Thrombotic and cardiovascular complications related to nonionic contrast media during cardiac catheterization: analysis of 8,517 patients

The incidence of major complications associated with nonionic contrast media has not been defined in a large study. Accordingly, cardiovascular complications, especially thrombotic events, were prospectively evaluated in 8,5l7 consecutive patients undergoing diagnostic cardiac catheterization with either lepamidol (n = 6,293) or lehexol (n = 2,224). Thrombotic events were defined as coronary embolus, coronary occlusion, transient ischemic attack or stroke occurring at the time of catheterization. Thrombotic events occurred in 15 patients (0.18%). Coronary thrombus or embolus occurred in 7 patients, a thromboembolus ft= the ventricular catheter occurred in 1 patient and transient ischemic attack or stroke occurred in 7 patients. Six of 15 patients with thrombotic events were premedicated with heparin. Thrombotic events were unusual in that they tended to occur in clusters within short time intervals. On 1 occasion, a thrombus was observed in the catheter tip before embelization. Other cardiovascular complications were similarly low with an incidence of ventricular tachycardia/fibrillation of 0.1%, profound bradycardia of 0.2% and prolonged angina of 0.3%. There were 2 deaths unrelated to thrombotic events. Although the clinical thrombotic events associated with nonionic contrast have an unusual temperal clustering and may result in major complications, the overall incidence (0.18%) of these thrombotic complications with nonionic contrast agents is quite similar to that reported with ionic contrast media. (Am J Cardiol 1990;6S:1481-1484)
Contrast media are substances used in imaging procedures and allow visualization of heart function during cardiac catheterization (when a catheter is fed through a blood vessel to a chamber of the heart). Some complications have been associated with these media, especially ionic media (which are charged substances, like acids). In studies of small groups of patients, nonionic contrast media have been reported to cause fewer complications, but they can not prevent clotting as ionic media can. The incidence of complications related to nonionic contrast media, used during cardiac catheterization, was studied in 8,517 patients. Thrombotic events, including coronary thrombus (blood clot in a coronary artery), transient ischemic attack (inadequate blood flow in the brain), or stroke (brain damage caused by obstruction of blood flow), occurred in 15 patients, a frequency of 0.18 percent. Six of the patients with thromboses (clot formation) had been premedicated with heparin, an anticoagulant. The events occurred in clusters during the course of the study, but could not be related to the lot number of the media, equipment, or staff members. There was a low frequency of other cardiovascular events, such as rapid and slow heartbeat, and arrhythmia (abnormal heart rhythm). Two deaths, unrelated to contrast media, occurred. The results confirm that there is a low incidence of cardiovascular and thrombotic events in catheterization procedures which use nonionic contrast media, and suggest that pretreatment with heparin does not affect thrombotic outcome. (Consumer Summary produced by Reliance Medical Information, Inc.)