Correlation and prognostic ability of admission lung ultrasound and late peak atrial longitudinal strain in patients with ST-elevation myocardial infarction

Abstract

Abstract Background Acute heart failure is common after ST-elevation myocardial infarction (STEMI), leading to lung congestion. Speckle tracking echocardiography has increased sensitivity to detect subclinical myocardial compliance disorders and may help to better understand the physiopathology in this setting. Purpose This study sought to determine the correlation and prognostic ability of admission lung congestion evaluated by lung ultrasound (LUS) and peak atrial longitudinal strain (PALS) performed after the acute phase of STEMI. Methods This was a prospective cohort of STEMI patients treated in a tertiary care hospital. LUS was performed by two independent operators before primary percutaneous coronary intervention (PCI). Our protocol consisted of eight scanning sites, which were considered positive for congestion if there were three or more B-lines in at least one site. Echocardiography was performed in all patients 2–4 days after STEMI, and the images were interpreted offline by two operators blinded to LUS findings. PALS <30 was considered abnormally reduced atrial contraction. Major cardiovascular events (MACE) were considered as new myocardial infarction, stroke or death in 30 days. Results Of the 339 patients admitted with STEMI, 208 (61%) performed LUS and had interpretable PALS. The mean age was 61 (±12) years and 65% were male. Lung congestion was present in 48% patients. Mean left ventricular ejection fraction (LVEF) was 49%, 21% of patients had EF<40%. Pearson correlation between the number of positive LUS sites and PALS was 0.18 (P=0.029). A subanalysis including only patients with left ventricle ejection fraction >50% showed similar results (correlation 0.10, P=0.349). All 10 (5%) patients with unsuccessful primary PCI had PALS <30. No patients with PALS>30 experienced 30-day MACE, while patients with PALS <30 with and without lung congestion had 1.6% and 13.8% 30-day MACE, respectively. Conclusion In a cohort of STEMI patients, the correlation of positive LUS sites and the PALS was low. Impaired PALS was associated with unsuccessful primary PCI, while normal PALS was associated with uneventful follow-up. The PALS assessment in addition to LUS profile was able to identify patients at higher risk for MACE. Although timing difference between lung ultrasound and echocardiography is a limitation of this analysis, our findings are consistent with the “lung water cascade theory”. Funding Acknowledgement Type of funding sources: None.