Preoperative Risk Score for Mortality Within 3 Years of Visceral Segment Fenestrated Endovascular Aortic Repair

The purpose of this study was to create a risk score for the event of mortality within 3 years of complex fenestrated visceral segment endovascular aortic repair, utilizing variables existing at the time of preoperative presentation. The first step in development of the risk score was univariable analysis for the primary outcome of mortality within 3 years of surgery. χ2 analysis was performed for categorical variables and comparison of means with independent Student t-test was performed for ordinal variables. Variables that achieved a univariable significance of P-value less than .1 were then placed into Cox regression multivariable time-dependent analysis for the development of mortality within 3 years. Variables that achieved a multivariable significance of less than .1 were utilized for the risk score with point weighting based on the beta-coefficient. Variables with a beta-coefficient of 0.25 to 0.49 were assigned 1 point, 0.5 to 0.74 2 points, 0.75 to 0.99 3 points, and 1.0 to 1.25 4 points. Statistically significant (P < .05) multivariable association with 3-year mortality was noted for: age; female gender; body mass index (BMI) <20 kg/m2; BMI>30 kg/m2 (protective); chronic obstructive pulmonary disease (COPD); renal insufficiency; prior endovascular aortic aneurysm repair; and, increasing maximal abdominal aortic aneurysm (AAA) diameter. Other variables with P < .1 that were included in the risk score were hypertension and active tobacco smoking (Table I). Testing the model resulted in an area under the curve (AUC) of .706. Hosmer and Lemeshow goodness of fit test for logistic regression utilizing the 15 different risk score total groups revealed a model predictive accuracy of 87.3%. Very significant escalations in 3-year mortality were noted to occur at scores of 6 and greater (Fig 1). A novel risk score for mortality within 3 years of fenestrated visceral segment aortic endograft has been developed which has excellent accuracy in predicting which patients will survive and derive the strongest benefit from intervention. This facilitates risk-benefit analysis and counseling of patients and families with realistic long-term expectations. This potentially enhances patient-centered decision-making.TableMultivariable Cox regression for the outcome of mortality within 3 years of surgeryVariableVariable within cohort (n)Multivariable HR (95% CI)P-valueAge, years Age at mortality75.4 (± 7.6)1.04 (1.02-1.05)< .001 Age without mortality73.05 (± 8.3)Gender Male11.7 (172/1468) Female16.3 (73/448)1.49 (1.12-1.99).007Hx of HTN Yes Hx of HTN13.4 (228/1707)1.66 (.995-2.78).052 No Hx of HTN8.1 (17/209)Hx of COPD Yes Hx of COPD19.1 (139/727)2.03 (1.56-2.63)< .001 No Hx of COPD8.9 (106/1189)Hx of CVA Yes Hx of CVA17.9 (33/184)1.35 (.93-1.95).118 No Hx of CVA12.2(212/1732)Hx of CAD Yes Hx of CAD15.3 (89/581)1.19 (.90-1.58).214 No Hx of CAD11.7 (156/1335)Hx of CHF Yes Hx of CHF20.1 (54/268)1.34 (.97-1.86).08 No Hx of CHF11.6 (191/1648)Hx of CRI Yes Hx of CRI18.3 (91/496)1.54 (1.16-2.04).003 No Hx of CRI10.8 (154/1420)On HD Yes on HD38.5 (10/26)2.83 (1.42-5.64)< .001 No not on HD12.4 (235/1890)Hx of anemia Yes Hx of anemia20.0 (23/115)1.01 (.65-1.58).965 No Hx of anemia12.3 (222/1801)BMI <20 kg/m2 Yes BMI <20 kg/m225.6 (31/121)1.67 (1.13-2.48).01 No BMI < 20 kg/m211.9 (214/1795)BMI >30 kg/m2 Yes BMI >30 kg/m29.0 (50/558).70 (.50- .97).03 No BMI >30 kg/m214.4 (195/1358)Active smoker Yes active smoker15.1 (91/601)1.29 (.98-1.71).067 No not active smoker11.7 (154/1315)Prior endovascular aortic repair Yes prior endovascular aortic repair22.2 (35/158)1.70 (1.17-2.46)< .001 No prior endovascular aortic repair11.9 (210/1758)Preoperative AAA diameter, mm AAA diameter at mortality62.86 (± 11.24)1.02 (1.01-1.03)< .001 AAA diameter survivors60.07 (± 10.36)Preoperative any visceral artery stenosis >50% Yes visceral stenosis > 50%16.5 (40/242).97 (.68-1.39).877 No visceral stenosis >50%12.2 (205/1674)Zone 5 coverage Yes zone 5 coverage16.5 (57/345)1.26 (.93-1.71).136 No zone 5 coverage12.0 (188/1571)BMI, Body mass index; CAD, coronary artery disease; CHF, congestive heart failure; CI, confidence interval; COPD, chronic obstructive pulmonary disease; CRI, chronic renal insufficiency; CVA, cerebrovascular accident; DM, diabetes mellitus; HD, hemodialysis; HTN, high blood pressure; Hx, history.Data are presented as percentage (number/total) or mean (± standard deviation) except where noted.Cox regression utilizing variables with univariable P < .10. Open table in a new tab