Coronary Artery Disease and Intradialytic Myocardial Ischemia in Hemodialysis: An Exploratory Study Using Intradialytic Imaging

Rationale & Objective: Recurrent segmental myocardial ischemia (myocardial stunning) is a well-recognized consequence of hemodialysis leading to fixed contractile deficits and increased morbidity and cardiac mortality. Although epicardial coronary artery disease (CAD) is not a prerequisite, hemodialysis patients commonly have significant arterial plaque burden, and the interaction with established CAD and hemodialysis-induced myocardial ischemic injury is currently unknown. Study Design: A single-center cross-sectional study. Setting & Participants: Thirteen patients on maintenance hemodialysis (London, Ontario, and Canada). Exposure: The presence of significant coronary stenoses as assessed using coronary computed tomography (CT) angiography. Outcomes: Principal aim was to identify changes in myocardial perfusion and stunning as assessed by CT and echocardiography, respectively. Analytical Approach: We used CT angiography with intradialytic CT perfusion and echocardiography to evaluate perfusion and ventricular contractile response during dialysis in patients with and without CAD. Coronary artery images were acquired before dialysis (baseline). The CT perfusion scans were conducted at baseline, peak-dialysis stress, and 30 minutes after dialysis to quantify global and segmental perfusion of the left ventricular myocardium. At each timepoint, segmental myocardial stunning was identified as intradialytic development of regional wall motion abnormalities using longitudinal strain analysis from 2D echocardiograms. Results: Among 13 participants, 3 were identified with asymptomatic CAD. Among the 10 participants with no identifiable CAD, there was a decrease in global myocardial perfusion from baseline to peak dialysis and a recovery to baseline level after dialysis. In asymptomatic CAD participants, the number of myocardial segments experiencing regional wall motion abnormalities was elevated at peak and after dialysis. No significant intradialytic changes in global myocardial perfusion were observed, but the presence of CAD showed additive effects on segmental perfusion and contractile response to HD. Limitations: This study was an exploratory study with a small sample size. Conclusions: This study demonstrated hemodialysis-induced circulatory stress, by a reduction in perfusion and development of myocardial stunning in the absence of CAD.