Contrast Utilization in High Risk Patients Undergoing PTCA - COURT

Description:

Iodixanol vs. ioxaglate contrast for in-hospital outcomes in high risk PTCA.

Hypothesis:

To assess iodixanol and ioxaglate contrast media for high risk angioplasty.

Study Design

Study Design:

Patients Screened: 1,444
Patients Enrolled: 815

Patient Populations:

High-risk patients with rest angina (Braunwald class IIIB or IIIC), evolving MI within 72 hours, or post-MI angina within 2 weeks of infarction.

Primary Endpoints:

In-hospital MACE events (abrupt closure, emergent recatheterization or rePTCA, stroke, periprocedural MI, unplanned CABG, cardiac death).

Secondary Endpoints:

Non-cardiac death, clinically significant arrhythmia requiring therapy, symptoms of angina with ECG changes, hypotension requiring intervention, major bleeding complications post-procedure, or clinically significant renal failure.

Drug/Procedures Used:

Iodixanol vs. ioxaglate contrast media

Concomitant Medications:

Abciximab, ticlopidine, or low molecular weight heparin were used at the discretion of the performing physician.

Principal Findings:

This multicenter, prospective, randomized trial evaluated high-risk intervention patients; over half had unstable angina, about one-third had an acute evolving myocardial infarction (MI), and the remainder had post-MI ischemia.

Patients were randomized to either iodixanol (n=405) or ioxaglate (n=410) following coronary intervention, including percutaneous transluminal coronary angioplasty (PTCA), stenting, atherectomy, or laser angioplasty. An additional 629 patients who underwent diagnostic catheterization but no further intervention were assigned to a companion registry. The treatment groups were similar with regard to demographics, indications, primary device used, and abciximab use.

There was a low incidence of in-hospital clinical events in both groups. The composite endpoint of in-hospital major adverse coronary events (MACE) occurred in 5.2% of the iodixanol group vs. 9.5% of the ioxaglate group (p=0.018). This represented a 4.3% absolute reduction and a 45% relative reduction in MACE events.

A post-hoc analysis showed that among patients receiving abciximab (42% in both groups), there was no difference in in-hospital MACE, regardless of the contrast agent used. Conversely, a larger benefit was detected for patients who did not receive abciximab, with in-hospital MACE rates of 1.7% for the iodixanol group and 8.1% for the ioxaglate group (p=0.001).
The composite secondary endpoint for in-hospital clinical events favored iodixanol (4.9% vs 7.8%), but this did not reach statistical significance (p=0.094).

Angiographic and procedural outcomes were identical for the 2 groups. Core angiographic laboratory analysis reported a higher procedural success rate in the iodixanol group (90% vs. 85%, p=0.016).

The only significant multivariate predictors of major in-hospital clinical events were the use of ioxaglate and a de novo lesion.

Interpretation:

Iodixanol is a new dimeric, nonionic contrast agent formulated and supplemented to produce an osmolality that approximates that of plasma. Because of its physical properties, iodixanol generally causes less frequent and less intense discomfort on injection compared to other contrast media. Furthermore, there is evidence suggesting it produces a lower incidence of adverse events than other nondimeric contrast media (Drugs 1996;52:899-927).

A similar French study by Michel Bertrand showed no significant differences between iodixanol and ioxaglate. The COURT study, which included only "high risk" patients, may suggest that plaque instability may contribute to the positive results. The differences in outcomes for unstable patients appears to be overcome by abciximab.

References:

1. Presented at 71st Scientific Sessions, American Heart Association, Dallas TX, 1998.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Aortic Surgery, Cardiac Surgery and Arrhythmias

Keywords: Ioxaglic Acid, Angioplasty, Laser, Contrast Media, Myocardial Infarction, Triiodobenzoic Acids, Atherectomy, Catheterization, Immunoglobulin Fab Fragments, Angioplasty, Balloon, Coronary


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