Association Between Systemic Inflammation Response Index, Worsening of Left Ventricular Systolic Function and Prognosis in Patients with Coronary Artery Disease

Background: Inflammation contributes substantially to the progression and adverse prognosis of coronary artery disease (CAD). Worsening of left ventricular (LV) systolic function is a key contributor to poor prognosis in CAD patients. However, whether inflammation influences prognosis through worsening of left ventricular systolic function remains uncertain. Methods: This retrospective study enrolled patients from Cardiorenal Improvement-II who were initially hospitalised between 2007 and 2020 and had both baseline and follow-up echocardiographic information. Participants were stratified by systemic inflammation response index (SIRI) into 4 quartiles (Q1-Q4) for comparison. Worsening of LV systolic function served as the primary endpoint and was identified by an absolute decrease of 10% or more in LV ejection fraction from baseline to 12 months following hospital discharge. Secondary outcomes included cardiovascular and all-cause mortality. Logistic regression models were utilized to evaluate the association of SIRI with worsening of left ventricular systolic function. Mediation analysis was used to investigate the proportion of fatalities mediated by worsening of left ventricular systolic function. Results: Among the 6307 enrolled participants with CAD (62.0 ±10.7 years, 20.6% female), a total of 521 (8.3%) worsening of left ventricular systolic function occurred in 1 year, and 523 (8.3%) cardiovascular deaths and 1022 (16.2%) all-cause deaths were recorded with a median observation period of 4.2 years. After fully adjusting, the logistic regression analysis revealed that Q4 group patients (with SIRI ≥2.61) were associated with a higher risk of worsening of LV systolic function (adjusted odds ratio: 1.52, 95% confidence intervals: 1.15-2.01, P =0.003). Approximately 4.0% and 2.0% of the overall association of SIRI with cardiovascular and all-cause mortality were mediated by worsening of left ventricular systolic function (P <0.05), respectively. Conclusion: SIRI serve as a potential risk factor for worsening of LV systolic function in CAD patients, and further contributes to poor prognosis, indicating that anti-inflammatory treatment represents a viable approach to improve the prognosis for CAD patients.