Otakar Boček

VERIFY (VERification of Instantaneous Wave-Free Ratio and Fractional Flow Reserve for the Assessment of Coronary Artery Stenosis Severity in EverydaY Practice): a multicenter study in consecutive patients.

OBJECTIVES This study sought to compare fractional flow reserve (FFR) with the instantaneous wave-free ratio (iFR) in patients with coronary artery disease and also to determine whether the iFR is independent of hyperemia. BACKGROUND FFR is a validated index of coronary stenosis severity. FFR-guided percutaneous coronary intervention (PCI) improves clinical outcomes compared to angiographic guidance alone. iFR has been proposed as a new index of stenosis severity that can be measured without adenosine. METHODS We conducted a prospective, multicenter, international study of 206 consecutive patients referred for PCI and a retrospective analysis of 500 archived pressure recordings. Aortic and distal coronary pressures were measured in duplicate in patients under resting conditions and during intravenous adenosine infusion at 140 μg/kg/min. RESULTS Compared to the FFR cut-off value of ≤0.80, the diagnostic accuracy of the iFR value of ≤0.80 was 60% (95% confidence interval [CI]: 53% to 67%) for all vessels studied and 51% (95% CI: 43% to 59%) for those patients with FFR in the range of 0.60 to 0.90. iFR was significantly influenced by the induction of hyperemia: mean ± SD iFR at rest was 0.82 ± 0.16 versus 0.64 ± 0.18 with hyperemia (p < 0.001). Receiver operating characteristics confirmed that the diagnostic accuracy of iFR was similar to resting Pd/Pa and trans-stenotic pressure gradient and significantly inferior to hyperemic iFR. Analysis of our retrospectively acquired dataset showed similar results. CONCLUSIONS iFR correlates weakly with FFR and is not independent of hyperemia. iFR cannot be recommended for clinical decision making in patients with coronary artery disease.

Instantaneous wave-free ratio or fractional flow reserve without hyperemia: novelty or nonsense?

We read the paper by Sen et al. ([1][1]) with great interest. We have a number of concerns regarding the proposed index, instantaneous wave-free ratio (iFR). First, the validity of iFR depends on the assumption that minimum resting myocardial resistance during diastole is equivalent to the mean

The value of novel invasive hemodynamic parameters added to the TIMI risk score for short-term prognosis assessment in patients with ST segment elevation myocardial infarction

BACKGROUND We compared the prognostic capacity of conventional and novel invasive parameters derived from the slope of the preload recruitable stroke work relationship (PRSW) in STEMI patients and assessed their contribution to the TIMI risk score. METHODS Left ventricular end-diastolic pressure (EDP), ejection fraction (EF), pressure adjusted maximum rate of pressure change in the left ventricle (dP/dt/P), aortic systolic pressure to EDP ratio (SBP/EDP) and end-diastolic volume adjusted stroke work (EW), derived from the slope of the PRSW relationship, were obtained during the emergency cardiac catheterization in 523 STEMI patients. The predictive power of the analyzed parameters for 30-day and 1-year mortality was evaluated using C-statistics and reclassification analysis was adopted to assess the improvement in TIMI score. RESULTS The highest area under the curve (AUC) values for 30-day mortality were observed for EW (0.872(95% confidence interval 0.801-0.943)), SBP/EDP (0.843(0.758-0.928)) and EF (0.833(0.735-0.931)); p<0.001 for all values. For 1-year mortality the best predictive value was found for EW (0.806(0.724-0.887) and EF (0.793(0.703-0.883)); p<0.001 for both. The addition of EDP, SBP/EDP ratio and EW to TIMI score significantly increased the AUC according to De Longs test. For 30-day mortality, increased discriminative power following addition to the TIMI score was observed for EW and SBP/EDP (Integrated Discrimination Improvement was 0.086(0.033-0.140), p=0.002 and 0.078(0.028-0.128), p=0.002, respectively). CONCLUSIONS EW and SBP/EDP are prognostic markers with high predictive value for 30-day and 1-year mortality. Both parameters, easily obtained during emergency catheterization, improve the discriminatory capacity of the TIMI score for 30-day mortality.

Radial artery neointimal hyperplasia after transradial PCI-Serial optical coherence tomography volumetric study

Aims Transradial catheterization (TRC) is a dominant access site for coronary catheterization and percutaneous coronary interventions (PCI) in many centers. Previous studies reported higher intimal thickness of the radial artery (RA) wall in patients with a previous history of TRC. In this investigation the aim was to assess the intimal changes of RA using the optical coherence tomography (OCT) intravascular imaging in a serial manner. Methods and results 100 patients with the diagnosis of non-ST-elevation myocardial infarction (nSTEMI) treated by PCI were enrolled (6 patients were excluded from this analysis because of occluded RA at follow-up [2 patients] and insufficient quality of OCT images [4 patients]). An 54mm long OCT run of the RA was performed immediately after the index PCI and repeated 9 months later. Volumetric analyses of the intimal layer and lumen changes were conducted. Median intimal volume at baseline versus 9 months was 33.9mm3 (19.0; 69.4) versus 39.0mm3 (21.7; 72.6) (p<0.001); and median arterial lumen volume was 356.3mm3 (227.8; 645.3) versus 304.7mm3 (186.1; 582.7) (p<0.001). There was no significant difference in the effect of any clinical factor on the RA volume changes. Conclusions OCT volumetric analyses at baseline and 9 months showed a significant increase in the radial artery intimal layer volume and a decrease in lumen volume after transradial PCI. No significant factors affecting this process were identified.

TCT-547 Radial artery changes after transradial PCI – A serial optical coherence tomography volumetric study

Transradial catheterization (TRC) is a dominant access site for coronary catheterization and percutaneous coronary interventions (PCI) in many centers. Previous studies reported higher intimal thickness of the radial artery (RA) wall in patients with a previous history of TRC. In this investigation

Short sheath benefit in radial artery injury after PCI -optical coherence tomography serial study

BACKGROUND AND AIMS Transradial catheterization is the predominant access site for coronary catheterization and percutaneous coronary interventions (PCI). Previous studies have reported a high incidence of radial artery (RA) injury. The aim of this investigation was to evaluate the incidence of RA injury using last generation optical coherence tomography (OCT) intravascular imaging in a serial manner. METHODS 100 patients with a diagnosis of non-ST-elevation myocardial infarction (nSTEMI) treated by PCI were enrolled. OCT of RA was performed immediately after the index PCI. OCT was repeated 9 months later. RESULTS There were 11 patients with RA injuries (11.0%) at baseline, including 3 patients with RA medial dissection and 8 patients with intimal tears. In the follow-up OCT data, the number of RA injuries was 10 (10.0%), including 7 patients with RA medial dissection and 3 patients with intimal tear. All injuries were clinically asymptomatic and there was no finding of vessel perforation. There was no significant difference between the baseline and follow-up procedure in terms of number of injuries. CONCLUSION The study showed no significant difference between baseline and follow-up RA injury incidence. There was a higher risk of radial injury for repeated catheterization in women. The conclusion is that radial catheterization is a very safe procedure in terms of radial artery damage. This is evidenced by considerably fewer injuries compared to published studies. The use of the short radial sheath (7 cm in this study) is protective and reduces the incidence of radial injury.