Unravelling the Complexities of Myocardial Injury in Patients with Chronic Kidney Disease

In patients with chronic kidney disease (CKD), specifically end stage kidney disease (ESKD), incidence of cardiovascular disease (CVD) events and CVD mortality is substantially higher than in the general population 1) .Furthermore, heart failure (HF) is the most common among CVDs in this population 2) .The causes of HF include ischemic heart disease due to coronary artery disease, hypertensive heart disease, and various types of cardiomyopathies.However, pathophysiological mechanisms are highly complex, and details often remain unclear.For example, we sometimes encounter patients who exhibit remarkable pulmonary congestion and globally reduced cardiac systolic function, thus requiring urgent hospitalization for HF.Although coronary angiography is usually conducted for such cases, we often find that patients have no significant coronary artery stenosis.Apart from coronary artery disease, numerous factors, including volume overload, hypertension, diabetes mellitus, anemia, uremic toxins, renin-aldosterone-angiotensin system, sympathetic nerve system, CKD-mineral bone disorder, malnutrition, inflammation, and oxidative stress, contribute to myocardial injury in patients with ESKD (Fig. 1).Furthermore, one of the contributors to myocardial injury in this population is believed to be coronary microcirculatory disturbance.Coronary flow reser ve (CFR), an indicator of coronar y microcirculation, is reported to decrease with declining glomerular filtration rate 3,4) , and most hemodialysis patients exhibit extremely low CFR.Additionally, it has been reported that reduced CFR is associated with mortality in hemodialysis patients 5) .Thus, impaired coronary microcirculation leads to