Imperial College London

Dr Sukhjinder Singh Nijjer

Faculty of MedicineNational Heart & Lung Institute

Honorary Senior Clinical Lecturer
 
 
 
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Contact

 

s.nijjer Website

 
 
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Location

 

Block B Hammersmith HospitalHammersmith Campus

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Summary

 

Publications

Publication Type
Year
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181 results found

Nijjer SS, Petraco R, Sen S, 2020, Optimal management of acute coronary syndromes in the era of COVID-19, HEART, Vol: 106, Pages: 1609-1616, ISSN: 1355-6037

Journal article

Seligman H, Shun-Shin M, Vasireddy A, Cook C, Ahmad Y, Howard J, Sen S, Al-Lamee R, Nijjer S, Chamie D, Davies J, Mayet J, Francis D, Petraco Ret al., 2019, Fractional flow reserve derived from microcatheters versus standard pressure wires: a stenosis-level meta-analysis, Open Heart, Vol: 6, ISSN: 2053-3624

Aims: To determine the agreement between sensor-tipped microcatheter (MC) and pressure wire (PW) derived Fractional Flow Reserve (FFR). Methods and results: Studies comparing FFR obtained from MC (FFRMC, Navvus Microcatheter System, ACIST Medical Systems, Minnesota, USA) versus standard PW (FFRPW) were identified and a meta-analysis of numerical and categorical agreement was performed. The relative levels of drift and device failure of MC and PW systems from each study were assessed. Six studies with 440 lesions (413 patients) were included. The mean overall bias between FFRMC and FFRPW was -0.029 (FFRMC lower). Bias and variance were greater for lesions with lower FFRPW (p <0.001). Using a cut-off of 0.80, 18% of lesions were re-classified by FFRMC versus FFRPW (with 15% being false-positives). The difference in reported drift between FFRPW and FFRMC was small. Device failure was more common with MC than PW (7.1% versus 2%). Conclusion: FFRMC systematically overestimates lesion severity, with increased bias in more severe lesions. Using FFRMC changes revascularisation guidance in approximately 1 out of every 5 cases. Pressure wire drift was similar between systems. Device failure was higher with MC.

Journal article

van der Hoeven NW, de Waard GA, Quiros A, De Hoyos A, Broyd CJ, Nijjer SS, van de Hoef TP, Petraco R, Driessen RS, Mejia-Renteria H, Kikuta Y, Pinto ME, van de Ven PM, Meuwissen M, Knaapen P, Piek JJ, Davies JE, van Royen N, Escaned Jet al., 2019, Comprehensive physiological evaluation of epicardial and microvascular coronary domains using vascular conductance and zero flow pressure, EUROINTERVENTION, Vol: 14, Pages: E1593-E1600, ISSN: 1774-024X

Journal article

Garcia D, Harbaoui B, van de Hoef TP, Meuwissen M, Nijjer SS, Echavarria-Pinto M, Davies JE, Piek JJ, Lantelme Pet al., 2019, Relationship between FFR, CFR and coronary microvascular resistance - Practical implications for FFR-guided percutaneous coronary intervention, PLOS ONE, Vol: 14, ISSN: 1932-6203

Journal article

Nijjer SS, 2018, Clinical outcomes of potent antiplatelets compared with clopidogrel in ST elevation myocardial infarction, HEART, Vol: 104, Pages: 1645-1646, ISSN: 1355-6037

Journal article

Cook C, Ahmad Y, Howard J, Shun-Shin M, Sethi A, Clesham G, Tang K, Nijjer S, Kelly P, Davies J, Malik I, Kaprielian R, Mikhail G, Petraco R, Warisawa T, Al-Janabi F, Karamasis G, Gamma R, Al-Lamee R, Keeble T, Mayet J, Sen S, Francis D, Davies Jet al., 2018, Predicting angina-limited exercise capacity using coronary physiology, 30th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B42-B42, ISSN: 0735-1097

Conference paper

Cook CM, Ahmad Y, Howard JP, Shun-Shin MJ, Sethi A, Clesham GJ, Tang KH, Nijjer SS, Kelly PA, Davies JR, Malik IS, Kaprielian R, Mikhail G, Petraco R, Al-Janabi F, Karamasis GV, Mohdnazri S, Gamma R, Al-Lamee R, Keeble TR, Mayet J, Sen S, Francis DP, Davies JEet al., 2018, Impact of percutaneous revascularization on exercise hemodynamics in patients with stable coronary disease, Journal of the American College of Cardiology, Vol: 72, Pages: 970-983, ISSN: 0735-1097

BACKGROUND: Recently, the therapeutic benefits of percutaneous coronary intervention (PCI) have been challenged in patients with stable coronary artery disease (SCD). OBJECTIVES: The authors examined the impact of PCI on exercise responses in the coronary circulation, the microcirculation, and systemic hemodynamics in patients with SCD. METHODS: A total of 21 patients (mean age 60.3 ± 8.4 years) with SCD and single-vessel coronary stenosis underwent cardiac catheterization. Pre-PCI, patients exercised on a supine ergometer until rate-limiting angina or exhaustion. Simultaneous trans-stenotic coronary pressure-flow measurements were made throughout exercise. Post-PCI, this process was repeated. Physiological parameters, rate-limiting symptoms, and exercise performance were compared between pre-PCI and post-PCI exercise cycles. RESULTS: PCI reduced ischemia as documented by fractional flow reserve value (pre-PCI 0.59 ± 0.18 to post-PCI 0.91 ± 0.07), instantaneous wave-free ratio value (pre-PCI 0.61 ± 0.27 to post-PCI 0.96 ± 0.05) and coronary flow reserve value (pre-PCI 1.7 ± 0.7 to post-PCI 3.1 ± 1.0; p < 0.001 for all). PCI increased peak-exercise average peak coronary flow velocity (p < 0.0001), coronary perfusion pressure (distal coronary pressure; p < 0.0001), systolic blood pressure (p = 0.01), accelerating wave energy (p < 0.001), and myocardial workload (rate-pressure product; p < 0.01). These changes observed immediately following PCI resulted from the abolition of stenosis resistance (p < 0.0001). PCI was also associated with an immediate improvement in exercise time (+67 s; 95% confidence interval: 31 to 102 s; p < 0.0001) and a reduction in rate-limiting angina symptoms (81% reduction in rate-limiting angina symptoms post-PCI; p < 0.001). CONCLUSIONS: In patients with SCD and severe single-vessel stenosis, objective physiological

Journal article

Escaned J, Ryan N, Mejia-Renteria H, Cook CM, Dehbi H-M, Alegria-Barrero E, Alghamdi A, Al-Lamee R, Altman J, Ambrosia A, Baptista SB, Bertilsson M, Bhindi R, Birgander M, Bojara W, Brugaletta S, Buller C, Calais F, Silva PC, Carlsson J, Christiansen EH, Danielewicz M, Di Mario C, Doh J-H, Erglis A, Erlinge D, Gerber RT, Going O, Gudmundsdottir I, Haerle T, Hauer D, Hellig F, Indolfi C, Jakobsen L, Janssens L, Jensen J, Jeremias A, Karegren A, Karlsson A-C, Kharbanda RK, Khashaba A, Kikuta Y, Krackhardt F, Koo B-K, Koul S, Laine M, Lehman SJ, Lindroos P, Malik IS, Maeng M, Matsuo H, Meuwissen M, Nam C-W, Niccoli G, Nijjer SS, Olsson H, Olsson S-E, Omerovic E, Panayi G, Petraco R, Piek JJ, Ribichini F, Samady H, Samuels B, Sandhall L, Sapontis J, Sen S, Seto AH, Sezer M, Sharp ASP, Shin E-S, Singh J, Takashima H, Talwar S, Tanaka N, Tang K, Van Belle E, van Royen N, Varenhorst C, Vinhas H, Vrints CJ, Walters D, Yokoi H, Frobert O, Patel MR, Serruys P, Davies JE, Gotberg Met al., 2018, Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes, JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 11, Pages: 1437-1449, ISSN: 1936-8798

Journal article

Al-Lamee R, Howard JP, Shun-Shin MJ, Thompson D, Dehbi H-M, Sen S, Nijjer S, Petraco R, Davies J, Keeble T, Tang K, Malik IS, Cook C, Ahmad Y, Sharp ASP, Gerber R, Baker C, Kaprielian R, Talwar S, Assomull R, Cole G, Keenan NG, Kanaganayagam G, Sehmi J, Wensel R, Harrell FE, Mayet J, Thom SA, Davies JE, Francis DPet al., 2018, Fractional flow reserve and instantaneous wave-free ratio as predictors of the placebo-controlled response to percutaneous coronary intervention in stable single-vessel coronary artery disease: physiology-stratified analysis of ORBITA, Circulation, Vol: 138, Pages: 1780-1792, ISSN: 0009-7322

BACKGROUND : There are no data on how fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are associated with the placebo-controlled efficacy of percutaneous coronary intervention (PCI) in stable single-vessel coronary artery disease. METHODS : We report the association between prerandomization invasive physiology within ORBITA (Objective Randomised Blinded Investigation With Optimal Medical Therapy of Angioplasty in Stable Angina), a placebo-controlled trial of patients who have stable angina with angiographically severe single-vessel coronary disease clinically eligible for PCI. Patients underwent prerandomization research FFR and iFR assessment. The operator was blinded to these values. Assessment of response variables, treadmill exercise time, stress echocardiography score, symptom frequency, and angina severity were performed at prerandomization and blinded follow-up. Effects were calculated by analysis of covariance. The ability of FFR and iFR to predict placebo-controlled changes in response variables was tested by using regression modeling. RESULTS : Invasive physiology data were available in 196 patients (103 PCI and 93 placebo). At prerandomization, the majority had Canadian Cardiovascular Society class II or III symptoms (150/196, 76.5%). Mean FFR and iFR were 0.69±0.16 and 0.76±0.22, respectively; 97% had ≥1 positive ischemia tests. The estimated effect of PCI on between-arm prerandomization-adjusted total exercise time was 20.7 s (95% confidence interval [CI], -4.0 to 45.5; P=0.100) with no interaction of FFR (Pinteraction=0.318) or iFR (Pinteraction=0.523). PCI improved stress echocardiography score more than placebo (1.07 segment units; 95% CI, 0.70-1.44; P<0.00001). The placebo-controlled effect of PCI on stress echocardiography score increased progressively with decreasing FFR (Pinteraction<0.00001) and

Journal article

Broyd CJ, Rigo F, Nijjer S, Sen S, Petraco R, Al-Lamee R, Foin N, Chukwuemeka A, Anderson J, Parker J, Malik IS, Mikhail GW, Francis DP, Parker K, Hughes AD, Mayet J, Davies JEet al., 2018, Regression of left ventricular hypertrophy provides an additive physiological benefit following treatment of aortic stenosis: Insights from serial coronary wave intensity analysis., Acta Physiologica, Vol: 2018, Pages: e13109-e13109, ISSN: 1748-1708

AIM: Severe aortic stenosis frequently involves the development of left ventricular hypertrophy (LVH) creating a dichotomous haemodynamic state within the coronary circulation. Whilst the increased force of ventricular contraction enhances its resultant relaxation and thus increases the distal diastolic coronary "suction" force, the presence of LVH has a potentially opposing effect on ventricular-coronary interplay. The aim of this study was to use non-invasive coronary wave intensity analysis (WIA) to separate and measure the sequential effects of outflow tract obstruction relief and then LVH regression following intervention for aortic stenosis. METHODS: Fifteen patients with unobstructed coronary arteries undergoing aortic valve intervention (11 surgical aortic valve replacement [SAVR], 4 TAVI) were successfully assessed before and after intervention, and at 6 and 12 months post-procedure. Coronary WIA was constructed from simultaneously acquired coronary flow from transthoracic echo and pressure from an oscillometric brachial cuff system. RESULTS: Immediately following intervention, a decline in the backward decompression wave (BDW) was noted (9.7 ± 5.7 vs 5.1 ± 3.6 × 103  W/m2 /s, P < 0.01). Over 12 months, LV mass index fell from 114 ± 19 to 82 ± 17 kg/m2 . Accompanying this, the BDW fraction increased to 32.8 ± 7.2% at 6 months (P = 0.01 vs post-procedure) and 34.7 ± 6.7% at 12 months (P < 0.001 vs post-procedure). CONCLUSION: In aortic stenosis, both the outflow tract gradient and the presence of LVH impact significantly on coronary haemodynamics that cannot be appreciated by examining resting coronary flow rates alone. An immediate change in coronary wave intensity occurs following intervention with further effects appreciable with hypertrophy regression. The improvement

Journal article

Kikuta Y, Cook CM, Sharp ASP, Salinas P, Kawase Y, Shiono Y, Giavarini A, Nakayama M, De Rosa S, Sen S, Nijjer SS, Al-Lamee R, Petraco R, Malik IS, Mikhail GW, Kaprielian RR, Wijntjens GWM, Mori S, Hagikura A, Mates M, Mizuno A, Hellig F, Lee K, Janssens L, Horie K, Mohdnazri S, Herrera R, Krackhardt F, Yamawaki M, Davies J, Takebayashi H, Keeble T, Haruta S, Ribichini F, Indolfi C, Mayet J, Francis DP, Piek JJ, Di Mario C, Escaned J, Matsuo H, Davies JEet al., 2018, Pre-Angioplasty Instantaneous Wave-Free Ratio Pullback Predicts Hemodynamic Outcome In Humans With Coronary Artery Disease Primary Results of the International Multicenter iFR GRADIENT Registry, JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 11, Pages: 757-767, ISSN: 1936-8798

ObjectivesThe authors sought to evaluate the accuracy of instantaneous wave-Free Ratio (iFR) pullback measurements to predict post-percutaneous coronary intervention (PCI) physiological outcomes, and to quantify how often iFR pullback alters PCI strategy in real-world clinical settings.BackgroundIn tandem and diffuse disease, offline analysis of continuous iFR pullback measurement has previously been demonstrated to accurately predict the physiological outcome of revascularization. However, the accuracy of the online analysis approach (iFR pullback) remains untested.MethodsAngiographically intermediate tandem and/or diffuse lesions were entered into the international, multicenter iFR GRADIENT (Single instantaneous wave-Free Ratio Pullback Pre-Angioplasty Predicts Hemodynamic Outcome Without Wedge Pressure in Human Coronary Artery Disease) registry. Operators were asked to submit their procedural strategy after angiography alone and then after iFR-pullback measurement incorporating virtual PCI and post-PCI iFR prediction. PCI was performed according to standard clinical practice. Following PCI, repeat iFR assessment was performed and the actual versus predicted post-PCI iFR values compared.ResultsMean age was 67 ± 12 years (81% male). Paired pre- and post-PCI iFR were measured in 128 patients (134 vessels). The predicted post-PCI iFR calculated online was 0.93 ± 0.05; observed actual iFR was 0.92 ± 0.06. iFR pullback predicted the post-PCI iFR outcome with 1.4 ± 0.5% error. In comparison to angiography-based decision making, after iFR pullback, decision making was changed in 52 (31%) of vessels; with a reduction in lesion number (−0.18 ± 0.05 lesion/vessel; p = 0.0001) and length (−4.4 ± 1.0 mm/vessel; p < 0.0001).ConclusionsIn tandem and diffuse coronary disease, iFR pullback predicted the physiological outcome of PCI with a high degree of accuracy. Compared with angiography alone, availability of iFR pullback

Journal article

Kikuta Y, van de Hoef T, Da Cunha RP, Echavarria-Pinto M, Wijntjens G, Shiono Y, Nijjer S, Al-Lamee R, Sen S, Meuwissen M, Mejia-Renteria H, Danad I, Knaapen P, Van Royen N, Escaned J, Davies J, Piek JJet al., 2018, AGREEMENT OF FRACTIONAL FLOW RESERVE AND INSTANTANEOUS WAVE-FREE RATIO WITH CORONARY FLOW CAPACITY: A SUB-ANALYSIS OF THE IBERIAN-DUTCH-ENGLISH (IDEAL) STUDY, 67th Annual Scientific Session and Expo of the American-College-of-Cardiology (ACC), Publisher: ELSEVIER SCIENCE INC, Pages: 1180-1180, ISSN: 0735-1097

Conference paper

de Waard G, Cook C, Petraco R, Nijjer S, van de Hoef T, Echavarria Pinto M, Sen S, Meuwissen M, Knaapen P, Escaned J, Piek J, van Royen N, Davies Jet al., 2017, Diastolic-systolic velocity ratio to detect coronary stenoses, 29th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B170-B170, ISSN: 0735-1097

Conference paper

Echavarria-Pinto M, van de Hoef TP, Nijjer S, Gonzalo N, Nombela-Franco L, Ibanez B, Sen S, Petraco R, Jimenez-Quevedo P, Nunez-Gil IJ, Cerrato E, Salinas P, Quiros A, Garcia-Garcia HM, Fernandez-Ortiz A, Macaya C, Davies J, Piek J, Escaned Jet al., 2017, Influence of the amount of myocardium subtended to a coronary stenosis on the index of microcirculatory resistance. Implications for the invasive assessment of microcirculatory function in ischaemic heart disease, EUROINTERVENTION, Vol: 13, Pages: 944-952, ISSN: 1774-024X

Journal article

Gotberg M, Cook CM, Sen S, Nijjer S, Escaned J, Davies JEet al., 2017, The Evolving Future of Instantaneous Wave-Free Ratio and Fractional Flow Reserve, JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY, Vol: 70, Pages: 1379-1402, ISSN: 0735-1097

Journal article

Cook CM, Petraco R, Shun-Shin MJ, Ahmad Y, Nijjer S, Al-Lamee R, Kikuta Y, Shiono Y, Mayet J, Francis DP, Sen S, Davies JEet al., 2017, Diagnostic accuracy of computed tomography-derived fractional flow reserve a systematic review, JAMA Cardiology, Vol: 2, Pages: 803-810, ISSN: 2380-6591

Importance Computed tomography–derived fractional flow reserve (FFR-CT) is a novel, noninvasive test for myocardial ischemia. Clinicians using FFR-CT must be able to interpret individual FFR-CT results to determine subsequent patient care.Objective To provide clinicians a means of interpreting individual FFR-CT results with respect to the range of invasive FFRs that this interpretation might likely represent.Evidence Review We performed a systematic review in accordance with guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A systematic search of MEDLINE (January 1, 2011, to 2016, week 2) and EMBASE (January 1, 2011, to 2016, week 2) was performed for studies assessing the diagnostic accuracy of FFR-CT. Title words used were computed tomography or computed tomographic and fractional flow reserve or FFR. Results were limited to publications in peer-reviewed journals. Duplicate studies and abstracts from scientific meetings were removed. All of the retrieved studies, including references, were reviewed.Findings There were 908 vessels from 536 patients in 5 studies included in the analysis. A total of 365 (68.1%) were male, and the mean (SD) age was 63.2 (9.5) years. The overall per-vessel diagnostic accuracy of FFR-CT was 81.9% (95% CI, 79.4%-84.4%). For vessels with FFR-CT values below 0.60, 0.60 to 0.70, 0.70 to 0.80, 0.80 to 0.90, and above 0.90, diagnostic accuracy of FFR-CT was 86.4% (95% CI, 78.0%-94.0%), 74.7% (95% CI, 71.9%-77.5%), 46.1% (95% CI, 42.9%-49.3%), 87.3% (95% CI, 85.1%-89.5%), and 97.9% (95% CI, 97.9%-98.8%), respectively. The 82% (overall) diagnostic accuracy threshold was met for FFR-CT values lower than 0.63 or above 0.83. More stringent 95% and 98% diagnostic accuracy thresholds were met for FFR-CT values lower than 0.53 or above 0.93 and lower than 0.47 or above 0.99, respectively.Conclusions and Relevance The diagnostic accuracy of FFR-CT varies markedly across the spectrum of disease. This ana

Journal article

Cook C, Kikuta Y, Sharp A, Salinas P, Nakayama M, Wijntjens G, Sen S, da Cunha RP, Al-Lamee R, Nijjer S, Mizuno A, Mates M, Janssens L, Hellig F, Horie K, Davies J, Yamawaki M, Keeble T, Ribichini F, Indolfi C, Piek J, Di Mario C, Escaned J, Matsuo H, Davies Jet al., 2017, INSTANTANEOUS WAVE-FREE RATIO SCOUT PULLBACK (IFR SCOUT) PRE-ANGIOPLASTY PREDICTS HEMODYNAMIC OUTCOME IN HUMANS WITH CORONARY ARTERY DISEASE: PRIMARY RESULTS OF INTERNATIONAL MULTICENTRE IFR GRADIENT REGISTRY, JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY, Vol: 69, Pages: 1050-1050, ISSN: 0735-1097

Journal article

Davies JE, Sen S, Dehbi H-M, Al-Lamee R, Petraco R, Nijjer SS, Bhindi R, Lehman SJ, Walters D, Sapontis J, Janssens L, Vrints CJ, Khashaba A, Laine M, Van Belle E, Krackhardt F, Bojara W, Going O, Harle T, Indolfi C, Niccoli G, Ribichini F, Tanaka N, Yokoi H, Takashima H, Kikuta Y, Erglis A, Vinhas H, Silva PC, Baptista SB, Alghamdi A, Hellig F, Koo B-K, Nam C-W, Shin E-S, Doh J-H, Brugaletta S, Alegria-Barrero E, Meuwissen M, Piek JJ, van Royen N, Sezer M, Di Mario C, Gerber RT, Malik IS, Sharp ASP, Talwar S, Tang K, Samady H, Altman J, Seto AH, Singh J, Jeremias A, Matsuo H, Kharbanda RK, Patel MR, Serruys P, Escaned Jet al., 2017, Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI, NEW ENGLAND JOURNAL OF MEDICINE, Vol: 376, Pages: 1824-1834, ISSN: 0028-4793

Journal article

Cook CM, Jeremias A, Ahmad Y, Shun-Shin M, Petraco R, Nijjer S, de Waard G, Sen S, Van de Hoef T, Echavarria-Pinto M, van Lavieren M, Al-Lamee R, Kikuta Y, Shiono Y, Buch A, Meuwissen M, Danad I, Knaapen P, Maeharah A, Koo B-K, Mintz GS, Piek J, Van Royen N, Davies Jet al., 2017, Discordance in Stenosis Classification by Pressure Only Indices of Stenosis Severity is Related to Differences in Coronary Flow Reserve: - The DISCORD Study, JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 10, Pages: S27-S27, ISSN: 1936-8798

Journal article

Cook C, Petraco R, Ahmad Y, Shun-Shin M, Nijjer S, Al-Lamee R, Kikuta Y, Shiono Y, Mayet J, Francis D, Sen S, Davies Jet al., 2017, Diagnostic Accuracy of FFR-CT: Implications for Clinical Decision Making, JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 10, Pages: S50-S50, ISSN: 1936-8798

Journal article

Nijjer SS, Luther V, Lefroy DC, 2017, Diagnosis of ventricular tachycardia, BRITISH JOURNAL OF HOSPITAL MEDICINE, Vol: 78, Pages: C2-C5, ISSN: 1750-8460

Journal article

Luther V, Nijjer SS, Lefroy DC, 2017, Management of ventricular tachycardia, BRITISH JOURNAL OF HOSPITAL MEDICINE, Vol: 78, Pages: C6-C9, ISSN: 1750-8460

Journal article

de Waard GA, Nijjer SS, van Lavieren MA, van der Hoeven NW, Petraco R, van de Hoef TP, Echavarria-Pinto M, Sen S, van de Ven PM, Knaapen P, Escaned J, Piek JJ, Davies JE, van Royen Net al., 2016, Invasive minimal Microvascular Resistance Is a New Index to Assess Microcirculatory Function Independent of Obstructive Coronary Artery Disease, Journal of the American Heart Association, Vol: 5, ISSN: 2047-9980

Background-—Coronary microcirculatory dysfunction portends a poor cardiovascular outcome. Invasive assessment ofmicrocirculatory dysfunction by coronary flow reserve (CFR) and hyperemic microvascular resistance (HMR) is affected bycoronary artery disease (CAD). In this study we propose minimal microvascular resistance (mMR) as a new measure ofmicrocirculatory dysfunction and aim to determine whether mMR is influenced by CAD.Methods and Results-—We obtained 482 simultaneous measurements of intracoronary Doppler flow velocity and pressure. ThemMR is defined as the ratio between distal coronary pressure and flow velocity during the hyperemic wave-free period.Measurements were divided into 2 cohorts. Cohort 1 was a paired analysis involving 81 pairs with a vessel with and without CAD toinvestigate whether HMR, CFR, and mMR are modulated by CAD. CFR was lower, and HMR was higher, in vessels with CAD than invessels without CAD: 2.12 0.79 versus 2.56 0.63 mm Hgcm 1s, P<0.001, and 2.61 1.22 versus 2.31 0.89 mm Hgcm 1s,P=0.04, respectively. mMR was equal in vessels with and without CAD: 1.54 0.77 versus 1.53 0.57 mm Hgcm 1s, P=0.90.Differences for CFR occurred when FFR was 0.60 to 0.80 or ≤0.60 but not when FFR ≥0.80. For HMR, the difference occurred onlywhen FFR ≤0.60. For mMR, no difference was observed in any FFR stratum. Cohort 2 was used for validation and showed significantrelationships for CFR and HMR with FFR: Pearson r=0.488, P<0.001 and 0.159, P=0.03, respectively; mMR had no associationwith FFR: Pearson r=0.055; P=0.32.Conc

Journal article

Cook C, Jeremias A, Ahmad Y, Shun-Shin M, Nijjer S, de Waard G, Sen S, van de Hoef T, Pinto ME, van Lavieren M, Petraco R, Al-Lamee R, Meuwissen M, Danad I, Knaapen P, Maehara A, Koo BK, Mintz G, Escaned J, Stone G, Piek J, van Royen N, Davies Jet al., 2016, TCT-513 Discordance In Stenosis Classification by pressure-Only indices of stenosis severity is Related to Differences in coronary flow reserve: The RESOLVING DISCORD study., J Am Coll Cardiol, Vol: 68, Pages: B206-B207, ISSN: 0735-1097

Journal article

van der Hoeven N, Quirós A, de Waard G, Broyd C, Nijjer S, van de Hoef T, Petraco R, Driessen R, Mejía-Rentería H, van Lavieren M, Meuwissen M, Danad I, Knaapen P, Piek J, Davies J, van Royen N, Escaned Jet al., 2016, TCT-523 Instantaneous Hyperemic Diastolic Velocity Pressure Slope for comprehensive physiological evaluation of epicardial and microvascular status., J Am Coll Cardiol, Vol: 68, Pages: B211-B211

Journal article

Cook C, Ahmad Y, Petraco R, Nijjer S, Shun-Shin M, Al-Lamee R, Kikuta Y, Shiono Y, Mayet J, Francis D, Sen S, Davies Jet al., 2016, TCT-9 A per-vessel level systematic review of computed tomography-derived FFR (FFR-CT) diagnostic accuracy studies: Implications for clinical decision-making., J Am Coll Cardiol, Vol: 68, Pages: B4-B4

Journal article

de Waard G, Nijjer S, van Lavieren M, van der Hoeven N, Petraco R, van de Hoef T, Pinto ME, Sen S, van de Ven P, Knaapen P, Escaned J, Piek J, Davies J, van Royen Net al., 2016, TCT-524 Invasive minimal Microvascular Resistance (mMR); a new index to assess microcirculatory dysfunction that is not modulated by the presence of angiographic coronary artery disease., J Am Coll Cardiol, Vol: 68, Pages: B211-B212

Journal article

Raphael CE, Cooper R, Parker KH, Collinson J, Vassiliou V, Pennell DJ, de Silva R, Hsu LY, Greve AM, Nijjer S, Broyd C, Ali A, Keegan J, Francis DP, Davies JE, Hughes AD, Arai A, Frenneaux M, Stables RH, Di Mario C, Prasad SKet al., 2016, Mechanisms of myocardial ischemia in hypertrophic cardiomyopathy: insights from wave intensity analysis and magnetic resonance., Journal of the American College of Cardiology, Vol: 68, Pages: 1651-1660, ISSN: 1558-3597

BACKGROUND: Angina is common in hypertrophic cardiomyopathy (HCM) and is associated with abnormal myocardial perfusion. Wave intensity analysis improves the understanding of the mechanics of myocardial ischemia. OBJECTIVES: Wave intensity analysis was used to describe the mechanisms underlying perfusion abnormalities in patients with HCM. METHODS: Simultaneous pressure and flow were measured in the proximal left anterior descending artery in 33 patients with HCM and 20 control patients at rest and during hyperemia, allowing calculation of wave intensity. Patients also underwent quantitative first-pass perfusion cardiac magnetic resonance to measure myocardial perfusion reserve. RESULTS: Patients with HCM had a lower coronary flow reserve than control subjects (1.9 ± 0.8 vs. 2.7 ± 0.9; p = 0.01). Coronary hemodynamics in HCM were characterized by a very large backward compression wave during systole (38 ± 11% vs. 21 ± 6%; p < 0.001) and a proportionately smaller backward expansion wave (27% ± 8% vs. 33 ± 6%; p = 0.006) compared with control subjects. Patients with severe left ventricular outflow tract obstruction had a bisferiens pressure waveform resulting in an additional proximally originating deceleration wave during systole. The proportion of waves acting to accelerate coronary flow increased with hyperemia, and the magnitude of change was proportional to the myocardial perfusion reserve (rho = 0.53; p < 0.01). CONCLUSIONS: Coronary flow in patients with HCM is deranged. Distally, compressive deformation of intramyocardial blood vessels during systole results in an abnormally large backward compression wave, whereas proximally, severe left ventricular outflow tract obstruction is associated with an additional deceleration wave. Perfusion abnormalities in HCM are not simply a consequence of supply/demand mismatch or remodeling of the intramyocardial blood vessels; th

Journal article

Foin N, Lee R, Bourantas C, Mattesini A, Soh N, Lim JE, Torii R, Ng J, Liang LH, Caiazzo G, Fabris E, Kilic D, Onuma Y, Low AF, Nijjer S, Sen S, Petraco R, Al Lamee R, Davies JE, Di Mario C, Wong P, Serruys PWet al., 2016, Bioresorbable vascular scaffold radial expansion and conformation compared to a metallic platform: insights from in vitro expansion in a coronary artery lesion model, EUROINTERVENTION, Vol: 12, Pages: 834-844, ISSN: 1774-024X

Journal article

Ladwiniec A, White PA, Nijjer SS, O'Sullivan M, West NE, Davies JE, Hoole SPet al., 2016, Diastolic Backward-Traveling Decompression (Suction) Wave Correlates With Simultaneously Acquired Indices of Diastolic Function and Is Reduced in Left Ventricular Stunning., Circulation: Cardiovascular Interventions, Vol: 9, ISSN: 1941-7640

BACKGROUND: Wave intensity analysis can distinguish proximal (propulsion) and distal (suction) influences on coronary blood flow and is purported to reflect myocardial performance and microvascular function. Quantifying the amplitude of the peak, backwards expansion wave (BEW) may have clinical utility. However, simultaneously acquired wave intensity analysis and left ventricular (LV) pressure-volume loop data, confirming the origin and effect of myocardial function on the BEW in humans, have not been previously reported. METHODS AND RESULTS: Patients with single-vessel left anterior descending coronary disease and normal ventricular function (n=13) were recruited prospectively. We simultaneously measured LV function with a conductance catheter and derived wave intensity analysis using a pressure-low velocity guidewire at baseline and again 30 minutes after a 1-minute coronary balloon occlusion. The peak BEW correlated with the indices of diastolic LV function: LV dP/dtmin (rs=-0.59; P=0.002) and τ (rs=-0.59; P=0.002), but not with systolic function. In 12 patients with paired measurements 30 minutes post balloon occlusion, LV dP/dtmax decreased from 1437.1±163.9 to 1299.4±152.9 mm Hg/s (median difference, -110.4 [-183.3 to -70.4]; P=0.015) and τ increased from 48.3±7.4 to 52.4±7.9 ms (difference, 4.1 [1.3-6.9]; P=0.01), but basal average peak coronary flow velocity was unchanged, indicating LV stunning post balloon occlusion. However, the peak BEW amplitude decreased from -9.95±5.45 W·m(-2)/s(2)×10(5) to -7.52±5.00 W·m(-2)/s(2)×10(5) (difference 2.43×10(5) [0.20×10(5) to 4.67×10(5); P=0.04]). CONCLUSIONS: Peak BEW assessed by coronary wave intensity analysis correlates with invasive indices of LV diastolic function and mirrors changes in LV diastolic function confirming the origin of the suction wave. This may have implications for physiological lesion assessment af

Journal article

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