[The creatinine-to-albumin ratio predicts short-term mortality and in-hospital adverse events after thoracic endovascular aortic repair for type B aortic dissection].

Objective

To evaluate the predictive value of the admission creatinine-to-albumin ratio (CAR) for 30-day all-cause mortality and in-hospital adverse events in patients with type B aortic dissection (TBAD) undergoing thoracic endovascular aortic repair (TEVAR).

Methods

This retrospective cohort study analyzed clinical data from 968 consecutive TBAD patients undergoing TEVAR at Guangdong Provincial People's Hospital from January 2010 to January 2024. Admission serum creatinine and albumin levels within 24 hours were used to calculate CAR. The optimal cut-off value of CAR was identified via maximally selected rank statistics for predicting 30-day all-cause mortality. Patients were stratified into high-CAR (≥the cut-off value of CAR) and low-CAR (<the cut-off value of CAR) groups. The primary endpoint was 30-day all-cause mortality. The secondary endpoints were in-hospital adverse events with particular focus on new-onset dialysis. Analyses included Kaplan-Meier survival, multivariable Cox and logistic regression, restricted cubic spline (RCS) analysis. Subgroup analyses were performed by age (<65 vs.≥65 years), sex, clinical phase of TBAD (acute, subacute, chronic), TBAD type (complicated vs. uncomplicated), DeBakey classification, and maximum aortic diameter. Sensitivity analyses were conducted by excluding patients with stage Ⅳ to V chronic kidney disease or cirrhosis.

Results

A total of 968 patients were included, with an age of (55.2±11.4) years, and 835 (86.3%) were male. CAR predicted 30-day mortality with an area under the curve of 0.714. The optimal cut-off value was 3.00, yielding a low-CAR group (n=621) and a high-CAR group (n=347). The 30-day mortality was 4.6% (16/347) in the high-CAR group versus 1.1% (7/621) in the low-CAR group (P<0.01). Kaplan-Meier survival analysis yielded consistent results (Plog-rank<0.01). RCS analysis indicated a non-linear association between CAR and 30-day mortality risk (non-linearity P=0.03). The multivariable Cox regression analysis showed that CAR was an independent risk factor for 30 d all-cause mortality (HR=1.10, 95%CI 1.03-1.17). In-hospital adverse events were more frequent in the high-CAR group than in the low-CAR group (15.9% (55/347) vs. 5.6% (35/621), P<0.01), and logistic regression confirmed CAR as an independent predictor (OR=1.10, 95%CI 1.05-1.17). Notably, new-onset dialysis showed the most pronounced intergroup difference among all individual adverse events (5.8% (20/347) vs. 0.6% (4/621), P<0.01) and multivariable logistic regression further confirmed CAR as an independent predictor of new-onset dialysis (OR=1.09, 95%CI 1.02-1.16). Subgroup analyses demonstrated consistent predictive performance for 30-day mortality and in-hospital adverse events across major clinical subgroups (all interaction P>0.05). For new-onset dialysis, the effect of CAR was significantly stronger in complicated TBAD than in uncomplicated TBAD (interaction P=0.02). Results held after excluding patients with Ⅳ-Ⅴ time renal disease or cirrhosis.

Conclusions

Admission CAR≥3.00 independently predicts 30-day mortality and in-hospital adverse events in TBAD patients following TEVAR, with a non-linear dose-response relationship. Among all endpoints, CAR demonstrates the strongest predictive value for postoperative severe renal deterioration (new-onset dialysis), an effect that appears amplified in complicated TBAD.