Coronary Microvascular Dysfunction, Left Ventricular Remodeling, and Clinical Outcomes in Patients With Chronic...

Area of Science:

• Cardiology
• Nephrology
• Cardiovascular Imaging

Background:

• Patients with chronic kidney disease (CKD) often experience cardiac dysfunction and cardiovascular events, even without obstructive coronary artery disease.
• The underlying mechanisms linking CKD to cardiac impairment and adverse outcomes remain unclear.
• Coronary microvascular dysfunction (CMD) is hypothesized to bridge the relationship between renal dysfunction and cardiac issues.

Purpose of the Study:

• To investigate the associations between CKD, CMD, cardiac dysfunction, and cardiovascular outcomes.
• To determine if CMD mediates the link between CKD and adverse cardiovascular events in patients without overt coronary artery disease.

Main Methods:

• Longitudinal study of 352 patients undergoing cardiac stress positron emission tomography (PET) and echocardiography.
• Renal function assessed via estimated glomerular filtration rate (eGFR).
• Coronary flow reserve (CFR) measured by PET; cardiac mechanics assessed by echocardiography (diastolic and systolic indices).
• Patients followed for composite outcomes of death, myocardial infarction, or heart failure hospitalization.
• Statistical analyses included multivariable models and mediation analyses.

Main Results:

• 35% of patients had eGFR <60 mL·min^-1·1.73 m^-2; median CFR was 1.8.
• Both eGFR and CFR were associated with cardiac mechanics and cardiovascular events (P<0.05).
• In multivariable models, CFR, but not eGFR, was independently associated with cardiac mechanics and cardiovascular events.
• The relationship between eGFR, cardiac mechanics, and cardiovascular events was partly mediated by CFR.

Conclusions:

• Coronary microvascular dysfunction, rather than eGFR alone, is independently linked to abnormal cardiac mechanics and increased cardiovascular event risk.
• CMD may serve as a key mediator connecting CKD to cardiac dysfunction and adverse cardiovascular outcomes in patients without overt coronary artery disease.