Prognostic implications of resting distal coronary-to-aortic pressure ratio compared with fractional flow reserve: a 10-year follow-up study after deferral of revascularisation.

INTRODUCTION: The distal coronary-to-aortic pressure ratio (Pd/Pa) is a non-hyperaemic physiological index to assess the functional severity of coronary stenoses. Studies comparing Pd/Pa with fractional flow reserve (FFR) show superior diagnostic efficiency for myocardial ischaemia. Nevertheless, a direct comparison regarding long-term clinical outcomes is still not available. The present observational study compared the prognostic value of Pd/Pa and FFR for major adverse cardiac events (MACE) during a 10-year follow-up period after deferral of revascularisation. METHODS: Between April 1997 and September 2006, we evaluated 154 coronary stenoses (154 patients) in which revascularisation was deferred with intracoronary pressure and flow measurements during the resting and hyperaemic state. Long-term follow-up (median: 11.8 years) was performed to document the occurrence of MACE, defined as a composite of cardiac death, myocardial infarction and target vessel revascularisation. RESULTS: The study population comprised angiographically intermediate coronary stenoses, with a mean diameter stenosis of 53 ± 8%, and intermediate physiological severity with a median FFR of 0.82 (Q1, Q3: 0.76, 0.88). The association of Pd/Pa with long-term MACE was similar to that of FFR [FFR-standardised hazard ratio (sHR): 0.77, 95% confidence interval (CI): 0.61-0.98; Pd/Pa-sHR: 0.80, 95% CI: 0.67-0.96]. In the presence of disagreement between Pd/Pa and FFR, normal Pd/Pa was generally associated with high coronary flow reserve (CFR) and a favourable clinical outcome, whereas abnormal Pd/Pa was generally associated with CFR around the ischaemic cut-point and an impaired clinical outcome, regardless of the accompanying FFR value. CONCLUSION: The present study suggests that Pd/Pa provides at least equivalent prognostic value compared with FFR. When Pd/Pa disagreed with FFR, the baseline index conferred superior prognostic value in this study population.

Simplified hybrid algorithms for pressure wire interrogation exploiting advantages of a baseline and contrast Pd/Pa ratio indexes to predict stenosis significance: Insight from the SPARE multicenter prospective study.

BACKGROUND: Simplification of functional stenosis assessment with pressure guidewires may facilitate adoption of physiology-guided revascularization. An important step in this regard is the avoidance of hyperemic agents, required for fractional flow reserve (FFR) calculation. We evaluate the merits of a hybrid algorithms that combines the translesional pressure ratio (Pd/Pa) obtained at rest, after contrast medium injection (cFFR) and after adenosine administration (FFR). METHODS AND RESULTS: Eighty-six patients with 108 de novo intermediate coronary stenoses were included in this prospective, multicenter study. Using prespecified cut-off values that correctly identified stenosis with a 95% of agreement (<0.89 and >0.96 for Pd/Pa; <0.84 and > 0.87 for cFFR) we tested the efficiency of three different multi-step strategies combining the three indices to classify stenosis severity, using FFR-only measurement as reference. All three different hybrid algorithms (Pd/Pa-FFR; cFFR-FFR; Pd/Pa-cFFR-FFR) have more than 95% of agreement with FFR. Yet, the novel Pd/Pa-cFFR-FFR hybrid strategy demonstrated the best performance, avoiding the need of adenosine and medium contrast in 90% and 48% of cases, respectively. CONCLUSIONS: A hybrid Pd/Pa-cFFR-FFR decision-making algorithm could be an alternative and valuable strategy to increase the adoption of a physiology-guided PCI using conventional pressure guidewires and consoles.

Use of fractional flow reserve in contemporary scenarios of coronary revascularization.

Fractional flow reserve (FFR), an invasive pressure-derived index of stenosis severity, can be performed easily, rapidly, and safely in patients with coronary artery disease as a surrogate of non-invasive detection of ischemia. Over the last decades, profound clinical and scientific evaluation has demonstrated that FFR is one of the few diagnostic modalities that improve patient outcome and, at the same time, are cost-effective and cost-saving. The increasing use of PCI to treat multivessel disease and complex anatomical subsets has created new demands for accurate, "per stenosis" assessment, since revascularisation should be performed only in those stenosis that are ischaemia generating. Recent studies have demonstrated that this attitude results in better patient outcomes. Altogether, current evidence clearly supports the measurement of FFR in catheterization laboratories in order to provide objective and complementary data to coronary angiography. The purpose of this review is to discuss the value of FFR in the diagnosis and treatment of patients with different anatomical subsets, including intermediate stenosis, multivessel disease, left main disease, serial stenosis, ostial and bifurcation lesions, saphenous vein graft disease and in-stent restenosis, as well as in those presenting with acute coronary syndromes.

Optimizing vessel healing following drug eluting stent implantation with biodegradable polymer DES.

The introduction of coronary drug eluting stents (DES) more than 10 years ago drastically decreased the occurrence of restenosis, compared with first generation bare metal stents (BMS). However, the optimism created by the first studies was soon shadowed by the demonstration of higher rates of late and very late stent thrombosis (ST). The research performed in this phenomenon highlighted the causative role played by incomplete stent strut coverage, hypersensitivity reactions caused by the drug eluting polymer, and neoatherosclerosis, all markers of an inadequate vascular response to DES implantation. Over the following years, new development in stent and eluting polymer technologies have been incorporated in second generation DES to optimize the process of vessel healing and, thus, to avoid these complications. Furthermore, it is envisaged that adequate vessel healing would be followed by less dependence on double antiplatelet, a limiting aspect for DES use in different clinical scenarios. In this review, we focused on the use of biodegradable eluting polymers to increase DES safety, revisiting the rationale for its use and the synergic action with other changes in stent technology aimed to optimize vessel healing after DES implantation.