Systolic Pressure Intervention Trial (SPRINT) is a large scale randomized trial of ~ 9250 adults aged 50 years or older with high cardiovascular risk sponsored by NIH. The study is designed to recruit 45% of the study population with Chronic Kidney Disease (CKD). The trial will test the effects of low systolic blood pressure (SBP) goal of < 120 mm Hg versus the standard goal of < 140 mm Hg on the primary composite of cardiovascular events and death. One of the pre-specified secondary outcome is the progression of kidney disease. In this ancillary named SPRINT - Factors affecting Atherosclerosis STudy (FAST), the investigators plan to take advantage of the unique opportunities afforded by the parent study to examine issues that are of significant public health importance.

This is an observational study in SPRINT participants. This study will examine mechanistically, the factors affecting the progression of atherosclerosis in CKD.

Inclusion Criteria

• Systolic Pressure Intervention Trial (SPRINT) participants

Exclusion Criteria

• Contraindications to MRI (such as intracranial metal prostheses, weight > 300 pounds, claustrophobia and certain types of hardware used in pacemakers, prostheses, etc.)

Clinical characteristics of the SPRINT-FAST population will reflect those of the parent study. In this ancillary study, one non-CKD participant (control) will be recruited for each CKD participant (case). SPRINT CKD stratum will likely comprise of those with eGFR between 20-59 ml/min/1.73 m2.