The BASIL survival prediction model in patients with peripheral arterial disease undergoing revascularization in a university hospital setting and comparison with the FINNVASC and modified PREVENT scores.

BACKGROUND: Critical limb ischemia carries a significant risk of morbidity and mortality. The development of scores to predict risk can aid clinical decision making. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial investigators developed a model to predict death, which has not been previously validated. METHODS: Data were collected in a prospectively maintained database on all patients who underwent angioplasty or arterial bypass for peripheral artery disease in a university hospital between January 2008 and June 2010. The main outcome measures were all-cause mortality and amputation-free survival at 3, 6, 12, and 24 months after the index intervention. The BASIL survival predictor, Finland National Vascular (FINNVASC) registry, and Edifoligide for the Prevention of Infrainguinal Vein Graft Failure (PREVENT) models were applied and receiver-operating characteristic (ROC) curve analysis was used to evaluate their predictive power. RESULTS: Data on 342 patients were collected. Patients with isolated iliac disease or claudication were excluded. The 6-, 12-, and 24-month all-cause mortality rates were 11.6%, 17.9%, and 26.8%, respectively. The area under the ROC curve (95% confidence interval) using the BASIL score to predict mortality at 6, 12, and 24 months was 0.700 (0.60-0.80; P<.001), 0.651 (0.56-0.74; P<.003), and 0.681 (0.59-0.74; P<.001), respectively. ROC curve analysis indicated that the performance of the BASIL score in this cohort was comparable to other validated predictive scores. CONCLUSIONS: The BASIL survival prediction model can moderately predict short-term and medium-term mortality in patients with limb ischemia and may be a useful adjunct to decision making in everyday clinical practice.

Volume-outcome relationships in lower extremity arterial bypass surgery.

OBJECTIVE: We sought to investigate whether a volume-outcome relationship exists for lower extremity arterial bypass (LEAB) surgery. METHODS: All LEAB procedures performed in England between 2002 and 2006 were identified from Hospital Episode Statistics data. A Charlson-type risk profile, including operating hospital annual case volume, was identified per patient. Outcome measures of revision bypass, amputation, death and a composite measure were established during the index admission and at 1 year.Quintile analysis and multilevel multivariate modeling were used to identify the existence of a volume-outcome relationship and allow adjustment of results for significant determinants of outcome. RESULTS: A total of 27,660 femoropopliteal bypass and 4161 femorodistal bypass procedures were identified.As volume increased, in-hospital mortality after popliteal bypass decreased from 6.5% to 4.9% (P = 0.0045), with a corresponding odds ratio of 0.980 [95% confidence interval (CI), 0.929-0.992; P = 0.014] for every increase of 50 patients per year. Major amputation decreased from 4.1% to 3.2% (P = 0.006) in high-volume hospitals, with a reduction in risk of 0.955 (95% CI, 0.928-0.983; P = 0.002) at 1 year.For distal bypass, in-hospital mortality decreased from 9.8% to 5.5% (P = 0.004) and 1-year major amputation decreased from 25.4% to 18.2% (P < 0.001), with a corresponding odds ratio of 0.658 (95% CI, 0.517-0.838; P < 0.0001) as the volume increased.An increase in the chance of revision surgery (10.6% vs 8.2%, P < 0.001) was seen with higher volume, with an increased odds ratio of 1.031 (95% CI, 1.005-1.057; P = 0.018). CONCLUSIONS: A positive volume-outcome relationship exists for LEAB procedures even after employing multilevel risk adjustment models. There are benefits in terms of mortality and limb salvage both in the short-term and at 1 year postsurgery.