Renal Function is the Main Predictor of Acute Kidney Injury after Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Postoperative acute kidney injury (AKI) may occur in up to 18% of elective endovascular abdominal aortic aneurysm repair (EVAR) and has been associated with poor outcome; however, it is not clear which patients are at highest risk, to target renoprotection effectively. We sought to determine the predictive factors of AKI after elective EVAR.

METHODS

Overall, 947 patients undergoing elective EVAR between January 2004 and December 2014 were analyzed, using prospectively collected data. Postoperative AKI was defined by serum creatinine change within 48 hr, as per the Kidney Disease Improving Global Outcomes guidelines. Cardiovascular and kidney-disease risk factors were entered in univariate and multivariate analyses to assess influence on AKI development.

RESULTS

Overall, 167 (17.6%) patients developed AKI but only 2 patients required dialysis perioperatively. At multivariate analysis, adjusted for established AKI-risk factors and parameters that differed between groups at baseline, preoperative estimated glomerular filtration rate (eGFR; as per the chronic kidney disease epidemiology [CKD] formula); odds ratio (OR): 1.02 (per unit decrease); 95% confidence interval (CI): 1.003-1.041; P = 0.025; and chronic kidney disease (CKD) stage > 2 (OR: 1.28; 95% CI: 1.249-2.531, P = 0.001) were associated with development of AKI.

CONCLUSIONS

AKI was common after elective infrarenal EVAR and preoperative renal function appears to be the main factor associated with AKI. Patients with a low eGFR need to be targeted with more aggressive renal protection.

Long-Term Renal Function after Endovascular Aneurysm Repair

BACKGROUND AND OBJECTIVES

Endovascular repair (EVAR) is a common treatment for abdominal aortic aneurysm (AAA). However, its long-term effects on renal function remain unclear. We aimed to assess long-term renal dysfunction after EVAR using a contemporary estimate of GFR and to compare long-term renal outcomes in patients after EVAR with open aneurysm repair (OAR) and in patients without an AAA.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

We performed a nested case-matched analysis of 726 patients (using a prospectively maintained database for repairs that took place between January 2000 and May 2010 in a tertiary center): 121 patients undergoing OAR (with data at baseline and 5 years postrepair) were case matched (age, sex, smoking, diabetes, baseline eGFR) to patients undergoing suprarenal and infrarenal fixation EVAR (242 in each group) and to 121 patients undergoing carotid endarterectomy (CEA) without AAA. Changes in eGFR were compared (1 and 5 years).

RESULTS

The OAR patients lost an average of 7.4 ml/min per 1.73 m2 at 5 years (95% confidence interval [95% CI], 4.8 to 10.6), compared with 8.2 ml/min per 1.73 m2 (95% CI, 6.5 to 10.8; P<0.001) for infrarenal-fixation EVAR, 16.9 ml/min per 1.73 m2 (95% CI, 13.0 to 21.9, P<0.001) for suprarenal-fixation EVAR, and 5.4 ml/min per 1.73 m2 (95% CI, 1.7 to 7.5; P<0.001) for CEA. The decrease in eGFR was steeper during the first postoperative year, with each group losing -2.2 ml/min per 1.73 m2 (infrarenal-fixation EVAR), -10.7 ml/min per 1.73 m2 (suprarenal-fixation EVAR), and -4.6 ml/min per 1.73 m2 (OAR), compared with -1.9 ml/min per 1.73 m2 for CEA.

CONCLUSIONS

Elective EVAR is associated with a significant decline in eGFR after 5 years, which is steeper in the first postoperative year and more pronounced compared with a similar population with atherosclerotic disease.

Economic evaluation of a single-pill triple antihypertensive therapy with valsartan, amlodipine, and hydrochlorothiazide against its dual components

The aim of this study was to compare the cost-utility of the first available single-pill triple combination antihypertensive therapy containing valsartan (V), amlodipine (A) and hydrochlorothiazide (H), with each of the same components dual combinations in patients with moderate to severe hypertension.

A Markov model with eight health states was constructed. The short-term effect of antihypertensive treatment on blood pressure was extrapolated through the Hellenic SCORE and Framingham risk equations, estimating the long-term survival and quality-adjusted life-years (QALYs) saved. Costs and outcomes were evaluated over lifetime, divided into annual cycles and discounted at 3.0 % with 2013 as reference year. The analysis was conducted by the Greek third-party-payer perspective.

The triple combination treatment cost was estimated at €16,525 compared to €15,480 for V/A, €14,125 for V/H and €11,690 for A/H. The QALYs saved with the triple combination were 12.76 vs. 12.64, 12.61 and 12.38 for double combinations respectively. The incremental cost-effectiveness ratio of the triple combination versus V/A and A/H was far lower than the Greek GDP per capita (€8,690/QALY and €12,695/QALY, respectively) and really close for V/H (€16,192/QALY), suggesting V/A/H combination to be cost-effective. Extensive sensitivity analyses confirmed the robustness of the results. The probability that the triple combination is cost effective was more than 90 % at a willingness-to-pay threshold of €18,000/QALY.

This is the first study to evaluate the cost-utility of a single-pill triple combination. The single-pill V/A/H therapy is a cost-effective antihypertensive choice for the treatment of moderate to severe hypertension, compared to its dual components.

Incidence of Acute Kidney Injury (AKI) after Endovascular Abdominal Aortic Aneurysm Repair (EVAR) and Impact on Outcome

BACKGROUND

Acute kidney injury (AKI) is an important post-operative complication that may impact on mortality, morbidity, and cost. The incidence after endovascular aneurysm repair (EVAR) remains unknown, as the current literature has not employed consistent definitions. The aim of this study is to assess the incidence of AKI after elective EVAR and examine the impact of AKI on mortality and cardiovascular morbidity using the current universally accepted definitions.

METHODS

This was a cohort study using prospectively collected data, including consecutive patients undergoing elective EVAR for an infrarenal abdominal aortic aneurysm (AAA). Those with end stage renal failure were excluded. The primary endpoint was incidence of AKI as per the "Acute Kidney Injury Network" (AKIN), and "Kidney Disease Improving Global Outcomes" (KDIGO) criteria. Secondary endpoints included AKI stage, drop in estimated glomerular filtration rate (eGFR), and mortality and cardiovascular morbidity.

RESULTS

149 patients were included (16 females, 11%; mean age: 69 ± 8 years; mean AAA diameter: 6.0 ± 1.1 cm), 28 (18.8%) of whom developed AKI (26 patients classified as stage 1 and 2 as stage 2). Within 48 hours, those with AKI dropped their eGFR from 61 ± 20 mL/kg/1.73 m(2) to 51 ± 20 units (p < .001), and those without from 75 ± 9 to 74 ± 10 units (p < .001). None required dialysis during a 33 ± 11 month follow up. Development of AKI was associated with mortality (HR 0.035, 95% CI: 0.005 to 0.240, p < .001) and cardiovascular morbidity (HR: 0.021, 95% CI: 0.004 to 0.11, p < .001) on adjusted regression analysis.

CONCLUSIONS

The incidence of AKI after EVAR is significant and is independently associated with medium-term mortality and morbidity.

Review of blood pressure control rates and outcomes

Despite the high prevalence of hypertension and documented benefits of blood pressure (BP) control, >40% of patients with hypertension are not controlled. A majority of uncontrolled hypertensive patients receive two or more antihypertensive drugs. The current review examined the relationship between antihypertensive combination drug therapy, achievement of goal BP, and cardiovascular (CV) outcomes. Articles were selected from a PubMed search using a prespecified search strategy. Randomized, controlled clinical trials of adult human subjects published in English between January 1991 and January 2013 were included. From 2319 identified articles, 28 met inclusion criteria and contained a total of 226,877 subjects. There were seven placebo-controlled studies and 21 treatment comparator and combination therapy studies. The studies included in this review reported a positive association between the degree of BP lowering, number of medications, and CV outcomes. As combination therapy became available, it was increasingly utilized in clinical trials and enabled an increased proportion of patients to achieve a prespecified BP target. Adverse events with monotherapy and combination therapy were as anticipated for the specific classes of antihypertensive therapy. Although many patients reach BP goal, combination antihypertensive therapy is often needed to reach BP goal. Effective BP lowering has been shown to result in improvements in CV outcomes.