Mikael Laredo

Dr. Mikael Laredo

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 April 2023 in European Heart Journal
Verified
Journal Article
Open access
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RTRoland Richard Tilz
Roland Richard Tilz
VSVanessa Schmidt
Vanessa Schmidt
HPHelmut Pürerfellner
Helmut Pürerfellner
PMPhilippe Maury
Philippe Maury
KCK R J Ulian Chun
K R J Ulian Chun
Christian-H HeegerChristian-H Heeger
Christian-H Heeger
Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management, and outcome are sparse. This international multicentre registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553 729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed, at 214 centres in 35 countries. In 78 centres 138 patients [0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (P < 0.0001)] were diagnosed with an oesophageal fistula. Peri-procedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0–60) days and 21 (15, 29.5; range: 2–63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0–42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8% and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) [odds ratio 7.463 (2.414, 23.072) P < 0.001]. Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high. Summary of the POTTER-AF study results. CI, confidence interval; OR, odds ratio.

17 September 2024 in European Heart Journal
Verified
Journal Article
Open access
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AGAlessio Gasperetti
Alessio Gasperetti
RCRichard T Carrick
Richard T Carrick
APAlexandros Protonotarios
Alexandros Protonotarios
BMBrittney Murray
Brittney Murray
MLMikael Laredo
Mikael Laredo
CJCynthia A James
Cynthia A James
Pathogenic variants in the desmoplakin (DSP) gene are associated with the development of a distinct arrhythmogenic cardiomyopathy phenotype not fully captured by either dilated cardiomyopathy (DCM), non-dilated left ventricular cardiomyopathy (NDLVC), or arrhythmogenic right ventricular cardiomyopathy (ARVC). Prior studies have described baseline DSP cardiomyopathy genetic, inflammatory, and structural characteristics. However, cohort sizes have limited full clinical characterization and identification of clinical and demographic predictors of sustained ventricular arrhythmias (VAs), heart failure (HF) hospitalizations, and transplant/death. In particular, the relevance of acute myocarditis-like episodes for subsequent disease course is largely unknown. All patients with pathogenic/likely pathogenic (P/LP) DSP variants in the worldwide DSP-ERADOS Network (26 academic institutions across nine countries) were included. The primary outcomes were the development of sustained VA and HF hospitalizations during follow-up. Fine–Gray regressions were used to test association between clinical and instrumental parameters and the development of outcomes. Eight hundred patients [40.3 ± 17.5 years, 47.5% probands, left ventricular ejection fraction (LVEF) 49.5 ± 13.9%] were included. Over 3.7 [1.4–7.1] years, 139 (17.4%, 3.9%/year) and 72 (9.0%, 1.8%/year) patients experienced sustained VA and HF episodes, respectively. A total of 32.5% of individuals did not fulfil diagnostic criteria for ARVC, DCM, or NDLVC; their VA incidence was 0.5%/year. In multivariable regression, risk features associated with the development of VA were female sex [adjusted hazard ratio (aHR) 1.547; P = .025], prior non-sustained ventricular tachycardia (aHR 1.721; P = .009), prior sustained VA (aHR 1.923; P = .006), and LVEF ≤ 50% (aHR: 1.645; P = .032), while for HF, they were the presence of T-wave inversion in 3+ electrocardiogram leads (aHR 2.036, P = .007) and LVEF ≤ 50% (aHR 3.879; P < .001). Additionally, 70 (8.8%) patients experienced a myocardial injury episode at presentation or during follow-up. These episodes were associated with an increased risk of VA and HF thereafter (HR 2.394; P < .001, and HR 5.064, P < .001, respectively). Patients with P/LP DSP variants experience high rates of sustained VA and HF hospitalizations. These patients demonstrate a distinct clinical phenotype (DSP cardiomyopathy), whose most prominent risk features associated with adverse clinical outcomes are the presence of prior non-sustained ventricular tachycardia or sustained VA, T-wave inversion in 3+ leads on electrocardiogram, LVEF ≤ 50%, and myocardial injury events. Graphical summary reporting the main findings of the study. Features associated with risk of events include predictors from multivariable models as well as analysis of implications of myocardial injury episodes. aHR, adjusted hazard ratio; ARVC, arrhythmogenic right ventricular cardiomyopathy; DCM, dilated cardiomyopathy; HF, heart failure; HR, hazard ratio; LVEF, left ventricular ejection fraction; NDLVC, non-dilated left ventricular cardiomyopathy; (N)SVT, (non)sustained ventricular tachycardia; PVC, premature ventricular contraction; TFC, 2010 Task Force Criteria; TWI, T-wave inversion; VA, ventricular arrhythmia. Created with BioRender.com.

16 July 2024 in European Heart Journal
Verified
Journal Article
Open access
PDF file
RCRichard T Carrick
Richard T Carrick
AGAlessio Gasperetti
Alessio Gasperetti
APAlexandros Protonotarios
Alexandros Protonotarios
BMBrittney Murray
Brittney Murray
MLMikael Laredo
Mikael Laredo
CJCynthia A James
Cynthia A James
Pathogenic desmoplakin (DSP) gene variants are associated with the development of a distinct form of arrhythmogenic cardiomyopathy known as DSP cardiomyopathy. Patients harbouring these variants are at high risk for sustained ventricular arrhythmia (VA), but existing tools for individualized arrhythmic risk assessment have proven unreliable in this population. Patients from the multi-national DSP-ERADOS (Desmoplakin SPecific Effort for a RAre Disease Outcome Study) Network patient registry who had pathogenic or likely pathogenic DSP variants and no sustained VA prior to enrolment were followed longitudinally for the development of first sustained VA event. Clinically guided, step-wise Cox regression analysis was used to develop a novel clinical tool predicting the development of incident VA. Model performance was assessed by c-statistic in both the model development cohort (n = 385) and in an external validation cohort (n = 86). In total, 471 DSP patients [mean age 37.8 years, 65.6% women, 38.6% probands, 26% with left ventricular ejection fraction (LVEF) < 50%] were followed for a median of 4.0 (interquartile range: 1.6–7.3) years; 71 experienced first sustained VA events {2.6% [95% confidence interval (CI): 2.0, 3.5] events/year}. Within the development cohort, five readily available clinical parameters were identified as independent predictors of VA and included in a novel DSP risk score: female sex [hazard ratio (HR) 1.9 (95% CI: 1.1–3.4)], history of non-sustained ventricular tachycardia [HR 1.7 (95% CI: 1.1–2.8)], natural logarithm of 24-h premature ventricular contraction burden [HR 1.3 (95% CI: 1.1–1.4)], LVEF < 50% [HR 1.5 (95% CI: .95–2.5)], and presence of moderate to severe right ventricular systolic dysfunction [HR 6.0 (95% CI: 2.9–12.5)]. The model demonstrated good risk discrimination within both the development [c-statistic .782 (95% CI: .77–.80)] and external validation [c-statistic .791 (95% CI: .75–.83)] cohorts. The negative predictive value for DSP patients in the external validation cohort deemed to be at low risk for VA (<5% at 5 years; n = 26) was 100%. The DSP risk score is a novel model that leverages readily available clinical parameters to provide individualized VA risk assessment for DSP patients. This tool may help guide decision-making for primary prevention implantable cardioverter-defibrillator placement in this high-risk population and supports a gene-first risk stratification approach. The desmoplakin risk score provides individualized predictions of 5-year ventricular arrhythmia risk in patients with pathogenic/likely pathogenic (P/LP) desmoplakin variants based on five readily available clinical risk factors (www.dsp-risk.com). The desmoplakin risk score demonstrated strong discrimination of ventricular arrhythmia risk (c-statistic .79 during external validation) and accurately stratifies patients into low- (0%–5% risk at 5 years), intermediate- (5%–20% risk at 5 years), and high-risk (>20% risk at 5 years) groups for the purposes of guiding primary prevention implantable cardiac defibrillator decision-making. DSP, desmoplakin; LVEF, left ventricular ejection fraction; NSVT, non-sustained ventricular tachycardia; PVC, premature ventricular contraction; RV, right ventricular; VA, ventricular arrhythmia.

1 November 2018 in Canadian Journal of Cardiology
Verified
Journal Article
Closed access
MLMikael Laredo
Mikael Laredo
VWVictor Waldmann
Victor Waldmann
PKPaul Khairy
Paul Khairy
SNStanley Nattel
Stanley Nattel

27 October 2020 in Circulation
Verified
Journal Article
Closed access
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VWVictor Waldmann
Victor Waldmann
ABAbdeslam Bouzeman
Abdeslam Bouzeman
GDGuillaume Duthoit
Guillaume Duthoit
LKLinda Koutbi
Linda Koutbi
FBFrancis Bessiere
Francis Bessiere
MHMélèze Hocini
Mélèze Hocini
Background: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. Methods: A Nationwide French Registry including all patients with tetralogy of Fallot with an ICD was initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event end point was the time from ICD implantation to first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. Results: A total of 165 patients (mean age, 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (interquartile range) follow-up of 6.8 (2.5–11.4) years, 78 (47.3%) patients received at least 1 appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively; P =0.03). Overall, 71 (43.0%) patients presented with at least 1 ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) patients in primary prevention, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with, respectively, 0, 1, 2, or ≥3 guidelines-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (hazard ratio, 3.47 [95% CI, 1.19–10.11]), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 ( P =0.006). Patients with congestive heart failure or reduced left ventricular ejection fraction had a higher risk of nonarrhythmic death or heart transplantation (hazard ratio, 11.01 [95% CI, 2.96–40.95]). Conclusions: Patients with tetralogy of Fallot and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03837574.

1 July 2019 in International Journal of Cardiology
Verified
Journal Article
Closed access
VWVictor Waldmann
Victor Waldmann
MLMikael Laredo
Mikael Laredo
SASylvia Abadir
Sylvia Abadir
BMBlandine Mondésert
Blandine Mondésert
PKPaul Khairy
Paul Khairy