Prognostic Value of Right Ventricular-pulmonary Arterial Coupling Assessed by Echocardiography in Septic Patients: A Prospective Observational Study

Sepsis and septic shock are common clinical conditions, representing a significant healthcare challenge due to their high mortality rates and increasing incidence. Sepsis-induced cardiomyopathy is a frequent complication, occurring in up to 44% of septic patients. This condition is associated with a two- to three-fold increase in mortality. Although sepsis-induced cardiomyopathy is typically diagnosed via echocardiography to assess left ventricular systolic function, both ventricles may be affected. Several studies have demonstrated that right ventricular dysfunction (RVD)/ right ventricular failure (RVF) was prevalent in sepsis and septic shock, with significant implications for prognosis and mortality.

The right ventricle (RV) has a distinct anatomical structure and function compared to the left ventricle, characterized by its high sensitivity to afterload variations. Even minor increases in afterload can severely impair RV contractile function. Meanwhile, septic patients often experience hypoxemic respiratory failure and require mechanical ventilation. This condition generates hypoxia-induced pulmonary vasoconstriction, which, combined with positive pressure ventilation, leads to increased pulmonary vascular resistance and elevated pulmonary arterial pressure. Additionally, systemic vasodilation reduces RV preload, while septic shock and vasopressor use further compromise right coronary perfusion, exacerbating RV contractile dysfunction. Consequently, simultaneous assessment of RV contractility and its afterload is crucial in septic patients.

Tricuspid annular plane systolic excursion (TAPSE) is a widely used echocardiographic parameter for evaluating RV systolic function. Pulmonary artery systolic pressure (sPAP) reflects RV afterload and can be estimated in the presence of tricuspid regurgitation. Recently, the TAPSE/sPAP ratio has been proposed as a clinical tool to assess right ventricle-pulmonary artery (RV-PA) coupling. This index has been shown to be associated with mortality in patients with pulmonary hypertension and heart failure. Several studies have been conducted to evaluate RV-PA coupling in sepsis and septic shocks, but these studies have limitations in terms of study design and patient selection.

In Vietnam, the issues of RVD/RVF in sepsis/septic shock have not been thoroughly investigated. Le Minh Khoi and colleagues reported that the incidence of reduced RV strain in septic patients was as high as 55.1%. Currently, no studies have specifically evaluated RV function, nor have any studies assessed RV-PA coupling in septic patients.