Reassessing Cardiovascular Risk in Patients With Peripheral Artery Disease Undergoing Myocardial Perfusion Imaging.

Area of Science:

• Cardiology
• Vascular Medicine
• Nuclear Cardiology

Background:

• Coronary artery disease (CAD) and peripheral artery disease (PAD) share risk factors and are linked to major adverse cardiovascular events (MACE).
• The independent contribution of PAD to MACE risk, beyond shared pathophysiology and myocardial perfusion abnormalities, remains unclear.

Purpose of the Study:

• To determine if PAD independently elevates MACE risk or if this is attributable to myocardial perfusion abnormalities.
• To investigate the specific mediators of MACE risk in patients with PAD.

Main Methods:

• Analysis of 45,252 patients from an international registry undergoing SPECT myocardial perfusion imaging.
• Quantification of myocardial perfusion abnormalities using total perfusion deficit (TPD).
• Propensity-score matching to compare MACE risk between patients with and without PAD, adjusting for confounding factors.

Main Results:

• A history of PAD alone was not independently associated with an increased MACE risk after propensity-score matching (P = 0.064).
• Isolated CAD conferred a higher MACE risk (aHR, 1.92) than isolated PAD (aHR, 1.20).
• Concomitant CAD and PAD showed a similar MACE risk (aHR, 1.57) to isolated CAD.

Conclusions:

• PAD itself is not an independent predictor of MACE when myocardial perfusion abnormalities and other factors are accounted for.
• Assessing myocardial ischemic burden is crucial for accurate risk stratification in patients with PAD.
• Prompt initiation of disease-modifying therapies is recommended for PAD patients based on ischemic burden.