Four preoperative variables – age over 76 years, creatinine concentration greater than 2.0 mg/dL, pH less than 7.2, and lowest ever systolic blood pressure less than 70 mm Hg – predicted 30-day mortality following repair of ruptured abdominal aortic aneurysms (rAAAs), in a retrospective study of 303 patients treated at Harborview Medical Center at the University of Washington, Seattle.
Brandon T. Garland, MD, and his colleagues at Harborview, reviewed the data set of patients, noting 50% were aged older than 76 years and 80% were male. Many patients had typical vascular risk factors: 65% had hypertension, 39% had coronary artery disease, and 22% had chronic obstructive vascular disease. Patients who were treated for rAAA after 2007 and had preoperative computed tomography scans were assessed for endovascular aneurysm repair (rEVAR) based on infrarenal neck length and diameter and access vessel size. Noneligible patients and all patients treated prior to 2007 had open repair (rOR) surgery.
A primary screen of selected preoperative variables included age, hematocrit, systolic blood pressure values, use of cardiopulmonary resuscitation, pH, international normalized ratio, creatinine concentration, temperature, partial thromboplastin time, weight, history of coronary artery disease, and loss of consciousness at any time.
The four statistically significant associations were age over 76 years (odds ratio, 2.11; P less than 0.11), creatinine concentration over 2.0 mg/dL (OR, 3.66; P less than .001), pH less than 7.2 (OR 2.58; P less than .009) and lowest ever systolic blood pressure less than 70 mm Hg (OR, 2.70; P less than .002) Each of the four predictive preoperative rAAA variables was assigned a value of 1 point. Individualized scores are simply calculated by totaling the number of preoperative risk predictors.
Of the original 303 patients, 154 were alive at 30 days following rAAA repair, and there was a significant benefit from using rEVAR. Overall, patients with 1-, 2-, 3-, and 4-point mortality scores had 30-day mortality risks of 22%, 69%, 80%, and 100%, respectively. rEVAR mortalities dropped to 7% for a 1-point score and to 70% for a 3-point score. There were no 30-day survivors with 4-point risk scores regardless of whether they had rEVAR or rOR procedures.
The predictive risk scores for rAAA mortality outcomes provide helpful guides for patient care recommendations, and can be used to supplement the rOR-validated Glasgow Aneurysm Score, Hardman index, and Vascular Study Group of New England risk-predicting algorithms to “aid in clinical decision-making in the endovascular era,” the researchers wrote. The scores also add “prognostic information to the decision to transfer patients to tertiary care centers and aid in preoperative discussions with patients and their families.”
The authors reported that they had no conflicts of interest.
SOURCE: Garland BT et al. J Vasc Surg. 2018 May 9. doi: 10.1016/j.jvs.2017.12.075.