Systemic Immune-Inflammation Index Predicted Short-Term Outcomes in Patients Undergoing Isolated Tricuspid Valve Surgery

Abstract

Systemic immune-inflammation index (SII, platelet × neutrophil/lymphocyte ratio) has recently been identified as an inflammatory marker. We aimed to evaluate the prognostic implications of preoperative SII in patients undergoing isolated tricuspid valve (TV) surgery. In total, 213 patients who underwent isolated TV surgery between January 2000 and December 2018 were enrolled. They were divided into two groups, as follows: low SII (<455.6 × 10⁹/L), and high SII (≥455.6 × 10⁹/L). The correlation between SII and clinical outcomes was analyzed via the Cox regression and the Kaplan-Meier analyses. The primary outcomes considered were all-cause mortality and major postoperative complications within a 30-day period after isolated TV surgery, including major adverse cardiovascular or cerebrovascular events, pulmonary and renal complications, stroke, sepsis, multi-organ failure, wound, and gastrointestinal complications. In total, 82 (38.5%) patients experienced postoperative complications. Multivariable analyses revealed that high preoperative SII values were independently associated with the major 30-day postoperative complications (hazard ratio 3.58, 95% confidence interval 1.62-7.95, p = 0.001). Additionally, Kaplan-Meier analysis revealed that the probability of undergoing major 30-day postoperative complications was significantly elevated in patients with high versus low SII values (p < 0.001). These results indicate that SII, a readily available parameter, is significantly associated with poor outcomes in patients undergoing isolated TV surgery.

Keywords: postoperative complications; prognosis; systemic immune-inflammation index; tricuspid valve.

Figure 1

Flowchart of the patient selection and classification. SII, systemic immune-inflammation index.

Figure 2

Receiver operating characteristics (ROC) analysis showing the prediction of major postoperative complication via systemic immune-inflammation index after isolated tricuspid valve surgery. AUC, area under the curve; CI, confidence interval.

Figure 3

Kaplan–Meier curves for the probability of major postoperative complications between patients with different SII groups; SII, systemic immune-inflammation index; Low SII group, red; High SII group, blue.