Evaluation of the nephrotoxicity of iodixanol in patients with predisposing factors to contrast medium induced nephropathy referred for contrast enhanced computed tomography

Three-dimensional transesophageal echocardiography is an attractive alternative to cardiac multi-detector computed tomography for aortic annular sizing: Systematic review and meta-analysis

BACKGROUND

Cardiac imaging is the cornerstone of the pretranscatheter aortic valve replacement (TAVR) assessment. Multi-detector computed tomography (MDCT) is considered the conventional imaging modality. However, there is still no definitive gold standard. Targeted cohort of inoperable high-risk patients with underlying comorbidities, particularly renal impairment, makes apparent the need for MDCT alternative. We aimed to demonstrate the correlation extent between MDCT and three-dimensional transesophageal echocardiography (3DTEE) aortic annular area measures and to answer the question: Is 3DTEE a good alternative to MDCT?

METHODS

A systematic literature search and meta-analysis were conducted to evaluate the degree of correlation and agreement between 3DTEE and MDCT aortic annular sizing. A thorough assessment of EMBASE, PubMed, and Cochrane Central Register of Controlled Trials (CENTRAL) was performed. All studies comparing 3DTEE and MDCT in relation to aortic annular sizing were included.

RESULTS

Thirteen studies were included (N = 1228 patients). A strong linear correlation was found between 3DTEE and MDCT measurements of aortic annulus area (r = 0.84, P < 0.001), mean perimeter (r = 0. 0.85, P < 0.001), and mean diameter (r = 0.80, P < 0.001). Bland-Altman plots revealed smaller mean 3DTEE values in comparison to MDCT for aortic annular area, the mean difference being -2.22 mm² with 95% limits of agreement -12.79 to 8.36.

CONCLUSION

Aortic annulus measurements obtained by 3DTEE demonstrated a high level of correlation with those evaluated by MDCT. This makes 3DTEE a feasible choice for aortic annulus assessment, with advantage of real time assessment, lack of contrast, and no radiation exposure.

Contrast-induced acute kidney injury after computed tomography prior to transcatheter aortic valve implantation

AIM

To identify independent predictors of contrast medium-induced acute kidney injury (CI-AKI) after enhanced multidetector-row computed tomography (MDCT) prior to transcatheter aortic valve implantation (TAVI) in high-risk patients.

MATERIALS AND METHODS

The present single-centre study analysed retrospectively 361 patients who were assessed using MDCT prior to TAVI. CI-AKI was defined as an increase in serum creatinine (SCr) of ≥ 25% or ≥ 0.5 mg/dl in at least one sample over baseline (24 h before MDCT) and at 24, 48, and 72 h after MDCT.

RESULTS

A total of 38 patients (10.5%) experienced CI-AKI. As compared to patients without CI-AKI, they presented more frequently with estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2), (81.6% versus 64.4%, p = 0.045) and tended to receive higher volumes of iodinated contrast media (ICM; 55.3% versus 39%, p = 0.057). There was a significant interaction between baseline eGFR and the amount of intravenous ICM administered (pfor interaction = <0.001) identifying the amount of ICM >90 ml as independent predictive factor of CI-AKI only in patients with baseline eGFR <60 ml/min/1.73m(2) (OR 2.615; 95% CI: 1.21-5.64).

CONCLUSION

One in ten elderly patients with aortic stenosis undergoing MDCT to plan a TAVI procedure experienced CI-AKI after intravenous ICM injection. Intravenous administration of <90 ml of ICM reduces this risk in patients with or without pre-existing impaired renal function. However, in the majority of patients renal function recovers before the TAVI procedure.

Meta-analysis: serum creatinine changes following contrast enhanced CT imaging

PURPOSE

Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN.

MATERIALS AND METHODS

A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach.

RESULTS

Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0-8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01-0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6-2.1%). Patients with chronic kidney disease (odds ratio 2.26, p<0.001) or diabetes mellitus (odds ratio 3.10, p<0.001) were at increased risk for the development of CIN.

CONCLUSION

CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.

Creatinine increases after intravenous contrast administration: incidence and impact

OBJECTIVE

The incidence of creatinine increases after intravenous contrast (postcontrast creatinine increases, PCCI) is controversial, ranging from 0% to >25%. We sought to determine what factors influenced these divergent estimates of PCCI incidence. Where possible, the association of PCCI with long-term adverse outcomes was also studied.

MATERIALS AND METHODS

Both observational studies and prospective randomized trials were reviewed. Definitions of clinically significant PCCI, incidence of PCCI, and its association with baseline kidney function, the setting in which intravenous contrast was administered, and the short- and long-term consequences of PCCI were extracted.

RESULTS

Baseline renal function impairment and inpatient versus outpatient status are the major risk factors for PCCI. PCCI is possibly associated with clinically significant short- and long-term adverse events.

CONCLUSIONS

PCCI occurs despite a number of potential confounding issues. The incidence is increased as kidney function at baseline is diminished and for inpatients. There is limited data on long-term outcomes following PCCI in this setting.

The PREDICT study: a randomized double-blind comparison of contrast-induced nephropathy after low- or isoosmolar contrast agent exposure

OBJECTIVE

The objective of the PREDICT (patients with renal impairment and diabetes undergoing computed tomography) study was to compare the incidence of contrast-induced nephropathy (CIN) after administration of low-osmolar (iopamidol 370, 796 mOsm/kg) or isoosmolar (iodixanol 320, 290 mOsm/kg) contrast medium in patients with diabetes and chronic kidney disease undergoing CT.

SUBJECTS AND METHODS

Two hundred sixty-three patients with moderate to severe chronic kidney disease (estimated glomerular filtration rate [GFR] = 20-59 mL/min/1.73 m(2)) and diabetes mellitus were randomized to receive at least 65 mL of iopamidol 370 or iodixanol 320 for a CT procedure. Serum creatinine levels were measured at baseline and 48-72 hours after contrast administration. CIN was defined as an increase in the serum creatinine level after contrast administration of >or= 25% from the baseline level. The incidence of CIN in the total study population and the incidence of CIN in patients at increased risk for CIN were compared using Fisher's exact test.

RESULTS

Two hundred forty-eight patients were included in the CIN analysis: 125 receiving iopamidol 370 and 123 receiving iodixanol 320. Study population demographics were comparable, as was baseline renal function (estimated GFR = 47.6 mL/min/1.73 m(2) for the iopamidol 370 group vs 49.9 mL/min/1.73 m(2) for the iodixanol 320 group; p = 0.16). Increases in the serum creatinine value of >or= 25% occurred in seven patients (5.6%) receiving iopamidol 370 and in six patients (4.9%) receiving iodixanol 320 (95% CI, -4.8% to 6.3%; p = 1.0). The mean serum creatinine change from the baseline level was 0.04 mg/dL in both groups (analysis of covariance, p = 0.80). In patients with a baseline serum creatinine value of >or= 2.0 mg/dL, baseline estimated GFR of <or= 40 mL/min/1.73 m(2), or those receiving > 140 mL of contrast medium, the incidence of CIN was low and comparable between the two study groups (p = 1.0 in all instances).

CONCLUSION

The incidence of CIN in patients with diabetes and chronic kidney disease receiving IV contrast medium was not significantly different after CT using iopamidol 370 or iodixanol 320.

Iso-osmolality versus low-osmolality iodinated contrast medium at intravenous contrast-enhanced CT: effect on kidney function

PURPOSE

To determine the effects of iso-osmolality contrast medium compared with a low-osmolality agent on renal function (serum creatinine [SCr] and glomerular filtration rate [GFR]) in high-risk patients undergoing intravenous contrast material-enhanced CT.

MATERIALS AND METHODS

This HIPAA-compliant study was IRB-approved; formal consent was obtained. One hundred seventeen patients (83 men, 34 women; mean age, 64.3 years; range, 18-86 years) with decreased renal function underwent contrast-enhanced CT with either iso-osmolality iodixanol (n = 61) or low-osmolality iopromide (n = 56). Outcome measures were of SCr increase or GFR decrease for 3 days after CT, a SCr increase (of >or=0.5 mg/dL [44.2 micromol/L, 25%] or >or=1.0 mg/dL [88.4 micromol/L, 50%]), a GFR reduction (of >or=5 mL/min), and patient outcome at 30- and 90-day follow-up.

RESULTS

Iodixanol decreased SCr (mean +/- standard deviation) from 1.77 mg/dL +/- 0.24 (156.47 micromol/L +/- 21.22) at baseline to 1.65 mg/dL +/- 0.35 (145.86 micromol/L +/- 30.94, P = .046) at day 1, 1.73 mg/dL +/- 0.53 (152.93 micromol/L +/- 46.85, not significant) at day 2, and 1.73 mg/dL +/- 0.55 (152.93 micromol/L +/- 48.62, not significant) at day 3 (not significant). Iopromide increased SCr from 1.75 mg/dL +/- 0.32 (154.7 micromol/L +/- 28.29) at baseline to 1.8 mg/dL +/- 0.42 (159.12 micromol/L +/- 15.59) at day 1, 1.77 mg/dL +/- 0.49 (156.47 micromol/L +/- 43.32) at day 2, and 1.77 mg/dL +/- 0.62 (156.47 micromol/L +/- 54.81) at day 3 (not significant). Iodixanol increased and iopromide decreased GFR on all 3 days after CT (not significant). Fewer patients in the iodixanol group (8.5%) than in the iopromide group (27.8%) had SCr increase 0.5 mg/dL or higher (>or=25%, P = .012). Two patients in each group had SCr increase of 1.0 mg/dL or more (not significant). More patients in the iopromide group (42.3%) than in the iodoxanol group (24.1%) had a GFR reduction of 5 mL/min or higher (P = .0426). No patient had a contrast material-related adverse event at 30- or 90-day follow-up.

CONCLUSION

Intravenous contrast material application in high-risk patients is unlikely to be associated with permanent adverse outcomes. SCr levels after contrast material administration are lower in iodixanol than iopromide groups.