]. The serum BUN, Cr and UA levels in the compliance group were significantly higher and the serum K(+), CHO, LDL-C level were significantly lower than baseline values. The serum BUN, UA levels in the compliance group were significantly higher while the serum K(+), cholesterol levels were significantly lower than those in the noncompliance group (all P < 0.05). CONCLUSIONS: This study indicates that patient compliance could affect the long-term outcome and antihypertensive efficacy in hypertensive patients receiving HCTZ based combination therapy with spironolactone or captopril.