Microvascular perfusion in infarcted and remote myocardium after successful primary PCI: angiographic and CMR findings.
OBJECTIVES
The aim of this study was to investigate the association between TIMI myocardial perfusion (TMP) grading acute and cardiac magnetic resonance (CMR) first-pass perfusion early and at 4 months in patients with ST-segment-elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI).


MATERIAL AND METHODS
One hundred ninety-eight STEMI patients were recruited from the POSTEMI study. TMP grade was assessed after PCI; CMR was performed at day 2 and after 4 months. Signal intensity was measured on first-pass perfusion images, and a maximum contrast enhancement index (MCE) was calculated.


RESULTS
Patients with TMP grade 2-3 (n = 108) after PCI had significantly better EF (59 ± 10 vs. 51 ± 13, p < 0.001) and smaller infarct volume (12 ± 8 vs. 19 ± 12 %, p < 0.001) at 4 months compared with patients with TMP grade 0-1 (n = 81). MCE in the infarcted (MCEi) and remote myocardium (MCEr) improved from early to follow-up CMR, MCEi from 94 ± 56 to 126 ± 59, p < 0.001, and MCEr from 112 ± 51 to 127 ± 50, p < 0.001. In patients with the lowest CMR perfusion early, perfusion at 4 months remained decreased compared with the other groups, MCEi 108 ± 75 vs. 133 ± 51, p = 0.01, and MCEr 115 ± 41 vs. 131 ± 52, p = 0.047.


CONCLUSION
TMP grade and early CMR first-pass perfusion were associated with CMR outcomes at 4 months. First-pass perfusion improved after 4 months in the infarcted and remote myocardium. However, in patients with the lowest CMR perfusion early, perfusion was still reduced after 4 months.


KEY POINTS
• Cardiac magnetic resonance myocardial first-pass perfusion and TMP grading after successful PCI helps to assess risk in patients with ST elevation myocardial infarction. • Cardiac magnetic resonance myocardial first-pass perfusion shows that microvascular perfusion after ST elevation myocardial infarction can be impaired in both infarcted and non-infarcted myocardium. • Microvascular perfusion improves over time in patients with ST elevation myocardial infarction treated with primary PCI.
['Bethke|Anne|A|http://orcid.org/0000-0001-7419-1899', 'Shanmuganathan|Limalanathan|L|', 'Andersen|Geir Øystein|GØ|', 'Eritsland|Jan|J|', 'Swanson|David|D|', 'Kløw|Nils Einar|NE|', 'Hoffmann|Pavel|P|']
D000368:Aged D017023:Coronary Angiography D003326:Coronary Circulation D005260:Female D006801:Humans D008279:Magnetic Resonance Imaging D008297:Male D008833:Microcirculation D008875:Middle Aged D009206:Myocardium D062645:Percutaneous Coronary Intervention D000072657:ST Elevation Myocardial Infarction D016037:Single-Blind Method
Percutaneous coronary intervention ST elevation myocardial infarction Magnetic resonance imaging Myocardial reperfusion