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Published on: March 15, 2022
Thrombolysis in Myocardial Infarction Frame Count for Coronary Blood Flow Evaluation during Interventional Diagnostic
Tatsuro Yamazaki1, Yuichi Saito1, Hideki Kitahara1
1Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
Insights
Thrombolysis In Myocardial Infarction frame count (TFC) shows modest correlation with coronary blood flow surrogates during invasive diagnostic procedures for ischemia with no obstructive coronary arteries (INOCA). Acetylcholine provocation impacts TFC assessment in INOCA patients.
Area of Science:
- Cardiology
- Diagnostic Procedures
- Vascular Physiology
Background:
- Ischemia with no obstructive coronary arteries (INOCA) diagnosis relies on invasive procedures.
- Intracoronary acetylcholine (ACh) provocation and coronary physiological testing are invasive standards for INOCA.
- Thrombolysis In Myocardial Infarction frame count (TFC) is a suggested alternative for diagnosing coronary microvascular dysfunction.
Purpose of the Study:
- To evaluate Thrombolysis In Myocardial Infarction frame count (TFC) trajectories during interventional diagnostic procedures (IDP).
- To assess the impact of acetylcholine (ACh) provocation on TFC during IDP for INOCA.
- To correlate TFC with coronary physiological indices like mean transit time (Tmn).
Main Methods:
- Retrospective single-center study of 104 patients undergoing IDP for INOCA.
- Patients divided into positive and negative ACh provocation test groups.
- Thrombolysis In Myocardial Infarction frame count (TFC) measured pre-ACh, post-isosorbide dinitrate (ISDN), and post-hyperemia.
Main Results:
- 55.8% of patients had a positive ACh test.
- Positive ACh group showed higher resting mean transit time (Tmn) and baseline resistance index.
- Post-ISDN TFC correlated with resting Tmn (r = 0.31, p = 0.002).
- TFC values were highest pre-ACh, decreasing post-ISDN and post-hyperemia.
Conclusions:
- Thrombolysis In Myocardial Infarction frame count (TFC) is modestly correlated with mean transit time (Tmn), a coronary blood flow surrogate.
- Acetylcholine provocation significantly influences coronary blood flow assessment during IDP for INOCA.
- TFC assessment timing is crucial in the context of ACh provocation.
Abstract:
Background and Objectives: An interventional diagnostic procedure (IDP), including intracoronary acetylcholine (ACh) provocation and coronary physiological testing, is recommended as an invasive diagnostic standard for patients suspected of ischemia with no obstructive coronary arteries (INOCA). Recent guidelines suggest Thrombolysis In Myocardial Infarction frame count (TFC) as an alternative to wire-based coronary physiological indices for diagnosing coronary microvascular dysfunction. We evaluated trajectories of TFC during IDP and the impact of ACh provocation on TFC. Materials and Methods: This was a single-center, retrospective study. Patients who underwent IDP to diagnose INOCA were included and divided into two groups according to the positive or negative ACh provocation test. Wire-based invasive physiological assessment was preceded by ACh provocation tests and intracoronary isosorbide dinitrate (ISDN). We evaluated TFC at three different time points during IDP; pre-ACh, post-ISDN, and post-hyperemia. Results: Of 104 patients, 58 (55.8%) had positive ACh provocation test. In the positive ACh group, resting mean transit time (Tmn) and baseline resistance index were significantly higher than in the negative ACh group. Post-ISDN TFC was significantly correlated with resting Tmn (r = 0.31, p = 0.002). Absolute TFC values were highest at pre-ACh, followed by post-ISDN and post-hyperemia in both groups. All between-time point differences in TFC were statistically significant in both groups, except for the change from pre-ACh to post-ISDN in the positive ACh group. Conclusions: In patients suspected of INOCA, TFC was modestly correlated with Tmn, a surrogate of coronary blood flow. The positive ACh provocation test influenced coronary blood flow assessment during IDP.
