SPRINT: The Study Nephrologists Might Take With a Grain of Salt

A critical review of chronic kidney disease as a risk factor for coronary artery disease

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD). In addition to common CVD risk factors, the presence of CKD is independently associated with an elevated cardiovascular (CV) risk. We examined the association between CKD and CVD, focusing on coronary artery disease (CAD) in both primary and secondary CVD. A total of 94 articles were included for this review using search strategies on Pubmed and Google scholar. The main findings of our review included that besides sharing common risk factors, CKD induces several physiological microscopic changes leading to increased CV risk. These microscopic changes manifest macroscopically with evidence of the development of primary CAD in CKD patients, in addition to accelerating CAD in those with pre-established CV pathology, with CKD consequently being a risk factor for both primary and secondary CAD progression. Current CV guideline recommendations do not discriminate between those patients with and without CKD. Future research is needed in this area, examining if there may be a role for tighter modifiable risk factor targets in this high-risk population.

Impact of the SPRINT Trial on Hypertension Management

The Systolic Blood Pressure Intervention Trial is the first large prospective randomized controlled trial to demonstrate the benefit of an intensive systolic blood pressure (SBP) treatment target (<120 mm Hg) compared to a standard target (<140 mm Hg) in reducing cardiovascular morbidity and mortality and all-cause mortality in high-risk hypertensive patients. The impact of SPRINT on hypertension treatment has been large, but major questions remain about the feasibility of achieving the SPRINT intensive SBP target in routine practice, the generalizability of the SPRINT findings to hypertensive populations that were excluded from the trial, and the cost effectiveness of adopting the SPRINT intensive treatment goal. In this review, we discuss the generalizability of SPRINT data to the general population of adults with hypertension and with various comorbidities, the cost effectiveness of intensive SBP-lowering therapy, and the implications of SPRINT for future hypertension guideline development and clinical practice.

Physical Activity In Renal Disease (PAIRED) and the effect on hypertension: study protocol for a randomized controlled trial

BACKGROUND

The prevalence of hypertension among people with chronic kidney disease is high with over 60% of people not attaining recommended targets despite taking multiple medications. Given the health and economic implications of hypertension, additional strategies are needed. Exercise is an effective strategy for reducing blood pressure in the general population; however, it is not known whether exercise would have a comparable benefit in people with moderate to advanced chronic kidney disease and hypertension.

METHODS

This is a parallel-arm trial of adults with hypertension (systolic blood pressure greater than 130 mmHg) and an estimated glomerular filtration rate of 15-45 ml/min 1.73 m2. A total of 160 participants will be randomized, with stratification for estimated glomerular filtration rate, to a 24-week, aerobic-based exercise intervention or enhanced usual care. The primary outcome is the difference in 24-h ambulatory systolic blood pressure after 8 weeks of exercise training. Secondary outcomes at 8 and 24 weeks include: other measurements of blood pressure, aortic stiffness (pulse-wave velocity), change in the Defined Daily Dose of anti-hypertensive drugs, medication adherence, markers of cardiovascular risk, physical fitness (cardiopulmonary exercise testing), 7-day accelerometry, quality of life, and adverse events. The effect of exercise on renal function will be evaluated in an exploratory analysis. The intervention is a thrice-weekly, moderate-intensity aerobic exercise supplemented with isometric resistance exercise delivered in two phases. Phase 1: supervised, facility-based, weekly and home-based sessions (8 weeks). Phase 2: home-based sessions (16 weeks).

DISCUSSION

To our knowledge, this study is the first trial designed to provide a precise estimate of the effect of exercise on blood pressure in people with moderate to severe CKD and hypertension. The findings from this study should address a significant knowledge gap in hypertension management in CKD and inform the design of a larger study on the effect of exercise on CKD progression.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03551119 . Registered on 11 June 2018.