Preoperative red blood cell distribution width is associated with prolonged mechanical ventilation and in-hospital mortality after acute type A aortic dissection repair

Abstract

Red blood cell distribution width (RDW) has emerged as a potential prognostic marker in cardiovascular diseases. This study aimed to investigate the association between preoperative RDW and the incidence and mortality of prolonged mechanical ventilation (PMV) in patients with acute type A aortic dissection (ATAAD) undergoing surgical repair. A total of 618 ATAAD patients were retrospectively analyzed. PMV was defined as postoperative mechanical ventilation lasting more than 48 h. Logistic regression and restricted cubic spline (RCS) analyses were performed to evaluate the association between RDW and PMV, while Cox regression analysis was used to assess the association between RDW and in-hospital mortality among patients with PMV. The incremental value of RDW was assessed using net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Among all patients, 321 (51.9%) developed PMV. Higher preoperative RDW was independently associated with increased PMV risk (adjusted OR, 1.275; 95% CI, 1.097–1.482; P =0.002), and RCS analysis showed a positive dose–response relationship ( P for nonlinear=0.091). Adding RDW to the reference model based on Yu et al. nomogram predictors provides incremental prognostic information, as reflected by increases in category-free NRI (0.3945) and IDI (0.0285). Among patients with PMV, 56 (17.4%) died during hospitalization. Multivariate Cox regression revealed that RDW was an independent risk factor of in-hospital mortality in this subgroup (HR, 1.212; 95% CI, 1.036–1.418; P =0.016). Elevated preoperative RDW was independently associated with PMV and with in-hospital mortality among patients who developed PMV after ATAAD repair. Adding RDW improved NRI and IDI in this cohort, although discrimination did not improve significantly. Prospective external validation and clinical-impact studies are required before RDW can be recommended to guide perioperative management.