Importance of the TIMI frame count: implications for future trials

Appleby, Mark A; Michaels, Andrew D.; Chen, Michael; Michael, C Gibson

doi:10.1186/cvm-1-1-031

Cited by 26 publications

(7 citation statements)

References 21 publications

(30 reference statements)

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“…with the exception of signi cant increase in TFC with nitrate administration in both healthy and diseased coronary vessels [17]. Reproducibility for prior trials involving manual TFC has been reported as intraobserver reproducibility of 0.75 ± 4.3 frames [18] and 0.91 ± 3.2 frames [19], and correlation between observers of 0.97-0.99 [19], [20]. Here, we report a reproducibility of 1.253 ± 1.814 frames when we randomly reanalyzed a representative 30 of our study's 97 participants' angiographic image series for reproducibility of automatic TFC values for the same angiographic image series, ED frames, and vessel length for a given study participant.…”

Section: Discussionmentioning

confidence: 99%

Diagnostic Performance of Quantitative Flow Ratio (QFR) Values Generated from Automatic TIMI Frame-Counting

Devineni

Levine

Melaku

et al. 2022

Preprint

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Background: QFR (quantitative flow ratio) is a computational measurement of FFR (fractional flow reserve), calculated from coronary angiography. Latest QFR software automates TIMI frame counting (TFC), which occurs during the flow step of QFR analyses, making the analysis faster and more reproducible. The objective is to determine the diagnostic performance of QFR values obtained from analyses using automatic TFC compared to those obtained from analyses using manual TFC, in the assessment of hemodynamically significant coronary lesions. Methods and Results: This was a single-arm clinical trial that used the prospective analysis of retrospective data to compare the automatic and current gold standard manual TFC QFR values of 97 patients who underwent coronary angiography. The diagnostic performance of automatic TFC QFR values was measured as follows: sensitivity was 0.8696 (95% CI 0.6641–0.9722) and specificity was 1.00 (95% CI 0.9514-1.00), positive predictive value (PPV) was 1.00 (95%CI 1.00–1.00), while the NPV was 0.9610 (95% CI 0.9610–0.9936). Overall accuracy was 96.91% (95% CI 91.23%-99.36%). The agreement as illustrated by the Bland-Altman plot shows a bias of 0.0023 (SD 0.0208) and narrow limits of agreement (LOA): Upper LOA 0.0573 and Lower LOA − 0.0528. The area under curve (AUC) was 0.996. Conclusions: QFR values generated from automatic TFC are comparable to those generated from manual TFC in diagnostic capability. The most recent software update is equivalent to the previous manual option and therefore it can be used interchangeably.

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Section: Discussionmentioning

confidence: 99%

Diagnostic Performance of Quantitative Flow Ratio (QFR) Values Generated from Automatic TIMI Frame-Counting

Devineni

Levine

Melaku

et al. 2022

Preprint

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“…TIMI flow is currently the method of choice for the evaluation of the coronary flow on a cineangiogram. Be that as it may, this favorable method is not entirely devoid of pitfalls, first and foremost amongst which are its significant interobserver variability and its diagnosis of many patients with different blood flow velocities as normal (TIMI 3 flow) ( 3 ). TFC is a quantitative, reproducible, and objective index of the coronary flow that allows standardization of TIMI flow grades ( 2 ).…”

Section: Discussionmentioning

confidence: 99%

“…The number of frames needed until the contrast media opacify the total length of a vessel from the beginning to the standard distal landmarks is counted ( 2 ). The correlation of this method with the results of doppler has been demonstrated ( 3 ). The well-known TIMI flow assessment, which describes coronary flow as categories of 0 to 3, has some drawbacks.…”

Section: Introductionmentioning

confidence: 96%

Coronary flow assessment in unstable angina/non st-segment elevation myocardial infarction patients via thrombolysis in myocardial infarction frame count in angiography

et al. 2013

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Background:TIMI Frame Count (TFC) is one of the methods to estimate the coronary blood flow velocity. This is a simple, inexpensive, quantitative, reproducible, and continuous variable method. Many studies have been conducted on TFC assessment in ST elevation myocardial infarction (STEMI) patients.Objectives:The present study is aimed to measure the TFC in the coronary arteries of UA/NSTEMI patients to find abnormalities in diseased or patent vessels and compare with the normal values.Patients and Methods:The participants were 105 consecutive UA/NSTEMI patients who underwent coronary angiography in Shahid Rajaie Cardiovascular Medical and Research Center, Tehran, Iran in 2009. Exclusion criteria were history of CABG, PCI, or STEMI or presence of occluded arteries in angiography. We measured the coronary TFC in these patients. We examined also 55 stable patients without coronary lesions and with TIMI 3 flow to have an estimation of normal TFCs.Results:From a total of 105 patients, 25 (23.8%) had no significant coronary lesion (> 60%); 35 (33.3%) were diagnosed with single vessel disease; 22 (21%) were 2VD; and 23 (21.9%) were 3 VD.). In overall, mean TFC in UA/NSTEMI group was 28.7 (± 14) frames compared to 23.8 (± 7.8) frames in the normal group (P < 0.05). In the vessels with significant lesions, TFC was significantly higher than normal (30.84 vs. 23.8; P < 0.001) and also significantly higher than patent vessels of the same patients (30.84 vs. 26.10; P = 0.029). In these patients, patent vessels had higher TFC values compared to normal coronaries (26.10 vs. 23.8), but the difference was not significant (P = 0.12). In the patients with significant lesions, mean TFC was higher than the same value in acute coronary patients without significant lesions (29.3 vs. 27.2), but the difference was not significant (P = 0.114). In the patients who underwent PCI and stenting, TFC changed significantly after PCI toward the normal value (P = 0.001). In the patients with elevated cardiac enzymes, TFC was higher but the difference was not significant (P = 0.35).Conclusions:Patent coronaries of UA/NSTEMI patients have a trend to higher TFCs compared to normal values. Presence of significant coronary lesions in these patients significantly increases TFC.

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“…Выраженность интракоронарного тромбоза обусловлена реактивностью тромбоцитов, активностью плазменного гемостаза и эндогенного фибринолиза (ЭФ), а также Кровоток по ИСА классифицировали с помощью шкалы TIMI Grade Flow [8]. По данным КГ, у 63 пациентов отмечался кровоток по ИСА TIMI 0-1, в то время как у 30 пациентов регистрировался кровоток TIMI 2-3.…”

Section: заключениеunclassified

The state of platelet and plasma hemostasis as a predictor of coronary blood flow in patients with acute myocardial infarction

et al. 2022

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Aim To study the relationship of the platelet function and plasma homeostasis with the blood flow in the infarct-related artery (IRA) and with the course of acute myocardial infarction (AMI).Material and methods This study included 93 patients with AMI (75 patients with ST-elevation AMI and 18 patients without ST segment elevation). 63 patients had TIMI 0-1 blood flow in the IRA and 30 patients had TIMI 2–3. Rotational thromboelastometry, impedance aggregometry, the endothelium-dependent vasodilation (EDVD) test, and the thrombodynamics test were performed for all patients. The primary clinical endpoint included the totality of in-hospital complications of AMI, and the secondary endpoint included the totality of out-of-hospital complications of AMI. Major bleedings (BARC 3-5) and minor bleedings (BARC 1-2) were evaluated separately.Results Patients with IRA TIMI 0–1 flow were characterized by a shorter blood clotting time (BCT), larger thrombus size and density, more intense platelet aggregation induced by arachidonic acid and ADP, and lower values of the EDVD test. It was found that the parameters of platelet aggregation induced by arachidonic acid (AUC Asa) in combination with BCT allowed assessment of the severity of IRA blood flow disorder (sensitivity 76 %, specificity 71 %) in patients with AMI, regardless of the presence of ST segment elevation on the ECG. In addition, the incidence of the primary endpoint was greater in patients with IRA TIMI 0–1 flow (41.3% and 16.7%, respectively; p=0.015). In patients with TIMI 2–3 flow in the long-term period of the disease, the incidence of minor bleedings was significantly higher (8.5% and 30.4 %, respectively; p=0.045).Conclusion Compared to patients with preserved blood flow, patients with AMI and IRA TIMI 0–1 flow are characterized by endothelial dysfunction and more intense processes of thrombogenesis and platelet aggregation. It has been shown for the first time that the combination of two simple criteria for assessing hemostasis (AUC Asa; BCT) allows assessment of the degree of IRA blood flow disorder in patients with AMI.

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Importance of the TIMI frame count: implications for future trials

Cited by 26 publications

References 21 publications

Diagnostic Performance of Quantitative Flow Ratio (QFR) Values Generated from Automatic TIMI Frame-Counting

Diagnostic Performance of Quantitative Flow Ratio (QFR) Values Generated from Automatic TIMI Frame-Counting

Coronary flow assessment in unstable angina/non st-segment elevation myocardial infarction patients via thrombolysis in myocardial infarction frame count in angiography

The state of platelet and plasma hemostasis as a predictor of coronary blood flow in patients with acute myocardial infarction

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