Publications
207 results found
Cook CM, Ahmad Y, Shun-Shin MJ, et al., 2016, Quantification of the Effect of Pressure Wire Drift on the Diagnostic Performance of Fractional Flow Reserve, Instantaneous Wave-Free Ratio, and Whole-Cycle Pd/Pa, Circulation: Cardiovascular Interventions, Vol: 9, ISSN: 1941-7640
Background—Small drifts in intracoronary pressure measurements (±2 mmHg) can affect stenosis categorization usingpressure indices. This has not previously been assessed for fractional flow reserve (FFR), instantaneous wave-free ratio(iFR), and whole-cycle distal pressure/proximal pressure (Pd/Pa) indices.Methods and Results—Four hundred forty seven stenoses were assessed with FFR, iFR, and whole-cycle Pd/Pa. Cut pointvalues for significance were predefined as ≤0.8, <0.90, and <0.93, respectively. Pressure wire drift was simulated byoffsetting the distal coronary pressure trace by ±2 mmHg. FFR, iFR, and whole-cycle Pd/Pa indices were recalculatedand stenosis misclassification quantified. Median (±median absolute deviation) values for FFR, iFR, and whole-cycle Pd/Pa were 0.81 (±0.11), 0.90 (±0.07), and 0.93 (±0.06), respectively. 34.6% (155), 50.1% (224), and 62.2% (278) of valueslay within ±0.05 U of the cut point for FFR, iFR, and whole-cycle Pd/Pa, respectively. With ±2 mmHg pressure wire drift,21% (94), 25% (110), and 33% (148) of the study population were misclassified with FFR, iFR, and whole-cycle Pd/Pa,respectively. Both FFR and iFR had significantly lower misclassification than whole-cycle Pd/Pa (P<0.001). There wasno statistically significant difference between the diagnostic performance of FFR and iFR (P=0.125).Conclusions—In a substantial proportion of cases, small amounts of pressure wire drift are enough to causestenoses to change classification. Whole-cycle Pd/Pa is more vulnerable to such reclassification than FFR and iFR.
Broyd CJ, Nijjer S, Sen S, et al., 2016, Estimation of coronary wave intensity analysis using noninvasive techniques and its application to exercise physiology, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, Vol: 310, Pages: H619-H627, ISSN: 0363-6135
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- Citations: 11
Echavarria-Pinto M, Petraco R, van de Hoef TP, et al., 2016, Fractional flow reserve and minimum P-d/P-a ratio during intravenous adenosine infusion: very similar but not always the same, Eurointervention, Vol: 11, Pages: 1013-1019, ISSN: 1969-6213
Petraco R, Sen S, Nijjer S, et al., 2015, ECG-Independent Calculation of Instantaneous Wave-Free Ratio, JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 8, Pages: 2043-2046, ISSN: 1936-8798
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- Citations: 13
van de Hoef TP, Meuwissen M, Escaned J, et al., 2015, Head-to-head comparison of basal stenosis resistance index, instantaneous wave-free ratio, and fractional flow reserve: diagnostic accuracy for stenosis-specific myocardial ischaemia, EUROINTERVENTION, Vol: 11, Pages: 914-925, ISSN: 1774-024X
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- Citations: 44
Nijjer SS, de Waard GA, Sen S, et al., 2015, Coronary pressure and flow relationships in humans: phasic analysis of normal and pathological vessels and the implications for stenosis assessment: a report from the Iberian-Dutch-English (IDEAL) collaborators, European Heart Journal, Vol: 37, Pages: 2069-2080, ISSN: 1522-9645
BACKGROUND: Our understanding of human coronary physiological behaviour is derived from animal models. We sought to describe physiological behaviour across a large collection of invasive pressure and flow velocity measurements, to provide a better understanding of the relationships between these physiological parameters and to evaluate the rationale for resting stenosis assessment. METHODS AND RESULTS: Five hundred and sixty-seven simultaneous intracoronary pressure and flow velocity assessments from 301 patients were analysed for coronary flow velocity, trans-stenotic pressure gradient (TG), and microvascular resistance (MVR). Measurements were made during baseline and hyperaemic conditions. The whole cardiac cycle and the diastolic wave-free period were assessed. Stenoses were assessed according to fractional flow reserve (FFR) and quantitative coronary angiography DS%. With progressive worsening of stenoses, from unobstructed angiographic normal vessels to those with FFR ≤ 0.50, hyperaemic flow falls significantly from 45 to 19 cm/s, Ptrend < 0.001 in a curvilinear pattern. Resting flow was unaffected by stenosis severity and was consistent across all strata of stenosis (Ptrend > 0.05 for all). Trans-stenotic pressure gradient rose with stenosis severity for both rest and hyperaemic measures (Ptrend < 0.001 for both). Microvascular resistance declines with stenosis severity under resting conditions (Ptrend < 0.001), but was unchanged at hyperaemia (2.3 ± 1.1 mmHg/cm/s; Ptrend = 0.19). CONCLUSIONS: With progressive stenosis severity, TG rises. However, while hyperaemic flow falls significantly, resting coronary flow is maintained by compensatory reduction of MVR, demonstrating coronary auto-regulation. These data support the translation of coronary physiological concepts derived from animals to patients with coronary artery disease and furthermore, suggest that resting pressure indices can be used to detect the haemodynamic significance of co
Cook C, Ahmad Y, Petraco R, et al., 2015, Accounting for right atrial pressure in the calculation of Fractional Flow Reserve (FFR) significantly increases the number of physiologically significant stenoses suitable for PCI, 27th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B18-B19, ISSN: 0735-1097
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- Citations: 2
Foin N, Lee RD, Bourantas C, et al., 2015, Bioabsorbable Vascular Scaffold Radial Expansion and Conformation Compared to a Metallic platform: Insights from In-vitro Expansion in a Coronary Artery Lesion Model, 27th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B209-B209, ISSN: 0735-1097
Ahmad Y, Sen S, Shun-Shin M, et al., 2015, Intra-aortic balloon pump therapy does not reduce mortality in acute myocardial infarction, with or without cardiogenic shock: application of a baseline inequality index to account for differential outcomes in randomized and observational studies, 27th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B103-B103, ISSN: 0735-1097
Cook C, Ahmad Y, Nijjer SS, et al., 2015, Quantification of the effect of measurement drift on the diagnostic performance of FFR, iFR and whole cycle Pd/Pa, 27th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B15-B16, ISSN: 0735-1097
Ahmad Y, Sen S, Keene D, et al., 2015, Thrombus aspiration does not reduce mortality in STEMI patients: a meta-analysis of 20,192 patients, with implications for future trial design, 27th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B103-B104, ISSN: 0735-1097
Ahmad Y, Nijjer SS, Cook C, et al., 2015, Patients consider PCI and CABG equal: Derivation of a novel patient-centered, quantitative analysis of Major Adverse Cardiac Events (MACE) and its application to trials comparing PCI to CABG, 27th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B195-B196, ISSN: 0735-1097
Sen S, Petraco R, Nijjer S, et al., 2015, Can Resting Indices Obviate the Need for Hyperemia and Promote the Routine Use of Physiologically Guided Revascularization?, Interv Cardiol Clin, Vol: 4, Pages: 459-469
This article assesses the data from contemporary human studies to address some of the common assumptions regarding hyperemic and baseline physiology in the context of the baseline pressure-derived index of instant wave-free ratio and the hyperemic index of fractional flow reserve. The article aims to determine if the available evidence supports the continued investigation, development, and use of baseline indices.
Ahmad Y, Nijjer S, Cook CM, et al., 2015, A new method of applying randomised control study data to the individual patient: A novel quantitative patient-centred approach to interpreting composite end points, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 195, Pages: 216-224, ISSN: 0167-5273
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- Citations: 18
Patel N, Petraco R, Dall'Armellina E, et al., 2015, Zero-Flow Pressure Measured Immediately After Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction Provides the Best Invasive Index for Predicting the Extent of Myocardial Infarction at 6 Months An OxAMI Study (Oxford Acute Myocardial Infarction), JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 8, Pages: 1410-1421, ISSN: 1936-8798
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- Citations: 46
Cook CM, Petraco R, Nijjer S, et al., 2015, Accounting for right atrial pressure in the calculation of fractional flow reserve (FFR) significantly increases the number of physiologically significant stenoses suitable for PCI, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 858-858, ISSN: 0195-668X
Cook C, Ahmad Y, Shun-Shin M, et al., 2015, Instantaneous wave-free ratio (iFR) provides the most robust measure of any resting physiological index: the effects of pressure drift and measurement variability on stenosis misclassification, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 296-297, ISSN: 0195-668X
Nijjer SS, Sen SS, Petraco R, et al., 2015, Investigation of human coronary haemodynamics in normal and stenosed vessels to develop systems to quantify stenosis significance and predict the functional gain of intervention, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 297-298, ISSN: 0195-668X
Nijjer SS, De Waard G, Sen S, et al., 2015, Hyperemic flow velocity falls with worsening stenosis severity: the challenge for non-invasive predictors of coronary physiology, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 299-299, ISSN: 0195-668X
Nijjer SS, Sen S, Petraco R, et al., 2015, Advances in Coronary Physiology, CIRCULATION JOURNAL, Vol: 79, Pages: 1172-1184, ISSN: 1346-9843
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- Citations: 20
Nijjer S, de Waard G, van de Hoef T, et al., 2015, CHANGES IN RESTING MICROVASCULAR RESISTANCE EXPLAIN WHY RESTING FLOW IS PRESERVED DESPITE INCREASING STENOSIS SEVERITY: THE RESULTS OF THE LARGEST INTERNATIONAL COMBINED CORONARY PRESSURE AND FLOW STUDY, British-Cardiac-Society (BCS) Annual Conference on Hearts and Genes, Publisher: BMJ PUBLISHING GROUP, Pages: A59-A60, ISSN: 1355-6037
Nijjer S, Sen S, Petraco R, et al., 2015, VIRTUAL PCI WITH IFR-PULLBACK IN COMPLEX CORONARY DISEASE: THE POTENTIAL FOR REDUCING STENT LENGTH, British-Cardiac-Society (BCS) Annual Conference on Hearts and Genes, Publisher: BMJ PUBLISHING GROUP, Pages: A60-A60, ISSN: 1355-6037
Nijjer S, Sen S, Davies J, et al., 2015, VIRTUAL-PCI WITH IFR-PULLBACK CAN PLAN CORONARY INTERVENTION IN COMPLEX CORONARY DISEASE WITH A PREDICTION OF FUNCTIONAL GAIN, British-Cardiac-Society (BCS) Annual Conference on Hearts and Genes, Publisher: BMJ PUBLISHING GROUP, Pages: A61-A61, ISSN: 1355-6037
Nijjer SS, Petraco R, van de Hoef TP, et al., 2015, Change in Coronary Blood Flow After Percutaneous Coronary Intervention in Relation to Baseline Lesion Physiology Results of the JUSTIFY-PCI Study, CIRCULATION-CARDIOVASCULAR INTERVENTIONS, Vol: 8, ISSN: 1941-7640
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- Citations: 29
Nijjer S, De Waard G, Van De Hoef T, et al., 2015, Determination of the Behavior of Coronary Physiology Under Resting Conditions: The Implications for Stenosis Assessment, 20th Cardiovascular Summit on Transcatheter Cardiovascular Therapeutics Asia Pacific (TCTAP), Publisher: ELSEVIER SCIENCE INC, Pages: S56-S57, ISSN: 0735-1097
Petraco R, Sen S, Nijjer S, et al., 2015, Development of an ECG-Independent Algorithm for the Calculation of Instantaneous Wave-Free Ratio (iFR): A Step Towards Further Simplification of Physiological Lesion Assessment, 20th Cardiovascular Summit on Transcatheter Cardiovascular Therapeutics Asia Pacific (TCTAP), Publisher: ELSEVIER SCIENCE INC, Pages: S58-S58, ISSN: 0735-1097
Cook CM, Petraco R, Sen S, et al., 2015, Accounting for Right Atrial Pressure in the Calculation of Fractional Flow Reserve Significantly Increases the Number of Physiologically Significant Stenoses Suitable for Revascularization, 20th Cardiovascular Summit on Transcatheter Cardiovascular Therapeutics Asia Pacific (TCTAP), Publisher: ELSEVIER SCIENCE INC, Pages: S57-S57, ISSN: 0735-1097
Foin N, Chico JLG, Nakatani S, et al., 2015, Incomplete Stent Apposition Causes High Shear Flow Disturbances and Delay in Neointimal Coverage as a Function of Strut to Wall Detachment Distance: Implications for Stent Optimization, 20th Cardiovascular Summit on Transcatheter Cardiovascular Therapeutics Asia Pacific (TCTAP), Publisher: ELSEVIER SCIENCE INC, Pages: S43-S43, ISSN: 0735-1097
Nijjer SS, Sen S, Petraco R, et al., 2015, The Instantaneous wave-Free Ratio (iFR) pullback: a novel innovation using baseline physiology to optimise coronary angioplasty in tandem lesions, CARDIOVASCULAR REVASCULARIZATION MEDICINE, Vol: 16, Pages: 167-171, ISSN: 1553-8389
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- Citations: 49
Foin N, Lee RD, Torii R, et al., 2014, Impact of stent strut design in metallic stents and biodegradable scaffolds, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 177, Pages: 800-808, ISSN: 0167-5273
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- Citations: 118
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