Imperial College London

DrAhranArnold

Faculty of MedicineNational Heart & Lung Institute

Clinical Research Fellow
 
 
 
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ahran.arnold

 
 
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Fellows' RoomBlock B Hammersmith HospitalHammersmith Campus

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Summary

 

Publications

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37 results found

Howard J, Wood F, Finegold J, Nowbar A, Thompson DM, Arnold A, Rajkumar C, Connolly S, Cegla J, Stride C, Sever P, Northon C, Thom S, Shun-Shin M, Francis Det al., 2021, Side effect patterns in a crossover trial of statin, placebo and no treatment, Journal of the American College of Cardiology, Vol: 78, Pages: 1210-1222, ISSN: 0735-1097

BackgroundMost people who begin statins abandon them, most commonly because of side-effects. ObjectivesAssess daily symptom scores on statin, placebo and no treatment in participants who had abandoned statins.MethodsParticipants received 12 one-month medication bottles, 4 containing atorvastatin 20mg, 4 placebo and 4 empty. We measured daily symptom intensity for each using an app (scale 1-100). We also measured the nocebo ratio: the ratio of symptoms induced by taking statin that was also induced by taking placebo. Results60 participants were randomized and 49 completed the 12-month protocol. Mean symptom score was 8.0 (95% confidence interval 4.7 to 11.3) in no-tablet months. It was higher in statin months (16.3, 13.0 to 19.6, p<0.001), but also in placebo months (15.4, 12.1 to 18.7, p<0.001), with no difference between the two (p=0.388). The corresponding nocebo ratio was 0.90.In the individual-patient daily data, neither symptom intensity on starting (odds ratio 1.02, 95% CI 0.98 to 1.06, p=0.28) nor extent of symptom relief on stopping (1.01, 95% CI 0.98 to 1.05, p=0.48) distinguished between statin and placebo.Stopping was no more frequent for statin than placebo (p=0.173), and subsequent symptom relief was similar between statin and placebo.6 months after the trial, 30/60 (50%) of participants were back taking statins. ConclusionsThe majority of symptoms caused by statin tablets were nocebo. Clinicians should not interpret symptom intensity or timing of symptom onset or offset (on starting or stopping statin tablets) as indicating pharmacological causation, because the pattern is identical for placebo.

Journal article

Arnold AD, Shun-Shin MJ, Ali N, Keene D, Howard JP, Chow J-J, Qureshi NA, Koa-Wing M, Tanner M, Lefroy DC, Linton NWF, Ng FS, Lim PB, Peters NS, Kanagaratnam P, Francis DP, Whinnett ZIet al., 2021, Left ventricular activation time and pattern are preserved with both selective and non-selective his bundle pacing, Heart Rhythm O2, ISSN: 2666-5018

BackgroundHis bundle pacing (HBP) can be achieved in two ways: selective HBP (S-HBP), where the His bundle is captured alone, and non-selective HBP (NS-HBP), where local myocardium is also captured resulting a pre-excited ECG appearance.ObjectiveWe assessed the impact of this ventricular pre-excitation on left and right ventricular dys-synchrony.MethodsWe recruited patients who displayed both S-HBP and NS-HBP. We performed non-invasive epicardial electrical mapping for left and right ventricular activation time (LVAT and RVAT) and pattern.Results20 patients were recruited. In the primary analysis, the mean within-patient change in LVAT from S-HBP to NS-HBP was -5.5ms (95% confidence interval: -0.6 to -10.4, non-inferiority p<0.0001). NS-HBP did not prolong RVAT (4.3ms, -4.0 to 12.8, p=0.296) but did prolong QRS duration (QRSd, 22.1ms, 11.8 to 32.4, p = 0.0003). In patients with narrow intrinsic QRS (n=6), NS-HBP preserved LVAT (-2.9ms, -9.7 to 4.0, p=0.331) but prolonged QRS duration (31.4ms, 22.0 to 40.7, p=0.0003) and mean RVAT (16.8ms, -5.3 to 38.9, p=0.108) compared to S-HBP. Activation pattern of the left ventricular surface was unchanged between S-HBP and NS-HBP but NS-HBP produced early basal right ventricular activation that was not seen in S-HBP.ConclusionCompared to S-HBP, local myocardial capture during NS-HBP produces pre-excitation of the basal right ventricle resulting in QRS duration prolongation. However, NS-HBP preserves the left ventricular activation time and pattern of S-HBP. Left ventricular dys-synchrony is not an important factor when choosing between S-HBP and NS-HBP in most patients.

Journal article

Ahmad Y, Kane C, Arnold AD, Cook C, Keene D, Shun-Shin M, Cole G, Al-Lamee R, Francis D, Howard Jet al., 2021, Randomized blinded placebo-controlled trials of renal sympathetic denervation for hypertension: a meta-analysis, Cardiovascular Revascularization Medicine, ISSN: 1553-8389

BackgroundThe efficacy of renal denervation has been controversial, but the procedure has now undergone several placebo-controlled trials. New placebo-controlled trial data has recently emerged, with longer follow-up of one trial and the full report of another trial (which constitutes 27% of the total placebo-controlled trial data). We therefore sought to evaluate the effect of renal denervation on ambulatory and office blood pressures in patients with hypertension.MethodsWe systematically identified all blinded placebo-controlled randomized trials of catheter-based renal denervation for hypertension. The primary efficacy outcome was ambulatory systolic blood pressure change relative to placebo. A random-effects meta-analysis was performed.Results6 studies randomizing 1232 patients were eligible. 713 patients were randomized to renal denervation and 519 to placebo. Renal denervation significantly reduced ambulatory systolic blood pressure (−3.52 mmHg; 95% CI −4.94 to −2.09; p < 0.0001), ambulatory diastolic blood pressure (−1.93 mmHg; 95% CI −3.04 to −0.83, p = 0.0006), office systolic blood pressure size (−5.10 mmHg; 95% CI −7.31 to −2.90, p < 0.0001) and office diastolic pressure (effect size −3.11 mmHg; 95% CI −4.43 to −1.78, p < 0.0001). Adverse events were rare and not more common with denervation.ConclusionsThe totality of blinded, randomized placebo-controlled data shows that renal denervation is safe and provides genuine reduction in blood pressure for at least 6 months post-procedure. If this effect continues in the long term, renal denervation might provide a life-long 10% relative risk reduction in major adverse cardiac events and 7.5% relative risk reduction in all-cause mortality.

Journal article

Arnold AD, Shun-Shin MJ, Keene D, Howard JP, Chow J-J, Lim E, Lampridou S, Miyazawa AA, Muthumala A, Tanner M, Qureshi NA, Lefroy DC, Koa-Wing M, Linton NWF, Boon Lim P, Peters NS, Kanagaratnam P, Auricchio A, Francis DP, Whinnett ZIet al., 2021, Electrocardiographic predictors of successful resynchronization of left bundle branch block by His bundle pacing, JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Vol: 32, Pages: 428-438, ISSN: 1045-3873

Journal article

Wood FA, Howard JP, Finegold JA, Nowbar AN, Thompson DM, Arnold AD, Rajkumar CA, Connolly S, Cegla J, Stride C, Sever P, Norton C, Thom SAM, Shun-Shin MJ, Francis DPet al., 2020, N-of-1 trial of a statin, placebo, or No treatment to assess side effects., New England Journal of Medicine, Vol: 383, Pages: 2182-2184, ISSN: 0028-4793

Journal article

Keene D, Shun-Shin MJ, Arnold AD, March K, Qureshi N, Ng FS, Tanner M, Linton N, Lim PB, Lefroy D, Kanagaratnam P, Peters NS, Francis DP, Whinnett ZIet al., 2020, Within-patient comparison of His-bundle pacing, right ventricular pacing, and right ventricular pacing avoidance algorithms in patients with PR prolongation: Acute hemodynamic study, Journal of Cardiovascular Electrophysiology, Vol: 31, Pages: 2964-2974, ISSN: 1045-3873

AimsA prolonged PR interval may adversely affect ventricular filling and, therefore, cardiac function. AV delay can be corrected using right ventricular pacing (RVP), but this induces ventricular dyssynchrony, itself harmful. Therefore, in intermittent heart block, pacing avoidance algorithms are often implemented. We tested His‐bundle pacing (HBP) as an alternative.MethodsOutpatients with a long PR interval (>200 ms) and intermittent need for ventricular pacing were recruited. We measured within‐patient differences in high‐precision hemodynamics between AV‐optimized RVP and HBP, as well as a pacing avoidance algorithm (Managed Ventricular Pacing [MVP]).ResultsWe recruited 18 patients. Mean left ventricular ejection fraction was 44.3 ± 9%. Mean intrinsic PR interval was 266 ± 42 ms and QRS duration was 123 ± 29 ms. RVP lengthened QRS duration (+54 ms, 95% CI 42–67 ms, p < .0001) while HBP delivered a shorter QRS duration than RVP (−56 ms, 95% CI −67 to −46 ms, p < .0001). HBP did not increase QRS duration (−2 ms, 95% CI −8 to 13 ms, p = .6). HBP improved acute systolic blood pressure by mean of 5.0 mmHg (95% CI 2.8–7.1 mmHg, p < .0001) compared to RVP and by 3.5 mmHg (95% CI 1.9–5.0 mmHg, p = .0002) compared to the pacing avoidance algorithm. There was no significant difference in hemodynamics between RVP and ventricular pacing avoidance (p = .055).ConclusionsHBP provides better acute cardiac function than pacing avoidance algorithms and RVP, in patients with prolonged PR intervals. HBP allows normalization of prolonged AV delays (unlike pacing avoidance) and does not cause ventricular dyssynchrony (unlike RVP). Clinical trials may be justified to assess whether these acute

Journal article

Ahmad Y, Howard JP, Arnold AD, Ali ZD, Francis D, Moses JW, Leon MB, Kirtane AJ, Karmpaliotis D, Stone GWet al., 2020, Drug-eluting stents versus bypass surgery for left main disease: an updated meta-analysis of randomized controlled trials with long-term follow-up, American Journal of Cardiology, Vol: 132, Pages: 168-172, ISSN: 0002-9149

Journal article

Ahmad Y, 2020, Mortality after drug-eluting stents versus coronary artery bypass grafting for left main coronary artery disease: A meta-analysis of randomized controlled trials, European Heart Journal, Vol: 41, Pages: 3228-3235, ISSN: 0195-668X

Aims The optimal method of revascularization for patients with left main coronary artery disease (LMCAD) is controversial. Coronary artery bypass graft surgery (CABG) has traditionally been considered the gold standard therapy, and recent randomized trials comparing CABG with percutaneous coronary intervention (PCI) with drug-eluting stents (DES) have reported conflicting outcomes. We, therefore, performed a systematic review and updated meta-analysis comparing CABG to PCI with DES for the treatment of LMCAD.Methods and results We systematically identified all randomized trials comparing PCI with DES vs. CABG in patients with LMCAD. The primary efficacy endpoint was all-cause mortality. Secondary endpoints included cardiac death, myocardial infarction (MI), stroke, and unplanned revascularization. All analyses were by intention-to-treat. There were five eligible trials in which 4612 patients were randomized. The weighted mean follow-up duration was 67.1 months. There were no significant differences between PCI and CABG for the risk of all-cause mortality [relative risk (RR) 1.03, 95% confidence interval (CI) 0.81–1.32; P = 0.779] or cardiac death (RR 1.03, 95% CI 0.79–1.34; P = 0.817). There were also no significant differences in the risk of stroke (RR 0.74, 95% CI 0.35–1.50; P = 0.400) or MI (RR 1.22, 95% CI 0.96–1.56; P = 0.110). Percutaneous coronary intervention was associated with an increased risk of unplanned revascularization (RR 1.73, 95% CI 1.49–2.02; P < 0.001).Conclusion The totality of randomized clinical trial evidence demonstrated similar long-term mortality after PCI with DES compared with CABG in patients with LMCAD. Nor were there significant differences in cardiac death, stroke, or MI between PCI and CABG. Unplanned revascularization procedures were less common after CABG compared with PCI. These findings may inform clinica

Journal article

Arnold AD, Whinnett Z, Vijayaraman P, 2020, His-Purkinje Conduction System Pacing: State of the Art in 2020, ARRHYTHMIA & ELECTROPHYSIOLOGY REVIEW, Vol: 9, Pages: 136-145, ISSN: 2050-3369

Journal article

Hendry BM, Stafford N, Arnold AD, Sangwaiya A, Manglam V, Rosen SD, Arnold Jet al., 2020, Hypothesis: Pentoxifylline is a potential cytokine modulator therapeutic in COVID-19 patients, PHARMACOLOGY RESEARCH & PERSPECTIVES, Vol: 8, ISSN: 2052-1707

Journal article

Howard JP, Arnold AD, Ahmad Y, 2020, Bias, heterogeneity, and uncertainty in meta-analysis, EUROPEAN HEART JOURNAL, Vol: 41, Pages: 2712-2712, ISSN: 0195-668X

Journal article

Ahmad Y, 2020, Complete revascularisation by percutaneous coronary intervention for patients with ST-segment elevation myocardial infarction and multivessel coronary artery disease: an updated meta-analysis and meta-regression of randomized trials, Journal of the American Heart Association, Vol: 9, Pages: 1-83, ISSN: 2047-9980

BackgroundFor patients with ST‐segment–elevation myocardial infarction (STEMI) and multivessel coronary artery disease, the optimal treatment of the non‐infarct‐related artery has been controversial. This up‐to‐date meta‐analysis focusing on individual clinical end points was performed to further evaluate the benefit of complete revascularization with percutaneous coronary intervention for patients with STEMI and multivessel coronary artery disease.Methods and ResultsWe systematically identified all randomized trials comparing complete revascularization with percutaneous coronary intervention to culprit‐only revascularization for multivessel disease in STEMI and performed a random‐effects meta‐analysis. The primary efficacy end point was cardiovascular death analyzed on an intention‐to‐treat basis. Secondary end points included all‐cause mortality, myocardial infarction, and unplanned revascularization. Ten studies (7542 patients) were included: 3664 patients were randomized to complete revascularization and 3878 to culprit‐only revascularization. Across all patients, complete revascularization was superior to culprit‐only revascularization for reduction in the risk of cardiovascular death (relative risk [RR], 0.68; 95% CI, 0.47–0.98; P=0.037; I2=21.8%) and reduction in the risk of myocardial infarction (RR, 0.65; 95% CI, 0.54–0.79; P<0.0001; I2=0.0%). Complete revascularization also significantly reduced the risk of unplanned revascularization (RR, 0.37; 95% CI, 0.28–0.51; P<0.0001; I2=64.7%). The difference in all‐cause mortality with percutaneous coronary intervention was not statistically significant (RR, 0.85; 95% CI, 0.69–1.04; P=0.108; I2=0.0%).ConclusionsFor patients with STEMI and multivessel disease, complete revascularization with percutaneous coronary intervention significantly improves hard clinical outcomes including cardiovascular death and myocardial infarction. These data have implications for clinical practice gu

Journal article

Bohm M, Kario K, Kandzari DE, Mahfoud F, Weber MA, Schmieder RE, Tsioufis K, Pocock S, Konstantinidis D, Choi JW, East C, Lee DP, Ma A, Ewen S, Cohen DL, Wilensky R, Devireddy CM, Lea J, Schmid A, Weil J, Agdirlioglu T, Reedus D, Jefferson BK, Reyes D, D'Souza R, Sharp ASP, Sharif F, Fahy M, DeBruin V, Cohen SA, Brar S, Townsend RRet al., 2020, Efficacy of catheter-based renal denervation in the absence of antihypertensive medications (SPYRAL HTN-OFF MED Pivotal): a multicentre, randomised, sham-controlled trial, LANCET, Vol: 395, Pages: 1444-1451, ISSN: 0140-6736

Journal article

Kaura A, Arnold AD, Vasileios P, Glampson B, Davies J, Mulla A, Woods K, Omigie J, Shah AD, Channon KM, Weber JN, Thursz MR, Elliott P, Hemingway H, Williams B, Asselbergs FW, OSullivan M, Lord GM, Melikian N, Lefroy DC, Francis DP, Shah AM, Kharbanda R, Perera D, Patel RS, Mayet Jet al., 2020, Prognostic significance of troponin level in 3,121 patients presenting with atrial fibrillation (The NIHR Health Informatics Collaborative TROP-AF study), Journal of the American Heart Association, Vol: 9, ISSN: 2047-9980

Background-—Patients presenting with atrial fibrillation (AF) often undergo a blood test to measure troponin, but interpretation of theresult is impeded by uncertainty about its clinical importance. We investigated the relationship between troponin level, coronaryangiography, and all-cause mortality in real-world patients presenting with AF.Methods and Results-—We used National Institute of Health Research Health Informatics Collaborative data to identify patients admitted between 2010 and 2017 at 5 tertiary centers in the United Kingdom with a primary diagnosis of AF. Peak troponin results 7 were scaled as multiples of the upper limit of normal. A total of 3121 patients were included in the analysis. Over a median followup of 1462 (interquartile range, 929–1975) days, there were 586 deaths (18.8%). The adjusted hazard ratio for mortality associatedwith a positive troponin (value above upper limit of normal) was 1.20 (95% CI, 1.01–1.43; P<0.05). Higher troponin levels were associated with higher risk of mortality, reaching a maximum hazard ratio of 2.6 (95% CI, 1.9–3.4) at 250 multiples of the upper limit of normal. There was an exponential relationship between higher troponin levels and increased odds of coronary angiography.The mortality risk was 36% lower in patients undergoing coronary angiography than in those who did not (adjusted hazard ratio, 0.61; 95% CI, 0.42–0.89; P=0.01).Conclusions-—Increased troponin was associated with increased risk of mortality in patients presenting with AF. The lower hazard ratio in patients undergoing invasive management raises the possibility that the clinical importance of troponin release in AF may be mediated by coronary artery disease, which may be responsive to revascularization.

Journal article

Pucci N, Kwan CH, Yates DC, Arnold AD, Keene D, Whinnett ZI, Mitcheson PDet al., 2020, Effect of fields generated through wireless power transfer on implantable biomedical devices, 2019 IEEE PELS Workshop on Emerging Technologies: Wireless Power Transfer (WoW), Publisher: IEEE, Pages: 1-5

This paper assesses the safety of pacemakers when exposed to the electromagnetic (EM) field generated by high frequency inductive power transfer (HF-IPT) systems. It includes both simulation and experimental results, showing temperature variations to ensure conformity with the EN standards, changes in detected lead impedance and determining whether EM field strength can affect the operating mode of the device. This is the first time the interaction between 6.78MHz, 100W HF-IPT systems and pacemaker devices was tested up to distances of 5 cm to 10 cm, Temporary decrease of detected lead's impedance and interruption of communications are the most relevant effects recorded through in-vitro tests. No permanent alteration of the device's operation was recorded, indicating good early stage evidence of safety for pacemaker users in proximity of this new emerging technology.

Conference paper

Arnold A, Howard J, Chiew K, Kerrigan W, de Vere F, Johns H, Churilov L, Ahmad Y, Keene D, Shun-Shin M, Cole G, Kanagaratnam P, Sohaib S, Varnava A, Francis D, Whinnett Zet 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.

Journal article

Keene D, Arnold A, Jastrzębski M, Burri H, Zweibel S, Crespo E, Chandrasekaran B, Bassi S, Joghetaei N, Swift M, Moskal P, Francis D, Foley P, Shun-Shin M, Whinnett Zet al., 2019, His bundle pacing, learning curve, procedure characteristics, safety, and feasibility: Insights from a large international observational study, Journal of Cardiovascular Electrophysiology, Vol: 30, Pages: 1984-1993, ISSN: 1045-3873

BackgroundHis‐bundle pacing (HBP) provides physiological ventricular activation. Observational studies have demonstrated the techniques feasibility however, data has come from a limited number of centres.ObjectivesWe set out to explore contemporary global practise in HBP focusing on learning curve, procedural characteristics and outcomes.MethodsThis is a retrospective, multi‐centre observational study of patients undergoing attempted HBP at seven centres. Pacing indication, fluoroscopy time, HBP thresholds and lead re‐intervention and deactivation rates were recorded. Where centres had systematically recorded implant success rates from the outset, these were collated.Results529 patients underwent attempted HBP during the study period (2014‐19) with mean follow‐up of 217±303 days. Most implants were for bradycardia indications.In the three centres with systematic collation of all attempts, overall implant success rate was 81% which improved to 87% after completion of 40 cases.All seven centres reported data on successful implants. Mean fluoroscopy time was 11.7±12.0 minutes, His‐bundle capture threshold at implant was 1.4±0.9V at 0.8±0.3 ms and was 1.3±1.2V at 0.9±0.2ms at last device check.HBP lead re‐intervention or deactivation (for lead displacement or rise in threshold) occurred in 7.5% of successful implants.There was evidence of a learning curve: fluoroscopy time and HBP capture threshold reduced with greater experience, plateauing after ~30‐50 cases.ConclusionWe found that it is feasible to establish a successful HBP program, using the currently available implantation tools. For physicians who are experienced at pacemaker implantation the steepest part of the learning curve appears to be over the first 30‐50 cases.

Journal article

Keene D, Shun-Shin M, Arnold A, Howard J, Lefroy D, Davies W, Lim PB, Ng FS, Koa-Wing M, Qureshi N, Linton N, Shah J, Peters N, Kanagaratnam P, Francis D, Whinnett Zet 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.

Journal article

Howard J, Fisher L, Shun-Shin M, Keene D, Arnold A, Ahmad Y, Cook C, Moon J, Manisty C, Whinnett Z, Cole G, Rueckert D, Francis Det 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.

Journal article

Kaura A, Arnold A, Panoulas V, Ben G, Davies J, Mulla A, Woods K, Omigie J, Shah AD, Channon K, Weber JN, Thursz MR, Elliott P, Hemingway H, Williams B, Asselbergs F, O'Sullivan M, Lord G, Melikian N, Lefroy D, Francis D, Shah A, Perera D, Kharbanda R, Patel R, Mayet Jet al., 2019, THE PROGNOSTIC IMPLICATION OF TROPONIN LEVEL IN OVER 3000 PATIENTS PRESENTING WITH ATRIAL FIBRILLATION (NIHR HEALTH INFORMATICS COLLABORATIVE AF-TROP STUDY), Annual Conference of the British-Cardiovascular-Society (BCS) - Digital Health Revolution, Publisher: BMJ PUBLISHING GROUP, Pages: A26-A27, ISSN: 1355-6037

Conference paper

Kaura A, Arnold A, Panoulas V, Glampson B, Davies J, Woods K, Mulla A, Omigie J, Shah AD, Channon K, Weber JN, Thursz MR, Elliott P, Hemingway H, Williams B, Asselbergs FW, Kharbanda R, Lord GM, Melikian N, Patel R, Perera D, Shah A, Lefroy D, Francis D, Mayet Jet al., 2019, CLINICAL IMPORTANCE OF TROPONIN LEVEL IN 3,121 PATIENTS PRESENTING WITH ATRIAL FIBRILLATION (AF-TROP STUDY), 68th Annual Scientific Session and Expo of the American-College-of-Cardiology (ACC), Publisher: ELSEVIER SCIENCE INC, Pages: 410-410, ISSN: 0735-1097

Conference paper

Arnold A, Shun-Shin M, Keene D, Howard J, Sohaib S, wright I, Cole G, Qureshi N, lefroy D, Koa-Wing M, Linton N, Lim P, Peters N, Davies D, muthumala A, Tanner M, ellenbogen K, Kanagaratnam P, Francis D, Whinnett Zet al., 2018, His resynchronization versus biventricular pacing in patients with heart failure and left bundle branch block, Journal of the American College of Cardiology, Vol: 72, Pages: 3112-3122, ISSN: 0735-1097

Background His bundle pacing is a new method for delivering cardiac resynchronization therapy (CRT).Objectives The authors performed a head-to-head, high-precision, acute crossover comparison between His bundle pacing and conventional biventricular CRT, measuring effects on ventricular activation and acute hemodynamic function.Methods Patients with heart failure and left bundle branch block referred for conventional biventricular CRT were recruited. Using noninvasive epicardial electrocardiographic imaging, the authors identified patients in whom His bundle pacing shortened left ventricular activation time. In these patients, the authors compared the hemodynamic effects of His bundle pacing against biventricular pacing using a high-multiple repeated alternation protocol to minimize the effect of noise, as well as comparing effects on ventricular activation.Results In 18 of 23 patients, left ventricular activation time was significantly shortened by His bundle pacing. Seventeen patients had a complete electromechanical dataset. In them, His bundle pacing was more effective at delivering ventricular resynchronization than biventricular pacing: greater reduction in QRS duration (−18.6 ms; 95% confidence interval [CI]: −31.6 to −5.7 ms; p = 0.007), left ventricular activation time (−26 ms; 95% CI: −41 to −21 ms; p = 0.002), and left ventricular dyssynchrony index (−11.2 ms; 95% CI: −16.8 to −5.6 ms; p < 0.001). His bundle pacing also produced a greater acute hemodynamic response (4.6 mm Hg; 95% CI: 0.2 to 9.1 mm Hg; p = 0.04). The incremental activation time reduction with His bundle pacing over biventricular pacing correlated with the incremental hemodynamic improvement with His bundle pacing over biventricular pacing (R = 0.70; p = 0.04).Conclusions His resynchronization delivers better ventricular resynchronization, and greater improvement in hemodynamic parameters, than biventricular pacing.

Journal article

Ahmad Y, Howard J, Arnold A, Shun-Shin MJ, Cook C, Francis D, Sen Set 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.

Journal article

Keene D, Arnold A, Shun-Shin MJ, Howard JP, Sohaib SA, Moore P, Tanner M, Quereshi N, Muthumala A, Chandresekeran B, Foley P, Leyva F, Adhya S, Falaschetti E, Tsang H, Vijayaraman P, Cleland JGF, Stegemann B, Francis DP, Whinnett ZIet al., 2018, Rationale and design of the randomized multicentre His Optimized Pacing Evaluated for Heart Failure (HOPE-HF) trial, ESC Heart Failure, Vol: 5, Pages: 965-976, ISSN: 2055-5822

AIMS: In patients with heart failure and a pathologically prolonged PR interval, left ventricular (LV) filling can be improved by shortening atrioventricular delay using His-bundle pacing. His-bundle pacing delivers physiological ventricular activation and has been shown to improve acute haemodynamic function in this group of patients. In the HOPE-HF (His Optimized Pacing Evaluated for Heart Failure) trial, we are investigating whether these acute haemodynamic improvements translate into improvements in exercise capacity and heart failure symptoms. METHODS AND RESULTS: This multicentre, double-blind, randomized, crossover study aims to randomize 160 patients with PR prolongation (≥200 ms), LV impairment (EF ≤ 40%), and either narrow QRS (≤140 ms) or right bundle branch block. All patients receive a cardiac device with leads positioned in the right atrium and the His bundle. Eligible patients also receive a defibrillator lead. Those not eligible for implantable cardioverter defibrillator have a backup pacing lead positioned in an LV branch of the coronary sinus. Patients are allocated in random order to 6 months of (i) haemodynamically optimized dual chamber His-bundle pacing and (ii) backup pacing only, using the non-His ventricular lead. The primary endpoint is change in exercise capacity assessed by peak oxygen uptake. Secondary endpoints include change in ejection fraction, quality of life scores, B-type natriuretic peptide, daily patient activity levels, and safety and feasibility assessments of His-bundle pacing. CONCLUSIONS: Hope-HF aims to determine whether correcting PR prolongation in patients with heart failure and narrow QRS or right bundle branch block using haemodynamically optimized dual chamber His-bundle pacing improves exercise capacity and symptoms. We aim to complete recruitment by the end of 2018 and report in 2020.

Journal article

Sharma PS, Naperkowski A, Bauch TD, Chan JYS, Arnold AD, Whinnett ZI, Ellenbogen KA, Vijayaraman Pet al., 2018, Permanent His Bundle Pacing for Cardiac Resynchronization Therapy in Patients With Heart Failure and Right Bundle Branch Block, CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY, Vol: 11, ISSN: 1941-3149

Journal article

Ahmad Y, Howard J, Arnold A, Shun-Shin M, Cook C, Petraco R, Sutaria N, Malik I, Mayet J, Francis DP, Sen Set al., 2018, PFO closure is superior to medical therapy for cryptogenic stroke: a meta-analysis of randomised controlled trials, European-Society-of-Cardiology Congress, Publisher: OXFORD UNIV PRESS, Pages: 111-111, ISSN: 0195-668X

Conference paper

Arnold AD, Shun-Shin MJ, Sohaib A, Chiew K, Howard JP, Keene D, Leong K, Ahmad Y, Cole G, Lefroy D, Kanagaratnam P, Varnava A, Francis DP, Whinnett ZIet al., 2018, Automated, high-precision echocardiographic and haemodynamic assessment of the effect of atrioventricular interval during right ventricular pacing in obstructed hypertrophic cardiomyopathy, European-Society-of-Cardiology Congress, Publisher: OXFORD UNIV PRESS, Pages: 729-729, ISSN: 0195-668X

Conference paper

Shun-Shin M, Arnold A, Keene D, Howard J, Sohaib A, Lim PB, Tanner M, Lefroy D, Peters N, Kanagaratnam P, Davies DW, Francis D, Whinnett Zet al., 2018, The magnitude of LV activation time reduction with His bundle pacing over biventricular pacing in LBBB predicts the incremental improvement in acute cardiac function, European-Society-of-Cardiology Congress, Publisher: OXFORD UNIV PRESS, Pages: 385-385, ISSN: 0195-668X

Conference paper

Murray MI, Arnold A, Younis M, Varghese S, Zeiher AMet al., 2018, Cryoballoon versus radiofrequency ablation for paroxysmal atrial fibrillation: a meta-analysis of randomized controlled trials, Clinical Research in Cardiology, Vol: 107, Pages: 658-669, ISSN: 1861-0684

Objective: The aim of this study was to evaluate the clinical efficacy and safety outcomes of the treatment with cryoballoon (CB) compared to the treatment with traditional irrigated radiofrequency ablation (RF) for pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (pAF) and refractory to antiarrhythmic drug therapy (AAD). Design: We conducted a systemic review to find and include more than two randomized controlled trials (RCTs) with at least 20 patients in each of the CB and RF groups. Thereafter, we performed a meta-analysis to compare the treatment with CB and RF in primary outcomes including 1 year free from AF, complications and re-ablation procedures. Additionally, we evaluated procedure time and fluoroscopy duration in both groups. Risk of bias in the individual studies and across studies was assessed using Cochrane methods. Data extraction and synthesis: Two reviewers extracted study data and assessed risk of bias. Primary outcome data were extracted from the time point 1 year after the procedure. The random-effects model was used to calculate the odds ratio with 95% confidence interval. Data sources: Data sources utilized were PubMed and CENTRAL databases up to 16 June 2016. Eligibility criteria for selecting studies: Included studies were RCTs in adults with pAF and refractory to AAD in which CB therapy, including 1st and 2nd generation CB, was compared to the traditional irrigated RF therapy. Clinical outcomes assessed in each RCT were 1 year AF-free survival, complication rates, re-ablations, fluoroscopy time and procedure time. Results: The systematic review identified four randomized controlled trials that reported on comparative clinical outcomes involving 1284 patients. Our meta-analysis demonstrated that CB ablation had a non-significant higher success rate than RF therapy (OR 1.13; 95% CI 0.72–1.77). However, our study showed a relatively higher rate of complications in the CB group (OR 1.20; 95% CI 0.58–2.

Journal article

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