Left ventricular global longitudinal strain and long-term prognosis in patients with chronic obstructive pulmonary disease after acute myocardial infarction

Abstract

Patients with chronic obstructive pulmonary disease (COPD) have an increased risk of hospitalization and death due to cardiovascular diseases.1 Particularly, among patients with ST-segment elevation myocardial infarction (STEMI), the presence of COPD has been independently associated with higher mortality when compared with patients without COPD.2-4 The underlying factors explaining this mortality difference include delayed diagnosis and reperfusion treatment of a STEMI and underuse of secondary prevention therapy. 5 These may lead to large left ventricular (LV) infarct size and adverse remodelling (dilation) during follow-up, increasing the risk of heart failure and cardiovascular mortality. Left ventricular ejection fraction (LVEF) is frequently used in clinical practice as a marker of the myocardial damage (infarct size) after STEMI and is a well-known prognostic determinant. However, in a recent large cohort of STEMI patients, COPD patients had comparable LVEF as patients without COPD.6 Two-dimensional (2D) speckle tracking echocardiography is an advanced technique to assess myocardial deformation. In contrast to LVEF which reflects a change in LV volume, 2D speckle tracking echocardiography evaluates the active contraction of the myocardium reflecting directly the myocardial function. LV global longitudinal strain (GLS) measured with 2D speckle tracking echocardiography is currently one of the most frequent variables to reflect LV systolic function and has been associated with prognosis after STEMI.7 In contrast to LVEF, LV GLS showed that STEMI patients with COPD had larger myocardial damage than patients without. 6 Therefore, LV GLS may have more discriminative power than LVEF to identify the patients with increased mortality risk after STEMI. The present study evaluated the prognostic value of LV GLS in STEMI patients with COPD and investigated whether LV GLS has incremental value over conventional echocardiographic parameters for LV systolic function.