FFR-guided Revascularization Research Articles

Fractional Flow Reserve–Guided Revascularization: Practical Implications of a Diagnostic Gray Zone and Measurement Variability on Clinical Decisions

This study sought to evaluate the effects of fractional flow reserve (FFR) measurement variability on FFR-guided treatment strategy. Current appropriateness guidelines recommend the utilization of FFR to guide coronary revascularization based on a fixed cut-off of 0.8. This rigid approach does not take into account the intrinsic biological variability of a single FFR result and the clinical judgment of experienced interventional cardiologists. [corrected]. FFR reproducibility data from the landmark Deferral Versus Performance of PTCA in Patients Without Documented Ischemia (DEFER) trial was analyzed (two repeated FFR measurements in the same lesion, 10 min apart) and the standard deviation of the difference (SDD) between repeated measurements was calculated. The measurement certainty (probability that the FFR-guided revascularization strategy will not change if the test is repeated 10 min later) was subsequently established across the whole range of FFR values, from 0.2 to 1. Outside the [0.75 to 0.85] FFR range, measurement certainty of a single FFR result is >95%. However, closer to its cut-off, certainty falls to less than 80% within 0.77 to 0.83, reaching a nadir of 50% around 0.8. In clinical practice, that means that each time a single FFR value falls between 0.75 and 0.85, there is a chance that the FFR-derived revascularization recommendation will change if the measurement is repeated 10 min later, with this chance increasing the closer the FFR result is to 0.8. A measurement FFR gray-zone is found between 0.75 and 0.85]. Therefore, clinicians should make revascularization decisions based on broadened clinical judgment when a single FFR result falls within this uncertainty zone, particularly between 0.77 and 0.83, when measurement certainty falls to less than 80%.

FFR-guided revascularization versus medical therapy—the debate goes on

Coronary artery disease: FFR-guided revascularization versus medical therapy—the debate goes on

Treatment of non-culprit lesions detected during primary PCI: long-term follow-up of a randomised clinical trial

There are conflicting data regarding optimal treatment of non-culprit lesions detected during primary percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI) and multi-vessel disease (MVD). We aimed to investigate whether ischaemia-driven early invasive treatment improves the long-term outcome and prevents major adverse cardiac events (MACE). 121 patients with at least one non-culprit lesion were randomised in a 2:1 manner, 80 were randomised to early fractional flow reserve (FFR)-guided PCI (invasive group), and 41 to medical treatment (conservative group). The primary endpoint was MACE at 3years. Three-year follow-up was available in 119 patients (98.3%). There was no significant difference in all-cause mortality between the invasive and conservative strategy, 4 patients (3.4%) died, all in the invasive group (P = 0.29). Re-infarction occurred in 14 patients (11.8%) in the invasive group versus none in the conservative group (p = 0.002). Re-PCI was performed in 7 patients (8.9%) in the invasive group and in 13 patients (32.5%) in the conservative group (P = 0.001). There was no difference in MACE between these two strategies (35.4 vs 35.0%, p = 0.96). In STEMI patients with MVD, early FFR-guided additional revascularisation of the non-culprit lesion did not reduce MACE at three-year follow-up compared with a more conservative strategy. The rate of MACE in the invasive group was predominantly driven by death and re-infarction, whereas in the conservative group the rate of MACE was only driven by repeat interventions.

Fractional Flow Reserve: The Past, Present and Future

Revascularization of coronary artery stenosis should be based on the objective evidence of ischemia. It is common practice for physicians to make decisions on revascularization in the cardiac catheterization laboratory based on the results of angiography, despite the fact that angiographic information does not correlate well with the functional significance of a coronary lesion. Fractional flow reserve (FFR) is a physiologic parameter which can be measured easily during the invasive procedure and can assess the functional significance of coronary stenosis. FFR-guided revascularization strategy is reported to be more effective than angiography-guided strategy in patients with coronary artery disease. Moreover, novel technologies based on FFR have been developed and will soon be incorporated into clinical practice.

Abstract 17709: Central Coronary Venous Troponin Concentrations as a Guide to the Identification of the Culprit Vessel in Multivessel Coronary Artery Disease

Background: In patients with non ST elevation acute coronary syndromes (NSTE ACS) culprit vessel identification remains a challenge. Notably, in the FAME trial routine multivessel stenting was not superior to FFR-guided revascularization. We hypothesized that a culprit stenosis in the LAD can be identified because troponin concentrations assessed in the great cardiac vein (GCV) would be higher than elsewhere in the coronary venous tree. In addition, in case of a RCX/RCA culprit we expected the concentration to be higher elsewhere in the coronary venous tree. Methods: we studied 36 consecutive patients with NSTE ACS who underwent early coronary angiography. In case of normal coronary arteries or a total occlusion a patient was excluded. Right sided catheterization and cannulation of the coronary sinus was performed. The catheter was introduced in the GCV with subsequent blood sampling. This procedure was repeated at the orifice of posterolateral vein and the middle cardiac vein. The culprit was assessed by a blinded committee using ECG, echo and coronary angiography. Results: As proof of concept 12 patients with single vessel disease were studied. All 5 with a LAD culprit had the highest troponin concentration in the GCV. In 6/7 patients with a non-LAD culprit the highest concentration was measured distally from the GCV in the coronary venous tree. As a pilot validation set, performed in multivessel disease patients with a definite culprit, the distinction LAD/non-LAD was correct in 14/15. In 9 patients in whom the culprit was unclear, the GCV concentration was highest in two. Conclusion: Despite careful study by a blinded committee, the culprit vessel can not be identified with certainty in ~25% of patients with NSTE ACS using conventional information. Assessment of the troponin concentration in the great cardiac vein can reliably distinguish between LAD and non-LAD culprits. Additional studies will address the diagnostic accuracy with regard to RCX and RCA culprits.

Sténoses intermédiaires sur plusieurs vaisseaux : intérêt de la mesure de la réserve coronaire pour déterminer la stratégie de revascularisation

Most patients undergoing a catheterization did not have any previous non-invasive testing. Therefore, most decisions about revascularization are taken solely on the basis of the angiogram. Nowadays, it is possible to gain reliable functional information during catheterization by measuring fractional flow reserve (FFR). FFR is obtained by simple pressure measurements distal to the stenosis during maximal hyperemia. FFR-guided revascularization provides better clinical outcomes than angiographically-guided decisions. This is especially relevant in patients with multi-vessel disease and mild to moderate coronary plaque burden. FFR is able to determine the hemodynamic significance of each lesion individually and enables therefore guidance of the revascularization treatment. The case of a 62-year-old man with stable angina is reported. He underwent percutaneous coronary intervention of the left anterior descending 10 years ago. Repeat coronary angiogram revealed multi-vessel disease with a moderate stenosis in all main coronary arteries. Non-invasive functional assessment by myocardial perfusion imaging was inconclusive to evaluate presence or absence of ischemia. The use of FFR in this clinical scenario may be very useful to determine treatment strategy.

Fractional Flow Reserve: A Practical Update

This article serves as a practical update on the performance and clinical application of fractional flow reserve (FFR) in the evaluation of intermediate coronary stenoses. We review several methods for the induction of hyperemia, viability after myocardial infarction, the impact of diabetes, and the use of FFR in myocardial bridging. New data on the correlation of FFR with noninvasive imaging in multivessel disease are presented. Additionally, we touch on the growing body of FFR-guided revascularization trials.