High-risk situations and procedures

Feasibility of Reduced Iodine Loads for Vascular Assessment Prior to Transcatheter Aortic Valve Implantation (TAVI) Using Spectral Detector CT

Reduced iodine loads for computed tomography (CT)-based vascular assessment prior to transcatheter aortic valve implantation (TAVI) may be feasible in conjunction with a spectral detector CT scanner. This prospective single-center study considered 100 consecutive patients clinically referred for pre-TAVI CT. They were examined on a dual-layer detector CT scanner to obtain an ECG-gated cardiac scan and a non-ECG-gated aortoiliofemoral scan. Either a standard contrast media (SCM) protocol using 80 mL Iohexol 350 mgI/mL (iodine load: 28 gI) or a body-mass-index adjusted reduced contrast media (RCM) protocol using 40-70 mL Iohexol 350 mgI/mL (iodine load: 14-24.5 gI) were employed. Conventional images and virtual monoenergetic images at 40-80 keV were reconstructed. A threshold of 250 HU was set for sufficient attenuation along the arterial access pathway. A qualitative assessment used a five-point Likert scale. Sufficient attenuation in the thoracic aorta was observed for all patients in both groups using conventional images. In the abdominal, iliac, and femoral segments, sufficient attenuation was observed for the majority of patients when using virtual monoenergetic images (SCM: 96-100% of patients, RCM: 88-94%) without statistical difference between both groups. Segments with attenuation measurements below the threshold remained qualitatively assessable as well. Likert scores were 'excellent' for virtual monoenergetic images 50 keV and 55 keV in both groups (RCM: 1.2-1.4, SCM: 1.2-1.3). With diagnostic image quality maintained, it can be concluded that reduced iodine loads of 14-24.5 gI are feasible for pre-TAVI vascular assessment on a spectral detector CT scanner.

Renal transplant recipients undergoing endovascular abdominal aortic aneurysm repair have increased risk of perioperative acute kidney injury but no difference in late mortality

OBJECTIVE

Renal transplant is associated with substantial survival advantage in patients with end-stage renal disease. However, little is known about the outcomes of renal transplant recipients (RTRs) after endovascular abdominal aortic aneurysm repair (EVAR). This study aimed to study the effect of renal transplant on perioperative outcomes and long-term survival after elective infrarenal EVAR.

METHODS

The Vascular Quality Initiative database was queried for all patients undergoing elective EVAR from 2003 to 2021. Functioning RTRs were compared with non-renal transplant recipients without a diagnosis of end-stage renal disease (non-RTRs). The outcomes included 30-day mortality, acute kidney injury (AKI), new renal failure requiring renal replacement therapy (RRT), endoleak, aortic-related reintervention, major adverse cardiac events, and 5-year survival. A logistic regression analysis was used to assess the association between RTRs and perioperative outcomes.

RESULTS

Of 60,522 patients undergoing elective EVAR, 180 (0.3%) were RTRs. RTRs were younger (median, 71 years vs 74.5 years; P < .001), with higher incidence of hypertension (92% vs 84%; P = .004) and diabetes (29% vs 21%; P = .005). RTRs had higher median preoperative serum creatinine (1.3 mg/dL vs 1.0 mg/dL; P < .001) and lower estimated glomerular filtration rate (51.6 mL/min vs 69.4 mL/min; P < .001). There was no difference in the abdominal aortic aneurysm diameter and incidence of concurrent iliac aneurysms. Procedurally, RTRs were more likely to undergo general anesthesia with lower amount of contrast used (median, 68.6 mL vs 94.8 ml; P < .001) and higher crystalloid infusion (median, 1700 mL vs 1500 mL; P = .039), but no difference was observed in the incidence of open conversion, endoleak, operative time, and blood loss. Postoperatively, RTRs experienced a higher rate of AKI (9.4% vs 2.7%; P < .001), but the need for new RRT was similar (1.1% vs 0.4%; P = .15). There was no difference in the rates of postoperative mortality, aortic-related reintervention, and major adverse cardiac events. After adjustment for potential confounders, RTRs remained associated with increased odds of postoperative AKI (odds ratio, 3.33; 95% confidence interval, 1.93-5.76; P < .001) but had no association with other postoperative complications. A subgroup analysis identified that diabetes (odds ratio, 4.21; 95% confidence interval, 1.17-15.14; P = .02) is associated with increased odds of postoperative AKI among RTRs. At 5 years, the overall survival rates were similar (83.4% vs 80%; log-rank P = .235).

CONCLUSIONS

Among patients undergoing elective infrarenal EVAR, RTRs were independently associated with increased odds of postoperative AKI, without increased postoperative renal failure requiring RRT, mortality, endoleak, aortic-related reintervention, or major adverse cardiac events. Furthermore, 5-year survival was similar. As such, while EVAR may confer comparable benefits and technical success perioperatively, RTRs should have aggressive and maximally optimized renal protection to mitigate the risk of postoperative AKI.

Long-Term Outcomes After Transfemoral-Transcatheter Aortic Valve Implantation in Very Old Patients Using the Balloon-Expandable Bioprosthesis

Transcatheter aortic valve implantation (TAVI) can be safely performed in old patients. Increasing longevity raises often the question whether TAVI can be still useful for patients beyond a certain age limit. Data on long-term outcomes of elderly patients after TAVI are sparse. We sought to assess the impact of very advanced age on long-term outcomes after transfemoral (TF)-TAVI. Data of 103 patients undergoing TF-TAVI with the balloon-expandable bioprosthesis between May/2014 and May/2019 were analyzed. We divided the cohort into two age groups: ≥85 years (group1: n = 37; 87.5 ± 2.6 years; STS-Score 3.9 ± 1.4) versus < 85 years (group2: n = 66; 80 ± 3.1 years; STS-Score 3.4 ± 1.8). We conducted up to 6 years clinical follow-up. Overall mortality at 30 days was 3.8% without significant differences between the two age groups. Incidence of major vascular injury (8.6 vs. 6.3%, p = .695) and stroke (2.8 vs. 3%, p = 1) was not significantly different between group 1 and 2, respectively. More than mild paravalvular leakage was found in 1 patient (group 1). The mean long-term survival probability was 51.3 months [95% CI: 42.234–60.430] in group 1 versus 49.5 months [95% CI: 42.155–56.972] in group2 (p = .921). Long-term outcomes of very old patients after TF-TAVI show a similar treatment benefit compared to the younger patients.

Serial Urinary Tissue Inhibitor of Metalloproteinase-2 and Insulin-Like Growth Factor-Binding Protein 7 and the Prognosis for Acute Kidney Injury over the Course of Critical Illness

INTRODUCTION

Over the course of critical illness, there is a risk of acute kidney injury (AKI), and when it occurs, it is associated with increased length of stay, morbidity, and mortality. The urinary cell-cycle arrest markers tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7) have been utilized to predict the risk of AKI over the next 12 h from the time of sampling. The aim of this analysis was to evaluate the utility of [TIMP-2] × [IGFBP7] measured serially to anticipate the occurrence of AKI over the first 7 days of critical illness.

METHODS

This analysis is from a prospective, blinded, observational, international study of patients admitted to intensive care units. We designed the analysis to emulate a clinician-driven serial testing strategy. Urine samples collected every 12 h up to 3 days from 530 patients were considered for analysis. We evaluated [TIMP-2] × [IGFBP7] results for the first 3 measurements (baseline, 12 and 24 h) and continued to evaluate additional results if any of the first 3 were positive >0.3 (ng/mL)2/1,000. Patients were stratified by number of [TIMP-2] × [IGFBP7] results >0.3 (ng/mL)2/1,000 and number of results >2.0 (ng/mL)2/1,000. The primary endpoint was AKI stage 2-3 defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria.

RESULTS

The median (interquartile range) age was 64 (53-74) years, 61% were men, and 79% were Caucasian. The median APACHE III score was 71 (51-93), and 82% required mechanical ventilation. Baseline serum creatinine was 0.8 mg/dL and 164/530 (31%) developed the primary endpoint by day 7 with a median time from baseline to stage 2/3 AKI of 26 (8-56) h. In patients with negative values for the first 3 tests (≤0.3 (ng/mL)2/1,000), the cumulative incidence of the primary endpoint at 7 days was 13.0%. Conversely, for those with one, two, or three strongly positive values (>2.0 (ng/mL)2/1,000), the cumulative incidence for the primary endpoint at 7 days was 57.7, 75.0, and 94.4%, respectively, p < 0.001 for trend. There were 3.4% with test results between 0.3 and 2.0 (ng/mL)2/1,000 at all measurements; one third of those patients developed the primary endpoint. We observed a graded increase in the primary endpoint in Kaplan-Meier plots for successively positive test results over time.

CONCLUSION

Serial urinary [TIMP-2] × [IGFBP7] at baseline, 12 and 24 h, and up through 3 days are prognostic for the occurrence of stage 2/3 AKI over the course of critical illness. Three consecutive negative values (≤0.3 (ng/mL)2/1,000) are associated with very low (13.0%) incidence of stage 2/3 AKI over the course of 7 days. Conversely, emerging or persistent, strongly positive results [>2.0 [ng/mL]2/1,000] predict very high incidence rates (up to 94.4%) of stage 2/3 AKI. There was a low rate of test results between 0.3 and 2.0 (ng/mL)2/1,000, where the primary endpoint was observed in a third of cases.

CT angiography prior to TAVI procedure using third-generation scanner with wide volume coverage: feasibility, renal safety and diagnostic accuracy for coronary tree

OBJECTIVE:

To evaluate feasibility, image quality and accuracy of a reduced contrast volume protocol for pre-procedural CT imaging in transcatheter aortic valve implantation (TAVI) using a third generation wide array CT scanner.

METHODS:

115 consecutive patients (51F, mean age 82.5 ± 6.2 y, mean BMI 26.7 ± 3.6) referred for TAVI were examined with wide-array CT scanner with a combined scan protocol and a total amount of 50 ml contrast agent. A 4-point visual scale (4-1) was used to assess image quality . Contrast attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the level of the aortic root, ascending/descending aorta, subrenal aorta and at the level of right and left common femoral arteries. Coronary tree was assessed and compared with invasive coronary angiography (ICA). Aortic annulus measurements were compared with final procedural results. Patients creatinine was monitored at the baseline and 72 h after procedure.

RESULTS:

Median quality score value was >3. Mean CNR at the level of the aortic root, ascending/descending aorta, subrenal aorta and at the level of right and left common femoral arteries were 14.8 ± 2.3, 15.7 ± 1.7, 14.9 ± 3.1, 15.8 ± 4.7, 20.3 ± 9.9, 20.8 ± 6.9 respectively. Only 1 patient had moderate paravalvular regurgitation. In comparison with ICA for coronary assessment CTA showed in a segment based analysis sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 97, 85, 99,62 and 88% respectively. Mean creatinine before CT and 72 h after procedure were 1.21 ± 0.52 and1.22 ± 0.49 mg dl^-1. Mean DLP was 442.4 ± 21.2 mGy/cm.

CONCLUSION:

CT with low contrast volume is feasible and clinically useful, allowing precise pre-procedural TAVI planning with accurate assessment of coronary tree.

ADVANCES IN KNOWLEDGE:

third generation CT scanner with whole heart coverage allows examinations for assessment of aorta and coronary arteries in TAVI planning using low dose of contrast medium maintaining good quality and high diagnostic accuracy.

Graft Contrast-Induced Nephropathy Caused by Prerenal Transplant Computed Tomography: A Case Report

BACKGROUND

We report a case of posttransplant contrast-induced nephropathy (CIN) that occurred after performing computed tomography (CT) scanning for pretransplant cardiac and vascular evaluation.

CASE PRESENTATION

The patient had an 8-year history of hemodialysis and was admitted to the hospital for a kidney transplant from a deceased donor. Cardiac CT imaging and 3-dimensional low-extremity CT angiography were performed to confirm the patient's cardiac and iliac artery function. After successful transplantation surgery, the patient had a urine output of 250 mL and a reduced creatinine level from 8.8 to 2.3 mg/dL on postoperative day 4. However, urine output suddenly decreased to 30 mL and the creatinine level suddenly increased to 7.6 md/dL without any symptoms such as fever or graft tenderness. The patient tested negative for panel-reactive antibodies and donor-specific antibodies, and he was discharged 1 week later with an improvement in symptoms. Results of a graft biopsy indicated CIN, and the contrast-enhanced kidney was observed on noncontrast CT imaging that was performed immediately after transplantation to rule out vascular problems as well as other complications.

CONCLUSIONS

There may be residual contrast present from pretransplant CT imaging, which could affect the functional kidney grafts after transplantation and can lead to CIN. This scenario could potentially lead to loss of graft function, suggesting that caution should be observed when ordering CT imaging in this patient population.

Incidence, Predictors, and Impact on Six-Month Mortality of Three Different Definitions of Contrast-Induced Acute Kidney Injury After Coronary Angiography

We assessed incidence, predictors, and impact on 6-month mortality of contrast-induced acute kidney injury (CI-AKI) after coronary angiography with or without percutaneous coronary intervention in patients with acute coronary syndrome (ACS), according to 3 different CI-AKI definitions. Serum creatinine (sCr) was assessed at baseline and 48 to 72 hours after procedure to classify patients into 3 CI-AKI groups: Group 1: increase in sCR ≥25% over baseline but absolute increase <0.5 mg/dl; Group 2: absolute increase ≥0.5 mg/dl; Group 3: absolute increase ≥0.3 mg/dl or ≥50% over baseline. The association between CI-AKI and all-cause 6-month mortality was assessed using multivariate Cox regression. Among 1,002 patients included, median age was 68 [57 to 79] years. The sample had the following characteristics: 70% men, 25% diabetics, 22% had a history of myocardial infarction, 21% had baseline estimated glomerular filtration rate (as calculated by the Modification of Diet in Renal Disease)  <60 ml/min/1.72 m², 34% had ST-segment elevation myocardial infarction, 61% underwent percutaneous coronary intervention, and 43% had multivessel disease. Based on changes in sCr, 89 patients (8.9%) were classified in Group 1; 69 (6.9%) in Group 2; and 157 (15.7%) in Group 3, whereas sCr did not increase >25% in the remaining 844 (84.2%). CI-AKI was significantly associated with 6-month all-cause mortality using the definitions for Group 2 (hazard ratio 3.1, 95% confidence interval [CI] 1.5 to 6.6, p = 0.002) and Group 3 (hazard ratio 2.03, 95% CI 1.03 to 4.0, p = 0.04), but not Group 1. In conclusion, based on the definition used for CI-AKI, CI-AKI is observed in 6% to 15.7% of patients. An increase of 25% over baseline sCr does not identify high-risk patients. CI-AKI defined as an increase in sCr >0.3 mg/dl identifies 15.7% of the population at 2-fold higher risk of mortality.

Contrast-induced acute kidney injury in kidney transplant recipients: A systematic review and meta-analysis

AIM

To evaluate the incidence of contrast-induced acute kidney injury (CIAKI) in kidney transplant recipients.

METHODS

A literature search was performed using MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews from the inception of the databases through July 2016. Studies assessing the incidence of CIAKI in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of CIAKI.

RESULTS

Six studies of 431 kidney transplant recipients were included in the analyses to assess the incidence of CIAKI in kidney transplant recipients. The estimated incidence of CIAKI and CIAKI-requiring dialysis were 9.6% (95%CI: 4.5%-16.3%) and 0.4% (95%CI: 0.0%-1.2%), respectively. A sensitivity analysis limited only to the studies that used low-osmolar or iso-osmolar contrast showed the estimated incidence of CIAKI was 8.0% (95%CI: 3.5%-14.2%). The estimated incidences of CIAKI in recipients who received contrast media with cardiac catheterization, other types of angiogram, and CT scan were 16.1% (95%CI: 6.6%-28.4%), 10.1% (95%CI: 4.2%-18.0%), and 6.1% (95%CI: 1.8%-12.4%), respectively. No graft losses were reported within 30 d post-contrast media administration. However, data on the effects of CIAKI on long-term graft function were limited.

CONCLUSION

The estimated incidence of CIAKI in kidney transplant recipients is 9.6%. The risk stratification should be considered based on allograft function, indication, and type of procedure.

Diagnostic accuracy of serum cystatin C for early recognition of contrast induced nephropathy in Western Indians undergoing cardiac catheterization

Aims

We aimed to compare the diagnostic efficacy of serum cystatin C (sCyC) for contrast induced nephropathy (CIN) in Western Indians undergoing cardiac catheterization. We also aimed to propose a clinically applicable cut-off of sCyC for early identification of CIN in this ethnic group.

Methods

In this prospective study, 253 patients undergoing coronary angiography and/or percutaneous coronary intervention were enrolled. The demographic and risk factor details, levels of sCr at baseline, 24 and 48 h after the procedure, whereas baseline and 24 h levels of sCyC were noted. Increase of 0.5 mg/dl or ≥25% from baseline sCr was used to define CIN. Optimum cut off of sCyC for CIN diagnosis was obtained using Receiver Operating Characteristic (ROC) curve analysis.

Results

After 48 h of contrast media (CM) exposure, the incidence of CIN was 12.25% (31 patients) according to sCr definition, where only 3.9% (10 patients) had sCr rise in 24 h. Overall significant (p < 0.0001) rise in mean levels of sCr (48 h) and sCyC (24 h) was observed in CIN patients. However, the mean sCr rise at 24 h was non-significant. The optimum cut off of sCyC for diagnosing CIN was found to be a rise of ≥10% from baseline (AUC – 0.901; sensitivity – 100%, specificity – 77.89%). According to sCyC, 94 (37.15%) patients had CIN.

Conclusion

We may conclude that a rise of ≥10% in sCyC at 24 h could be used as a reliable marker for identification of CIN in western Indians undergoing cardiac catheterization.

Adverse effects of drugs on the kidney

The number of drugs presently marketed is countless, their prescription is relentlessly growing, such that the likelihood of adverse effects is strikingly increasing. As many drugs are cleared by the body through kidney excretion, renal adverse events are likely. In this review we shall concisely describe the pathophysiologic mechanisms of renal damage by drugs, the different clinical presentations outlining renal toxicity in the course of pharmacologic treatment, and the main offending agents.

Acute Kidney Injury Risk Prediction in Patients Undergoing Coronary Angiography in a National Veterans Health Administration Cohort With External Validation

BACKGROUND

Acute kidney injury (AKI) occurs frequently after cardiac catheterization and percutaneous coronary intervention. Although a clinical risk model exists for percutaneous coronary intervention, no models exist for both procedures, nor do existing models account for risk factors prior to the index admission. We aimed to develop such a model for use in prospective automated surveillance programs in the Veterans Health Administration.

METHODS AND RESULTS

We collected data on all patients undergoing cardiac catheterization or percutaneous coronary intervention in the Veterans Health Administration from January 01, 2009 to September 30, 2013, excluding patients with chronic dialysis, end-stage renal disease, renal transplant, and missing pre- and postprocedural creatinine measurement. We used 4 AKI definitions in model development and included risk factors from up to 1 year prior to the procedure and at presentation. We developed our prediction models for postprocedural AKI using the least absolute shrinkage and selection operator (LASSO) and internally validated using bootstrapping. We developed models using 115 633 angiogram procedures and externally validated using 27 905 procedures from a New England cohort. Models had cross-validated C-statistics of 0.74 (95% CI: 0.74-0.75) for AKI, 0.83 (95% CI: 0.82-0.84) for AKIN2, 0.74 (95% CI: 0.74-0.75) for contrast-induced nephropathy, and 0.89 (95% CI: 0.87-0.90) for dialysis.

CONCLUSIONS

We developed a robust, externally validated clinical prediction model for AKI following cardiac catheterization or percutaneous coronary intervention to automatically identify high-risk patients before and immediately after a procedure in the Veterans Health Administration. Work is ongoing to incorporate these models into routine clinical practice.

Low contrast media volume in pre-TAVI CT examinations

PURPOSE

To evaluate image quality using reduced contrast media (CM) volume in pre-TAVI assessment.

METHODS

Forty-seven consecutive patients referred for pre-TAVI examination were evaluated. Patients were divided into two groups: group 1 BMI < 28 kg/m(2) (n = 29); and group 2 BMI > 28 kg/m(2) (n = 18). Patients received a combined scan protocol: retrospective ECG-gated helical CTA of the aortic root (80kVp) followed by a high-pitch spiral CTA (group 1: 70 kV; group 2: 80 kVp) from aortic arch to femoral arteries. All patients received one bolus of CM (300 mgI/ml): group 1: volume = 40 ml; flow rate = 3 ml/s, group 2: volume = 53 ml; flow rate = 4 ml/s. Attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the levels of the aortic root (helical) and peripheral arteries (high-pitch). Diagnostic image quality was considered sufficient at attenuation values > 250HU and CNR > 10.

RESULTS

Diagnostic image quality for TAVI measurements was obtained in 46 patients. Mean attenuation values and CNR (HU ± SD) at the aortic root (helical) were: group 1: 381 ± 65HU and 13 ± 8; group 2: 442 ± 68HU and 10 ± 5. At the peripheral arteries (high-pitch), mean values were: group 1: 430 ± 117HU and 11 ± 6; group 2: 389 ± 102HU and 13 ± 6.

CONCLUSION

CM volume can be substantially reduced using low kVp protocols, while maintaining sufficient image quality for the evaluation of aortic root and peripheral access sites.

KEY POINTS

• Image quality could be maintained using low kVp scan protocols. • Low kVp protocols reduce contrast media volume by 34-67 %. • Less contrast media volume lowers the risk of contrast-induced nephropathy.

Ultra-low contrast computed tomographic angiography (CTA) with 20-mL total dose for transcatheter aortic valve implantation (TAVI) planning

Transcatheter aortic valve implantation workup includes assessment of the aorta and the iliofemoral arteries by computed tomographic angiography. An important group of transcatheter aortic valve implantation candidates have severe renal failure. We tested a novel computed tomographic angiography protocol (128-detector-row dual-source scanner, high-pitch helical mode) with ultralow contrast volume (20 mL) in 8 patients, compared with 8 controls. Contrast-to-noise ratio and subjective image quality, albeit lower than in the controls, were suitable for interpretation in the ultralow contrast volume group throughout all measured locations.

Kidneys in chronic liver diseases

Acute kidney injury (AKI), defined as an abrupt increase in the serum creatinine level by at least 0.3 mg/dL, occurs in about 20% of patients hospitalized for decompensating liver cirrhosis. Patients with cirrhosis are susceptible to developing AKI because of the progressive vasodilatory state, reduced effective blood volume and stimulation of vasoconstrictor hormones. The most common causes of AKI in cirrhosis are pre-renal azotemia, hepatorenal syndrome and acute tubular necrosis. Differential diagnosis is based on analysis of circumstances of AKI development, natriuresis, urine osmolality, response to withdrawal of diuretics and volume repletion, and rarely on renal biopsy. Chronic glomerulonephritis and obstructive uropathy are rare causes of azotemia in cirrhotic patients. AKI is one of the last events in the natural history of chronic liver disease, therefore, such patients should have an expedited referral for liver transplantation. Hepatorenal syndrome (HRS) is initiated by progressive portal hypertension, and may be prematurely triggered by bacterial infections, nonbacterial systemic inflammatory reactions, excessive diuresis, gastrointestinal hemorrhage, diarrhea or nephrotoxic agents. Each type of renal disease has a specific treatment approach ranging from repletion of the vascular system to renal replacement therapy. The treatment of choice in type 1 hepatorenal syndrome is a combination of vasoconstrictor with albumin infusion, which is effective in about 50% of patients. The second-line treatment of HRS involves a transjugular intrahepatic portosystemic shunt, renal vasoprotection or systems of artificial liver support.

Arterial stiffness contributes to coronary artery disease risk prediction beyond the traditional risk score (RAMA-EGAT score)

Objectives

The traditional risk score (RAMA-EGAT) has been shown to be an accurate scoring system for predicting coronary artery disease (CAD). Arterial stiffness measured by the cardio–ankle vascular index (CAVI) is known to be a marker of atherosclerotic burden. A study was undertaken to determine whether CAVI improves the prediction of CAD beyond the RAMA-EGAT score.

Design

Cross-sectional study.

Patients

Patients with a moderate to high risk for CAD by the RAMA-EGAT score were enrolled between November 2005 and March 2006. 64-slice multidetector CT coronary angiography was used to evaluate the coronary artery calcium score and coronary stenosis. Arterial stiffness was assessed by CAVI.

Results

1391 patients of median age 59 years (range 31–88) were enrolled in the study, 635 (45.7%) men and 756 (54.3%) women. Of the 1391 patients, 346 (24.87%) had coronary stenosis. There was a correlation between CAVI and the prevalence of coronary stenosis after adjusting for traditional CAD risk factors (OR 3.29). In addition, adding CAVI into the RAMA-EGAT score (modified RAMA-EGAT score) improved the prediction of CAD incidence, increasing C-statistics from 0.72 to 0.85 and resulting in a net reclassification improvement of 27.7% (p<0.0001).

Conclusion

CAVI is an independent risk predictor for CAD. The addition of CAVI to the RAMA-EGAT score significantly improves the diagnostic yield of CAD.

Contrast-induced nephropathy in patients undergoing elective and urgent procedures

Contrast-induced nephropathy (CIN) is an acute and severe complication after contrast media administration. The most important step in preventing CIN is identifying high-risk patients. In this review, we evaluate and summarize the evidence regarding the CIN prophylaxis, including the withdrawal of the potentially nephrotoxic drugs, hydration by isotonic solution or NaHCO(3), pharmaceutical treatment with N-acetylcysteine (N-AC), adenosine antagonists, ascorbic acid, renal procedures including hemofiltration or dialysis, and to the optimal use of the contrast. We suggest it is possible to reduce the burden of CIN by carefully incorporating these recommendations. After review of published literature in this field, we conclude that the cornerstone of the CIN prevention should be combination of hydration (normal saline or NaHCO(3)) and the use of N-AC.

[Complications due to contrast agent administration: what has been confirmed in prevention?]

Computed tomography (CT) and magnetic resonance imaging (MRI) have been evaluated by internists to be the most important medical innovations. Often, intravenous contrast agent administration is required for answering the clinical questions to CT and MRI. In this review we present an overview of the most common and most important aspects that need to be considered prior to intravenous contrast agent administration. We discuss aspects of renal impairment (contrast-induced nephropathy, nephrogenic systemic fibrosis), allergy-like reactions, hyperthyroidism, and pregnancy and breast-feeding.

Nephrotoxicity of iodixanol versus iopamidol in patients with chronic kidney disease and diabetes mellitus undergoing coronary angiographic procedures

BACKGROUND

The choice of radiographic contrast media for use in patients at increased risk of contrast-induced nephropathy (CIN) is of ongoing interest.

METHODS

The current study is a prospective, multicenter, randomized, double-blind design comparing the renal effects of the non-ionic, iso-osmolal agent, iodixanol, versus the non-ionic, low-osmolal agent, iopamidol, in 526 subjects with impaired baseline renal function (chronic kidney disease) and diabetes mellitus undergoing diagnostic and/or therapeutic coronary angiographic procedures. The co-primary end points were the peak increase in serum creatinine (SCr) and the incidence of CIN (increase > or =0.5 mg/dL) in SCr from baseline within 3 days of receiving contrast media.

RESULTS

In 418 evaluable subjects with complete postcontrast media SCr data, the median peak increase in SCr in the iodixanol arm was 0.10 mg/dL, whereas in the iopamidol arm, the median peak increase was 0.09 mg/dL (P = .13). The overall CIN incidence was 10.5% (11.2% % in the iodixanol arm and 9.8% in the iopamidol arm, P = .7). The volume of contrast media, volume of saline administered, frequency of coronary interventional procedures, and severity of baseline kidney disease and of diabetes mellitus were similar between treatments.

CONCLUSIONS

In the present study, the overall rate of CIN in patients with chronic kidney disease and DM undergoing coronary angiographic procedures was 10.5%. There was no significant difference between iodixanol and iopamidol in either peak increase in SCr or risk of CIN.

Contrast-induced acute kidney injury

Cardiac angiography and coronary/vascular interventions depend on iodinated contrast media and consequently pose the risk of contrast-induced acute kidney injury (AKI). This is an important complication that accounts for a significant number of cases of hospital-acquired renal failure, with adverse effects on prognosis and health care costs. The epidemiology and pathogenesis of contrast-induced AKI, baseline renal function measurement, risk assessment, identification of high-risk patients, contrast medium use, and preventive strategies are discussed in this report. An advanced algorithm is suggested for the risk stratification and management of contrast-induced AKI as it relates to patients undergoing cardiovascular procedures. Contrast-induced AKI is likely to remain a significant challenge for cardiologists in the future because the patient population is aging and chronic kidney disease and diabetes are becoming more common.

Acute kidney injury with iodinated contrast

Diagnostic and interventional radiographic procedures in critically ill patients commonly depend on iodinated contrast media and consequently pose the risk of contrast-induced acute kidney injury. This is an important complication that accounts for a significant number of cases of hospital-acquired renal failure, with adverse effects on prognosis and healthcare costs. The epidemiology and pathogenesis of contrast-induced acute kidney injury, baseline renal function measurement, risk assessment, identification of high-risk patients, contrast medium use, and preventive strategies will be discussed in this article. An algorithm is suggested for the risk stratification and management of contrast-induced acute kidney injury as it relates to patients undergoing iodinated contrast exposure during critical illness. Contrast-induced acute kidney injury is likely to remain a significant challenge for intensivists in the future because the patient population is aging and chronic kidney disease and diabetes are becoming more common.

Serious renal dysfunction after percutaneous coronary interventions can be predicted

BACKGROUND

A prediction rule for determining the post-percutaneous coronary intervention (PCI) risk of developing contrast-induced nephropathy (> or = 25% or > or = 0.5 mg/dL increase in creatinine) has been reported. However, little work has been done on predicting pre-PCI patient-specific risk for developing more serious renal dysfunction (SRD; new dialysis, > or = 2.0 mg/dL absolute increase in creatinine, or a > or = 50% increase in creatinine). We hypothesized that preprocedural patient characteristics could be used to predict the risk of post-PCI SRD.

METHODS

Data were prospectively collected on a consecutive series of 11141 patients undergoing PCI without dialysis in northern New England from 2003 to 2005. Multivariate logistic regression model was used to identify the combination of patient characteristics most predictive of developing post-PCI SRD. The ability of the model to discriminate was quantified using a bootstrap validated C-Index (area under the receiver operating characteristic [ROC] curve). Its calibration was tested with a Hosmer-Lemeshow statistic. The model was validated on PCI procedures in 2006.

RESULTS

Serious renal dysfunction occurred in 0.74% of patients (83/11141) with an associated inhospital mortality of 19.3% versus 0.9% in those without SRD. The model discriminated well between patients who did and did not develop SRD after PCI (ROC 0.87, 95% CI 0.82-0.91). Preprocedural creatinine (37%), congestive heart failure (24%), and diabetes (15%) accounted for 76% of the predictive ability of the model. The other factors contributed 24%: urgent and emergent priority (10%), preprocedural intra-aortic balloon pump use (8%), age > or = 80 years (5%), and female sex (1%). Validation of the model was successful with ROC: 0.84 (95% CI 0.80-0.89).

CONCLUSIONS

Although infrequent, the occurrence of SRD after PCI is associated with a very high inhospital mortality. We developed and validated a robust clinical prediction rule to determine which patients are at high risk for SRD. Use of this model may help physicians perform targeted interventions to reduce this risk.

Radiologisch praxisrelevante Prophylaxe und Therapie von Nebenwirkungen jodhaltiger Kontrastmittel

Increased utilization of iodinated contrast media may be associated with increased incidence of adverse events. The most important side effects include contrast-induced nephropathy, anaphylactoid reaction, thyrotoxicosis, and extravasation. In patients with moderate renal dysfunction, saline hydration and reduction of contrast media volume are recommended. No regime to prevent anaphylactoid reactions has yet proven to be efficient. If subclinical hyperthyroidism has been determined, prophylaxis with sodium perchlorate is advised. Contrast-induced nephropathy is commonly transient and needs to be followed over time. Mild general anaphylactoid reactions may be treated with antihistaminic drugs and corticosteroids. Furthermore the choice of the X-ray contrast media might influence the risk of any adverse effects.

Postprocedure clinical management for the interventional radiologist

Interventional procedures for oncology patients are being used more frequently in the front line and palliative setting. It is important that interventional radiologists familiarize themselves with some of the frequently encountered symptoms and potential complications and develop guidelines to help manage and sometimes prevent these complications from occurring. Unfortunately, there is not much data to support various supportive measures specifically for the post-procedural patient. However, by extrapolating the information available for the management of systemic chemotherapy patients, as well as discussing the steps that can be taken to avoid certain complications like acute renal failure, we as oncologists and interventional radiologists can better care for this unique and often complicated patient population.