Rahman, Mahboob

Key Points Identifying ways to prevent AKI may reduce mortality further in the setting of intensive BP control. Creatinine-based ascertainment of AKI, enabled by electronic health record data, may be more sensitive and less biased than traditional serious adverse event adjudication. Background Adjudication of inpatient AKI in the Systolic Blood Pressure Intervention Trial (SPRINT) was based on billing codes and admission and discharge notes. The purpose of this study was to evaluate the effect of intensive versus standard BP control on creatinine-based inpatient and outpatient AKI, and whether AKI was associated with cardiovascular disease (CVD) and mortality. Methods We linked electronic health record (EHR) data from 47 clinic sites with trial data to enable creatinine-based adjudication of AKI. Cox regression was used to evaluate the effect of intensive BP control on the incidence of AKI, and the relationship between incident AKI and CVD and all-cause mortality. Results A total of 3644 participants had linked EHR data. A greater number of inpatient AKI events were identified using EHR data (187 on intensive versus 155 on standard treatment) as compared with serious adverse event (SAE) adjudication in the trial (95 on intensive versus 61 on standard treatment). Intensive treatment increased risk for SPRINT-adjudicated inpatient AKI (HR, 1.51; 95% CI, 1.09 to 2.08) and for creatinine-based outpatient AKI (HR, 1.40; 95% CI, 1.15 to 1.70), but not for creatinine-based inpatient AKI (HR, 1.20; 95% CI, 0.97 to 1.48). Irrespective of the definition (SAE or creatinine based), AKI was associated with increased risk for all-cause mortality, but only creatinine-based inpatient AKI was associated with increased risk for CVD. Conclusions Creatinine-based ascertainment of AKI, enabled by EHR data, may be more sensitive and less biased than traditional SAE adjudication. Identifying ways to prevent AKI may reduce mortality further in the setting of intensive BP control.

Background Blood pressure ( BP ) varies over time within individual patients and across different BP measurement techniques. The effect of different BP targets on concordance between BP measurements is unknown. The goals of this analysis are to evaluate concordance between (1) clinic and ambulatory BP , (2) clinic visit‐to‐visit variability and ambulatory BP variability, and (3) first and second ambulatory BP and to evaluate whether different clinic targets affect these relationships. Methods and Results The SPRINT (Systolic Blood Pressure Intervention Trial) ambulatory BP monitoring ancillary study obtained ambulatory BP readings in 897 participants at the 27‐month follow‐up visit and obtained a second reading in 203 participants 293±84 days afterward. There was considerable lack of agreement between clinic and daytime ambulatory systolic BP with wide limits of agreement in Bland‐Altman plots of −21 to 34 mm Hg in the intensive‐treatment group and −26 to 32 mm Hg in the standard‐treatment group. Overall, there was poor agreement between clinic visit‐to‐visit variability and ambulatory BP variability with correlation coefficients for systolic and diastolic BP all <0.16. We observed a high correlation between first and second ambulatory BP ; however, the limits of agreement were wide in both the intensive group (−27 to 21 mm Hg) and the standard group (−23 to 20 mm Hg). Conclusions We found low concordance in BP and BP variability between clinic and ambulatory BP and second ambulatory BP . Results did not differ by treatment arm. These results reinforce the need for multiple BP measurements before clinical decision making.

Blood pressure (BP) varies over time within individual patients and across different BP measurement techniques. The effect of different BP targets on the concordance between BP measurements is unknown. The goal of this analysis was to evaluate concordance in: 1) clinic BP and ambulatory BP, 2) clinic visit-to-visit variability and ambulatory BP variability and 3) initial and repeat ambulatory BP. We also sought to evaluate whether treatment assignment of intensive vs standard BP target affected these relationships. The Systolic Blood Pressure Intervention Trial (SPRINT) ambulatory blood pressure monitoring ancillary study obtained ambulatory BP readings in 897 SPRINT participants at the 27 month follow up visit and 203 consecutive repeat ambulatory BP readings taken an average of 9.8 months later. There was poor agreement between clinic systolic BP and daytime ambulatory systolic BP (limits of agreement in Bland-Altman plots of -21 to 34 mm Hg in the intensive treatment group and -26 to 32 mm Hg in the standard treatment group). There was poor agreement between clinic visit-to-visit variability (coefficient of variation) and ambulatory BP variability (coefficient of variation of a 24 hr ambulatory BP) with correlation coefficients for systolic BP <0.16. While there was a high correlation between ambulatory BP at 27 months and repeat ambulatory BP (r ~0.56), there was significant variability between repeat ambulatory BP assessments (limits of agreement of -27 to 21 mm Hg in the intensive group and -23 to 20 mm Hg in the standard group). In conclusion, irrespective of treatment target, we found low concordance in BP and BP variability between clinic BP and ambulatory BP, and additionally between repeat ambulatory BP assessments. These results reinforce the need for multiple guideline adherent BP measurements prior to clinical decision making.

Background: In individuals with a low diastolic blood pressure (DBP), the potential benefits or risks of intensive systolic blood pressure (SBP) lowering are unclear. Methods: SPRINT (Systolic Blood Pressure Intervention Trial) was a randomized controlled trial that compared the effects of intensive (target <120 mm Hg) and standard (target <140 mm Hg) SBP control in 9361 older adults with high blood pressure at increased risk of cardiovascular disease. The primary outcome was a composite of cardiovascular disease events. All-cause death and incident chronic kidney disease were secondary outcomes. This post hoc analysis examined whether the effects of the SBP intervention differed by baseline DBP. Results: Mean baseline SBP and DBP were 139.7±15.6 and 78.1±11.9 mm Hg, respectively. Regardless of the randomized treatment, baseline DBP had a U-shaped association with the hazard of the primary cardiovascular disease outcome. However, the effects of the intensive SBP intervention on the primary outcome were not influenced by baseline DBP level ( P for interaction=0.83). The primary outcome hazard ratio for intensive versus standard treatment was 0.78 (95% confidence interval, 0.57–1.07) in the lowest DBP quintile (mean baseline DBP, 61±5 mm Hg) and 0.74 (95% confidence interval, 0.61–0.90) in the upper 4 DBP quintiles (mean baseline DBP, 82±9 mm Hg), with an interaction P value of 0.78. Results were similar for all-cause death and kidney events. Conclusions: Low baseline DBP was associated with increased risk of cardiovascular disease events, but there was no evidence that the benefit of the intensive SBP lowering differed by baseline DBP. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01206062.

The appropriate target for BP in patients with CKD and hypertension remains uncertain. We report prespecified subgroup analyses of outcomes in participants with baseline CKD in the Systolic Blood Pressure Intervention Trial. We randomly assigned participants to a systolic BP target of <120 mm Hg (intensive group; n =1330) or <140 mm Hg (standard group; n =1316). After a median follow-up of 3.3 years, the primary composite cardiovascular outcome occurred in 112 intensive group and 131 standard group CKD participants (hazard ratio [HR], 0.81; 95% confidence interval [95% CI], 0.63 to 1.05). The intensive group also had a lower rate of all-cause death (HR, 0.72; 95% CI, 0.53 to 0.99). Treatment effects did not differ between participants with and without CKD ( P values for interactions ≥0.30). The prespecified main kidney outcome, defined as the composite of ≥50% decrease in eGFR from baseline or ESRD, occurred in 15 intensive group and 16 standard group participants (HR, 0.90; 95% CI, 0.44 to 1.83). After the initial 6 months, the intensive group had a slightly higher rate of change in eGFR (−0.47 versus −0.32 ml/min per 1.73 m 2 per year; P <0.03). The overall rate of serious adverse events did not differ between treatment groups, although some specific adverse events occurred more often in the intensive group. Thus, among patients with CKD and hypertension without diabetes, targeting an SBP<120 mm Hg compared with <140 mm Hg reduced rates of major cardiovascular events and all-cause death without evidence of effect modifications by CKD or deleterious effect on the main kidney outcome.