Based on four reported deaths after administration of an ultrasound contrast agent, the Food and Drug Administration issued a black box warning for all ultrasound contrast agents in October 2007, Dr. Mouaz H. Al-Mallah of Wayne State University, Detroit, Michigan and colleagues explain. “The use of these agents thereby became contraindicated in patients with acute cardiopulmonary syndromes, severe pulmonary hypertension, and QT prolongation.”
The contraindications were lifted in May 2008, but since then concerns have persisted and “the use of contrast agents in clinical echocardiography has significantly decreased.”
To see if this is warranted, the team conducted a meta-analysis of 8 studies reporting the incidence of MI and all-cause mortality after administration of contrast agents.
“The cumulative incidence of all-cause mortality in the contrast group was 0.34% (726 of 211,162 patients) compared with 0.9% (45,970 of 5,078,666 patients) in the noncontrast group. The pooled OR was 0.57 (p=0.052),” the researchers report.
The incidence of MI was 0.15% (86 of 57,264 patients) in the contrast group compared to 0.2% (92 of 44,503 patients) in the noncontrast group, yielding a pooled OR of 0.85 ( p=0.72).
Furthermore, the incidence of allergic reactions was 0.009% and that of anaphylactic reactions was 0.004%.
Dr. Al-Mallah and colleagues conclude that the cumulative evidence indicates that ultrasound contrast agents are safe. “This finding was seen in a wide range of patient populations, including inpatients and outpatients, at rest and stress echocardiography, and a significant number of patients with the previous black box contraindications.”
Meta-Analysis of Adverse Cardiovascular Events Associated With Echocardiographic Contrast Agents
Am J Cardiol 2010.