Publications
184 results found
Sen S, Ahmad Y, Dehbi H-M, et al., 2019, Clinical events after deferral of LAD revascularization following physiological coronary assessment, Journal of the American College of Cardiology, Vol: 73, Pages: 444-453, ISSN: 0735-1097
BACKGROUND: Physicians are not always comfortable deferring treatment of a stenosis in the left anterior descending (LAD) artery because of the perception that there is a high risk of major adverse cardiac events (MACE). The authors describe, using the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) trial, MACE rates when LAD lesions are deferred, guided by physiological assessment using fractional flow reserve (FFR) or the instantaneous wave-free ratio (iFR). OBJECTIVES: The purpose of this study was to establish the safety of deferring treatment in the LAD using FFR or iFR within the DEFINE-FLAIR trial. METHODS: MACE rates at 1 year were compared between groups (iFR and FFR) in patients whose physiological assessment led to LAD lesions being deferred. MACE was defined as a composite of cardiovascular death, myocardial infarction (MI), and unplanned revascularization at 1 year. Patients, and staff performing follow-up, were blinded to whether the decision was made with FFR or iFR. Outcomes were adjusted for age and sex. RESULTS: A total of 872 patients had lesions deferred in the LAD (421 guided by FFR, 451 guided by iFR). The event rate with iFR was significantly lower than with FFR (2.44% vs. 5.26%; adjusted HR: 0.46; 95% confidence interval [CI]: 0.22 to 0.95; p = 0.04). This was driven by significantly lower unplanned revascularization with iFR and numerically lower MI (unplanned revascularization: 2.22% iFR vs. 4.99% FFR; adjusted HR: 0.44; 95% CI: 0.21 to 0.93; p = 0.03; MI: 0.44% iFR vs. 2.14% FFR; adjusted HR: 0.23; 95% CI: 0.05 to 1.07; p = 0.06). CONCLUSIONS: iFR-guided deferral appears to be safe for patients with LAD lesions. Patients in whom iFR-guided deferral was performed had statistically significantly lower event rates than those with FFR-guided deferral.
Ahmad Y, Gotberg M, Cook C, et al., 2018, Coronary haemodynamics in patients with severe aortic stenosis and coronary artery disease undergoing Transcatheter Aortic Valve Replacement: implications for clinical indices of coronary stenosis severity, JACC: Cardiovascular Interventions, Vol: 11, Pages: 2019-2031, ISSN: 1936-8798
Objectives In this study, a systematic analysis was conducted of phasic intracoronary pressure and flow velocity in patients with severe aortic stenosis (AS) and coronary artery disease, undergoing transcatheter aortic valve replacement (TAVR), to determine how AS affects 1) phasic coronary flow; 2) hyperemic coronary flow; and 3) the most common clinically used indices of coronary stenosis severity, instantaneous wave-free ratio and fractional flow reserve.Background A significant proportion of patients with severe aortic stenosis (AS) have concomitant coronary artery disease. The effect of the valve on coronary pressure, flow, and the established invasive clinical indices of stenosis severity have not been studied.Methods Twenty-eight patients (30 lesions, 50.0% men, mean age 82.1 ± 6.5 years) with severe AS and coronary artery disease were included. Intracoronary pressure and flow assessments were performed at rest and during hyperemia immediately before and after TAVR.Results Flow during the wave-free period of diastole did not change post-TAVR (29.78 ± 14.9 cm/s vs. 30.81 ± 19.6 cm/s, p = 0.64). Whole-cycle hyperemic flow increased significantly post-TAVR (33.44 ± 13.4 cm/s pre-TAVR vs. 40.33 ± 17.4 cm/s post-TAVR, p = 0.006); this was secondary to significant increases in systolic hyperemic flow post-TAVR (27.67 ± 12.1 cm/s pre-TAVR vs. 34.15 ± 17.5 cm/s post-TAVR, p = 0.02). Instantaneous wave-free ratio values did not change post-TAVR (0.88 ± 0.09 pre-TAVR vs. 0.88 ± 0.09 post-TAVR, p = 0.73), whereas fractional flow reserve decreased significantly post-TAVR (0.87 ± 0.08 pre-TAVR vs. 0.85 ± 0.09 post-TAVR, p = 0.001).Conclusions Systolic and hyperemic coronary flow increased significantly post-TAVR; consequently, hyperemic indices that include systole underestimated coronary stenosis severity in patients with severe AS. Flow during the wave-free period of diastole did not change pos
Ahmad Y, Götberg M, Cook C, et al., 2018, Coronary hemodynamics in patients with severe aortic stenosis and coronary Artery disease undergoing transcatheter aortic valve replacement: implications for clinical indices of coronary stenosis severity, JACC: Cardiovascular Interventions, Vol: 11, Pages: 2019-2031, ISSN: 1936-8798
OBJECTIVES: In this study, a systematic analysis was conducted of phasic intracoronary pressure and flow velocity in patients with severe aortic stenosis (AS) and coronary artery disease, undergoing transcatheter aortic valve replacement (TAVR), to determine how AS affects 1) phasic coronary flow; 2) hyperemic coronary flow; and 3) the most common clinically used indices of coronary stenosis severity, instantaneous wave-free ratio and fractional flow reserve. BACKGROUND: A significant proportion of patients with severe aortic stenosis (AS) have concomitant coronary artery disease. The effect of the valve on coronary pressure, flow, and the established invasive clinical indices of stenosis severity have not been studied. METHODS: Twenty-eight patients (30 lesions, 50.0% men, mean age 82.1 ± 6.5 years) with severe AS and coronary artery disease were included. Intracoronary pressure and flow assessments were performed at rest and during hyperemia immediately before and after TAVR. RESULTS: Flow during the wave-free period of diastole did not change post-TAVR (29.78 ± 14.9 cm/s vs. 30.81 ± 19.6 cm/s, p = 0.64). Whole-cycle hyperemic flow increased significantly post-TAVR (33.44 ± 13.4 cm/s pre-TAVR vs. 40.33 ± 17.4 cm/s post-TAVR, p = 0.006); this was secondary to significant increases in systolic hyperemic flow post-TAVR (27.67 ± 12.1 cm/s pre-TAVR vs. 34.15 ± 17.5 cm/s post-TAVR, p = 0.02). Instantaneous wave-free ratio values did not change post-TAVR (0.88 ± 0.09 pre-TAVR vs. 0.88 ± 0.09 post-TAVR, p = 0.73), whereas fractional flow reserve decreased significantly post-TAVR (0.87 ± 0.08 pre-TAVR vs. 0.85 ± 0.09 post-TAVR, p = 0.001). CONCLUSIONS: Systolic and hyperemic coronary flow increased significantly post-TAVR; consequently, hyperemic indices that include systole underestimated coronary stenosis severity in patients with severe AS. Flow during the wave-free per
Ahmad Y, Howard J, Arnold A, et al., 2018, Reply: Assessing the quality of evidence supporting patent foramen ovale closure over medical therapy after cryptogenic stroke, European Heart Journal, Vol: 39, Pages: 3620-3620, ISSN: 1522-9645
This commentary refers to ‘Assessing the quality of evidence supporting patent foramen ovale closure over medical therapy after cryptogenic stroke’, by W.F. McIntyre et al., doi:10.1093/eurheartj/ehy496.
Cook CM, Ahmad Y, Howard JP, et 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
Escaned J, Ryan N, Mejia-Renteria H, et 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
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- Citations: 93
Ahmad Y, Howard J, Arnold A, et al., 2018, PFO CLOSURE IS SUPERIOR TO MEDICAL THERAPY FOR CRYPTOGENIC STROKE: A META-ANALYSIS OF RANDOMISED CONTROLLED TRIALS, Annual Conference of the British-Cardiovascular-Society on High Performing Teams, Publisher: BMJ PUBLISHING GROUP, Pages: A2-A2, ISSN: 1355-6037
Broyd CJ, Rigo F, Nijjer S, et 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
Petraco Da Cunha R, Dehbi H-M, Howard J, et al., 2018, Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel ‘V-plot’ methodology to display accuracy values, Open Heart, Vol: 5, ISSN: 2053-3624
Background Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test’s performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests.Methods and findings We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Cholrapid and Cholgold) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies).Conclusion No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard.
Al-Lamee R, Thompson D, Dehbi H-M, et al., 2018, Percutaneous coronary intervention in stable angina (ORBITA): a double-blind, randomised controlled trial, Lancet, Vol: 391, Pages: 31-40, ISSN: 0140-6736
BACKGROUND: Symptomatic relief is the primary goal of percutaneous coronary intervention (PCI) in stable angina and is commonly observed clinically. However, there is no evidence from blinded, placebo-controlled randomised trials to show its efficacy. METHODS: ORBITA is a blinded, multicentre randomised trial of PCI versus a placebo procedure for angina relief that was done at five study sites in the UK. We enrolled patients with severe (≥70%) single-vessel stenoses. After enrolment, patients received 6 weeks of medication optimisation. Patients then had pre-randomisation assessments with cardiopulmonary exercise testing, symptom questionnaires, and dobutamine stress echocardiography. Patients were randomised 1:1 to undergo PCI or a placebo procedure by use of an automated online randomisation tool. After 6 weeks of follow-up, the assessments done before randomisation were repeated at the final assessment. The primary endpoint was difference in exercise time increment between groups. All analyses were based on the intention-to-treat principle and the study population contained all participants who underwent randomisation. This study is registered with ClinicalTrials.gov, number NCT02062593. FINDINGS: ORBITA enrolled 230 patients with ischaemic symptoms. After the medication optimisation phase and between Jan 6, 2014, and Aug 11, 2017, 200 patients underwent randomisation, with 105 patients assigned PCI and 95 assigned the placebo procedure. Lesions had mean area stenosis of 84·4% (SD 10·2), fractional flow reserve of 0·69 (0·16), and instantaneous wave-free ratio of 0·76 (0·22). There was no significant difference in the primary endpoint of exercise time increment between groups (PCI minus placebo 16·6 s, 95% CI -8·9 to 42·0, p=0·200). There were no deaths. Serious adverse events included four pressure-wire related complications in the placebo group, which required PCI, and five major bleeding
Panoulas VF, Francis DP, Ruparelia N, et al., 2018, Female-specific survival advantage from transcatheter aortic valve implantation over surgical aortic valve replacement: Meta-analysis of the gender subgroups of randomised controlled trials including 3758 patients, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 250, Pages: 66-72, ISSN: 0167-5273
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- Citations: 28
Cook CM, Jeremias A, Petraco R, et al., 2017, Fractional Flow Reserve/Instantaneous Wave-Free Ratio Discordance in Angiographically Intermediate Coronary Stenoses: An Analysis Using Doppler-Derived Coronary Flow Measurements, JACC: Cardiovascular Interventions, Vol: 10, Pages: 2514-2524, ISSN: 1936-8798
ObjectivesThe study sought to determine the coronary flow characteristics of angiographically intermediate stenoses classified as discordant by fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR).BackgroundDiscordance between FFR and iFR occurs in up to 20% of cases. No comparisons have been reported between the coronary flow characteristics of FFR/iFR discordant and angiographically unobstructed vessels.MethodsBaseline and hyperemic coronary flow velocity and coronary flow reserve (CFR) were compared across 5 vessel groups: FFR+/iFR+ (108 vessels, n = 91), FFR–/iFR+ (28 vessels, n = 24), FFR+/iFR– (22 vessels, n = 22), FFR–/iFR– (208 vessels, n = 154), and an unobstructed vessel group (201 vessels, n = 153), in a post hoc analysis of the largest combined pressure and Doppler flow velocity registry (IDEAL [Iberian-Dutch-English] collaborators study).ResultsFFR disagreed with iFR in 14% (50 of 366). Baseline flow velocity was similar across all 5 vessel groups, including the unobstructed vessel group (p = 0.34 for variance). In FFR+/iFR– discordants, hyperemic flow velocity and CFR were similar to both FFR–/iFR– and unobstructed groups; 37.6 (interquartile range [IQR]: 26.1 to 50.4) cm/s vs. 40.0 [IQR: 29.7 to 52.3] cm/s and 42.2 [IQR: 33.8 to 53.2] cm/s and CFR 2.36 [IQR: 1.93 to 2.81] vs. 2.41 [IQR: 1.84 to 2.94] and 2.50 [IQR: 2.11 to 3.17], respectively (p > 0.05 for all). In FFR–/iFR+ discordants, hyperemic flow velocity, and CFR were similar to the FFR+/iFR+ group; 28.2 (IQR: 20.5 to 39.7) cm/s versus 23.5 (IQR: 16.4 to 34.9) cm/s and CFR 1.44 (IQR: 1.29 to 1.85) versus 1.39 (IQR: 1.06 to 1.88), respectively (p > 0.05 for all).ConclusionsFFR/iFR disagreement was explained by differences in hyperemic coronary flow velocity. Furthermore, coronary stenoses classified as FFR+/iFR– demonstrated similar coronary flow characteristics to angiographically unobstructed vessels.
Bennett J, Lucio DA, Frame A, et al., 2017, Stroke post-transcatheter aortic valve insertion (post-TAVI): risk factors, management and outcomes, Publisher: SAGE PUBLICATIONS LTD, Pages: 22-22, ISSN: 1747-4930
de Waard G, Cook C, Petraco R, et 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
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- Citations: 1
Wijntjens G, Kikuta Y, van de Hoef T, et al., 2017, Hemodynamic changes after percutaneous coronary interventions of stenoses with discordant fractional flow reserve and coronary flow reserve, 29th Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B138-B139, ISSN: 0735-1097
Davies JE, Sen S, Escaned J, 2017, Instantaneous Wave-free Ratio versus Fractional Flow Reserve Reply, NEW ENGLAND JOURNAL OF MEDICINE, Vol: 377, Pages: 1597-1598, ISSN: 0028-4793
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- Citations: 13
Jabbour RJ, Frame A, Sen S, et al., 2017, Day case TAVI: is this a reality?, EUROINTERVENTION, Vol: 13, Pages: 907-909, ISSN: 1774-024X
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- Citations: 1
Gotberg M, Cook CM, Sen S, et 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
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- Citations: 127
Jabbour RJ, Sen S, Mikhail GW, et al., 2017, Out-of-hospital cardiac arrest: Concise review of strategies to improve outcome, CARDIOVASCULAR REVASCULARIZATION MEDICINE, Vol: 18, Pages: 450-455, ISSN: 1553-8389
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- Citations: 7
Cook CM, Petraco R, Shun-Shin MJ, et 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
Cook C, Kikuta Y, Sharp A, et 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
Davies JE, Sen S, Dehbi H-M, et 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
Cook CM, Jeremias A, Ahmad Y, et 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
Cook C, Petraco R, Ahmad Y, et al., 2017, Diagnostic Accuracy of FFR-CT: Implications for Clinical Decision Making, JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 10, Pages: S50-S50, ISSN: 1936-8798
Demir OM, Ruparelia N, Frame A, et al., 2017, Management of failing bioprosthesis in elderly patients who have undergone transcatheter aortic valve replacement, EXPERT REVIEW OF MEDICAL DEVICES, Vol: 14, Pages: 763-771, ISSN: 1743-4440
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de Waard GA, Nijjer SS, van Lavieren MA, et 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
Cook C, Ahmad Y, Petraco R, et 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
de Waard G, Nijjer S, van Lavieren M, et 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
Cook C, Jeremias A, Ahmad Y, et 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
Foin N, Lee R, Bourantas C, et 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
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