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Documentation of impaired coronary blood flow by TIMI frame count method in patients with atrial fibrillation
Chufan Luo1, Xing Wu, Zhibin Huang
1Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. luochufan@yahoo.com.cn
Insights
Patients with atrial fibrillation (AF) show impaired coronary blood flow, evidenced by higher Thrombolysis in Myocardial Infarction (TIMI) frame counts (TFC). This finding holds true even without obstructive coronary artery disease (CAD).
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Medical Imaging
Background:
- Atrial fibrillation (AF) is linked to reduced coronary blood flow and myocardial perfusion.
- The impact of AF on coronary flow in the absence of obstructive coronary artery disease (CAD) requires further investigation.
Purpose of the Study:
- To evaluate coronary blood flow using Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) in patients with AF.
- To compare TFC in AF patients versus controls without obstructive CAD.
Main Methods:
- Prospective study comparing 146 AF patients with 150 age- and gender-matched controls.
- Coronary angiography was performed, followed by TFC assessment in the absence of obstructive CAD.
Main Results:
- AF patients exhibited significantly higher TFC in all three major coronary arteries and mean TFC compared to controls (p<0.001).
- Mean TFC increased with AF duration (paroxysmal, persistent, permanent).
- Multivariate analysis confirmed AF as an independent predictor of higher mean TFC.
Conclusions:
- Atrial fibrillation is associated with impaired coronary blood flow, indicated by elevated TIMI frame counts.
- This impairment occurs even in the absence of obstructive coronary artery disease.
Background:
Atrial fibrillation (AF) is associated with impaired coronary flow and diminished myocardial perfusion. In the present study we aimed to evaluate coronary blood flow by means of Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) in patients with AF in the absence of obstructive coronary artery disease (CAD).
Methods:
This prospective study initially enrolled 166 patients with AF and 332 age- and gender-matched control subjects without AF. After diagnostic coronary angiography, TFC was assessed in the participants without obstructive CAD, with 146 in the AF group and 150 in the control group.
Results:
The TFC for three major coronary arteries and the mean TFC were found to be significantly higher in AF patients compared to control subjects (34.1 ± 10.4 vs. 25.0 ± 10.4, 31.8 ± 9.7 vs. 23.7 ± 9.1, and 32.3 ± 9.5 vs. 24.1 ± 8.4 for each artery and 32.8 ± 9.2 vs. 24.3 ± 8.9 for mean TFC, p<0.001 for all comparisons). The mean TFC was 28.8 ± 7.9 in patients with paroxysmal AF, 33.7 ± 8.7 in those with persistent AF, and 39.0 ± 8.8 in those with long-standing or permanent AF (p<0.01 for all comparisons). After multivariate analysis, we found that the presence of AF remains to be independently associated with mean TFC. In AF group, baseline heart rate, left ventricular ejection fraction, AF duration and left atrium diameter were found to be independently associated with mean TFC.
Conclusions:
Patients with atrial fibrillation in the absence of obstructive coronary artery disease have significantly higher TIMI frame counts for all three coronary vessels, indicating impaired coronary blood flow, compared to the control subjects without atrial fibrillation.
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