More than a matter of the heart: the concept of intravascular multimorbidity in cardiac rehabilitation.

INTRODUCTION: Coronary artery disease (CAD) is the major cause of death of cardiovascular disease. It is initiated by atherosclerosis, which narrows the coronary arteries and limits blood flow and oxygen to the heart. Multiple pathophysiological conditions within the arteries, such as arterial wall thickening, endothelial dysfunction, and arterial stiffening, are associated with the development of atherosclerosis.

AREAS COVERED: We introduce a new concept of 'intravascular multimorbidity,' the presence and integration of multiple pathophysiological conditions within the arteries. We also introduce some measurements of intravascular multimorbidity and discuss how these measurements can be utilized in cardiac rehabilitation (CR).

EXPERT OPINION: We propose that the measures of intravascular multimorbidity in different arteries may provide information on disease severity and serve as unique prognostic 'barometers' to disease progression in patients with CAD. By measuring the underlying disease mechanisms within the arteries and understanding individual variability of disease progression/regression, these measures may also provide a unique prognostic window in CR. The window into intravascular multimorbidity can help guide clinical strategies, for example, assessing progress and appropriate titration of exercise. Intravascular multimorbidity may represent an important opportunity for more researchers and clinical professions to evaluate patients in CR.