For a patient with a history of CABG and aortic valve replacement who presents with worsening near-syncope upon standing, which complication should be evaluated?

In patients with a history of coronary artery bypass grafting (CABG) and aortic valve replacement, near-syncope upon standing can indicate hemodynamic changes, particularly in relation to the left ventricular outflow tract. Bioprosthetic aortic valves, while they generally provide good hemodynamic outcomes, can sometimes undergo changes resulting in stenosis over time. This is particularly relevant in a patient who has had an aortic valve replacement, as degeneration of the valve can lead to a narrowing that obstructs blood flow and contributes to symptoms like near-syncope.

Evaluating for bioprosthetic aortic valve stenosis is crucial in this scenario, as it can lead to systolic ejection obstruction, especially when the patient transitions to an upright position. This position can exacerbate symptoms due to decreased venous return and further compromise cardiac output, which may be reflected as worsening near-syncope.

With increasing age and time, bioprosthetic valves can undergo calcification and other degenerative changes, which may lead to functional impairment. Therefore, monitoring for this complication in patients who have undergone aortic valve replacement is essential in assessing their ongoing cardiovascular health and managing any emerging symptoms effectively.