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 μg 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. Catheter Cardiovasc Interv 2004;63:426–432. © 2004 Wiley-Liss, Inc.