[Safety and feasibility of conservative aortic valve surgery: single center experience]. / Segurança e Exequibilidade da Cirurgia Conservadora da Válvula Aórtica: Experiência de um Centro Cirúrgico Nacional.

BACKGROUND: In selected cases, aortic valve repair (RVAo) is an alternative to prostesic aortic valve replacement. AIM: To compare mid-term survival, need of reoperation and echocardiographic findings associated with RVAo. METHODS: Retrospective single-center cohort study including consecutive patients younger than 70 years-old, with non-stenotic aortic valve disease, who underwent RVAo between 2012 and 2017. A comparison was made with a group of patients who underwent mechanical aortic valve replacement (SVAo) in the same period. The groups were characterized and compared using Chi-Square and t-tests for independent samples and survival and reoperation were analyzed using Kaplan-Meier curves and Cox regressions. RESULTS: We included 72 patients submitted to RVAo. Mean follow-up time was 4 years, maximum 7. Although the mean age was relatively low (47±13 years), patients undergoing RVAo presented a lower prevalence of rheumatic etiology (3%). The cardiopulmonary bypass (148±74 minutes) and cross clamping aortic times (108±52 minutes) are the usual times for this type of surgery and similar to those of the comparing group (SVAo). In the echocardiographic follow-up (median of 3 months), we verified a left ventricular mass regression of 21% and a prevalence of aortic insufficiency of 4%. At 7 years, cumulative survival and freedom from reoperation of patients undergoing RVAo were 98.8% and 97.6%, respectively. CONCLUSION: RVAo can be a safe and effective alternative, with good mid-term results if patient selection is judicious.

Introdução: Em casos selecionados, a reparação da válvula aórtica (RVAo) constitui uma alternativa à substituição por prótese. Objetivo: Avaliar a sobrevida e necessidade de reoperação a médio prazo, bem como o resultado funcional após RVAo. Métodos: Estudo de coorte retrospetivo, unicêntrico incluindo consecutivamente doentes com idade ≤70 anos, submetidos a RVAo por doença da válvula aórtica não-estenótica, entre 2012-2017. Os resultados foram comparados com os obtidos após substituição valvular aórtica por prótese mecânica (SVAo) no mesmo período. Os grupos foram caracterizados e comparados utilizando testes Qui-Quadrado e t para amostras independentes e a sobrevida e reoperações foram analisadas através de curvas de Kaplan-Meier e regressões de Cox. Resultados: Foram incluídos 72 indivíduos submetidos a RVAo. O follow-up médio foi de 4 anos, máximo de 7. Apesar da idade média relativamente baixa à data da intervenção (47±13 anos), os doentes submetidos a RVAo apresentam uma baixa prevalência de etiologia reumática (3%). Os tempos de circulação extracorporal (148±74 minutos) e de clampagem aórtica (108±52 minutos) são os habituais para este tipo de cirurgias e semelhantes aos do grupo SVAo. Durante o seguimento ecocardiográfico (mediano de 3 meses) verificou-se uma regressão de massa do ventrículo esquerdo de 21% e uma prevalência de insuficiência aórtica de 4%. Aos 7 anos, a sobrevida cumulativa e a sobrevida livre de reoperação dos doentes submetidos a RVAo foram, respetivamente, 96,4% e 94,4%. Conclusões: Com uma seleção adequada dos doentes, a RVAo pode ser uma alternativa segura e efetiva, com bons resultados a médio prazo.

Mini-sternotomy versus full sternotomy aortic valve replacement: a single-centre experience.

BACKGROUND: full sternotomy (FS) is the gold standard approach to perform surgical aortic valve replacement (AVR). However, potential advantages of a less traumatic approach fomented the development of so-called minimally invasive procedures, which include upper mini-sternotomy (MS). OBJECTIVE: to compare immediate postoperative clinical results and mid-term mortality after AVR through MS and FS. METHODS: single-centre retrospective study including all patients who underwent isolated AVR through MS between January 1, 2011 and July 31, 2017. These were then matched with patients who underwent the same procedure through FS and by the same surgeons who performed MS, using coarsened exact matching for the variables age, gender, body mass index and diabetes mellitus. Groups were later characterized and compared regarding postoperative results using Qui- -squared and Mann-Whitney tests and regarding mid-term mortality through Kaplan-Meier curves. RESULTS: we included 82 patients (n=41 in each group). Aortic cross clamp [78 vs. 63 minutes, p=0.001] and cardiopulmonary bypass times [107 vs. 90 minutes, p=0.002] were significantly longer in the MS group vs. FS group, respectively. Although without reaching statistical significant difference, a smaller percentage of patients from the MS group required red blood cells transfusions during surgery (39.0% vs. 53.7%, p=0.184). Similar results were found regarding mechanical ventilation, inotropic support, morphine infusion, intensive care unit length of stay and incidence of de novo atrial fibrillation. Cumulative survival at 6 years was 86.7% after MS and 88.5% after FS (p=0.650). CONCLUSIONS: Aortic valve replacement through MS seems to be a safe alternative to the gold standard FS.

Introdução: a esternotomia completa (EC) é a abordagem gold standard da cirurgia de substituição valvular aórtica (SVA). Contudo, as potenciais vantagens de uma abordagem menos traumática promoveram o desenvolvimento de procedimentos minimamente invasivos, incluindo a mini-esternotomia (ME). Objetivo: comparar resultados clínicos no pós-operatório imediato e mortalidade, após SVA por ME e EC. Métodos: estudo retrospetivo unicêntrico incluindo todos os doentes submetidos a SVA isolada por ME, de 1 de janeiro de 2011 a 31 de julho de 2017, emparelhados com doentes submetidos ao mesmo procedimento, pelos mesmos cirurgiões por EC. Utilizou-se o método de emparelhamento coarsened exact matching para as variáveis idade, género, índice massa-corporal e diabetes mellitus. Os grupos foram caracterizados e comparados quanto aos resultados no pós-operatório imediato através de testes Qui-quadrado e Mann-Whitney e quanto à sobrevida através de curvas de Kaplan-Meier. Resultados: foram incluídos 82 doentes (n=41 em cada grupo). Os tempos de clampagem aórtica [78 vs. 63 minutos, p=0,001] e de circulação extracorporal [107 vs. 90 minutos, p=0.002] foram significativamente superiores no grupo ME vs. EC, respetivamente. Embora a frequência de transfusões sanguíneas durante a cirurgia fosse menor no grupo ME, essa diferença não foi estatisticamente significativa (39,0% vs. 53,7%, p=0,184). Os resultados foram semelhantes relativamente ao tempo de ventilação mecânica, suporte inotrópico, infusão de morfina, tempo de permanência em unidade de cuidados intensivos e incidência de fibrilação auricular de novo. A sobrevida cumulativa aos 6 anos foi de 86,7% após ME e 88,5% após EC (p=0,650). Conclusões: a SVA por ME parece ser uma alternativa segura comparativamente ao gold standard EC.

Survival After Bilateral Internal Mammary Artery In Coronary Artery Bypass Grafting: Are Women at Risk?

INTRODUCTION: To compare survival and safety of BIMA versus SIMA CABG between males and females at our tertiary care center. METHODS: Single-center retrospective cohort including consecutive patients with at least 2 left coronary system (LCS) vessel disease who underwent isolated CABG with at least 1 IMA conduit and a minimum of 2 conduits targeting the LCS between 2004 and 2013. All-cause mortality was the primary outcome, secondary outcomes were in-hospital mortality and reoperation due to sternal wound complications (SWC). Kaplan-Meier analysis after inverse probability weighting using propensity score (IPW) was used to compare BIMA and SIMA CABG amongst genders. Results were confirmed by subgroup analysis. RESULTS: BIMA CABG was performed in 39% out of 2424 eligible procedures and in 27% of 460 females. No differences were found in survival after BIMA and SIMA CABG (median and maximum follow-up of 5.5 and 12 years, respectively) but a statistical interaction was observed with gender (P<0.001). Females who underwent BIMA CABG showed higher mortality (weighted HR in females subset: 3.16; 95%CI: 1.56-6.29, P=0.001). BIMA CABG showed a higher incidence of reoperations due to SWC (IPW adjusted model OR: 1.74; 95% CI: 1.16-2.60) that were mostly ascribable to males (weighted OR in males: 3.10; 95%CI: 1.74-5.51, P<0.001). CONCLUSION: Females may experience higher mortality after BIMA CABG which should be further explored.

Freedom Solo Versus Trifecta Bioprotheses: Clinical and Hemodynamic Evaluation after Propensity Score Matching.

INTRODUCTION: To compare stentless Freedom Solo and stented Trifecta aortic bioprostheses regarding hemodynamic profile, left ventricular mass regression, early and late postoperative outcomes and survival. METHODS: Longitudinal cohort study of consecutive patients undergoing aortic valve replacement (from 2009 to 2016) with either Freedom Solo or Trifecta at one centre. Local databases and national records were queried. Postoperative echocardiography (3-6 months) was obtained for hemodynamic profile (mean transprosthetic gradient and effective orifice area) and left ventricle mass determination. After propensity score matching (21 covariates), Kaplan-Meier analysis and cumulative incidence analysis were performed for survival and combined outcome of structural valve deterioration and endocarditis, respectively. Hemodynamics and left ventricle mass regression were assessed by a mixed- -effects model including propensity score as a covariate. RESULTS: From a total sample of 397 Freedom Solo and 525 Trifecta patients with a median follow-up time of 4.0 (2.2- 6.0) and 2.4 (1.4-3.7) years, respectively, a matched sample of 329 pairs was obtained. Well-balanced matched groups showed no difference in survival (hazard ratio=1.04, 95% confidence interval=0.69-1.56) or cumulative hazards of combined outcome (subhazard ratio=0.54, 95% confidence interval=0.21-1.39). Although Trifecta showed improved hemodynamic profile compared to Freedom Solo, no differences were found in left ventricle mass regression. CONCLUSION: Trifecta has a slightly improved hemodynamic profile compared to Freedom Solo but this does not translate into differences in the extent of mass regression, postoperative outcomes or survival, which were good and comparable for both bioprostheses. Long-term follow-up is needed for comparisons with older models of bioprostheses.

Cardiac Catheterization After CABG With BIMA Grafting: Independent Predictors and Mid-term Bypass Viability.

INTRODUCTION: Coronary artery bypass graft (CABG) patency is an important variable, but rarely studied as the main outcome. The best use of bilateral internal mammary artery (BIMA) grafting regarding configuration type or combination with saphenous vein graft (SVG) is still debated. PURPOSE: To find independent predictors for need of cardiac catheterization and for significant lesions in CABG follow-up. METHODS: Retrospective cohort including all patients who underwent isolated CABG with BIMA grafts between 2004 and 2013 in a tertiary center. Preoperative, surgical and postoperative data were collected through clinical files and informatics databases. Kaplan-Meier curves, Cox regression and logistic regression were used to find predictors for the need of catheterization and for significant angiographic lesions after CABG. Secondary end-points studied were mid- term survival and need of re-revascularization either surgically or percutaneously. RESULTS: We included 1030 patients in this analysis. Median follow-up time was 5.5 years and 150 (15%) patients were re-catheterized in that period. Most of these procedures was due to ischemia suspicion (74%) and 61 (41%) were positive for significant angiographic lesions of conduits (IMA: 3.2% and SVG: 3.8%, p=0.488). In multivariate analysis, SVG use was found as an independent predictor of cardiac catheterization on follow-up (HR: 1.610, CI 95%: 1.038-2.499, p=0.034). On the other side, independent predictors of graft lesions were younger age (OR: 0.951, CI 95%: 0.921-0.982, p=0.002), female gender (OR: 2.231, CI 95%: 1.038-4.794, p=0.040), arterial hypertension (OR: 1.968, CI 95%: 1.022-3.791, p=0.043) and 3-vessel disease (OR: 2.820, CI 95%: 1.155-6.885, p=0.023). Among the patients with significant angiographic lesions, 48 underwent repeat revascularization (44 PCI e 4 CABG). Arterial hypertension and younger age were independent predictors of re-revascularization. CONCLUSION: In BIMA patients the addition of SVG predicts the need of catheterization; however prevalence of significant angiographic lesions was similar in IMA and SVG. Our results suggest that arterial hypertension is an independent predictor of graft patency and re-revascularization rate.

Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting Surgery.

INTRODUCTION: Postoperative atrial fibrillation (PoAF) is the most common arrhythmia following cardiac surgery, which increase the patient's morbidity and mortality. PURPOSE: The aim of this study was to evaluate new onset of atrial fibrillation (AF) after isolated coronary artery bypass grafting (CABG) surgery, its clinical and surgical predictors, and its impact in immediate and long-term outcomes. METHODS: Retrospective study including all CABG surgeries performed in a tertiary centre, between 2004 and 2011. Patients with documented episodes of AF or pacing rhythm before cardiac surgery were excluded. Preoperative, surgical and postoperative data were collected through clinical files and informatics databases. Qui-square tests and independent t-tests were used to compare categorical and continuous data, respectively, between patients with and without PoAF. A multivariate logistic regression model was used to identify independent risk factors of PoAF. To determine the effect of PoAF in long-term survival, we used Kaplan-Meier curves, Log Rank test and multivariate Cox regression (maximum follow-up time: 13 years). RESULTS: We included 2511 patients, mean age of 63±10 years, 78.7% being male. PoAF occurred in 450 patients (18.0%), 3±3 days after surgery, the majority pharmacologically cardioverted with amiodarone (96.2%). These patients were older (67±9 vs. 62±10 years, p<0.001), more frequently obese (27.8% vs. 22.9%, p=0.026), hypertensive (76.7% vs. 69.7%, p=0.003) and had lower preoperative creatinine clearance (CC) values (73.2±27.4 vs. 81.4±28.3 ml/min, p<0.001), longer cardiopulmonary bypass time (60.0% vs. 54.8%, p=0.043) compared with patients without PoAF. In multivariate analysis, older age (OR: 1.035, 95% CI: 1.015-1.056, p=0.001), lower preoperative CC values (OR: 0.992, 95% CI: 0.985-0.999, p=0.032) and larger left atrial diameter (OR: 1.058, 95% CI: 1.024-1.093, p=0.001) were determined as independent predictors of PoAF. These patients also revealed longer hospitalization time (8 [4 to 193] vs. 6 [4 to 114] days, p<0.001) and higher hospital mortality (2.9% vs. 0.8%, p<0.001). Regarding long-term survival, patients with PoAF showed lower cumulative survival than patients without AF events (52% vs. 66%, p<0.001). PoAF was also found as an independent predictor of mortality in multivariate Cox regression (HR: 1.394, 95% CI: 1.147- 1.695, p=0.001). CONCLUSION: PoAF incidence after CABG surgery was 18%. Older age, lower CC values and larger left atrial diameter were settled as PoAF independent predictors. Additionally, the occurrence of this arrhythmia was independently associated with lower long-term survival, after CABG surgery.

Endothelial Function and Vascular Properties in Severe Aortic Stenosis Before and After Aortic Valve Replacement Surgery.

INTRODUCTION: The degenerative process that results in aortic valve stenosis (AS) has pathophysiological features similar to the atherosclerotic process. We therefore hypothesized that, as in atherosclerosis, endothelial and vascular dysfunction could be a pathophysiologic feature of AS. AIM: To evaluate endothelial function before and after aortic valve replacement (AVR) surgery in patients with severe AS. To correlate endothelial function with severity of AS and clinical profile. METHODS: Two noninvasive methods were used to evaluate endothelial function (Reactive Hyperemia Index (RHI) measure with EndoPATTM2000 system) and vascular properties (carotid-femoral Pulse Wave Velocity (PWV) measured by Complior® Analyse) in 13 patients with severe AS undergoing AVR. Sample was collected by convenience in a single-center between February and July of 2017. Pre- -operative, surgical and post-operative data were collected through clinical files and informatics databases. PWV, RHI, Augmentation Index (AI) were assessed at the day of surgery and 2.4±1.2 months post-operatively. Mean transvalvular gradients (MTG), aortic valve area (AVA) and left ventricular function were evaluated by transthoracic echocardiography at 3.4±1.6 months of follow-up. Wilcoxon or paired t-tests were used to compare pre- and post-operative values of continuous variables. Spearman correlations (rho) were done to find associations between endothelial/ vascular function parameters and clinical data. RESULTS: In our sample, mean age was 70±8 years and 69% were females. Arterial hypertension was present in 11 (85%) patients, diabetes in 3 (23%) and pre-operative NYHA functional class ≥III in 4 (31%). No patient was currently smoker and only 2 had previous history of smoking. No significant changes were observed between pre- and post-operative endothelial/vascular function values. PWV (m/s), AI (%) and RHI before and after AVR surgery were: 10.5 (6.1 to 16) vs. 9.4 (4.7 to 21.6), p=0.701; 33% [-24 to 54] vs. 23% [0 to 47], p=0.116 and 1.83 (1.08 to 3.13) vs. 1.71 (1.06 to 3.12), p=0.638, respectively. We found a significant inverse correlation between pre- operative AVA and AI (rho= -0.652, p=0.016) and a positive correlation between age and post-operative PWV (rho= 0.639, p=0.019). Pre- and post-operative MTG and AVA were 54±5 mmHg and 0.7± 0.1 cm2 vs.12±4 mmHg and 2.0±0.5 cm2, respectively (p<0.001). CONCLUSION: Considering small sample size, no differences were found in indices of endothelial/vascular function before and after AVR surgery due to AS. However, it seems that endothelial dysfunction is associated with severity of AS assessed by AVA.