Comparison of intracoronary versus intravenous adenosine-induced maximal hyperemia for fractional flow reserve measurement: A systematic review and meta-analysis

Fractional Flow Reserve to Assess Coronary Artery Disease in Patients with Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation: Long-Term Outcomes

Background

The long-term outcomes of patients undergoing functional assessment of coronary lesions with fractional flow reserve (FFR) while awaiting transcatheter aortic valve implantation (TAVI) are unknown. Data on the safety of intracoronary adenosine use in this setting are scarce. The objectives of this study were to describe (1) the long-term outcomes based on the coronary artery disease (CAD) assessment strategy used and (2) the safety of intracoronary adenosine in patients with severe aortic stenosis (AS).

Methods

1023 patients with severe AS awaiting TAVI were included. Patients were classified according to their CAD assessment strategy: angiography guided or FFR guided. Patients were further subdivided according to the decision to proceed with percutaneous coronary intervention (PCI): angiography-guided PCI (375/1023), angiography-guided no-PCI (549/1023), FFR-guided PCI (50/1023), and FFR-guided no-PCI (49/1023). Patients were followed up for the occurrence of major adverse cardiac and cerebrovascular events (MACCEs).

Results

At a mean follow-up of 33.7 months, we observed no significant differences in terms of major adverse cardiovascular and cerebrovascular events (MACCE) in the angiography-guided group (42.4%) compared with the FFR-guided group (37.4%) (p = 0.333). When comparing outcomes of the FFR-guided no-PCI group (32.7%) with the angiography-guided PCI group (46.4%), no significant difference was noted (p = 0.999). Following intracoronary adenosine, a single adverse event occurred.

Conclusions

In this population, intracoronary adenosine is safe and well tolerated. We found no significant benefit to an FFR-guided strategy compared with an angiography-guided strategy with respect to MACCEs. Although clinically compelling, avoiding the procedural risks of PCI by deferring the intervention in functionally insignificant lesions failed to show a statistically significant benefit.

Intravascular Imaging versus Physiological Assessment versus Biomechanics-Which Is a Better Guide for Coronary Revascularization

Today, coronary artery disease (CAD) continues to be a prominent cause of death worldwide. A reliable assessment of coronary stenosis represents a prerequisite for the appropriate management of CAD. Nevertheless, there are still major challenges pertaining to some limitations of current imaging and functional diagnostic modalities. The present review summarizes the current data on invasive functional and intracoronary imaging assessment using optical coherence tomography (OCT), and intravascular ultrasound (IVUS). Amongst the functional parameters-on top of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR)-we point to novel angiography-based measures such as quantitative flow ratio (QFR), vessel fractional flow reserve (vFFR), angiography-derived fractional flow reserve (FFRangio), and computed tomography-derived flow fractional reserve (FFR-CT), as well as hybrid approaches focusing on optical flow ratio (OFR), computational fluid dynamics and attempts to quantify the forces exaggerated by blood on the coronary plaque and vessel wall.

Diagnostic accuracy of two-dimensional coronary angiographic-derived fractional flow reserve-Preliminary results

AIM

Noninvasive fractional flow reserve (NiFFR) is an emerging method for evaluating the functional significance of a coronary lesion during diagnostic coronary angiography (CAG). The method relies on the computational flow dynamics and the three-dimensional (3D) reconstruction of the vessel extracted from CAG. In the present study, we sought to evaluate the diagnostic performance and applicability of 2D-based NiFFR.

METHODS

In this prospective observational study, we evaluated 2D-based NiFFR in 279 candidates for invasive CAG and invasive fractional flow reserve (FFR). NiFFR was calculated via two methods: variable NiFFR, in which the contrast transport time was extracted from the angiographic view, and fixed NiFFR, in which a prespecified frame count was applied.

RESULTS

The final analysis was performed on 245 patients (250 lesions). Variable NiFFR had an area under the receiver operating characteristic curve of 81.5%, an accuracy of 80.0%, a sensitivity of 82.2%, a specificity of 82.2%, a negative predictive value of 91.4%, and a positive predictive value of 63.6%. The mean difference between FFR and NiFFR was -0.0244 ±.0616 (p ≤.0001). A pressure wire-free hybrid strategy was possible in 68.8% of our population with variable NiFFR.

CONCLUSIONS

Our 2D-based NiFFR yielded results comparable to those derived from 3D-based software. Our findings should; however, be confirmed in larger trials.