578 results found
Dehbi H-M, Francis DP, 2013, A 64,489-patient full-disclosure database of cardiovascular risk factors and events status analysed in a Bayesian framework: A unique contribution to predictive science, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 165, Pages: 3-6, ISSN: 0167-5273
Sen S, Nijjer S, Petraco R, et al., 2013, The Effect of Adenosine on Coronary Microvascular Resistance Is More Consistent During the Diastolic Wave-free Period: Should We Continue to Use the Complete Cardiac Cycle for Stenosis Assessment?, 18th Angioplasty Summit Transcatheter Cardiovascular Therapeutics Asia Pacific (TCTAP), Publisher: EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC, Pages: 100B-101B, ISSN: 0002-9149
Petraco R, Park JJ, Sen S, et al., 2013, Hybrid Ifr-FFR Decision-Making Strategy: Implications for Enhancing Universal Adoption of Physiology-Guided Coronary Revascularization., 18th Angioplasty Summit Transcatheter Cardiovascular Therapeutics Asia Pacific (TCTAP), Publisher: EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC, Pages: 54B-54B, ISSN: 0002-9149
Petraco R, Sen S, Nijjer S, et al., 2013, Implications of The Biological Variability of Fractional Flow Reserve on Coronary Revascularization Decisions., 18th Angioplasty Summit Transcatheter Cardiovascular Therapeutics Asia Pacific (TCTAP), Publisher: EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC, Pages: 51B-51B, ISSN: 0002-9149
Foin N, Di Mario C, Francis DP, et al., 2013, Stent flexibility versus concertina effect: Mechanism of an unpleasant trade-off in stent design and its implications for stent selection in the cath-lab, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 164, Pages: 259-261, ISSN: 0167-5273
Hughes AD, Park C, Davies J, et al., 2013, Limitations of augmentation index in the assessment of wave reflection in normotensive healthy individuals, PLOS One, Vol: 8, ISSN: 1932-6203
ObjectivesAugmentation index (AIx) is widely used as a measure of wave reflection. We compared the relationship between AIx and age, height and sex with ‘gold standard’ measures of wave reflection derived from measurements of pressure and flow to establish how well AIx measures wave reflection.Materials and MethodsMeasurements of carotid pressure and flow velocity were made in the carotid artery of 65 healthy normotensive individuals (age 21–78 yr; 43 male) and pulse wave analysis, wave intensity analysis and wave separation was performed; waveforms were classified into type A, B or C. AIx, the time of the first shoulder (Ts), wave reflection index (WRI) and the ratio of backward to forward pressure (Pb/Pf) were calculated.ResultsAIx did not correlate with log WRI or Pb/Pf. When AIx was restricted to positive values AIx and log WRI were positively correlated (r = 0.33; p = 0.04). In contrast log WRI and Pb/Pf were closely correlated (r = 0.66; p<0.001). There was no correlation between the Ts and the timing of Pb or the reflected wave identified by wave intensity analysis. Wave intensity analysis showed that the morphology of type C waveforms (negative AIx) was principally due to a forward travelling (re-reflected) decompression wave in mid-systole. AIx correlated positively with age, inversely with height and was higher in women. In contrast log WRI and Pb/Pf showed negative associations with age, were unrelated to height and did not differ significantly by gender.ConclusionsAIx has serious limitations as a measure of wave reflection. Negative AIx values derived from Type C waves should not be used as estimates of wave reflection magnitude.
Barakat MF, Chehab O, Hayat S, et al., 2013, ATTENUATIONS IN TISSUE DOPPLER-DERIVED LEFT VENTRICULAR SYSTOLIC VELOCITY PREDICT AN AMPLIFIED RISK OF LETHAL ARRHYTHMIAS IN ICD RECIPIENTS INDEPENDENTLY OF EJECTION FRACTION, 62nd Annual Scientific Session of the American-College-of-Cardiology, Publisher: ELSEVIER SCIENCE INC, Pages: E818-E818, ISSN: 0735-1097
Turner HK, Norrington K, Barakat MF, et al., 2013, EVOLUTION OF ERYTHROCYTE INDICES TOWARD AN IRON DEFICIENT PICTURE PREDICTS EARLY MORTALITY IN ACUTE DECOMPENSATED HEART FAILURE, 62nd Annual Scientific Session of the American-College-of-Cardiology, Publisher: ELSEVIER SCIENCE INC, Pages: E625-E625, ISSN: 0735-1097
Francis DP, 2013, How to reliably deliver narrow individual-patient error bars for optimization of pacemaker AV or VV delay using a "pick-the-highest" strategy with haemodynamic measurements, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 163, Pages: 221-225, ISSN: 0167-5273
Whinnett ZI, Francis DP, Denis A, et al., 2013, Comparison of different invasive hemodynamic methods for AV delay optimization in patients with cardiac resynchronization therapy: Implications for clinical trial design and clinical practice, International Journal of Cardiology, Vol: 168, Pages: 2228-2237, ISSN: 1874-1754
Blessing E, Esler MD, Francis DP, et al., 2013, Cardiac ablation and renal denervation systems have distinct purposes and different technical requirements., JACC Cardiovasc Interv, Vol: 6
Kyriacou A, Whinnett ZI, Davies JE, et al., 2013, First-in-man evidence of the mechanistic effects of biventricular pacing on coronary physiology, Spring Meeting for Clinician Scientists in Training, Publisher: ELSEVIER SCIENCE INC, Pages: 62-62, ISSN: 0140-6736
Davies JE, Manisty CH, Petraco R, et al., 2013, First-in-man safety evaluation of renal denervation for chronic systolic heart failure: Primary outcome from REACH-Pilot study, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 162, Pages: 189-192, ISSN: 0167-5273
Malcolme-Lawes LC, Lim PB, Koa-Wing M, et al., 2013, Robotic assistance and general anaesthesia improve catheter stability and increase signal attenuation during atrial fibrillation ablation, EUROPACE, Vol: 15, Pages: 41-47, ISSN: 1099-5129
Foin N, Alegria E, Sen S, et al., 2013, Importance of knowing stent design threshold diameters and post-dilatation capacities to optimise stent selection and prevent stent overexpansion/incomplete apposition during PCI, International journal of cardiology, Vol: 166, Pages: 755-758, ISSN: 1874-1754
Mielewczik M, Cole GD, Nowbar AN, et al., 2013, The C-CURE Randomized Clinical Trial (Cardiopoietic stem Cell therapy in heart failURE), Journal of the American College of Cardiology, Vol: 62, Pages: 2453-2453
Foin N, Sen S, Allegria E, et al., 2013, Maximal expansion capacity with current DES platforms: a critical factor for stent selection in the treatment of left main bifurcations?, EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology, Vol: 8, Pages: 1315-1325, ISSN: 1969-6213
AIMS: Left main stenting is increasingly performed and often involves deployment of a single stent across vessels with marked disparity in diameters. Knowing stent expansion capacity is critical to ensure adequate strut apposition after post-dilatation of the stent has been performed. Coronary stents are usually manufactured in only two or three different model designs with each design having a different maximal expansion capacity. Information about the different workhorse designs and their maximal achievable diameter is not commonly provided by manufacturers but, in the absence of this critically important information, stents implanted in segments with major changes in vessel diameter have the potential to become grossly overstretched and to remain incompletely apposed. METHODS AND RESULTS: We examined the differences in workhorse designs of six commercially available drug-eluting stents (DES): the PROMUS Element, Taxus Liberté, XIENCE Prime, Resolute Integrity, BioMatrix Flex and Cypher Select stents. Using micro-computed tomography, we tested oversizing capabilities above nominal pressures for the different workhorse designs of the six DES using 4.0, 5.0 and 6.0 mm post-dilatation balloons inflated to 14 atmospheres. MLD could be increased significantly in all stents, only restricted by workhorse design limitations. Minimal inner lumen diameter (MLD) achieved after two successive 6.0 mm post-dilatations of the largest design (4.0 mm stent) was 5.7 mm for the Element, 5.6 mm for the XIENCE Prime, 6.0 mm for the Taxus, 5.4 mm for the Resolute Integrity, 5.9 mm for the BioMatrix and 5.8 mm for the Cypher stent. Significant deformations were observed during stent oversizing with large changes in terms of cell opening and crowns expansion. These are affected by design structure and reveal important differences among all stents tested. Such extensive deformations may alter the functional ability of an individual stent to scaffold a lesion and prevent restenosis.
Sen S, Nijjer S, Petraco R, et al., 2013, THE EFFECT OF ADENOSINE ON CORONARY MICROVASCULAR RESISTANCE IS MORE CONSISTENT DURING THE DIASTOLIC WAVE–FREE PERIOD: SHOULD WE CONTINUE TO USE THE COMPLETE CARDIAC CYCLE FOR STENOSIS ASSESSMENT?, ISSN: 0735-1097
Jones DG, Haldar SK, Hussain W, et al., 2013, A randomized trial to assess catheter ablation versus rate control in the management of persistent atrial fibrillation in heart failure, J Am Coll Cardiol, Vol: 61, Pages: 1894-1903, ISSN: 1558-3597
OBJECTIVES: This study sought to compare catheter ablation with rate control for persistent atrial fibrillation (AF) in heart failure (HF). BACKGROUND: The optimal therapy for AF in HF is unclear. Drug-based rhythm control has not proved clinically beneficial. Catheter ablation improves cardiac function in patients with HF, but impact on physiological performance has not been formally evaluated in a randomized trial. METHODS: In a randomized, open-label, blinded-endpoint clinical trial, adults with symptomatic HF, radionuclide left ventricular ejection fraction (EF) </=35%, and persistent AF were assigned to undergo catheter ablation or rate control. Primary outcome was 12-month change in peak oxygen consumption. Secondary endpoints were quality of life, B-type natriuretic peptide, 6-min walk distance, and EF. Results were analyzed by intention-to-treat. RESULTS: Fifty-two patients (age 63 +/- 9 years, EF 24 +/- 8%) were randomized, 26 each to ablation and rate control. At 12 months, 88% of ablation patients maintained sinus rhythm (single-procedure success 68%). Under rate control, rate criteria were achieved in 96%. The primary endpoint, peak oxygen consumption, significantly increased in the ablation arm compared with rate control (difference +3.07 ml/kg/min, 95% confidence interval: 0.56 to 5.59, p = 0.018). The change was not evident at 3 months (+0.79 ml/kg/min, 95% confidence interval: -1.01 to 2.60, p = 0.38). Ablation improved Minnesota score (p = 0.019) and B-type natriuretic peptide (p = 0.045) and showed nonsignificant trends toward improved 6-min walk distance (p = 0.095) and EF (p = 0.055). CONCLUSIONS: This first randomized trial of ablation versus rate control to focus on objective exercise performance in AF and HF shows significant benefit from ablation, a strategy that also improves symptoms and neurohormonal status. The effects develop over 12 months, consistent with progressive amelioration of the HF syndrome. (A Randomised Trial to Assess Cat
Petraco da Cunha R, van de Hoef T, Nijjer S, et al., 2013, THE PERFORMANCE OF BASELINE HAEMODYNAMIC INDICES OF CORONARY DISEASE SEVERITY IN THE DEFER AND FAME STUDIES: AN ESTIMATED AGREEMENT OF STENOSES CLASSIFICATION WITH FRACTIONAL FLOW RESERVE, ISSN: 0735-1097
Petraco da Cunha R, Park JJ, Sen S, et al., 2013, A HYBRID DECISION-MAKING STRATEGY WITH INSTANTANEOUS WAVE-FREE RATIO AND FRACTIONAL FLOW RESERVE COULD ENHANCE ADOPTION OF PHYSIOLOGY-GUIDED CORONARY REVASCULARISATION, ISSN: 0735-1097
Nijjer S, Sen S, Cunha RPD, et al., 2013, INSTANTANEOUS WAVE–FREE RATIO (IFR) CAN DETECT IMPROVEMENT IN CORONARY HAEMODYNAMICS AFTER PCI, ISSN: 0735-1097
Petraco R, Park JJ, Sen S, et al., 2013, Hybrid iFR-FFR decision-making strategy: implications for enhancing universal adoption of physiology-guided coronary revascularisation, EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology, Vol: 8, Pages: 1157-1165, ISSN: 1969-6213
AIMS: Adoption of fractional flow reserve (FFR) remains low (6-8%), partly because of the time, cost and potential inconvenience associated with vasodilator administration. The instantaneous wave-Free Ratio (iFR) is a pressure-only index of stenosis severity calculated without vasodilator drugs. Before outcome trials test iFR as a sole guide to revascularisation, we evaluate the merits of a hybrid iFR-FFR decision-making strategy for universal physiological assessment. METHODS AND RESULTS: Coronary pressure traces from 577 stenoses were analysed. iFR was calculated as the ratio between Pd and Pa in the resting diastolic wave-free window. A hybrid iFR-FFR strategy was evaluated, by allowing iFR to defer some stenoses (where negative predictive value is high) and treat others (where positive predictive value is high), with adenosine being given only to patients with iFR in between those values. For the most recent fixed FFR cut-off (0.8), an iFR of <0.86 could be used to confirm treatment (PPV of 92%), whilst an iFR value of >0.93 could be used to defer revascularisation (NPV of 91%). Limiting vasodilator drugs to cases with iFR values between 0.86 to 0.93 would obviate the need for vasodilator drugs in 57% of patients, whilst maintaining 95% agreement with an FFR-only strategy. If the 0.75-0.8 FFR grey zone is accounted for, vasodilator drug requirement would decrease by 76%. CONCLUSION: A hybrid iFR-FFR decision-making strategy for revascularisation could increase adoption of physiology-guided PCI, by more than halving the need for vasodilator administration, whilst maintaining high classification agreement with an FFR-only strategy.
Petraco R, Sen S, Nijjer S, et al., 2013, Fractional flow reserve-guided revascularization: practical implications of a diagnostic gray zone and measurement variability on clinical decisions, JACC. Cardiovascular interventions, Vol: 6, Pages: 222-225, ISSN: 1876-7605
OBJECTIVES: This study sought to evaluate the effects of fractional flow reserve (FFR) measurement variability on FFR-guided treatment strategy. BACKGROUND: Current appropriateness guidelines recommend the utilization of FFR to guide coronary revascularization based on a fixed cut-off of 0.8. This rigid approach does not take into account the intrinsic biological variability of a single FFR result and the clinical judgment of experienced interventionists. METHODS: FFR reproducibility data from the landmark Deferral Versus Performance of PTCA in Patients Without Documented Ischemia (DEFER) trial was analyzed (two repeated FFR measurements in the same lesion, 10 min apart) and the standard deviation of the difference (SDD) between repeated measurements was calculated. The measurement certainty (probability that the FFR-guided revascularization strategy will not change if the test is repeated 10 min later) was subsequently established across the whole range of FFR values, from 0.2 to 1. RESULTS: Outside the [0.75 to 0.85] FFR range, measurement certainty of a single FFR result is >95%. However, closer to its cut-off, certainty falls to less than 80% within 0.77 to 0.83, reaching a nadir of 50% around 0.8. In clinical practice, that means that each time a single FFR value falls between 0.75 and 0.85, there is a chance that the FFR-derived revascularization recommendation will change if the measurement is repeated 10 min later, with this chance increasing the closer the FFR result is to 0.8. CONCLUSIONS: A measurement FFR gray-zone is found between 0.75 and 0.85]. Therefore, clinicians should make revascularization decisions based on broadened clinical judgment when a single FFR result falls within this uncertainty zone, particularly between 0.77 and 0.83, when measurement certainty falls to less than 80%.
Sen S, Asrress KN, Nijjer S, et al., 2013, Diagnostic Classification of the Instantaneous Wave-Free Ratio Is Equivalent to Fractional Flow Reserve and Is Not Improved With Adenosine Administration, Journal of the American College of Cardiology, Vol: 61, Pages: 1409-1420, ISSN: 0735-1097
Francis DP, Mielewczik M, Zargaran D, et al., 2013, Autologous bone marrow-derived stem cell therapy in heart disease: discrepancies and contradictions, International journal of cardiology, Vol: 168, Pages: 3381-3403
Moraldo M, Cecaro F, Shun-Shin M, et al., 2012, Evidence-based recommendations for PISA measurements in mitral regurgitation: systematic review, clinical and in-vitro study, Iinternational Journal of Cardiology
BackgroundGuidelines for quantifying mitral regurgitation (MR) using “proximal isovelocity surface area” (PISA) instruct operators to measure the PISA radius from valve orifice to Doppler flow convergence “hemisphere”. Using clinical data and a physically-constructed MR model we (A) analyse the actually-observed colour Doppler PISA shape and (B) test whether instructions to measure a “hemisphere” are helpful.Methods and resultsIn part A, the true shape of PISA shells was investigated using three separate approaches. First, a systematic review of published examples consistently showed non-hemispherical, “urchinoid” shapes. Second, our clinical data confirmed that the Doppler-visualized surface is non-hemispherical. Third, in-vitro experiments showed that round orifices never produce a colour Doppler hemisphere.In part B, six observers were instructed to measure hemisphere radius rh and (on a second viewing) urchinoid distance (du) in 11 clinical PISA datasets; 6 established experts also measured PISA distance as the gold standard. rh measurements, generated using the hemisphere instruction significantly underestimated expert values (−28%, p<0.0005), meaning rh2 was underestimated by approximately 2-fold. du measurements, generated using the non-hemisphere instruction were less biased (+7%, p=0.03).Finally, frame-to-frame variability in PISA distance was found to have a coefficient of variation (CV) of 25% in patients and 9% in in-vitro data. Beat-to-beat variability had a CV of 15% in patients.ConclusionsDoppler-visualized PISA shells are not hemispherical: we should avoid advising observers to measure a hemispherical radius because it encourages underestimation of orifice area by approximately two-fold. If precision is needed (e.g. to detect changes reliably) multi-frame averaging is essential.
Jones DG, Haldar SK, Sharma R, et al., 2012, A Randomised Trial to Assess Catheter Ablation versus Rate Control in the Management of Persistent Atrial Fibrillation in Chronic Heart Failure, Scientific Sessions of the American-Heart-Association, Publisher: LIPPINCOTT WILLIAMS & WILKINS, Pages: 2788-2788, ISSN: 0009-7322
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