Corrected TIMI frame count: applicability in modern digital catheter laboratories when different frame acquisition rates are used.

The original description of the TIMI frame count (TFC) method was based on angiograms acquired at 30 f/sec. Modern digital angiograms are acquired at lower frame rates (between 12.5 and 25 f/sec). Coronary angiography was acquired at 12.5 and 25 f/sec after 200 mug of intracoronary glyceryl trinitrate. Results of the corrected TIMI frame count (cTFC) at 12.5 and 25 f/sec for each vessel were: right coronary artery, 19.5 +/- 5.2 and 20.4 +/- 6.6 (P = 0.15); circumflex artery, 25.6 +/- 8.2 and 25.9 +/- 8.7 (P = 0.5); and left anterior descending artery, 22.5 +/- 8.1 and 23.8 +/- 10.4 (P = 0.15), respectively. The mean difference in the TFC between two injections by the same operator and by two operators was 0.4 (P = 0.7) and 0.4 (P = 0.2), respectively. The mean difference in the TFC for repeat measurements by the same observer and between two observers was 0.26 (P = 0.3) and 0.06 (P = 0.8), respectively. We confirm that the cTFC is a quantitative method to assess coronary flow that can be applied in a modern digital laboratory.

A randomized prospective trial of ioxaglate 320 (Hexabrix) vs. iodixanol 320 (Visipaque) in patients undergoing percutaneous coronary intervention.

We performed a randomized, prospective, double blind trial comparing the use of the ionic dimer contrast agent ioxaglate 320 (Hexabrix) with the nonionic dimer contrast agent iodixanol 320 (Visipaque) in 618 patients undergoing percutaneous coronary intervention (PCI) for stable or unstable coronary artery syndromes. The aim was to determine whether the different anticoagulant and antiplatelet properties of these two contrast agents resulted in a significant difference in the incidence of a combined endpoint comprising the major complications of PCI. Procedural success rates were marginally higher in the Visipaque group compared to the Hexabrix group, although this did not reach statistical significance (96.7% vs. 93.9%; P = 0.09). There was a borderline statistically significant higher requirement for bailout stenting in the Visipaque group compared to the Hexabrix group (6.8% vs. 3.2%; P = 0.05), although this was not a predefined endpoint. The incidence of the combined primary endpoint of failed catheter laboratory outcome/requirement for bailout stenting/requirement for abciximab/myocardial infarction/death before hospital discharge was higher in the Visipaque group compared to the Hexabrix group (17.9% vs. 14.8%), although this did not reach statistical significance (P = 0.29). When subgroup analysis was performed, the incidence of the combined endpoint in patients with stable coronary artery disease randomized to receive either Visipaque or Hexabrix was identical (13.7%). In patients with an acute coronary syndrome, there was a trend toward a reduced incidence of the combined endpoint in the Hexabrix compared to the Visipaque group, although this did not reach statistical significance (17.2% vs. 24.8%; P = 0.17). More adverse reactions occurred in the Hexabrix group compared to the Visipaque group (8.7% vs. 4.9%; P = 0.06). We conclude that there is no clear advantage with the use of an ionic contrast agent in a large population of patients undergoing PCI for both stable and unstable coronary artery disease. Although the study was underpowered to detect significant differences with the use of either agent when patients with either stable or unstable coronary disease were studied, it is highly unlikely that the ionicity of the contrast agent confers any advantage for patients with stable coronary disease. There remains a possibility that ionic agents do have advantages for patients with unstable coronary artery disease undergoing PCI, although a larger study than ours would be required to confirm or refute this.