Interaction of impaired coronary flow reserve and cardiomyocyte injury on adverse cardiovascular outcomes in patients...

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Biomarkers

Background:

• Minimally elevated serum cardiac troponin indicates myocardial injury and is linked to mortality, even without diagnosed coronary artery disease (CAD).
• Coronary flow reserve (CFR) assesses coronary vasomotor function and is a key indicator of overall coronary health.

Purpose of the Study:

• To investigate the association between low-level troponin elevation and impaired CFR in patients without overt CAD.
• To determine the independent and combined contributions of troponin levels and CFR to major adverse cardiovascular events (MACE).

Main Methods:

• 761 patients undergoing evaluation for suspected CAD were analyzed.
• Coronary flow reserve (CFR) was measured using stress/rest myocardial perfusion positron emission tomography.
• Patients were followed for major adverse cardiovascular events (MACE), excluding those with flow-limiting CAD or recent revascularization.

Main Results:

• Patients with elevated troponin had lower CFR and ejection fraction compared to those with negative troponin.
• Impaired CFR was independently associated with elevated troponin (OR 2.18).
• Both impaired CFR (HR 2.25) and elevated troponin (HR 2.42) were independently linked to MACE, with a significant interaction between them.

Conclusions:

• In patients without overt CAD, impaired CFR is linked to minimally elevated troponin and adverse cardiovascular outcomes.
• Impaired CFR, indicative of microvascular dysfunction, modifies the impact of positive troponin on adverse events.