589 results found
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
Stegemann B, Francis DP, 2012, Atrioventricular and interventricular delay optimization and response quantification in biventricular pacing: arrival of reliable clinical algorithms and research protocols, and how to distinguish them from unreliable counterparts, EUROPACE, Vol: 14, Pages: 1679-1683, ISSN: 1099-5129
Norrington KD, Turner HK, Barakat MF, et al., 2012, Prognostic Utility of the Hemoglobin/Hematocrit Equation for Estimating Plasma Volume Changes During Hospitalization for Acute Decompensated Heart Failure, CIRCULATION, Vol: 126, ISSN: 0009-7322
Konstantinou K, Aung N, Norrington K, et al., 2012, Evolving Iron Deficiency Confers Most of the Adversity Associated with a Temporal Rise in Red Cell Distribution Width, is More Ominous than a Falling Hemoglobin, and Blunts Left Ventricular Long Axis Function in Chronic Heart Failure, CIRCULATION, Vol: 126, ISSN: 0009-7322
Ghosh AK, Hardy RJ, Francis DP, et al., 2012, The Effect of Mid-life Blood Pressure Change and Anti-Hypertensive Treatment on Subsequent Left Ventricular Mass - A Life Course Approach, CIRCULATION, Vol: 126, ISSN: 0009-7322
Barron AJ, Wensel R, Francis DP, et al., 2012, The role for cardiopulmonary exercise testing in patients with atrial septal defects: A review, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 161, Pages: 68-72, ISSN: 0167-5273
Sen S, Davies JE, Malik IS, et al., 2012, Why Does Primary Angioplasty Not Work in Registries? Quantifying the Susceptibility of Real-World Comparative Effectiveness Data to Allocation Bias, CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES, Vol: 5, Pages: 759-766, ISSN: 1941-7705
Kyriacou A, Pabari PA, Francis DP, 2012, Cardiac resynchronization therapy is certainly cardiac therapy, but how much resynchronization and how much atrioventricular delay optimization?, HEART FAILURE REVIEWS, Vol: 17, Pages: 727-736, ISSN: 1382-4147
Terranova G, Ferro M, Carpeggiani C, et al., 2012, Low Quality and Lack of Clarity of Current Informed Consent Forms in Cardiology: How to Improve Them (vol 5, pg 649, 2012), JACC-CARDIOVASCULAR IMAGING, Vol: 5, Pages: 1190-1190, ISSN: 1936-878X
Foin N, Sen S, Petraco R, et al., 2012, Investigation of Fractional Flow Reserve Correlation with Direct Anatomical Parameters Using a Percutaneous Model of Coronary Artery Stenosis, Transcatheter Cardiovascular Therapeutics (TCT) Symposium, Publisher: ELSEVIER SCIENCE INC, Pages: B67-B67, ISSN: 0735-1097
Sen S, Petraco R, Nijjer S, et al., 2012, The Diastolic Wave-Free Period Is The Most Suitable Period In The Cardiac Cycle For The Assessment Of A Coronary Stenosis: Implications For The Accurate Calculation Of The Instantaneous Wave-Free Ratio (iFR), Transcatheter Cardiovascular Therapeutics (TCT) Symposium, Publisher: ELSEVIER SCIENCE INC, Pages: B68-B68, ISSN: 0735-1097
Kyriacou A, Whinnett ZI, Sen S, et al., 2012, Improvement in Coronary Blood Flow Velocity With Acute Biventricular Pacing Is Predominantly Due to an Increase in a Diastolic Backward-Travelling Decompression (Suction) Wave, CIRCULATION, Vol: 126, Pages: 1334-+, ISSN: 0009-7322
Davies JE, Alastruey J, Francis DP, et al., 2012, Attenuation of Wave Reflection by Wave Entrapment Creates a "Horizon Effect" in the Human Aorta, HYPERTENSION, Vol: 60, Pages: 778-+, ISSN: 0194-911X
Zaman N, Barron AJ, Cole GD, et al., 2012, Systematic review of the proportion of heart failure patients reporting side effects of beta-blockers in whom the medication is genuinely causative: ethical implications for informed consent, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 804-804, ISSN: 0195-668X
Sohaib SMA, Chen ZC, Whinnett Z, et al., 2012, Systematic review of genuine symptomatic response to cardiac resynchronization therapy: acknowledging the contribution of spontaneous response, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 995-995, ISSN: 0195-668X
Kyriacou A, Pabari PA, Whinnett ZI, et al., 2012, Fully Automatable, Reproducible, Noninvasive Simple Plethysmographic Optimization: Proof of Concept and Potential for Implantability, PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY, Vol: 35, Pages: 948-960, ISSN: 0147-8389
Jarman JW, Wong T, Kojodojojo P, et al., 2012, Spatiotemporal behavior of high dominant frequency during paroxysmal and persistent atrial fibrillation in the human left atrium., Circ Arrhythm Electrophysiol., Vol: 4, Pages: 650-658
BACKGROUNDSites of high dominant frequency (DF(peak)) are thought to indicate the location of drivers of atrial fibrillation (AF), but characterization of their spatiotemporal distribution and stability, critical to their relevance as targets for catheter ablation, requires simultaneous global mapping of the left atrium.METHODS AND RESULTS:Noncontact electrograms recorded simultaneously from 256 left atrial sites during spontaneous AF were analyzed. After subtraction of the ventricular component, fast Fourier transform identified the DF at each site. Focal areas of DF(peak) were defined as those having a DF >20% above all neighboring sites. Twenty-four patients with spontaneous AF (11 paroxysmal and 13 persistent) were studied. In paroxysmal AF, sites of DF(peak) (mean DF, 11.6±2.9 Hz) were observed in 100% of patients (present during 65% of the mapping period). In contrast, DF(peak) was detected in only 31% of patients with persistent AF (P<0.001) and for only 5% of the mapping period (P<0.001). In both groups, locations of DF(peak) varied widely in both consecutive and separated segments of AF (κ coefficient range, -0.07-0.22). Activation sequences around sites of DF(peak) did not demonstrate centrifugal activation that would be expected from focal drivers.CONCLUSIONS:Focal areas of high DF are more frequent in paroxysmal than persistent AF, are spatiotemporally unstable, are not the source of centrifugal activation, and are not, therefore, indicative of fixed drivers of AF. In the absence of spatiotemporal stability, the success of ablation at sites of DF(peak) cannot be explained by elimination of fixed drivers.
Shun-Shin M, Francis DP, 2012, Why Are Some Studies of Cardiovascular Markers Unreliable? The Role of Measurement Variability and What an Aspiring Clinician Scientist Can Do Before It Is Too Late, PROGRESS IN CARDIOVASCULAR DISEASES, Vol: 55, Pages: 14-24, ISSN: 0033-0620
Sobotka PA, Krum H, Boehm M, et al., 2012, The Role of Renal Denervation in the Treatment of Heart Failure, CURRENT CARDIOLOGY REPORTS, Vol: 14, Pages: 285-292, ISSN: 1523-3782
Finegold JA, Manisty CH, Cecaro F, et al., 2012, Choosing between velocity-time-integral ratio and peak velocity ratio for calculation of the dimensionless index (or aortic valve area) in serial follow-up of aortic stenosis, International Journal of Cardiology
It remains unclear which echocardiographic measure is most suitable for serial measurement in real-world aortic stenosis (AS) follow-up. We determine whether the dimensionless index (DI) between aortic valve and left ventricular outflow tract velocities is measured more consistently using velocity-time-integral (VTI) or peak velocities (V(peak)) in real life.METHODS:Serial echocardiograms acquired within 6months in subjects with AS were analysed with blinding, to compare the variability over time of DI calculated using V(peak), with that of DI calculated using VTI.RESULTS:Paired echocardiograms, acquired on average 72days apart, were analysed from 70 patients with a range of severities of AS (59% severe). DI, calculated using either V(peak) or VTI, did not significantly change over this short time. Coefficient of variation was significantly better when DI was calculated using V(peak) than VTI (12.6 versus 25.4%, p<0.0001). The variabilities of mean and peak trans-aortic valve 4v(2) and left ventricular outflow tract VTI were no better: 26.9%, 19.1% and 22.1% respectively.CONCLUSIONS:Serially-followed variables require minimal noise to maximise detection of genuine change. For AS surveillance, calculating DI - or effective orifice area - from the ratio of V(peak) rather than VTIs would reduce 95% confidence intervals from ±51% to a still-disappointing ±25%. Guidelines recommend noisy surveillance measures, causing conscientious echocardiographers to 'peek' at previous values, and impairing clinicians' faith in echocardiographically-observed changes when making clinical decisions. For us in echocardiography to improve our ability to contribute to AS follow-up requires us to first acknowledge and discuss this honestly.
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