BP variability linked to atheroma progression

A study of nearly 4,000 patients with coronary artery disease (CAD) has linked blood pressure variability (BPV) between clinic visits to significantly greater progression of coronary atheroma and major adverse events, suggesting BP stability might be an important factor in CAD care.

BPV is an established predictor of cardiovascular events and has been associated with arterial stiffness and endothelial dysfunction in heart patients, first author Donald Clark III, MD, MPH, and colleagues said in JAMA Cardiology, but it’s unknown whether BP variability has any bearing on coronary atheroma progression or regression.

“Despite the established prognostic importance of BPV, little is known about underlying mechanisms or therapeutic implications of this phenomenon,” Clark, of the University of Mississippi Medical Center, and co-authors wrote.

Clark and his team undertook a post hoc analysis of seven randomized clinical trials conducted between 2004 and 2016, all involving CAD patients at international, clinic-based primary and tertiary care centers who underwent serial intravascular ultrasonography (IVUS) in the setting of a range of medical therapies. The authors said IVUS is particularly useful in CAD patients, since it yields precise and reproducible volumetric measurements of coronary atheroma, and serial IVUS allows for a closer look at the link between BPV and atheroma progression.

The researchers considered 3,912 patients—mostly male and a majority white—whose visit-to-visit BPV was measured using intraindividual standard deviation over 3, 6, 12, 18 and 24 months. They found continuous change in percent atheroma volume (PAV) was associated with systolic BPV, diastolic BPV and pulse pressure variability, without a signal for differential effect greater or less than a mean BP of 140/90 mmHg.

The authors reported that PAV progression as a binary outcome was strongly linked to systolic BPV, with an odds ratio of 1.09. The associations between PAV and both diastolic BPV and pulse pressure variability didn’t reach statistical significance.

“Our results confirm prior work outlining BPV to be a predictor of cardiovascular events and further extends these findings to indicate that BPV, in particular systolic BPV, manifests as a proatherosclerotic process,” Clark et al. wrote. “This analysis thus demonstrates an association linking BPV and cardiovascular events and suggests maintaining BP stability may be important to further improve cardiovascular outcomes in patients with coronary artery disease.”

The team said survival curves also revealed a stepwise association between cumulative major adverse cardiovascular events, including death, MI, stroke, urgent revascularization for ACS and hospitalization for unstable angina, and increasing quartiles of systolic BPV. Those stepwise associations, while distinct for systolic figures, weren’t seen with diastolic BPV or pulse pressure variability.

“These findings suggest greater blood pressure variability is associated with a proatherosclerotic process, and maintaining stable blood pressure levels may improve cardiovascular outcomes in patients with coronary artery disease,” Clark and colleagues said.