Purpose: We aimed to investigate how AVPD and WT are affected globally and regionally from the sub-acute to the chronic phase after STEMI.
Methods: Patients from the CHILL-MI study who underwent cardiovascular magnetic resonance imaging 2-6 days and 6 months after STEMI (n=77, 58±10 years) and healthy controls (n=20, 62±11 years) were included. Left ventricular volumes and regional WT were quantified in short-axis and AVPD in 3 long-axis cine images.
Results: Infarct size decreased from 17±10% to 10±6% (p<0.001) and ejection fraction (EF) increased from 48±8% to 52±9% (p<0.001). This was accompanied by a global AVPD decrease in both the sub-acute (12±2 mm, p<0.001) and the chronic phase (13±2 mm, p<0.001) compared to controls (15±2 mm) with a partial recovery of AVPD (p<0.001) in the chronic phase. Patients with left anterior descending (LAD) and right coronary artery (RCA) infarcts had decreased AVPD in the chronic phase in both infarcted and remote segments.
Mean WT was decreased in patients with LAD infarction both in the sub-acute and the chronic phase in both infarcted and remote segments. The decrease in WT in patients with RCA and left circumflex (LCx) infarcts was more affected in the infarcted segments especially in the chronic phase.
Conclusion: Assessment of regional longitudinal and radial function after STEMI is complex. Decrease in regional function can be seen in segments without infarction, even in the chronic phase. This information is important to consider when combining functional measurements with infarct quantification for diagnosis of post-ischemic stunning and hibernation.
Figure 1. AVPD in mm and Wall thickening (WT) in % for each wall in patients with infarctions in LAD, LCx and RCA territory. Controls are showed for comparison. Chronic phase vs controls: * p<0.05, ** p<0.01, *** p<0.001. Sub-acute vs. cronic phase † p<0.05, †† p<0.01, ††† p<0.001