In 2009, Wald DS et al. conducted a meta-analysis of 42 RCTs targeting hypertension treatment, with a total of 10,968 patients enrolled in the trial. The results showed that the combination of any two of the four antihypertensive drugs, including diuretics, b-blockers, ACEIs, and calcium antagonists, had a synergistic hypotensive effect, and the synergistic hypotensive effect was five times greater than the effect of doubling the dose of one drug alone. Recently, the OSCAR study from Japan provided more meaningful information on the treatment of elderly patients with CKD combined with hypertension. This study was a multicenter randomized open blinded endpoint clinical study that selected patients with CKD aged 65-84 years who were all taking olmesartan 20 mg/day monotherapy at enrollment, and randomized patients into two groups if they did not meet blood pressure targets (<140/90 mmHg) and tolerated treatment well: 1. Double-dose olmesartan group (40 mg /day, high-dose ARB monotherapy group) 2. ARB combined with CCB group [in addition to olmesartan 20 mg/day, a CCB (amlodipine or azelnidipine) is added]. If blood pressure is still not up to standard, diuretics, b-blockers and other antihypertensive drugs can be added. The follow-up period was 3 years. The primary endpoint was the time to first event, and secondary endpoints included the incidence of each cardiovascular event, change in blood pressure during follow-up, and serious adverse events beyond the primary endpoint event. Patients were analyzed in subgroups for the presence of CKD (eGFR <60 ml/min/1.73 m2). Of the 1164 patients initially enrolled, 1078 patients ultimately completed the study, 353 of whom had CKD. subgroup analysis of older patients with CKD hypertension showed significantly lower systolic blood pressure in the combination therapy group than in the high-dose ARB monotherapy group (mean systolic blood pressure difference 3.7 mmHg, p=0.0051); the rate of the primary endpoint event in the high-dose ARB monotherapy group was 16.6% (63.0 events per 1000 patient-years) was significantly higher than the 9.3% (33.9 events per 1000 patient-years) in the combination group (HR 2.25, 95% confidence interval 1.20-4.20, p=0.0096); the secondary endpoint of cerebrovascular disease in the combination group (HR 3.45, 95% confidence interval 1.20-9.92 The incidence of cerebrovascular disease (HR 3.45, 95% confidence interval 1.20-9.92, p=0.0151) and heart failure (HR 9.27, 95% confidence interval 1.11-77.29, p=0.01486) were significantly lower in the combination group than in the high-dose ARB monotherapy group; there was no significant difference in the change of renal function between the two groups during the follow-up period. The efficacy of the combination of ARB and CCB was better than that of the high-dose ARB monotherapy group.