The Impact of frailty on the effectiveness of intensive blood pressure control for patients with type 2 diabetes: a secondary analysis of a randomised controlled trial

Background Frailty is an independent risk factor for cardiovascular events. It is uncertain whether frailty modifies the efficacy of intensive blood pressure (BP) control among participants with type 2 diabetes mellitus(T2DM). Methods The Action to Control Cardiovascular Risk in Diabetes Blood Pressure (ACCORD BP) trial, a two-by-two factorial trial, examined the effects of systolic BP (<120 vs <140 mm Hg) and glycaemic control on cardiovascular events in T2DM. We constructed a frailty index using the Rockwood cumulative deficit approach. Cox proportional hazard models were used to estimate the effectiveness of intensive BP treatment according to frailty status. The primary composite outcome was non-fatal myocardial infarction, non-fatal stroke or death from cardiovascular causes. Results There were 4733 participants (mean age: 62.7 years; 39.9% frailty). The mean average number of antihypertensive medications was higher in frail patients compared with non-frail patients in both the standard (2.2 vs 1.7) and intensive (3.1 vs 2.7) treatment groups. In the standard glycaemic arm, intensive BP treatment reduced the risk of the primary outcome (HR 0.75, 95% CI 0.58 to 0.97) regardless of frailty status (p value for interaction=0.86). The benefits of intensive BP intervention were consistent across the spectrum of the frailty index (p value for interaction=0.96) in the standard glycaemic arm. However, no benefits of intensive BP treatment (HR 1.08, 95% CI 0.82 to 1.43) were observed in the intensive glycaemic arm. Conclusions In the ACCORD BP study, the benefit of intensive BP treatment was consistent regardless of frailty in the setting of standard glycaemic control. Frailty should not be a barrier to intensive BP control in patients with T2DM treated with guideline-recommended standard glycaemic control.