Prognostic Value of the Left Ventricular Outflow Tract Velocity-time Integral in Predicting In-hospital Outcomes in Patients Undergoing Primary Percutaneous Coronary Intervention

ST-elevation myocardial infarction (STEMI) remains a leading cause of cardiovascular mortality globally, with an estimated incidence of 50-100 cases per 100,000 person and accounting for nearly 30% of acute coronary syndrome (ACS) presentations. Despite advances in reperfusion therapy, in-hospital complications such as cardiogenic shock (CS) and acute heart failure (HF) continue to affect 5-15% of STEMI patients, with CS-associated mortality exceeding 40%.

Primary percutaneous coronary intervention (PCI) is the standard of care in STEMI patients, but also early identification of high-risk patients is crucial to improving outcomes.

Echocardiographic evaluation of left ventricular outflow tract velocity-time integral (LVOT VTI) has gained attention as a dynamic, bedside echocardiographic parameter that reflects stroke volume (SV) and cardiac output (CO). Several studies in critically ill patients and those with heart failure have shown that low LVOT VTI values (<15 cm) are associated with impaired cardiac output and adverse outcomes, including hypotension, vasopressor requirement, and increased mortality. Moreover, in cardiogenic shock, LVOT VTI has demonstrated superior prognostic accuracy compared to conventional measures such as left ventricular ejection fraction (LVEF).

Despite this growing evidence, the prognostic role of LVOT VTI in STEMI patients remains under-investigated. Since STEMI-related LV dysfunction directly impacts stroke volume, LVOT VTI may offer an early, non-invasive indicator of impending hemodynamic deterioration ـــ potentially before clinical signs become evident. Early identification of those high-risk patients mandates careful hemodynamic monitoring and rapid management of any deterioration.