INTRODUCTION:It is uncertain whether using cardiac drugs prophylactically in combinations for DMD is better than ACE-inhibitor alone. Our previous study showed no differences in left ventricular function between perindopril-bisoprolol and matched placebo after 36 months. METHODS:This study aimed to determine whether heart measures diverged after 60-month total follow-up. All participants had commenced open-label perindopril and bisoprolol when the original study ended. All were reconsented for access to heart measures, undertaken as part of their clinical care. The primary outcome was the change in echo-measured ventricular ejection fraction from baseline according to original randomization. RESULTS:Of 75 participants reported originally, 65 (aged 16 ± 2.5 years) were re-recruited and had data for analysis. Adjusted primary outcomes included 44 participants (original arms: 'active' 21; 'placebo' 23), 48 for secondary outcomes, and 65 for 'headcount' analysis of those with ventricular dysfunction. Absolute LVEF% values reduced in both groups ('active': 62.5% ± 5.6% to 53.8% ± 4.0%; 'placebo': 60.6% ± 4.9% to 50.4% ± 8.5%). Despite trends favoring earlier introduction of therapy, change from baseline was similar between groups (adjusted mean difference: -7.7 (95% CI -16.4 to1.0%)). However, more in the 'placebo' arm had died, had reduced LVEF%, and were taking additional heart medications. CONCLUSION:While some patients may have benefited from 'early' (active) as opposed to 'delayed' (placebo) initiation of perindopril and bisoprolol, group-mean ventricular function did not differ between study arms after 60 months. Small numbers, absence of a control group, insensitivity of echo-ejection fraction, and additional drug use probably prevented divergence between groups.

Cardiomyopathy is a common co-morbidity in individuals with Duchenne muscular dystrophy (DMD). This retrospective single centre study investigated the relationship between age at loss of ambulation (LOA) and late stage left ventricular ejection fraction (LVEF) in 84 individuals (> 16 years old) with DMD taking glucocorticoid and ACE inhibitors treatment. Regression analyses showed a positive correlation between later age at LOA and higher LVEF in adulthood (linear regression estimate 1.49, 95 % CI: 0.13-2.84, p = 0.03). Each additional year of ambulation increased the odds of displaying a higher LVEF category (LVEF 40 %, 40 - 50 % or 50 %) by 35 % (p = 0.003). Sensitivity models excluding cardioprotective genotypes (absence of Dp116 isoform) and mild motor phenotypes (out of frame deletions amenable to skip exon 44 and 45) confirmed this association while models including age at respiratory impairment did not improve the model. Individuals who lost ambulation before age 11.92 (ROC AUC 0.73, 95 % CI: 0.60-0.85) reached a LVEF <40 % 5.21 years earlier than those who lost ambulation after that age (adjusted restricted mean survival time 19.08 vs 24.29 years, p < 0.001). These findings may suggest that prolonging ambulation does not impact cardiac function adversely in advance stages of DMD.

We investigated the comorbidities, associated factors, and the relationship between anthropometric measures and respiratory function and functional abilities in adults with Duchenne muscular dystrophy (DMD). This was a single-centre cross-sectional study in genetically diagnosed adults with DMD (>16 years old). Univariate and multivariate analyses identified factors associated with dysphagia, constipation, Body Mass Index (BMI), and weight. Regression analysis explored associations between BMI, weight, and respiratory/motor abilities. We included 112 individuals (23.4 ± 5.2 years old), glucocorticoid-treated 66.1 %. The comorbidities frequency was 61.6 % scoliosis (61.0 % of them had spinal surgery), 36.6 % dysphagia, 36.6 % constipation, and 27.8 % urinary conditions. The use of glucocorticoids delayed the time to spinal surgery. The univariate analysis revealed associations between dysphagia and constipation with age, lack of glucocorticoid treatment, and lower respiratory and motor function. In the multivariate analysis, impaired cough ability remained as the factor consistently linked to both conditions. Constipation associated with lower BMI and weight. BMI and weight positively correlated with respiratory parameters, but they did not associate with functional abilities. Glucocorticoids reduce the frequency of comorbidities in adults with DMD. The ability to cough can help identifying dysphagia and constipation. Lower BMI and weight in individuals with DMD with compromised respiratory function may suggest a higher calories requirement.

Aims Some patients with cardiac dystrophinopathy die suddenly. Whether such deaths are preventable by specific antiarrhythmic management or simply indicate heart failure overwhelming medical therapies is uncertain. The aim of this prospective, cohort study was to describe the occurrence and nature of cardiac arrhythmias recorded during prolonged continuous ECG rhythm surveillance in patients with established cardiac dystrophinopathy and relate them to abnormalities on cardiac MRI.Methods and results A cohort of 10 patients (36.3 years; 3 female) with LVEF<40% due to Duchenne (3) or Becker muscular (4) dystrophy or Duchenne muscular dystrophy-gene carrying effects in females (3) were recruited, had cardiac MRI, ECG signal-averaging and ECG loop-recorder implants. All were on standard of care heart medications and none had prior history of arrhythmias.No deaths or brady arrhythmias occurred during median follow-up 30 months (range 13–35). Self-limiting episodes of asymptomatic tachyarrhythmia (range 1–29) were confirmed in 8 (80%) patients (ventricular only 2; ventricular and atrial 6). Higher ventricular arrhythmia burden correlated with extent of myocardial fibrosis (extracellular volume%, p=0.029; native T1, p=0.49; late gadolinium enhancement, p=0.49), but not with LVEF% (p=1.0) on MRI and atrial arrhythmias with left atrial dilatation. Features of VT episodes suggested various underlying arrhythmia mechanisms.Conclusions The overall prevalence of arrhythmias was low. Even in such a small sample size, higher arrhythmia counts occurred in those with larger scar burden and greater ventricular volume, suggesting key roles for myocardial stretch as well as disease progression in arrhythmogenesis. These features overlap with the stage of left ventricular dysfunction when heart failure also becomes overt. The findings of this pilot study should help inform the design of a definitive study of specific antiarrhythmic management in dystrophinopathy.Trial registration number ISRCTN15622536.

Significant inconsistencies in respiratory care provision for Duchenne muscular dystrophy (DMD) are reported across different specialist neuromuscular centres in the UK. The absence of robust clinical evidence and expert consensus is a barrier to the implementation of care recommendations in public healthcare systems as is the need to increase awareness of key aspects of care for those living with DMD. Here, we provide evidenced-based and/or consensus-based best practice for the respiratory care of children and adults living with DMD in the UK, both as part of routine care and in an emergency.MethodologyInitiated by an expert working group of UK-based respiratory physicians (including British Thoracic Society (BTS) representatives), neuromuscular clinicians, physiotherapist and patient representatives, draft guidelines were created based on published evidence, current practice and expert opinion. After wider consultation with UK respiratory teams and neuromuscular services, consensus was achieved on these best practice recommendations for respiratory care in DMD.ResultThe resulting recommendations are presented in the form of a flow chart for assessment and monitoring, with additional guidance and a separate chart setting out key considerations for emergency management. The recommendations have been endorsed by the BTS.ConclusionsThese guidelines provide practical, reasoned recommendations for all those managing day-to-day and acute respiratory care in children and adults with DMD. The hope is that this will support patients and healthcare professionals in accessing high standards of care across the UK.

BACKGROUND AND PURPOSE:The transition to adult services, and subsequent glucocorticoid management, is critical in adults with Duchenne muscular dystrophy. This study aims (1) to describe treatment, functional abilities, respiratory and cardiac status during transition to adulthood and adult stages; and (2) to explore the association between glucocorticoid treatment after loss of ambulation (LOA) and late-stage clinical outcomes. METHODS:This was a retrospective single-centre study on individuals with Duchenne muscular dystrophy (≥16 years old) between 1986 and 2022. Logistic regression, Cox proportional hazards models and survival analyses were conducted utilizing data from clinical records. RESULTS:In all, 112 individuals were included. Mean age was 23.4 ± 5.2 years and mean follow-up was 18.5 ± 5.5 years. At last assessment, 47.2% were on glucocorticoids; the mean dose of prednisone was 0.38 ± 0.13 mg/kg/day and of deflazacort 0.43 ± 0.16 mg/kg/day. At age 16 years, motor function limitations included using a manual wheelchair (89.7%), standing (87.9%), transferring from a wheelchair (86.2%) and turning in bed (53.4%); 77.5% had a peak cough flow <270 L/min, 53.3% a forced vital capacity percentage of predicted <50% and 40.3% a left ventricular ejection fraction <50%. Glucocorticoids after LOA reduced the risk and delayed the time to difficulties balancing in the wheelchair, loss of hand to mouth function, forced vital capacity percentage of predicted <30% and forced vital capacity <1 L and were associated with lower frequency of left ventricular ejection fraction <50%, without differences between prednisone and deflazacort. Glucocorticoid dose did not differ by functional, respiratory or cardiac status. CONCLUSION:Glucocorticoids after LOA preserve late-stage functional abilities, respiratory and cardiac function. It is suggested using functional abilities, respiratory and cardiac status at transition stages for adult services planning.

Atrial fibrillation (AF) was largely ignored by cardiac electrophysiologists until it was first suggested in 1998 that it might be amenable to catheter ablation. In the 25 years since then, a vast body of knowledge has emerged, initially reporting the "hypes and hopes" that ablation was appropriate for all but more recently acknowledging that not all patients benefit from this approach. The AF "epidemic" and more holistic understanding of the complex contributors to its development question whether it is even meaningful to consider AF a single condition that is always responsive to ablation management. In this issue, Masuda et al 11 provide novel insights into the electrophysiologic "footprints" that they found in the body of the left atrium of patients who underwent a second ablation procedure after achieving pulmonary vein isolation. In conclusion, the findings require prospective validation but may show a way of achieving antiarrhythmic success in a cohort of patients responding unpredictably to current ablation strategies.

BACKGROUND AND AIMS:Emery-Dreifuss muscular dystrophy (EDMD) is caused by variants in EMD (EDMD1) and LMNA (EDMD2). Cardiac conduction defects and atrial arrhythmia are common to both, but LMNA variants also cause end-stage heart failure (ESHF) and malignant ventricular arrhythmia (MVA). This study aimed to better characterize the cardiac complications of EMD variants. METHODS:Consecutively referred EMD variant-carriers were retrospectively recruited from 12 international cardiomyopathy units. MVA and ESHF incidences in male and female variant-carriers were determined. Male EMD variant-carriers with a cardiac phenotype at baseline (EMDCARDIAC) were compared with consecutively recruited male LMNA variant-carriers with a cardiac phenotype at baseline (LMNACARDIAC). RESULTS:Longitudinal follow-up data were available for 38 male and 21 female EMD variant-carriers [mean (SD) ages 33.4 (13.3) and 43.3 (16.8) years, respectively]. Nine (23.7%) males developed MVA and five (13.2%) developed ESHF during a median (inter-quartile range) follow-up of 65.0 (24.3-109.5) months. No female EMD variant-carrier had MVA or ESHF, but nine (42.8%) developed a cardiac phenotype at a median (inter-quartile range) age of 58.6 (53.2-60.4) years. Incidence rates for MVA were similar for EMDCARDIAC and LMNACARDIAC (4.8 and 6.6 per 100 person-years, respectively; log-rank P = .49). Incidence rates for ESHF were 2.4 and 5.9 per 100 person-years for EMDCARDIAC and LMNACARDIAC, respectively (log-rank P = .09). CONCLUSIONS:Male EMD variant-carriers have a risk of progressive heart failure and ventricular arrhythmias similar to that of male LMNA variant-carriers. Early implantable cardioverter defibrillator implantation and heart failure drug therapy should be considered in male EMD variant-carriers with cardiac disease.

IntroductionWe provide succinct, evidence- and/or consensus-based best practice guidance for the cardiac care of children living with Duchenne muscular dystrophy (DMD) as well as recommendations for screening and managing potential cardiac involvement in females with mutations in the DMD-gene.MethodsInitiated by an expert working group (WG) of UK-based cardiologists, neuromuscular clinicians and DMD-patient representatives, draft guidelines were created based on published evidence, current practice and expert opinion. After wider consultation with UK-cardiologists, consensus was reached on these best-practice recommendations for cardiac care in dystrophinopathy. As part of DMD Care UK, close links were established with other expert WGs (including respiratory and emergency) to ensure a coherent approach to multi-disciplinary care in this multi-systemic disease.ResultsThe resulting recommendations for cardiac care of all children with DMD are presented in the form of a succinct care-pathway flow chart with brief justification. They are also relevant for patients with Becker muscular dystrophy (BMD) and female carriers of mutations in the DMD-gene. The guidance also signposts the evidence on which the recommendations are based. Guidelines for cardiac care of patients with more advanced cardiac dystrophinopathy at any age have also been considered. The recommendations have been endorsed by the British Cardiovascular Society (BCS).ConclusionThese guidelines provide succinct, reasoned recommendations for all health care professionals managing paediatric dystrophinopathy patients with early or advanced stages of cardiomyopathy as well as females at risk of or with cardiac dystrophinopathy. The hope is that they will result in more uniform delivery of high standards of care for children with cardiac dystrophinopathy, so improving heart health into adulthood through timely earlier interventions across the UK. Link to full guidance: Open Heart 2022;9:e001977. doi:10.1136/ openhrt-2022-001977Conflict of InterestFunded by Duchenne UK

•DMD female carriers are a complex clinical and still neglected patient group.•Greater clinical and research focus on DMD female carriers is needed.•Minimum care standard for DMD female carriers should include genetic testing.•Preventive and therapeutic approaches can improve patient outcomes.•Patient registries are required for natural history studies and clinical trials.

AIMS:To define the prevalence of non-sustained tachyarrhythmias and bradyarrhythmias in patients with the m.3243A>G mitochondrial genotype and a previously defined, profile, associated with 'high sudden-death risk'. METHODS AND RESULTS:Patients at high risk of sudden death because of combinations of ventricular hypertrophy, mitochondrial encephalopathy, lactic acidosis and stroke-like episodes family phenotype, epilepsy or high mutation load, due to the m.3243A>G mutation, were identified from a mitochondrial cohort of 209 patients. All recruited had serial ECG and echo assessments previously according to schedule, had an ECG-loop recorder implanted and were followed for as long as the device allowed. Devices were programmed to detect non-sustained brady- or tachy-arrhythmias. This provided comprehensive rhythm surveillance and automatic downloads of all detections to a monitoring station for cardiology interpretation. Those with sinus tachycardia were treated with beta-blockers and those with ventricular hypertrophy received a beta-blocker and ACE-inhibitor combination.Nine consecutive patients, approached (37.2±3.9 years, seven males) and consented, were recruited. None died and no arrhythmias longer than 30s duration occurred during 3-year follow-up. Three patients reported palpitations but ECGs correlated with sinus rhythm. One manifest physiological, sinus pauses >3.5 s during sleep and another had one asymptomatic episode of non-sustained ventricular tachycardia. CONCLUSIONS:Despite 'high-risk' features for sudden death, those studied had negligible prevalence of arrhythmias over prolonged follow-up. By implication, the myocardium in this genotype is not primarily arrhythmogenic. Arrhythmias may not explain sudden death in patients without Wolff-Parkinson-White or abnormal atrioventricular conduction or, it must require a confluence of other, dynamic, proarrhythmic factors to trigger them.

During different steady state growth conditions in Escherichia coli the level of the three tRNA-modifying enzymes, the tRNA(m5Urd)-, tRNA(m1Guo)- and tRNA(mam5s2Urd)methyltransferase and of five aminoacyl-tRNA synthetases, the leucyl-, valyl-, isoleucyl-, arginyl- and threonyl-tRNA-synthetase, has been determined. It is shown that those two classes of tRNA affecting enzymes are not coordinately regulated and that even within these two groups of enzymes the constituents are regulated independently of each other. Furthermore it is demonstrated that none of the aminoacyl-tRNA synthetases and only one of the three tRNA-methyltransferases, the tRNA(m5Urd)methyltransferase, is under control of the relA+-gene.

ObjectiveWe provide succinct, evidence-based and/or consensus-based best practice guidance for the cardiac care of children living with Duchenne muscular dystrophy (DMD) as well as recommendations for screening and management of female carriers of mutations in theDMD-gene.MethodsInitiated by an expert working group of UK-based cardiologists, neuromuscular clinicians and DMD-patient representatives, draft guidelines were created based on published evidence, current practice and expert opinion. After wider consultation with UK-cardiologists, consensus was reached on these best-practice recommendations for cardiac care in DMD.ResultsThe resulting recommendations are presented in the form of a succinct care pathway flow chart with brief justification. The guidance signposts evidence on which they are based and acknowledges where there have been differences in opinion. Guidelines for cardiac care of patients with more advanced cardiac dystrophinopathy at any age have also been considered, based on the previous published work of Quinlivanet aland are presented here in a similar format. The recommendations have been endorsed by the British Cardiovascular Society.ConclusionThese guidelines provide succinct, reasoned recommendations for all those managing paediatric patients with early or advanced stages of cardiomyopathy as well as females with cardiac dystrophinopathy. The hope is that this will result in more uniform delivery of high standards of care for children with cardiac dystrophinopathy, so improving heart health into adulthood through timely earlier interventions across the UK.

Introduction/Aims The DMD Care Considerations Working Group Guidelines 2010 recommended treating cardiac dystrophinopathy with angiotensin-converting enzyme-inhibitor (ACEi) and beta-blocker (BB) therapy to prevent the progressive decline in left ventricular function expected from earlier, natural history studies. The aim of this research was to audit change in measures of left ventricular function over 8 years to 4 years before and 4 years after deploying an ACEi/BB combination systematically at a dedicated "cardiology-muscle" clinic. Methods This is an institutionally registered, retrospective, case-file-based audit of serial echocardiographic measures of left ventricular fractional shortening accumulated over the period 1995 to 2015. Results Data from 104 genetically confirmed Duchenne muscular dystrophy (DMD) patients, aged 22.2 +/- 5.3 years at data censure, were included. Mean age at first detection of left ventricular dysfunction was 15.1 +/- 4.2 years, but older in those on maintenance steroid therapy (16.8 +/- 4.2 vs 14.5 +/- 4.1 years; P = .04). Group mean fractional shortening fell by 1.5%/year over the 4 years before therapy, but this decreased to 0.9%/year over the first 4 years after starting therapy. Analysis of limited left ventricular ejection fraction measures showed similar but nonsignificant changes. Neither age at detection of left ventricular dysfunction nor fractional shortening percent at time of therapy initiation affected the beneficial response. Discussion The results support the international DMD recommendations of the time. This combination of cardiac medications helps stabilize heart function. For the best long-term effects, therapy needs to be initiated no later than on first detection left ventricular impairment.

Objective Regular cardiac surveillance is advocated for patients with primary mitochondrial DNA disease. However, there is limited information to guide clinical practice in mitochondrial conditions caused by nuclear DNA defects. We sought to determine the frequency and spectrum of cardiac abnormalities identified in adult mitochondrial disease originated from the nuclear genome.Methods Adult patients with a genetically confirmed mitochondrial disease were identified and followed up at the national clinical service for mitochondrial disease in Newcastle upon Tyne, UK (January 2009 to December 2018). Case notes, molecular genetics reports, laboratory data and cardiac investigations, including serial electrocardiograms and echocardiograms, were reviewed.Results In this cohort-based observational study, we included 146 adult patients (92 women) (mean age 53.6±18.7 years, 95% CI 50.6 to 56.7) with a mean follow-up duration of 7.9±5.1 years (95% CI 7.0 to 8.8). Eleven different nuclear genotypes were identified: TWNK, POLG, RRM2B, OPA1, GFER, YARS2, TYMP, ETFDH, SDHA, TRIT1 and AGK. Cardiac abnormalities were detected in 14 patients (9.6%). Seven of these patients (4.8%) had early-onset cardiac manifestations: hypertrophic cardiomyopathy required cardiac transplantation (AGK; n=2/2), left ventricular (LV) hypertrophy and bifascicular heart block (GFER; n=2/3) and mild LV dysfunction (GFER; n=1/3, YARS2; n=1/2, TWNK; n=1/41). The remaining seven patients had acquired heart disease most likely related to conventional cardiovascular risk factors and presented later in life (14.6±12.8 vs 55.1±8.9 years, p<0.0001).Conclusions Our findings demonstrate that the risk of cardiac involvement is genotype specific, suggesting that routine cardiac screening is not indicated for most adult patients with nuclear gene-related mitochondrial disease.

OBJECTIVE:To determine whether a combination of 2 heart medications would be tolerated and could prevent/delay the onset of cardiomyopathy in boys with Duchenne muscular dystrophy (DMD) compared with placebo. METHODS:This multicenter, parallel group, 1:1 patient randomized, placebo-controlled study of prophylactic perindopril and bisoprolol recruited boys with DMD aged 5-13 years, with normal ventricular function. Repeat assessments of left ventricular (LV) function, electrocardiogram, and adverse event reporting were performed 6 monthly. The primary outcome was change in ejection fraction between arms after 36 months. The study was approved by the National Research Ethics Service Committee East Midlands-Derby. RESULTS:Eighty-five boys were recruited (76% on steroid therapy) and randomized to combination heart drugs or matched placebo. Group change in left ventricular ejection fraction (LVEF%) at 36 months from baseline was -2.2% ± 6.0% and -2.9% ± 6.1% in active and placebo arms (adjusted mean difference: -2.1, 95% CI -5.2 to 1.1). There was no difference between treatment arms over repeated assessments (analysis of variance) up to 36 months (trial arms p = 0.53); arm-over-time (p = 0.44). Four participants on placebo but none on active therapy were withdrawn due to deteriorations in LV function. Secondary outcomes did not differ between arms either. Thirty-six serious adverse events occurred none due to cardiac events or trial medication. CONCLUSIONS:Combination therapy was well tolerated. Consistent with the previous prophylactic perindopril heart study, there was no evidence of group benefit after 36-month treatment. CLASSIFICATION OF EVIDENCE:This study provides Class I evidence that combination perindopril-bisoprolol therapy was well tolerated but did not change decline in LVEF significantly in boys with DMD.

To determine whether a combination of 2 heart medications would be tolerated and could prevent/delay the onset of cardiomyopathy in boys with Duchenne muscular dystrophy (DMD) compared with placebo.This multicenter, parallel group, 1:1 patient randomized, placebo-controlled study of prophylactic perindopril and bisoprolol recruited boys with DMD aged 5-13 years, with normal ventricular function. Repeat assessments of left ventricular (LV) function, electrocardiogram, and adverse event reporting were performed 6 monthly. The primary outcome was change in ejection fraction between arms after 36 months. The study was approved by the National Research Ethics Service Committee East Midlands-Derby.Eighty-five boys were recruited (76% on steroid therapy) and randomized to combination heart drugs or matched placebo. Group change in left ventricular ejection fraction (LVEF%) at 36 months from baseline was -2.2% ± 6.0% and -2.9% ± 6.1% in active and placebo arms (adjusted mean difference: -2.1, 95% CI -5.2 to 1.1). There was no difference between treatment arms over repeated assessments (analysis of variance) up to 36 months (trial arms p = 0.53); arm-over-time (p = 0.44). Four participants on placebo but none on active therapy were withdrawn due to deteriorations in LV function. Secondary outcomes did not differ between arms either. Thirty-six serious adverse events occurred none due to cardiac events or trial medication.Combination therapy was well tolerated. Consistent with the previous prophylactic perindopril heart study, there was no evidence of group benefit after 36-month treatment.This study provides Class I evidence that combination perindopril-bisoprolol therapy was well tolerated but did not change decline in LVEF significantly in boys with DMD.

ObjectiveUnlike for patients with other forms of cardiomyopathies, those with severe ventricular dysfunction due to Duchenne muscular dystrophy (DMD) are not offered implantable cardioverter-defibrillator (ICD) therapy routinely. This prospective study aimed to determine the views of DMD-patients and their carers about discussing sudden death risk and their acceptance of ICDs.Design and settingAdults with DMD (n=9) and parents/carers (n=9) participated in audio-recorded, 60–90 min focus group sessions (patients 2; parents/carers 2) conducted through either a face-to-face session at a neutral venue or a videoconference. Sessions were facilitated by a clinical psychologist, experienced in conducting focus group research. All participants understood the rationale for the study and the nature of ICD therapy. The same predefined themes were explored with each group. Recordings were transcribed, analysed thematically by two researchers, working independently and then agreed. Differences in responses between patient and carer groups were also studied and compared. Participants all provided informed written consent and the study had ethical approval.ResultsThree main themes emerged: (1) access to/quality of information provided by professionals and patient engagement with them; (2) decision-making about ICDs; (3) individuals’ own ‘lived experience’ of DMD.ConclusionsThe main findings were: (1) patients with DMD want to have their risk of sudden arrhythmic death discussed, when relevant and (2) if ICD therapy were established as beneficial, they would welcome an individualised discussion about its appropriateness for them.

•For families, there is no ‘pre-symptomatic’ phase once dystrophinopathy is diagnosed.•A care-coordinator facilitated, multi-specialty adult follow-up model is advocated.•Hearts of patients with DMD should be considered abnormal ‘from the start’.•Ventricular dysfunction is preceded by changes, detectable by cardiac MR-imaging.•A patient's phenotype and not genotype should guide clinical decision-making.

IntroductionAlthough cardiologists were ‘late-comers’ to the multidisciplinary team—contributing to the complex care of patients with Duchenne muscular dystrophy (DMD), they now recognise the importance of systematic cardiac surveillance and timely therapy to prolonged survival in patients with DMD. Empirical deployment of cardioactive medications has already improved outcomes, but the evidence base for clinical decision making is weak. Fundamental questions remain as to whether prophylactic therapy is justified and convincingly superior to prompt deployment of the same therapies once left ventricular (LV) dysfunction is detected. Even if it were, at what age should therapy be introduced and with what specific drugs?Methods and analysisWe are conducting a multicentre, parallel group, randomised, placebo-controlled study of combination therapy with an ACE inhibitor (perindopril) and a beta-blocker (bisoprolol) in boys with DMD aged 5–13 years, with normal LV function by echocardiographic criteria at the time of recruitment. Boys are being followed-up for a minimum of 3 years and a maximum of 5 years and undergo repeat assessments of LV function, heart rate and ECG, forced expiratory volume in the 1 s and forced vital capacity, adverse event reporting and quality of life at 6 monthly intervals.The primary outcome is change in LV function between active and placebo-treated participants over the course of the study.Ethics and disseminationThe study was approved by ‘NRES Committee East Midlands – Derby’. The results will be disseminated through manuscript publications, an international workshop and presentations to scientific meetings and parent forums.Translational aspectsThe study seeks to establish the evidence for prophylactic heart therapies for children with DMD, define the optimum age for their introduction and identify any safety concerns.Article summaryThe protocol describes the design of an ongoing multicentre, double-blind, randomised placebo-controlled study to establish the evidence for the use of prophylactic heart therapies in children with DMD, define the optimum age for their introduction and identify any safety concerns.Trial registration numbersEudraCT2007-005932-10 andISRCTN50395346; Pre-results.