Personne : Girerd, Nicolas
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Girerd
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Nicolas
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Université Laval. Faculté de médecine
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Publication Accès libre Impact de la sévérité de la sténose aortique et de son interaction avec la disproportion patient-prothèse sur la mortalité opératoire suivant le remplacement valvulaire aortique(2010) Girerd, Nicolas; Pibarot, PhilippeLa sténose aortique est une pathologie très fréquente. Selon les recommandations actuelles, les indications de remplacement valvulaire aortique en présence d'une sténose sévère reposent sur l'apparition de symptômes et/ou l'altération de fonction ventriculaire gauche. La mesure de la fonction ventriculaire gauche repose classiquement sur la mesure de la fraction d'éjection. Cependant, dans le contexte d'une sténose aortique, cet outil semble inadapté. Une façon indirecte d'évaluer la fonction ventriculaire pourrait être de se baser sur le degré de sévérité de la sténose. Plusieurs études ont en effet montré que la sévérité de la sténose aortique est intimement corrélée à l'altération de paramètres fins de fonction systolique du ventricule gauche mesurés par 1' étude echocardiographique de la déformation myocardique. Une altération de la fraction d'éjection est universellement reconnue comme étant associée à une augmentation de la mortalité opératoire après une chirurgie cardiaque incluant le remplacement valvulaire aortique. Par définition, la grande majorité des patients subissant un remplacement valvulaire ont une sténose sévère telle que définie par une aire de l'orifice valvulaire aortique <1.0 cm2. Cependant, il demeure une variabilité inter-individuelle importante au sein de cette plage de sévérité, i.e. de « légèrement » sévère à très sévère. De façon surprenante, l'impact de la sévérité de la sténose sur la mortalité opératoire après un remplacement valvulaire aortique est inconnu. Notre objectif principal était donc d'étudier si la sévérité de la sténose était associée, de façon indépendante, à une augmentation de la mortalité opératoire. Les recommandations américaines considèrent que les patients n'ayant ni symptômes, ni altération de leur fraction d'éjection ne devraient pas bénéficier d'un remplacement valvulaire aortique à moins qu'ils n'aient une sténose aortique très sévère (<0.6 cm2) et un risque opératoire très bas (<1%). Cette recommandation ne repose pas sur des données scientifiques spécifiques. Comme la sévérité de la sténose aortique est associée, entre autres, à des altérations de la géométrie et de la fonction ventriculaire qui pourraient obscurcir le pronostic postopératoire, nous avons essayé de quantifier la contribution indépendante de la sévérité de la sténose à la mortalité opératoire. Nous avons trouvé que la sévérité de la sténose aortique est associée à une augmentation indépendante de la mortalité opératoire. Dans les modèles prédictifs que nous avons construits, la mortalité opératoire est supérieure à 1% chez les patients ayant une sténose aortique très sévère, indépendamment de la présence de co-morbidités. Nos résultats enjoignent à une chirurgie de remplacement valvulaire plus précoce chez les patients atteints de sténose aortique afin d'éviter une augmentation de la mortalité opératoire.Publication Restreint Rate, timing, correlates, and outcomes of hemodynamic valve deterioration after bioprosthetic surgical aortic valve replacement(American Heart Association, 2018-08-13) Mahjoub, Haïfa; Rodés-Cabau, Josep; Kalavrouziotis, Dimitri; Voisine, Pierre; Mohammadi, Siamak; Côté, Nancy; Yanagawa, Bobby; Girerd, Nicolas; Pibarot, Philippe; Juni, Peter; Clavel, Marie-Annick; Verma, Subodh; Puri, Rishi; Dagenais, François; Mathieu, Patrick; Salaun, ErwanBackground: The incidence of structural valve deterioration after bioprosthesis (BP) aortic valve replacement (AVR) established on the basis of reoperation may substantially underestimate the true incidence. The objective is to determine the rate, timing, correlates, and association between hemodynamic valve deterioration (HVD) and outcomes assessed by Doppler echocardiography after surgical BP AVR. Methods: A total of 1387 patients (62.2% male, 70.5±7.8 years of age) who underwent BP AVR were included in this retrospective study. Baseline echocardiography was performed at a median time of 4.1 (1.3–6.5) months after AVR. All patients had an echocardiographic follow-up ≥2 years after AVR (926 at least 5 years and 385 at least 10 years). HVD was defined by Doppler assessment as a ≥10 mm Hg increase in mean gradient or worsening of transprosthetic regurgitation ≥1/3 class. HVD was classified according to the timing after AVR: “very early,” during the first 2-years; “early,” between 2 and 5 years; “midterm,” between 5 and 10 years; and “long-term,” >10 years. Results: A total of 428 patients (30.9%) developed HVD. Among these patients, 52 (12.0%) were classified as “very early,” 129 (30.1%) as “early,” 158 (36.9%) as “midterm,” and 89 (20.8%) as “long-term” HVD. Factors independently associated with HVD occurring within the first 5 years after AVR were diabetes mellitus (P=0.01), active smoking (P=0.01), renal insufficiency (P=0.01), baseline postoperative mean gradient ≥15 mm Hg (P=0.04) or transprosthetic regurgitation ≥mild (P=0.04), and type of BP (stented versus stentless, P=0.003). Factors associated with HVD occurring after the fifth year after AVR were female sex (P=0.03), warfarin use (P=0.007), and BP type (P<0.001). HVD was independently associated with mortality (hazard ratio, 2.18; 95% CI, 1.86–2.57; P<0.001). Conclusions: HVD as identified by Doppler echocardiography occurred in one third of patients and was associated with a 2.2-fold higher adjusted mortality. Diabetes mellitus and renal insufficiency were associated with early HVD, whereas female sex, warfarin use, and stented BPs (versus stentless) were associated with late HVD.Publication Accès libre Predictors of atrial fibrillation following coronary artery bypass surgery : increased waist circumference rather than increased body mass index?(International Scientific Information, 2011-02-25) Girerd, Nicolas; Pibarot, Philippe; Mathieu, PatrickPublication Accès libre Postoperative atrial fibrillation predicts long-term survival after aortic-valve surgery but not after mitral-valve surgery : a retrospective study.(BMJ Publishing, 2011-10-27) Magne, Julien; Voisine, Pierre; Girerd, Nicolas; Pibarot, Philippe; Dagenais, François; Mathieu, PatrickBackground: Postoperative atrial fibrillation (POAF) has been reported to be associated with reduced long-term survival after isolated coronary artery bypass grafting surgery. The objective of this study was to determine the impact of POAF on long-term survival after valvular surgery. Methods: The authors retrospectively analysed the preoperative and operative data of 2986 consecutive patients with no preoperative history of atrial fibrillation undergoing first valvular surgery (aortic-valve replacement (AVR), mitral valve replacement or mitral valve repair (MVR/MVRp) with or without coronary artery bypass grafting surgery) in their institution between 1995 and 2008 (median follow-up 5.31 years, range 0.1-15.0). The authors investigated the impact of POAF on survival using multivariable Cox regression. Results: Patients with POAF were older, and were more likely to have hypertension or renal failure when compared with patients without POAF. The 12-year survival in patients with POAF was 45.7±2.8% versus 61.4±2.1% in patients without POAF (p<0.001). On a multivariable analysis, when adjusting for age and other potential confounding factors, POAF tended to be associated with lower long-term survival (HR for all-cause death (HR)=1.17, 95% CI 1.00 to 1.38, p=0.051). The authors also analysed this association separately in patients with AVR and those with MVR/MVRp. In the multivariable analysis, POAF was a significant predictor of higher long-term mortality in patients with AVR (HR=1.22, CI 1.02 to 1.45, p=0.03) but not in patients with MVR/MVRp (HR=0.87, CI 0.58 to 1.29, p=0.48). Conclusions: POAF is significantly associated with long-term mortality following AVR but not after MVR/MVRp. The underlying factors involved in the pathogenesis of POAF after MVR/MVRp may partially account for the lack of association between POAF and survival in these patients.Publication Restreint The impact of complete revascularization on long-term survival is strongly dependent on age(Little, Brown & Co., 2012-11-01) Charbonneau, Éric; Dumont, Éric; Magne, Julien; Baillot, Richard; Voisine, Pierre; Mohammadi, Siamak; Doyle, Daniel; Girerd, Nicolas; Pibarot, Philippe; Dagenais, François; Rabilloud, Muriel; Mathieu, PatrickBACKGROUND: Complete revascularization during coronary artery bypass grafting (CABG) has been reported to be associated with better short-term and long-term outcomes. We hypothesized that the survival benefit of complete revascularization would be less in old patients than in young patients. METHODS: We analyzed data from 6,539 consecutive patients who had undergone a first isolated on-pump CABG procedure between 2000 and 2008. We investigated the impact of complete revascularization and its interaction with age on operative and long-term survival using propensity-score-based analyses. RESULTS: Patients with incomplete (versus complete) revascularization (n=318 [4.9%]) were sicker overall. During a mean follow-up of 5.8±2.2 years, 909 patients died. In the propensity-score-matched analysis, operative mortality was not significantly different between patients with complete revascularization and those with incomplete revascularization (1.9% versus 2.8%; odds ratio [OR], 1.46; 95% confidence interval [CI], 0.56-3.46; p=0.48). In contrast, incomplete revascularization had an independent negative impact on long-term survival, which was strongly age dependent (hazard ratio [HR] for interaction, 0.96 per year increment; p=0.02). In a propensity-score-matched analysis, incomplete revascularization was independently associated with higher long-term mortality in patients younger than 60 years (HR, 3.27; 95% CI, 1.21-8.86; p=0.02), whereas it was not in patients 60 to 70 years and 70 years of age and older (p=0.87 and p=0.24, respectively). CONCLUSIONS: Contrary to what is observed in patients younger than 60 years, complete revascularization does not seem to improve long-term survival in older patients. This suggests that elderly patients at high operative risk may be considered, when deemed clinically appropriate, for limited coronary revascularizationPublication Restreint Elevated proportion of small, dense low-density lipoprotein particles and lower adiponectin blood levels predict early structural valve degeneration of bioprostheses(S. Karger, 2012-02-25) Arsenault, Benoit; Shetty, Rahul; Côté, Nancy; Girerd, Nicolas; Pibarot, Philippe; Després, Jean-Pierre; Mathieu, PatrickOBJECTIVES: Long-term durability of bioprosthetic heart valves (BPs) are limited by structural valve degeneration (SVD) leading to stenosis and/or regurgitation. In this study, we sought to determine the metabolic markers associated with SVD. METHODS: In a cohort of 220 patients with an aortic BP (mean follow-up of 2.5 ± 1.2 years), we compared the metabolic and blood lipid profile including the levels of adiponectin and the proportion of small, dense low-density lipoprotein (LDL) particles (%LDL(<)(255Å)) in individuals developing echocardiographic evidence of early BP hemodynamic dysfunction with subjects having no features of BP dysfunction. RESULTS: Patients developing BP dysfunction (n = 69; 31.3%) had a tendency of higher triglyceride levels. Moreover, patients with BP dysfunction had an increased proportion of %LDL(<)(255Å). In multivariate linear regression analysis, after adjustment for age, gender, BP size and hypertension, the %LDL(<)(255Å) (p = 0.04) was significantly associated with BP dysfunction. In addition, patients with an elevated level of %LDL(<)(255Å) along with a decreased plasma adiponectin level were at a very high risk of developing early BP hemodynamic dysfunction (OR = 2.54, p = 0.04). CONCLUSION: BP dysfunction is significantly associated with an increased proportion of small, dense LDL.Publication Restreint Middle-aged men with increased waist circumference and elevated C-reactive protein level are at higher risk for postoperative atrial fibrillation following coronary artery bypass grafting surgery(European Society of Cardiology, 2009-03-27) Fournier, Dominique; Voisine, Pierre; Daleau, Pascal; Girerd, Nicolas; Pibarot, Philippe; Després, Jean-Pierre; Mathieu, Patrick; O'Hara, GillesIntroduction: We recently demonstrated that metabolic syndrome (MetS) is an independent risk factor for postoperative atrial fibrillation (POAF) following coronary artery bypass grafting (CABG). In the present work, we sought to determine which feature of the MetS is associated with POAF. Methods and results: We retrospectively analysed the association between metabolic features and the incidence of new-onset POAF in a total of 2214 male patients <65 years who underwent first isolated CABG. Anthropometric data including waist circumference (WC) and complete preoperative lipid profile were available. We also conducted a nested case–control substudy including 147 patients who developed POAF, and were matched for age with a control population. In these patients, C-reactive protein, interleukin-6 (IL-6), and thiobarbituric acid-reactive substances (TBARS; evaluating the oxidative stress) blood levels were determined. In the whole cohort, 19.6% of patients developed POAF. On univariate analysis, body mass index (BMI; P = 0.002) and WC (P = 0.001) were the only anthropometric variables significantly associated with increased incidence of POAF. In the multivariable logistic model, the only independent predictors of POAF were a WC > 102 cm [odds ratio (OR) = 1.40, P = 0.04)] and older age (OR = 1.08, P < 0.001). In the nested case–control substudy C-reactive protein, IL-6, and TBARS levels were not significantly different in patients with or without POAF. Of particular significance, patients with elevated WC > 102 cm and C-reactive protein > 1.5 mg/L or IL-6 >2.2 pg/mL were at a high risk of developing POAF (respectively, OR = 2.32, P = 0.02 and OR = 2.27, P = 0.03). Conclusion: Patients with increased WC combined with elevated C-reactive protein levels are at higher risk for POAF. Thus, interventions targeting inflammation related to visceral obesity might help reducing the incidence of POAF.Publication Accès libre Quantification of treatment effect modification on both an additive and multiplicative scale(Public Library of Science, 2016-04-05) Girerd, Nicolas; Pibarot, Philippe; Rabilloud, Muriel; Mathieu, Patrick; Roy, PascalBackground: In both observational and randomized studies, associations with overall survival are by and large assessed on a multiplicative scale using the Cox model. However, clinicians and clinical researchers have an ardent interest in assessing absolute benefit associated with treatments. In older patients, some studies have reported lower relative treatment effect, which might translate into similar or even greater absolute treatment effect given their high baseline hazard for clinical events. Methods: The effect of treatment and the effect modification of treatment were respectively assessed using a multiplicative and an additive hazard model in an analysis adjusted for propensity score in the context of coronary surgery. Results: The multiplicative model yielded a lower relative hazard reduction with bilateral internal thoracic artery grafting in older patients (Hazard ratio for interaction/year = 1.03, 95%CI: 1.00 to 1.06, p = 0.05) whereas the additive model reported a similar absolute hazard reduction with increasing age (Delta for interaction/year = 0.10, 95%CI: -0.27 to 0.46, p = 0.61). The number needed to treat derived from the propensity score-adjusted multiplicative model was remarkably similar at the end of the follow-up in patients aged < = 60 and in patients >70. Conclusions: The present example demonstrates that a lower treatment effect in older patients on a relative scale can conversely translate into a similar treatment effect on an additive scale due to large baseline hazard differences. Importantly, absolute risk reduction, either crude or adjusted, can be calculated from multiplicative survival models. We advocate for a wider use of the absolute scale, especially using additive hazard models, to assess treatment effect and treatment effect modification.Publication Restreint Mitral repair versus replacement for ischemic mitral regurgitation : comparison of short-term and long-term survival(American Heart Association, 2009-09-15) Sénéchal, Mario; Charbonneau, Éric; Magne, Julien; Voisine, Pierre; Girerd, Nicolas; Pibarot, Philippe; Dumesnil, Jean G.; Dagenais, François; Mathieu, PatrickBackground— When compared to mitral valve replacement (MVR), mitral valve repair (MVRp) is associated with better survival in patients with organic mitral regurgitation (MR). However, there is an important controversy about the type of surgical treatment that should be used in patients with ischemic MR. The objective of this study was to compare the postoperative outcome of MVRp versus MVR in patients with ischemic MR. Methods and Results— Preoperative and operative data of 370 patients with ischemic MR who underwent mitral valve surgery were prospectively collected and retrospectively analyzed. MVRp was performed in 50% of patients (n=186) and MVR in 50% (n=184). Although operative mortality was significantly lower after MVRp compared to MVR (9.7% versus 17.4%; P=0.03), overall 6-year survival was not statistically different between procedures (73±4% versus 67±4%; P=0.17). After adjusting for other risk factors and propensity score, the type of procedure (MVRp versus MVR) did not come out as an independent predictor of either operative (OR, 1.5; 95% CI, 0.7–2.9; P=0.34) or overall mortality (HR, 1.2; 95% CI, 0.7–1.9; P=0.52). Conclusion— As opposed to what has been reported in patients with organic MR, the results of this study suggest that MVRp is not superior to MVR with regard to operative and overall mortality in patients with ischemic MR. These findings provide support for the realization of a randomized trial comparing these 2 treatment modalities.Publication Restreint Moderate patient–prosthesis mismatch can impact on mortality after aortic valve replacement(BMJ, 2009-03-15) Magne, Julien; Girerd, Nicolas; Pibarot, Philippe; Dumesnil, Jean G.