http://www.redheracles.net/media/upload/research/pdf/242115031391673869.pdf

Multicenter Core Laboratory Comparison of the Instantaneous Wave-Free Ratio and Resting Pd/Pa With Fractional Flow Reserve: The RESOLVE Study

Impact of microvascular obstruction on the assessment of coronary flow reserve, index of microcirculatory resistance, and fractional flow reserve after ST-segment elevation myocardial infarction.

Fractional flow reserve is routinely used to estimate the extent of myocardial ischaemia caused by the narrowing of a coronary artery. In this Review, the physiological basis of this measurement, its limitations, and its clinical use are discussed.

Fractional flow reserve as a surrogate for inducible myocardial ischaemia

Background—The assessment of functional coronary lesion severity using intracoronary physiological parameters such as coronary flow velocity reserve and the more widely used fractional flow reserve relies critically on the establishment of maximal hyperemia. We evaluated the diagnostic accuracy of the stenosis resistance index during nonhyperemic conditions, baseline stenosis resistance index, compared with established hyperemic intracoronary hemodynamic parameters, because achievement of hyperemia can be cumbersome in daily clinical practice. Methods and Results—A total of 228 patients, including 299 lesions (mean stenosis diameter 55%±11%), underwent myocardial perfusion scintigraphy for documentation of reversible perfusion defects. Distal coronary pressure and flow velocity were assessed with sensor-equipped guidewires during baseline and maximal hyperemia, induced by an intracoronary bolus of adenosine (20–40 µg). We determined stenosis resistance (SR) during baseline and hyperemic conditions as well...

Diagnostic Accuracy of Combined Intracoronary Pressure and Flow Velocity Information During Baseline Conditions Adenosine-Free Assessment of Functional Coronary Lesion Severity

Does the Instantaneous Wave-Free Ratio Approximate the Fractional Flow Reserve?

OBJECTIVE: To investigate the relationship between resting distal coronary pressure to aortic pressure ratio (Pd/Pa) and fractional flow reserve (FFR) obtained during maximal hyperemia. BACKGROUND: FFR is an invasive index of the functional severity of a coronary artery stenosis determined from coronary pressure measurements. It is generally believed that there is little correlation between resting Pd/Pa and FFR obtained during maximal hyperemia. We have therefore studied this relationship in a large cohort of patients who had undergone pressure- wire assessments. METHODS: 528 consecutive pressure-wire studies performed in 483 patients over a 2-year period were retrospectively analyzed. RESULTS: A linear correlation between resting Pd/Pa and FFR post-pharmacological hyperemia was observed (rho = 0.74; p or = 0.93 (> or = 0.96) had a negative predictive value (NPV) of 95.7% (93%). CONCLUSIONS: We demonstrate a strong correlation between resting Pd/Pa and FFR. Resting values of Pd/Pa can be used to predict a positive FFR result with relatively high PPV and NPV. This may potentially obviate the need for adenosine infusion in a proportion of pressure-wire studies.

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Elise Welch

Papers

Resting Pd/Pa measured with intracoronary pressure wire strongly predicts fractional flow reserve.