Evolution of left ventricular function among subjects with ST-elevation myocardial infarction after percutaneous
Ulrika Pahlm1,2, Ellen Ostenfeld1, Felicia Seemann1,3
1Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden.
Insights
Atrioventricular plane displacement (AVPD) and wall thickening (WT) show reduced function after ST-elevation myocardial infarction (STEMI). AVPD partially recovers, but WT remains decreased, impacting diagnosis of post-ischemic conditions.
Area of Science:
- Cardiology
- Medical Imaging
- Physiology
Background:
- Atrioventricular plane displacement (AVPD) assesses longitudinal left ventricular (LV) systolic function.
- Wall thickening (WT) evaluates regional radial LV function.
- The temporal changes of AVPD and WT post-ST-elevation myocardial infarction (STEMI) using cardiac magnetic resonance (CMR) are not well-documented.
Purpose of the Study:
- To investigate the global and regional effects of STEMI on AVPD and WT.
- To track the evolution of these cardiac function measures from the sub-acute to the chronic phase post-STEMI.
Main Methods:
- Prospective magnetic resonance imaging (MRI) in 77 STEMI patients and 20 healthy controls at 2-6 days and 6 months post-STEMI.
- AVPD measured from long-axis cine images; WT measured from short-axis cine images.
- Infarction quantified by late gadolinium enhancement (LGE) to define infarct and remote segments.
Main Results:
- No significant differences in AVPD or WT between cooling therapy and standard care groups.
- Global AVPD was reduced in sub-acute and chronic phases post-STEMI compared to controls, with partial recovery.
- Patients with LAD or RCA infarcts showed decreased AVPD. LAD infarcts led to decreased WT in both infarcted and remote segments; RCA/LCx infarcts primarily affected WT in infarcted segments.
Conclusions:
- AVPD serves as a global marker of cardiac function post-STEMI, potentially explaining the prognostic value of local mitral annular plane systolic excursion (MAPSE) measurements.
- Decreased WT in remote myocardium post-STEMI necessitates consideration when interpreting functional measurements alongside infarct quantification for diagnosing stunning and hibernation.
Background:
Atrioventricular plane displacement (AVPD) reflects longitudinal left ventricular (LV) systolic function, and wall thickening (WT) regional radial LV function. The temporal evolution of these measures after STEMI with CMR has not been evaluated. We aimed to investigate how AVPD and WT are affected globally and regionally from the sub-acute to the chronic phase after ST-elevation myocardial infarction (STEMI).
Methods:
Healthy volunteers without cardiovascular disease and medication (controls, n = 20) and patients from the CHILL-MI study ( NCT01379261 ) prospectively underwent magnetic resonance imaging (MRI) 2-6 days and 6 months after STEMI (n = 77). CHILL-MI randomized STEMI-patients to cooling therapy initiated before reperfusion or standard of care. AVPD was measured at six points in three long axis cine images and wall thickening in short axis cine images. Infarction was quantified using late gadolinium enhancement (LGE) and used to define infarct and remote segments.
Results:
There were no difference in AVPD either at acute or chronic phase (p = 0.90 and p = 0.40) or WT (p = 0.85 and p = 0.99) between patients randomized to cooling therapy and standard of care. Therefore, the results are presented for the pooled cohort. Global AVPD was decreased 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:
AVPD was a global rather than regional marker of cardiac function in this STEMI study and this may explain the prognostic importance of local measurements of mitral annular plane systolic excursion (MAPSE). The decrease in WT in remote myocardium even in the chronic phase needs to be taken into consideration when combining functional measurements with infarct quantification for diagnosis of post-ischemic stunning and hibernation.
