The Association between Hypoperfused Myocardium and Systolic Function in Patients With AMI Undergoing Complete Revascularization

Background

Timely restoring coronary blood flow reduces mortality in acute myocardial infarction (AMI), while epicardial flow restoration is non‐parallel to myocardial reperfusion. This prospective study examined temporal changes in myocardial perfusion and their association with left ventricular (LV) systolic function after complete revascularization.

Methods

AMI patients treated with complete revascularization underwent hybrid positron emission tomography/magnetic resonance imaging (PET/MR) at 2 months and 1 year after the index procedure. Hypoperfused myocardium was defined as reduced perfusion with preserved metabolism.

Results

Fifty‐five patients (60.42 ± 11.47 years, 80.0% male) were enrolled, and hypoperfused myocardium (median: 12% of LV) was detected in 25 (45.5%) patients 2 months post‐AMI. Patients with and without hypoperfused myocardium were classified as Group A and Group B, respectively. Higher high‐sensitivity C‐reactive protein (hs‐CRP) and lower T2 values were observed in Group A and independently predicted baseline hypoperfused myocardium. At 1‐year PET/MR follow‐up, six (31.6%) patients in Group A showed perfusion recovery; these patients were more frequently female ( p  = 0.025), less frequently diabetic ( p  = 0.044) or overweight ( p  = 0.035), and had better baseline global longitudinal strain (GLS) ( p  = 0.005). Significant LV ejection fraction improvement was observed in Group A (56.39% ± 9.76% vs. 54.58% ± 10.39%, p  = 0.016) but not in Group B (51.63% ± 13.09% vs. 50.79% ± 16.95%, p  = 0.615).

Conclusions

Even after complete revascularization, myocardial hypoperfusion may persistently exist and evolve over time in AMI patients. The reversal of myocardial hypoperfusion is possibly associated with improved LV systolic function.

Trial Registration: The study was retrospectively registered on 2022‐11‐24 under the name Evaluation of short—and long‐term cardiac structure and function in patients with acute coronary syndrome and made publicly available in the China Medical Research Registration Information System ( https://www.medicalresearch.org.cn/ ), with the registration number MR.‐11‐23‐000090.