Omar Chehab

Dr. Omar Chehab

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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8 August 2022 in JACC
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Journal Article
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OCOmar Chehab
Omar Chehab
RRRoss Roberts-Thomson
Ross Roberts-Thomson
ABAntonio Bivona
Antonio Bivona
HGHarminder Gill
Harminder Gill
TPTiffany Patterson
Tiffany Patterson
RRRonak Rajani
Ronak Rajani

13 February 2020 in Heart
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Journal Article
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OCOmar Chehab
Omar Chehab
RRRoss Roberts-Thomson
Ross Roberts-Thomson
CLClarissa Ng Yin Ling
Clarissa Ng Yin Ling
MMMichael Marber
Michael Marber
BPBernard Prendergast
Bernard Prendergast
SRSimon R Redwood
Simon R Redwood
Secondary mitral regurgitation (SMR) occurs as a result of multifactorial left atrioventricular dysfunction and maleficent remodelling. It is the most common and undertreated form of mitral regurgitation (MR) and is associated with a very poor prognosis. Whether SMR is a bystander reflecting the severity of the cardiomyopathy disease process has long been the subject of debate. Studies suggest that SMR is an independent driver of prognosis in patients with an intermediate heart failure (HF) phenotype and not those with advanced HF. There is also no universal agreement regarding the quantitative thresholds defining severe SMR and indeed there are challenges with echocardiographic quantification. Until recently, no surgical or transcatheter intervention for SMR had demonstrated prognostic benefit, in contrast with HF medical therapy and cardiac resynchronisation therapy. In 2018, the first two randomised controlled trials (RCTs) of edge-to-edge transcatheter mitral valve repair versus guideline-directed medical therapy in HF (Percutaneous Repair with the MitraClip Device for Severe (MITRA-FR), Transcather mitral valve repair in patients with heart failure (COAPT)) reported contrasting yet complimentary results. Unlike in MITRA-FR, COAPT demonstrated significant prognostic benefit, largely attributed to the selection of patients with disproportionately severe MR relative to their HF phenotype. Consequently, quantifying the degree of SMR in relation to left ventricular volume may be a useful discriminator in predicting the success of transcatheter intervention. The challenge going forward is the identification and validation of such parameters while in parallel maintaining a heart-team guided holistic approach.

8 July 2024 in JACC: Cardiovascular Interventions
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SLSebastian Ludwig
Sebastian Ludwig
BKBenedikt Koell
Benedikt Koell
JWJessica Weimann
Jessica Weimann
EDErwan Donal
Erwan Donal
DPDhairya Patel
Dhairya Patel
ACAugustin Coisne
Augustin Coisne

28 November 2024 in European Journal of Cardio-Thoracic Surgery
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Journal Article
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OCOmar Chehab
Omar Chehab
Edouard LongEdouard Long
Edouard Long
VAVitaliy Androshchuk
Vitaliy Androshchuk
HGHarminder Gill
Harminder Gill
VAVassilios Avlonitis
Vassilios Avlonitis
RRRonak Rajani
Ronak Rajani
OBJECTIVES: Right ventricular-to-pulmonary artery coupling has been associated with outcomes in mitral regurgitation treated by transcatheter approaches. We evaluated right ventricular-to-pulmonary artery coupling as a predictor of survival and postoperative length of hospital stay (LOS) in patients with mitral regurgitation undergoing mitral valve surgery. METHODS: In this retrospective analysis (median follow-up: 5.8 years), right ventricular-to-pulmonary artery coupling was quantified as the ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) using transthoracic echocardiography. Receiver operating characteristic curve analysis was used to determine the optimum cut-point of TAPSE/PASP to predict all-cause mortality, and the study population was dichotomized according to this value. The primary end point was all-cause mortality. A secondary end point of LOS was also assessed. RESULTS: Out of 142 patients (median age: 67, female: 49%), 35 showed impaired coupling at baseline (TAPSE/PASP ≤0.35). Patients with TAPSE/PASP ≤0.35 had higher absolute mortality (37% vs 8%, P < 0.001) and longer LOS (7 days vs 9 days, P = 0.04). Kaplan–Meier analysis revealed lower survival in patients with TAPSE/PASP ≤0.35 (log-rank: P < 0.0001). In multivariable Cox regression, TAPSE/PASP ≤0.35 was the most significant predictor of all-cause mortality (hazard ratio: 3.69, 95% confidence interval 1.31–10.1, P = 0.011), alongside chronic obstructive pulmonary disease and estimated glomerular filtration rate. TAPSE/PASP ≤0.35 was associated with significantly increased LOS (β: 4.6, 95% confidence interval 0.66–8.5, P = 0.022) alongside left ventricular ejection fraction, mitral valve replacement and urgent operation. CONCLUSIONS: In mitral regurgitation patients undergoing mitral valve surgery, TAPSE/PASP ≤0.35 is associated with increased mortality and LOS. Further validation is indicated in larger, prospective cohorts.

Verified
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OCOmar Chehab
Omar Chehab
GEGiulia Esposito
Giulia Esposito
Edouard LongEdouard Long
Edouard Long
CLClarissa Ng Yin Ling
Clarissa Ng Yin Ling
SHSamuel Hale
Samuel Hale
MMMichael Mullen
Michael Mullen
Background/Objectives: Contrast-induced acute kidney injury (AKI) is associated with early mortality and adverse events. However, in the setting of transcatheter aortic valve implantation (TAVI), previous literature has failed to establish a correlation between the absolute volume of contrast media administered and mortality. We aimed to investigate the impact of contrast volume administered normalised to estimated glomerular filtration rate (CV/eGFR) on the development of AKI and on 30-day all-cause mortality in TAVI patients. Methods: We retrospectively analysed a cohort of 1150 patients who underwent TAVI at our unit between 2015 and 2018. Results: Follow-up was complete for 1064 patients. There were 23 deaths within the follow-up period and 76 cases of AKI, 9 of which required new renal replacement therapy (RRT). Receiver-operating characteristic (ROC) curve analysis showed fair discrimination for 30-day all-cause mortality at a CV/eGFR ratio of 3.6 (area under the ROC curve (AUC) 0.671). Of patients in whom CV data were available, 86.0% (n = 757) had a CV/eGFR < 3.6 and 14.0% (n = 123) had a CV/eGFR ≥ 3.6. In multivariate logistic regression analysis, CV/eGFR ≥ 3.6 was the strongest predictor of 30-day all-cause mortality (odds ratio 5.06, 95% confidence interval [1.61–15.7], p = 0.004). Other independent predictors were procedural urgency (3.28 [1.04–10.3], p = 0.038) and being under general anaesthesia (4.81 [1.10–17.3], p = 0.023). CV/eGFR ≥ 3.6 was also independently associated with significantly increased odds of AKI (2.28 [1.20–4.17], p = 0.009) alongside significant non-left main stem coronary artery disease (2.56 [1.45–4.66], p = 0.001), and diabetes (1.82 [1.03–3.19], p = 0.037). In supplementary ROC curve analysis, a similar CV/eGFR cut point of 3.6 was found to be an excellent predictor for new RRT (AUC 0.833). Conclusions: In conclusion, a CV/eGFR ≥ 3.6 post-TAVI was found to be a strong predictor of 30-day mortality and AKI. The maximum contrast volume that can be safely administered in each patient without significantly increasing the risk of mortality and AKI can be calculated using this ratio.

28 April 2025 in Journal of Clinical Medicine
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Journal Article
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Edouard LongEdouard Long
Edouard Long
OCOmar Chehab
Omar Chehab
TRTanisha Rajah
Tanisha Rajah
RDRoberta Dunn
Roberta Dunn
VAVitaliy Androshchuk
Vitaliy Androshchuk
RRRonak Rajani
Ronak Rajani
Background/Objectives: Sex-related differences in the presentation and outcomes of patients with mitral regurgitation (MR) undergoing mitral valve (MV) surgery remain unclear. We aimed to identify these differences to inform personalized management. Methods: A total of 143 consecutive patients undergoing surgery for MR between 2017 and 2018 were stratified by sex and assessed for differences in characteristics. We performed 1:1 propensity score matching (PSM) by sex, with baseline characteristics as covariates, yielding 38 comparable pairs which were analyzed for differences in all-cause mortality and post-operative length of stay (LOS). Results: Females (n = 67) were more symptomatic (NYHA Class ≥ 3: 73% vs. 45%, p < 0.001), had higher logistic EuroSCORE (5.5 vs. 3.9, p = 0.006), had more urgent operations (25% vs. 11%, p = 0.020), MV replacements (28% vs. 11%, p = 0.007), and secondary MR (43% vs. 16%, p < 0.001). Females had significantly smaller end-diastolic and end-systolic left ventricular (LV) diameters, though indexed diameters showed no significant differences. After PSM, females had significantly longer LOS (7 days vs. 9 days, p = 0.033) and no differences in long-term mortality (hazard ratio [HR]: 1.25, 95% confidence interval [CI]: 0.34–4.76, p = 0.7, median follow-up: 6.67 years). An indexed LV end-systolic diameter (LVESDi) > 19 mm/m2 yielded greater specificity (46.0% vs. 26.7%) and comparable sensitivity (69.4% vs. 69.2%) to LVESD > 40 mm. In subgroup analyses, female patients undergoing concomitant tricuspid intervention (HR: 6.80 [1.63–37.92], p < 0.01) or urgent operation (HR: 4.85 [1.08–21.06], p = 0.04) had worse prognoses than males. Conclusions: Females undergoing MV surgery for MR had more symptoms, higher surgical risk, and longer LOS, but similar mortality compared to males. However, concomitant tricuspid intervention and urgent operations were associated with higher mortality. Our results add to the growing body of evidence that current non-indexed LV diameter thresholds may not adequately account for sex differences.