Publications
207 results found
Cook CM, Howard JP, Ahmad Y, et al., 2020, How Do Fractional Flow Reserve, Whole-Cycle PdPa, and Instantaneous Wave-Free Ratio Correlate With Exercise Coronary Flow Velocity During Exercise-Induced Angina?, CIRCULATION-CARDIOVASCULAR INTERVENTIONS, Vol: 13, ISSN: 1941-7640
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- Citations: 1
Howard JP, Tan J, Shun-Shin MJ, et al., 2020, Improving ultrasound video classification: an evaluation of novel deep learning methods in echocardiography., J Med Artif Intell, Vol: 3
Echocardiography is the commonest medical ultrasound examination, but automated interpretation is challenging and hinges on correct recognition of the 'view' (imaging plane and orientation). Current state-of-the-art methods for identifying the view computationally involve 2-dimensional convolutional neural networks (CNNs), but these merely classify individual frames of a video in isolation, and ignore information describing the movement of structures throughout the cardiac cycle. Here we explore the efficacy of novel CNN architectures, including time-distributed networks and two-stream networks, which are inspired by advances in human action recognition. We demonstrate that these new architectures more than halve the error rate of traditional CNNs from 8.1% to 3.9%. These advances in accuracy may be due to these networks' ability to track the movement of specific structures such as heart valves throughout the cardiac cycle. Finally, we show the accuracies of these new state-of-the-art networks are approaching expert agreement (3.6% discordance), with a similar pattern of discordance between views.
Lerman A, Toya T, El Hajj S, et al., 2020, COMPARISON OF INTRAVASCULAR ULTRASOUND-DERIVED MINIMUM LUMEN AREA AND INSTANTANEOUS WAVE-FREE RATIO IN LEFT MAIN CORONARY ARTERY DISEASE, Conference of American-College-of-Cardiology (ACC) / World Congress of Cardiology (WCC), Publisher: ELSEVIER SCIENCE INC, Pages: 1392-1392, ISSN: 0735-1097
Vendrik J, Ahmad Y, Eftekhari A, et al., 2020, Long-Term Effects of Transcatheter Aortic Valve Implantation on Coronary Hemodynamics in Patients With Concomitant Coronary Artery Disease and Severe Aortic Stenosis, JOURNAL OF THE AMERICAN HEART ASSOCIATION, Vol: 9, ISSN: 2047-9980
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- Citations: 26
Bachtiger P, Plymen CM, Pabari PA, et al., 2020, Artificial intelligence, data sensors and interconnectivity: future Opportunities for heart failure, Cardiac Failure Review, Vol: 6, Pages: e11-e11, ISSN: 2057-7540
A higher proportion of patients with heart failure have benefitted from a wide and expanding variety of sensor-enabled implantable devices than any other patient group. These patients can now also take advantage of the ever-increasing availability and affordability of consumer electronics. Wearable, on- and near-body sensor technologies, much like implantable devices, generate massive amounts of data. The connectivity of all these devices has created opportunities for pooling data from multiple sensors - so-called interconnectivity - and for artificial intelligence to provide new diagnostic, triage, risk-stratification and disease management insights for the delivery of better, more personalised and cost-effective healthcare. Artificial intelligence is also bringing important and previously inaccessible insights from our conventional cardiac investigations. The aim of this article is to review the convergence of artificial intelligence, sensor technologies and interconnectivity and the way in which this combination is set to change the care of patients with heart failure.
Chacko L, P Howard J, Rajkumar C, et al., 2020, Effects of percutaneous coronary intervention on death and myocardial infarction stratified by stable and unstable coronary artery disease: a meta-analysis of randomized controlled trials, Circulation: Cardiovascular Quality and Outcomes, Vol: 13, ISSN: 1941-7705
Background:In patients presenting with ST-segment–elevation myocardial infarction, percutaneous coronary intervention (PCI) reduces mortality when compared with fibrinolysis. In other forms of coronary artery disease (CAD), however, it has been controversial whether PCI reduces mortality. In this meta-analysis, we examine the benefits of PCI in (1) patients post–myocardial infarction (MI) who did not receive immediate revascularization; (2) patients who have undergone primary PCI for ST-segment–elevation myocardial infarction but have residual coronary lesions; (3) patients who have suffered a non–ST-segment–elevation acute coronary syndrome; and (4) patients with truly stable CAD with no recent infarct. This analysis includes data from the recently presented International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) and Complete versus Culprit-Only Revascularization Strategies to Treat Multivessel Disease after Early PCI for STEMI (COMPLETE) trials.Methods and Results:We systematically identified all randomized trials of PCI on a background of medical therapy for the treatment of CAD. The ISCHEMIA trial, presented in November 2019, was eligible for inclusion. Data were combined using a random-effects meta-analysis. The primary end point was all-cause mortality. Forty-six trials, including 37 757 patients, were eligible. In the 3 unstable scenarios, PCI had the following effects on mortality: unrevascularized post-MI relative risk (RR) 0.68 (95% CI, 0.45–1.03); P=0.07; multivessel disease following ST-segment–elevation myocardial infarction (RR, 0.84 [95% CI, 0.69–1.04]; P=0.11); non–ST-segment–elevation acute coronary syndrome (RR, 0.84 [95% CI, 0.72–0.97]; P=0.02). Overall, in these unstable scenarios PCI was associated with a significant reduction in mortality (RR, 0.84 [95% CI, 0.75–0.93]; P=0.02). In unstable CAD, PCI also reduced cardiac
de Marvao A, Dawes TJ, Howard JP, et al., 2020, Artificial intelligence and the cardiologist: what you need to know for 2020., Heart, Vol: 106, Pages: 399-400, ISSN: 1355-6037
Azarmehr N, Ye X, Sacchi S, et al., 2020, Segmentation of Left Ventricle in 2D Echocardiography Using Deep Learning, Editors: Zheng, Williams, Chen, Publisher: SPRINGER INTERNATIONAL PUBLISHING AG, Pages: 497-504, ISBN: 978-3-030-39342-7
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- Citations: 4
Al-lamee RK, Shun-Shin M, Howard J, et al., 2019, Dobutamine Stress Echocardiography Ischaemia as a Predictor of the Placebo-Controlled Efficacy of Percutaneous Coronary Intervention in Stable Coronary Artery Disease: The Stress Echo-Stratified Analysis of ORBITA, Resuscitation Science Symposium (ReSS), Publisher: LIPPINCOTT WILLIAMS & WILKINS, Pages: E985-E985, ISSN: 0009-7322
Gitto M, Gentile F, Nowbar AN, et al., 2019, Gender-related differences in clinical presentation and angiographic findings in patients with ischaemia and no obstructive coronary artery disease (INOCA): a single-center observational registry, 80th SIC National Congress, Publisher: OXFORD UNIV PRESS, Pages: J157-J157, ISSN: 1520-765X
Ahmad Y, Vendrik J, Eftekhari A, et al., 2019, Determining the Predominant Lesion in Patients With Severe Aortic Stenosis and Coronary Stenoses: A Multicenter Study Using Intracoronary Pressure and Flow, Circulation: Cardiovascular Interventions, Vol: 12, ISSN: 1941-7640
Background:Patients with severe aortic stenosis (AS) often have coronary artery disease. Both the aortic valve and the coronary disease influence the blood flow to the myocardium and its ability to respond to stress; leading to exertional symptoms. In this study, we aim to quantify the effect of severe AS on the coronary microcirculation and determine if this is influenced by any concomitant coronary disease. We then compare this to the effect of coronary stenoses on the coronary microcirculation.Methods:Group 1: 55 patients with severe AS and intermediate coronary stenoses treated with transcatheter aortic valve implantation (TAVI) were included. Group 2: 85 patients with intermediate coronary stenoses and no AS treated with percutaneous coronary intervention were included. Coronary pressure and flow were measured at rest and during hyperemia in both groups, before and after TAVI (group 1) and before and after percutaneous coronary intervention (group 2).Results:Microvascular resistance over the wave-free period of diastole increased significantly post-TAVI (pre-TAVI, 2.71±1.4 mm Hg·cm·s−1 versus post-TAVI 3.04±1.6 mm Hg·cm·s−1 [P=0.03]). Microvascular reserve over the wave-free period of diastole significantly improved post-TAVI (pre-TAVI 1.88±1.0 versus post-TAVI 2.09±0.8 [P=0.003]); this was independent of the severity of the underlying coronary stenosis. The change in microvascular resistance post-TAVI was equivalent to that produced by stenting a coronary lesion with an instantaneous wave-free ratio of ≤0.74.Conclusions:TAVI improves microcirculatory function regardless of the severity of underlying coronary disease. TAVI for severe AS produces a coronary hemodynamic improvement equivalent to the hemodynamic benefit of stenting coronary stenoses with instantaneous wave-free ratio values <0.74. Future trials of physiology-guided revascularization in severe AS may consider us
Al-Lamee R, Shun-Shin M, Howard J, et al., 2019, Dobutamine stress echocardiography ischemia as a predictor of the placebo-controlled efficacy of percutaneous coronary intervention in stable coronary artery disease: the stress echo-stratified analysis of ORBITA, Circulation, Vol: 140, Pages: 1971-1980, ISSN: 0009-7322
BackgroundDobutamine stress echocardiography (DSE) is widely used to test for ischemia in patients with stable coronary artery disease (CAD). In this analysis we studied the ability of pre-randomization stress echo score to predict the placebo-controlled efficacy of percutaneous coronary intervention (PCI) within the ORBITA trial. MethodsOne hundred and eighty-three patients underwent DSE before randomization. The stress echo score is broadly the number of segments abnormal at peak stress, with akinetic segments counting double and dyskinetic segments counting triple. The ability of pre-randomization stress echo to predict the placebo-controlled effect of PCI on response variables was tested using regression modelling.ResultsAt pre-randomization, the stress echo score was 1.561.77 in the PCI arm (n=98) and 1.611.73 in the placebo arm (n=85). There was a detectable interaction between pre-randomization stress echo score and the effect of PCI on angina frequency score with a larger placebo-controlled effect in patients with the highest stress echo score (pinteraction=0.031). With our sample size we were unable to detect an interaction between stress echo score and any other patient-reported response variables: freedom from angina (pinteraction=0.116), physical limitation (pinteraction=0.461), quality of life (pinteraction=0.689), EQ-5D-5L quality of life score (pinteraction=0.789) or between stress echo score and physician-assessed Canadian Cardiovascular Society angina class (pinteraction=0.693), and treadmill exercise time (pinteraction=0.426). ConclusionsThe degree of ischemia assessed by DSE predicts the placebo-controlled efficacy of PCI on patient-reported angina frequency. The greater the downstream stress echo abnormality caused by a stenosis, the greater the reduction in symptoms from PCI.
Howard JP, Cook CM, van de Hoef TP, et al., 2019, Artificial Intelligence for Aortic Pressure Waveform Analysis During Coronary Angiography Machine Learning for Patient Safety, JACC-CARDIOVASCULAR INTERVENTIONS, Vol: 12, Pages: 2093-2101, ISSN: 1936-8798
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- Citations: 17
Arnold A, Howard J, Chiew K, et al., 2019, Right ventricular pacing for hypertrophic obstructive cardiomyopathy: meta-analysis and meta-regression of clinical trials, European Heart Journal - Quality of Care and Clinical Outcomes, Vol: 5, Pages: 321-333, ISSN: 2058-5225
AimsRight ventricular pacing for left ventricular outflow tract gradient reduction in hypertrophic obstructive cardiomyopathy remains controversial. We undertook a meta-analysis for echocardiographic and functional outcomes.Methods and resultsThirty-four studies comprising 1135 patients met eligibility criteria. In the four blinded randomized controlled trials (RCTs), pacing reduced gradient by 35% [95% confidence interval (CI) 23.2–46.9, P < 0.0001], but there was only a trend towards improved New York Heart Association (NYHA) class [odds ratio (OR) 1.82, CI 0.96–3.44; P = 0.066]. The unblinded observational studies reported a 54.3% (CI 44.1–64.6, P < 0.0001) reduction in gradient, which was a 18.6% greater reduction than the RCTs (P = 0.0351 for difference between study designs). Observational studies reported an effect on unblinded NYHA class at an OR of 8.39 (CI 4.39–16.04, P < 0.0001), 450% larger than the OR in RCTs (P = 0.0042 for difference between study designs). Across all studies, the gradient progressively decreased at longer follow durations, by 5.2% per month (CI 2.5–7.9, P = 0.0001).ConclusionRight ventricular pacing reduces gradient in blinded RCTs. There is a non-significant trend to reduction in NYHA class. The bias in assessment of NYHA class in observational studies appears to be more than twice as large as any genuine treatment effect.
Warisawa T, Nour D, Seligman H, et al., 2019, Assessment of Interference Between Pressure-Wire and Coronary Stents Deployed in the Side-Branch: Insights From a Bench Test, 31st Annual Symposium on Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B575-B575, ISSN: 0735-1097
Sau A, Howard J, Al-Aidarous S, et al., 2019, Meta-analysis of randomized controlled trials of atrial fibrillation ablation with pulmonary vein isolation versus without, JACC: Clinical Electrophysiology, Vol: 5, Pages: 968-976, ISSN: 2405-5018
ObjectivesThis meta-analysis examined the ability of pulmonary vein isolation (PVI) to prevent atrial fibrillation in randomized controlled trials (RCTs) in which the patients not receiving PVI nevertheless underwent a procedure.BackgroundPVI is a commonly used procedure for the treatment of atrial fibrillation (AF), and its efficacy has usually been judged against therapy with anti-arrhythmic drugs in open-label trials. There have been several RCTs of AF ablation in which both arms received an ablation, but the difference between the treatment arms was inclusion or omission of PVI. These trials of an ablation strategy with PVI versus an ablation strategy without PVI may provide a more rigorous method for evaluating the efficacy of PVI.MethodsMedline and Cochrane databases were searched for RCTs comparing ablation including PVI with ablation excluding PVI. The primary efficacy endpoint was freedom from atrial fibrillation (AF) and atrial tachycardia at 12 months. A random-effects meta-analysis was performed using the restricted maximum likelihood estimator.ResultsOverall, 6 studies (610 patients) met inclusion criteria. AF recurrence was significantly lower with an ablation including PVI than an ablation without PVI (RR: 0.54; 95% confidence interval [CI]: 0.33 to 0.89; p 1⁄4 0.0147; I2 1⁄4 79.7%). Neither the type of AF (p 1⁄4 0.48) nor the type of non-PVI ablation (p 1⁄4 0.21) was a significant moderator of the effect size. In 3 trials the non-PVI ablation procedure was performed in both arms, whereas PVI was performed in only 1 arm. In these studies, AF recurrence was significantly lower when PVI was included (RR: 0.32; 95% CI: 0.14 to 0.73; p 1⁄4 0.007, I2 78%ConclusionIn RCTs where both arms received an ablation, and therefore an expectation amongst patients and doctors of benefit, being randomized to PVI had a striking effect, reducing AF recurrence by a half.
Whinnett Z, Sohaib SMA, Mason M, et al., 2019, Multicenter randomized controlled crossover trial comparing hemodynamic optimization against echocardiographic optimization of AV and VV delay of Cardiac Resynchronization Therapy: The BRAVO Trial, JACC: Cardiovascular Imaging, Vol: 12, Pages: 1407-1416, ISSN: 1936-878X
ObjectivesBRAVO (British Randomized Controlled Trial of AV and VV Optimization) is a multicenter, randomized, crossover, noninferiority trial comparing echocardiographic optimization of atrioventricular (AV) and interventricular delay with a noninvasive blood pressure method.BackgroundCardiac resynchronization therapy including AV delay optimization confers clinical benefit, but the optimization requires time and expertise to perform.MethodsThis study randomized patients to echocardiographic optimization or hemodynamic optimization using multiple-replicate beat-by-beat noninvasive blood pressure at baseline; after 6 months, participants were crossed over to the other optimization arm of the trial. The primary outcome was exercise capacity, quantified as peak exercise oxygen uptake. Secondary outcome measures were echocardiographic left ventricular (LV) remodeling, quality-of-life scores, and N-terminal pro–B-type natriuretic peptide.ResultsA total of 401 patients were enrolled, the median age was 69 years, 78% of patients were men, and the New York Heart Association functional class was II in 84% and III in 16%. The primary endpoint, peak oxygen uptake, met the criterion for noninferiority (pnoninferiority = 0.0001), with no significant difference between the hemodynamically optimized arm and echocardiographically optimized arm of the trial (mean difference 0.1 ml/kg/min). Secondary endpoints for noninferiority were also met for symptoms (mean difference in Minnesota score 1; pnoninferiority = 0.002) and hormonal changes (mean change in N-terminal pro–B-type natriuretic peptide -10 pg/ml; pnoninferiority = 0.002). There was no significant difference in LV size (mean change in LV systolic dimension 1 mm; pnoninferiority < 0.001; LV diastolic dimension 0 mm; pnoninferiority <0.001). In 30% of patients the AV delay identified as optimal was more than 20 ms from the nominal setting of 120 ms.ConclusionsOptimization of cardiac resynchronization therapy
Sau A, Al-Aidarous S, Howard J, et al., 2019, Optimum lesion set and predictors of outcome in persistent atrial fibrillation ablation: a meta-regression analysis, Europace, Vol: 21, Pages: 1176-1184, ISSN: 1099-5129
AIMS: Ablation of persistent atrial fibrillation (PsAF) has been performed by many techniques with varying success rates. This may be due to ablation techniques, patient demographics, comorbidities, and trial design. We conducted a meta-regression of studies of PsAF ablation to elucidate the factors affecting atrial fibrillation (AF) recurrence. METHODS AND RESULTS : Databases were searched for prospective studies of PsAF ablation. A meta-regression was performed. Fifty-eight studies (6767 patients) were included. Complex fractionated atrial electrogram (CFAE) ablation reduced freedom from AF by 8.9% [95% confidence interval (CI) -15 to -2.3, P = 0.009). Left atrial appendage [LAA isolation (three study arms)] increased freedom from AF by 39.5% (95% CI 9.1-78.4, P = 0.008). Posterior wall isolation (PWI) (eight study arms) increased freedom from AF by 19.4% (95% CI 3.3-38.1, P = 0.017). Linear ablation or ganglionated plexi ablation resulted in no significant effect on freedom from AF. More extensive ablation increased intraprocedural AF termination; however, intraprocedural AF termination was not associated with improved outcomes. Increased left atrial diameter was associated with a reduction in freedom from AF by 4% (95% CI -6.8% to -1.1%, P = 0.007) for every 1 mm increase in diameter. CONCLUSION : Linear ablation, PWI, and CFAE ablation improves intraprocedural AF termination, but such termination does not predict better long-term outcomes. Study arms including PWI or LAA isolation in the lesion set were associated with improved outcomes in terms of freedom from AF; however, further randomized trials are required before these can be routinely recommended. Left atrial size is the most important marker of AF chronicity influencing outcomes.
Cook C, Takayuki W, Howard J, et al., 2019, Algorithmic versus expert human interpretation of instantaneous wave-Free Ratio (iFR) coronary pressure-wire pullback data, JACC: Cardiovascular Interventions, Vol: 12, Pages: 1315-1324, ISSN: 1936-8798
BackgroundInterpretation of instantaneous wave-Free Ratio (iFR) pressure-wire pullback data can be complex and is subjective. ObjectivesTo investigate if algorithmic interpretation (AI) of iFR pressure-wire pullback data would be non-inferior to expert human interpretation.Methods Fifteen human experts interpreted 1008 iFR pullback traces (691 unique, 317 duplicate). For each trace, experts determined the hemodynamic appropriateness for percutaneous coronary intervention (PCI), and in such cases, the optimal physiological strategy for PCI. The Heart Team (HT) interpretation was determined by consensus of the individual expert opinions. The same 1008 pullback traces were also interpreted algorithmically. The co-primary hypotheses of this study were that AI would be non-inferior to that of the median expert human in determining 1) the hemodynamic appropriateness for PCI, and 2) the physiological strategy for PCI.ResultsRegarding the hemodynamic appropriateness for PCI, the median expert human demonstrated 89.3% agreement with the HT in comparison to 89.4% for AI (p<0.01 for non-inferiority). Across the 372 cases judged as hemodynamically appropriate for PCI according to the HT, the median expert human demonstrated 88.8% agreement with the HT in comparison to 89.7% for AI (p<0.0001 for non-inferiority). On reproducibility testing, the HT opinion itself changed 1-in-10 times for both the appropriateness for PCI and the physiological PCI strategy. In contrast, CI showed no change.ConclusionsAlgorithmic interpretation of iFR pressure-wire pullback data was non-inferior to expert human interpretation in determining both the hemodynamic appropriateness for PCI and the optimal physiological strategy for PCI.
Nowbar AN, gitto M, Howard J, et al., 2019, Mortality from Ischaemic Heart Disease: analysis of data from the World Health Organization and coronary artery disease risk factors from NCD-RisC, Circulation: Cardiovascular Quality and Outcomes, Vol: 12, ISSN: 1941-7705
BackgroundIschemic heart disease (IHD) has been considered the top cause of mortality globally. However, countries differ in their rates and there have been changes over time.Methods and ResultsWe analyzed mortality data submitted to the World Health Organization from 2005 to 2015 by individual countries. We explored patterns in relationships with age, sex, and income and calculated age-standardized mortality rates for each country in addition to crude death rates. In 5 illustrative countries which provided detailed data, we analyzed trends of mortality from IHD and 3 noncommunicable diseases (lung cancer, stroke, and chronic lower respiratory tract diseases) and examined the simultaneous trends in important cardiovascular risk factors. Russia, United States, and Ukraine had the largest absolute numbers of deaths among the countries that provided data. Among 5 illustrative countries (United Kingdom, United States, Brazil, Kazakhstan, and Ukraine), IHD was the top cause of death, but mortality from IHD has progressively decreased from 2005 to 2015. Age-standardized IHD mortality rates per 100 000 people per year were much higher in Ukraine (324) and Kazakhstan (97) than in United States (60), Brazil (54), and the United Kingdom (46), with much less difference in other causes of death. All 5 countries showed a progressive decline in IHD mortality, with a decline in smoking and hypertension and in all cases a rise in obesity and type II diabetes mellitus.ConclusionsIHD remains the single largest cause of death in countries of all income groups. Rates are different between countries and are falling in most countries, indicating great potential for further gains. On the horizon, future improvements may become curtailed by increasing hypertension in some developing countries and more importantly global growth in obesity.
Cook CM, Ahmad Y, Howard JP, et al., 2019, Association Between Physiological Stenosis Severity and Angina-Limited Exercise Time in Patients With Stable Coronary Artery Disease, JAMA CARDIOLOGY, Vol: 4, Pages: 569-574, ISSN: 2380-6583
Keene D, Shun-Shin M, Arnold A, et al., 2019, Quantification of Electromechanical Coupling to Prevent Inappropriate Implantable Cardioverter-Defibrillator Shocks, JACC: Clinical Electrophysiology, Vol: 5, Pages: 705-715, ISSN: 2405-500X
Objective To test specialised processing of laser Doppler signals for discriminating ventricular fibrillation(VF) from common causes of inappropriate therapies.BackgroundInappropriate ICD therapies remain a clinically important problem associated with morbidity and mortality.Tissue perfusion biomarkers, to assist automated diagnosis of VF, suffer the vulnerability of sometimes mistaking artefact and random noise for perfusion, which could lead to shocks being inappropriately withheld. MethodsWe developed a novel processing algorithm that combines electrogram data and laser Doppler perfusion monitoring, as a method for assessing circulatory status. We recruited 50 patients undergoing VF induction during ICD implantation. We recorded non-invasive laser Doppler and continuous electrograms, during both sinus-rhythm and VF. For each patient we simulated two additional scenarios that may lead to inappropriate shocks: ventricular-lead fracture and T-wave oversensing. We analysed the laser Doppler using three methods for reducing noise: (i)Running Mean, (ii)Oscillatory Height, (iii)a novel quantification of Electro-Mechanical coupling which gates laser Doppler against electrograms. We additionally tested the algorithm during exercise induced sinus tachycardia.ResultsOnly the Electro-mechanical coupling algorithm found a clear perfusion cut-off between sinus rhythm and VF (sensitivity and specificity 100%). Sensitivity and specificity remained 100% during simulated lead fracture and electrogram oversensing. (AUC: Running Mean 0.91, Oscillatory Height 0.86, Electro-Mechanical Coupling 1.00). Sinus tachycardia did not cause false positives.ConclusionsQuantifying the coupling between electrical and perfusion signals increases reliability of discrimination between VF and artefacts that ICDs may interpret as VF. Incorporating such methods into future ICDs may safely permit reductions of inappropriate shocks.
Azizi M, Schmieder RE, Mahfoud F, et al., 2019, Six-Month Results of Treatment-Blinded Medication Titration for Hypertension Control After Randomization to Endovascular Ultrasound Renal Denervation or a Sham Procedure in the RADIANCE-HTN SOLO Trial, CIRCULATION, Vol: 139, Pages: 2542-2553, ISSN: 0009-7322
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- Citations: 80
Howard J, Fisher L, Shun-Shin M, et al., 2019, Cardiac rhythm device identification using neural networks, JACC: Clinical Electrophysiology, Vol: 5, Pages: 576-586, ISSN: 2405-5018
BackgroundMedical staff often need to determine the model of a pacemaker or defibrillator (cardiac rhythm devices) quickly and accurately. Current approaches involve comparing a device’s X-ray appearance with a manual flow chart. We aimed to see whether a neural network could be trained to perform this task more accurately.Methods and ResultsWe extracted X-ray images of 1676 devices, comprising 45 models from 5 manufacturers. We developed a convolutional neural network to classify the images, using a training set of 1451 images. The testing set was a further 225 images, consisting of 5 examples of each model. We compared the network’s ability to identify the manufacturer of a device with those of cardiologists using a published flow-chart.The neural network was 99.6% (95% CI 97.5 to 100) accurate in identifying the manufacturer of a device from an X-ray, and 96.4% (95% CI 93.1 to 98.5) accurate in identifying the model group. Amongst 5 cardiologists using the flow-chart, median manufacturer accuracy was 72.0% (range 62.2% to 88.9%), and model group identification was not possible. The network was significantly superior to all of the cardiologists in identifying the manufacturer (p < 0.0001 against the median human; p < 0.0001 against the best human).ConclusionsA neural network can accurately identify the manufacturer and even model group of a cardiac rhythm device from an X-ray, and exceeds human performance. This system may speed up the diagnosis and treatment of patients with cardiac rhythm devices and it is publicly accessible online.
Sau A, Howard J, Al-Aidarous S, et al., 2019, Efficacy of pulmonary vein isolation in preventing atrial fibrillation: meta-analysis of randomized controlled trials with an invasive control procedure, Annual Conference of the British-Cardiovascular-Society (BCS) - Digital Health Revolution, Publisher: BMJ Publishing Group, Pages: A31-A31, ISSN: 1355-6037
Introduction Pulmonary vein isolation (PVI) is a commonly used element in treatment of atrial fibrillation (AF) but has never been tested in an intentionally placebo (sham) controlled trial. Nevertheless there have been several randomized controlled trials (RCTs) in which both arms receive an ablation procedure but the only difference between treatment arms is inclusion or omission of PVI. As long as both doctor and patient have reason to believe that the procedures in both arms are effective, such RCTs could be an effective proxy for placebo controlled trials.Methods Medline and Cochrane databases were searched for RCTs comparing catheter ablation including PVI with left atrial ablation excluding PVI. The primary efficacy endpoint was freedom from AF/atrial tachycardia at 6 months. A random-effects meta-analysis was performed using the restricted maximum likelihood (REML) estimator.Results Overall, seven studies (909 patients) met inclusion criteria. Across the 7 trials, mean age was 57.3, 70.2% of participants were male. In four trials (352 patients) the non-PVI ablation procedure was performed in both arms, while PVI was performed in only one arm. The non-PVI ablation procedures were complex fractionated atrial electrogram ablation (2 studies), ganglionated plexi ablation (1 study) and focal impulse and rotor modulation (1 study). In these, AF recurrence was significantly lower when PVI was included (RR 0.48, 95% CI 0.26-0.90, I2 64.4%)In an analysis of all 7 studies, AF recurrence was significantly lower in ablation with an ablation strategy including PVI compared to one without PVI (Figure 1, RR 0.67, 95% CI 0.53-0.85, p = 0.001, I2 0%). Neither type of AF (persistent vs. paroxysmal, p=0.43) nor type of non-PVI ablation (p=0.35) were significant moderators of the effect size. A sensitivity analysis omitting each study in turn showed similar results to the primary analysis. In particular exclusion of the retracted OASIS trial showed results similar to the primar
Nowbar A, Gitto M, Howard J, et al., 2019, GLOBAL AND TEMPORAL TRENDS IN MORTALITY FROM ISCHAEMIC HEART DISEASE: STATISTICS FROM THE WORLD HEALTH ORGANISATION, Annual Conference of the British-Cardiovascular-Society (BCS) - Digital Health Revolution, Publisher: BMJ PUBLISHING GROUP, Pages: A93-A93, ISSN: 1355-6037
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Warisawa T, Cook CM, Howard JP, et al., 2019, Physiological pattern of disease assessed by pressure-wire pullback has an influence on fractional flow reserve/instantaneous wave-free ratio discordance, Circulation: Cardiovascular Interventions, Vol: 12, ISSN: 1941-7640
BACKGROUND: Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) disagree on the hemodynamic significance of a coronary lesion in ≈20% of cases. It is unknown whether the physiological pattern of disease is an influencing factor for this. This study assessed whether the physiological pattern of coronary artery disease influences discordance between FFR and iFR measurement. METHODS AND RESULTS: Three-hundred and sixty intermediate coronary lesions (345 patients; mean age, 64.4±10.3 years; 76% men) with combined FFR, iFR, and iFR pressure-wire pullback were included for analysis from an international multicenter registry. Cut points for hemodynamic significance were FFR ≤0.80 and iFR ≤0.89, respectively. Lesions were classified into FFR+/iFR+ (n=154; 42.7%), FFR-/iFR+ (n=38; 10.6%), FFR+/iFR- (n=41; 11.4%), and FFR-/iFR- (n=127; 35.3%) groups. The physiological pattern of disease was classified according to the iFR pullback recordings as predominantly physiologically focal (n=171; 47.5%) or predominantly physiologically diffuse (n=189; 52.5%). Median FFR and iFR were 0.80 (interquartile range, 0.75-0.85) and 0.89 (interquartile range, 0.86-0.92), respectively. FFR disagreed with iFR in 22% (79 of 360). The physiological pattern of disease was the only influencing factor relating to FFR/iFR discordance: predominantly physiologically focal was significantly associated with FFR+/iFR- (58.5% [24 of 41]), and predominantly physiologically diffuse was significantly associated with FFR-/iFR+ (81.6% [31 of 38]; P<0.001 for pattern of disease between FFR+/iFR- and FFR-/iFR+ groups). CONCLUSIONS: The physiological pattern of coronary artery disease was an important influencing factor for FFR/iFR discordance.
Seligman H, Shun-Shin M, Vasireddy A, et 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.
Warisawa T, Howard JP, Cook C, et al., 2019, INTER-OBSERVER DIFFERENCES IN INTERPRETATION OF PRESSURE-WIRE PULLBACK TRACES, 68th Annual Scientific Session and Expo of the American-College-of-Cardiology (ACC), Publisher: ELSEVIER SCIENCE INC, Pages: 1417-1417, ISSN: 0735-1097
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.
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