Repeat survey of current practice regarding corticosteroid prophylaxis for patients at increased risk of adverse reaction to intravascular contrast agents

Novel risk model for predicting acute adverse drug reactions following cardiac catheterization from TRUST study (The Safety and toleRability of UltraviSt in Patients Undergoing Cardiac CaTheterization)

Background

Acute drug reactions (ADRs) are common complications of contrast administration following cardiac catheterization. Serious reactions may be life threatening. However, few risk models for predicting ADRs exist. The study aims to develop a novel tool for predicting the risk of ADRs [occurring within 1 hour in patients undergoing coronary angiography or percutaneous coronary intervention (PCI)].

Methods

A total of 17,139 consecutive patients included in the TRUST study were randomly (2:1) assigned to a development data set (n=11,426) or a validation data set (n=5,713). Multivariate logistic regression was applied to identify independent predictors of contrast-induced nephropathy (CIN), including age, contrast dose, premedication, and prehydration. The performance of our model was assessed using the c-statistic for discrimination and the Hosmer-Lemeshow test for calibration.

Results

The overall incidence of ADRs was 42 (0.37%) in the development data set: 0.09% in the low-risk category (score: 0-2), 0.36% in the moderate-risk category (score: 3-4), and 1.78% in the high-risk category (score ≥5). The risk score across the subgroup of the study population exhibited good discrimination and predictive ability for ADRs (c-statistic: 0.694). Meanwhile, the calibration was also demonstrated to be accurate by the Hosmer-Lemeshow goodness-of-fit test (P=0.305).

Conclusions

Our data showed that our simple risk model showed good discrimination and predictive ability of ADRs following cardiac catheterization.

Stratified premedication strategy for the prevention of contrast media hypersensitivity in high-risk patients

BACKGROUND

Although the severity of hypersensitivity reactions to iodinated contrast media varies, it is well correlated with the severity of recurrent reactions; however, prophylaxis protocols are not severity-stratified.

OBJECTIVE

To assess the outcomes of tailored prophylaxis according to the severity of hypersensitivity reactions to iodinated contrast media.

METHODS

Our premedication protocols were stratified based on the severity of previous reactions: (1) 4 mg of chlorpheniramine for mild reactions, (2) adding 40 mg of methylprednisolone for moderate reactions, and (3) adding multiple doses of 40 mg of methylprednisolone for severe index reactions. Cases of reexposure in patients with a history of hypersensitivity reactions were routinely monitored and mandatorily recorded.

RESULTS

Among a total of 850 patients who underwent enhanced computed tomography after severity-tailored prophylaxis, breakthrough reactions occurred in 17.1%, but most breakthrough reactions (89.0%) were mild and did not require medical treatment. Additional corticosteroid use did not reduce the breakthrough reaction rate in cases with a mild index reaction (16.8% vs 17.2%, P = .70). However, underpremedication with a single dose of corticosteroid revealed significantly higher rates of breakthrough reaction than did double doses of corticosteroid in cases with a severe index reaction (55.6% vs 17.4%, P = .02). Changing the iodinated contrast media resulted in an additional reduction of the breakthrough reaction rate overall (14.9% vs 32.1%, P = .001).

CONCLUSION

In a total severity-based stratified prophylaxis regimens and changing iodinated contrast media can be considered in patients with a history of previous hypersensitivity reaction to iodinated contrast media to reduce the risk of breakthrough reactions.

Clinical characteristics of adverse reactions to nonionic low osmolality contrast media in patients transferred from the CT room to the emergency room

Nonionic low osmolality contrast media (LOCMs) are used universally in computed tomography (CT) imaging. Although adverse reactions due to nonionic LOCMs are a common cause of emergency room (ER) admissions, few studies have investigated these adverse reactions. In the present study, we evaluated the characteristics of patients who were transferred from the CT room to the ER due to adverse reactions to contrast media, and we determined the risk factors for severe adverse reactions. A single-center retrospective study was conducted over a 41-month period. Baseline and clinical characteristics were evaluated and analyzed according to moderate and severe severity. In particular, risk factors of severe reactions were determined using logistic regression analysis. In total, 70 patients were admitted to the ER with adverse reactions due to nonionic LOCMs. Of these, 33 developed a moderate reaction, and 37 developed a severe reaction. Compared with the moderate reaction group, the severe reaction group was older, had higher blood pressures, showed more symptoms indicating the cardiovascular and central nervous system, and developed faster reactions to LOCMs. According to the multivariate logistic regression analysis, the age of the patient and time to onset of reaction demonstrated a statistical relationship with severe adverse reactions. In the receiver operating characteristic analysis, the optimal cutoff values for age and time to onset were 60 years and 5 min. In conclusion, clinicians should be attentive to anaphylaxis due to nonionic LOCM, in particular, for elderly patients aged older than 60 years and a time to reaction onset of less than 5 min.

Emergency pretreatment for contrast allergy before direct percutaneous coronary intervention for ST-elevation myocardial infarction

Patients with previous adverse contrast reactions occasionally present with ST-segment elevation myocardial infarction. Whether they can undergo catheterization safely using current contrast and medications is unknown. We reviewed catheterization laboratory records of all 501 patients (January 2005 to December 2006) presenting with ST-segment elevation myocardial infarction who underwent emergency coronary angiography. Six patients (1.2%) reported a previous contrast reaction including rash, acute bronchospasm, or anaphylaxis. All received a combination of intravenous steroids and H1 and H2 blockers in the emergency department or catheterization laboratory before catheterization. None of these had complications or evidence of allergy in any patient. In conclusion, some patients with previous contrast reaction may undergo emergency catheterization without adverse consequences, although the safety of this approach has not been proved.

Safety aspects of iodinated contrast media related to their physicochemical properties: a pharmacoepidemiology study in two Tuscany hospitals

BACKGROUND

More than 380,000 angiographic procedures are performed every year in Italian hospitals, with an increase rate of 8% per year. Although contrast media (CM) are considered relatively safe, adverse drug reactions (ADRs) remain an important issue.

OBJECTIVES

The objective of this study was to quantify the incidence of immediate and delayed nonrenal ADRs to iodinated CM in an Italian cohort and to evaluate whether their different physicochemical properties are able to affect the incidence of immediate or delayed ADRs.

METHODS

A prospective intensive monitoring study was conducted on a cohort of patients undergoing radiodiagnostic procedures with iodinated CM enrolled in two hospitals in Tuscany, Italy. To evaluate both immediate (within 1 h after CM administration) and delayed (>1 h to 1 week after CM administration) ADRs to CM, two questionnaires were administered. Adverse events (AEs) were analyzed to check the causality assessment between CM and ADR. If more than one symptom occurred in the same patient, they were treated as a single event.

RESULTS

One thousand five hundred and fourteen subjects who were exposed to iodinated CM completed the questionnaires. Mean age [standard deviation (SD)] was 65.4 (13.3) years, and 57.9% were male patients. A total of 178 [11.8%; 95% confidence interval (CI) 10.1-13.4] ADRs were reported. Thirty-four (2.2%; 1.5-3.1) and 144 (9.5%; 8.0-11.1) developed immediate and delayed ADRs, respectively. Both types of ADRs were experienced by six subjects (0.4%; 0.1-0.8). One hundred and seventy-six cases (98.8%; 96.0-99.8) were classified as possible and two (1.1%; 0.1-3.9) as probable ADRs. Monomeric low-osmolal (iopromide, iomeprol, iobitridol) and dimeric iso-osmolal (iodixanol) groups mainly reported delayed allergy-like ADRs of mild severity. Only one immediate reaction was severe. Multivariate analysis confirmed a higher risk of immediate reactions occurring for monomeric CM (OR 4.3; 95% CI 1.2-15.7), whereas the risk of delayed ADRs was significantly higher for the dimeric group (OR 1.8; 1.1-2.5).

CONCLUSIONS

Monomeric CM were more frequently involved in immediate ADRs, whereas dimeric CM were involved in delayed reactions. Although severe life-threatening ADRs to CM were confirmed to be rare, due to the large use of these drugs, they still retain clinical and epidemiological significance.

The prevention of anaphylactoid reactions to iodinated radiological contrast media: a systematic review

Background

Anaphylactoid reactions to iodinated contrast media are relatively common and potentially life threatening. Opinion is divided as to the utility of medications for preventing these reactions. We performed a systematic review to assess regimes for the prevention of anaphylactoid reactions to iodinated contrast media.

Methods

Searches for studies were conducted in the Medline, EMBASE, CINAHL and CENTRAL databases. Bibliographies of included studies and review articles were examined and experts were contacted. Randomised clinical trials that examined agents given prior to iodinated contrast material for the prevention of anaphylactoid reactions were included in the review. The validity of the included studies was examined using a component approach.

Results

Six studies met the inclusion criteria, but only one of these fulfilled all of the validity criteria. There were four studies that examined the use of H1 antihistamines, each was used to prevent anaphylactoid reactions to ionic contrast. The random effects pooled relative risk demonstrated a significant reduction in the overall rate of anaphylactoid reactions (RR = 0.4, 95% CI 0.18-0.9, p = 0.027). There were insufficient studies to produce a pooled statistic for the use of corticosteroids, however regimes of steroids (methylprednisolone 32 mg) given at least six hours and again two hours prior to the administration of contrast suggested a reduction in the incidence of anaphylactoid reactions.

Conclusion

In conclusion, there are few high quality randomised clinical trials that have addressed the question of the optimal methods to prevent allergic type reactions to iodinated radiological contrast media. Allowing for these limitations, the results suggest that H1 antihistamines given immediately prior to the administration of ionic contrast may be useful in preventing reactions to ionic contrast and are suggestive of a protective effect of corticosteroids when given in two doses at least six hours prior and again two hours prior to the administration of contrast, both ionic and non-ionic. These agents should be considered for use in patients who are at high risk of an anaphylactoid reaction to contrast media and for who prophylactic therapy is considered necessary. Further research is needed before definitive recommendations can be made.