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Published on: October 22, 2014
Prevalence and predictors of slow flow in angiographically normal coronary arteries
Yaron Arbel1, Efrat Rind, Shmuel Banai
1Departments of Cardiology, Tel Aviv Sourasky Medical Center, Affiliated to The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Insights
Slow coronary flow (SCF) affects 34% of patients with normal coronary arteries. This systemic condition, impacting all three major arteries, is strongly linked to current smoking habits.
Area of Science:
- Cardiology
- Vascular Biology
- Diagnostic Imaging
Background:
- Coronary angiography reveals angiographically normal coronary arteries (ANCA) in approximately 20% of patients.
- A subset of ANCA patients exhibits abnormally slow coronary flow (SCF), a condition whose prevalence and etiology remain unclear.
Purpose of the Study:
- To determine the prevalence of SCF in patients with ANCA.
- To investigate the underlying causes and characteristics of SCF in this population.
Main Methods:
- A study involving 114 consecutive ANCA patients.
- Coronary flow (CF) assessed using corrected TIMI Frame Count (cTFC) and Coronary Clearance Frame Count (CCFC).
- Multivariable analysis to identify associations between SCF and clinical, inflammatory, and metabolic factors.
Main Results:
- 34% of ANCA patients (39 individuals) were diagnosed with SCF.
- Slow coronary flow was a systemic finding, consistent across all three major coronary arteries within individuals.
- Current smoking emerged as the most significant predictor of SCF, with smokers being 4.7 times more likely to have SCF (41% vs. 15%, p=0.002).
Conclusions:
- Slow coronary flow is a prevalent condition (34%) in patients presenting with angiographically normal coronary arteries.
- SCF in ANCA patients is a systemic phenomenon affecting all major coronary arteries.
- Current smoking is significantly associated with the presence of slow coronary flow in this patient group.
Background:
One out of 5 patients undergoing coronary angiography has angiographically normal coronary arteries (ANCA). Some of them have abnormally slow coronary flow (SCF). The prevalence and causes of SCF in these patients are not clear.
Methods:
We studied 114 consecutive patients with ANCA. Each angiogram was independently evaluated by 2 physicians unaware of all other clinical features of the case. Coronary flow (CF) was graded using the corrected TIMI Frame Count (cTFC) and Coronary Clearance Frame Count (CCFC) methodologies. SCF was defined as a cTFC exceeding the reported normal (mean cTFC + 2 SD) in each of the three major coronary arteries. The association between SCF and various clinical, inflammatory, and metabolic variables was tested using a multivariable analysis model.
Results:
Thirty-nine (34%) patients had SCF. Inter-individual CF varied substantially among them (range 10-143 frames/sec, mean: 37 ± 22 frames/sec). The intra-individual CF did not vary: CF correlated well in the three major epicardial coronary arteries of a given individual (r = 0.7, p = 0.0001). Multivariable analysis revealed that current smoking was the most significant variable related to SCF (odds ratio = 4.7, p = 0.006, CI 95% 1.6-13.3). The SCF group included significantly more smokers (41% versus 15%, p = 0.002).
Conclusions:
SCF is a common finding (34%) among patients with angiographically normal coronary arteries. In these patients, slow flow is a systemic phenomenon that involves all three coronary arteries rather than a local event and is associated with current smoking.
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