Author's reply (in reference to letter to editor proposed by Etem Caliskan, Catherine J. Pachuk, Louis P. Perrault, Maximilian Y Emmert and entitled: preservation solutions to improve graft patency: The devil is in the detail).

Not applicable.

Do storage solutions protect endothelial function of arterialized vein graft in an experimental rat model?

BACKGROUND: This study aims to compare the effects of storage solutions commonly used in coronary artery bypass grafting on the vascular reactivity in vein graft interposed in arterial position in syngeneic rats. METHODS: Twenty-seven male Lewis rats were sacrified to sample a vein graft implanted 6 weeks ago into abdominal aorta position. The vein grafts were inferior venae cavae initially pretreated with heparinized saline solution (HS) or autologous heparinized blood (AHB) or our referent solution, GALA. The endothelial functionality, the in situ Reactive Oxygen Species (ROS) levels and the histological characteristics were conducted from segments of arterialized vein graft. RESULTS: At 6 weeks, graft thrombosis occurred respectively in 22% of AHB group, 62.5% in the HS group and 82.5% in the GALA group. In each group, significative intimal hyperplasia was observed. After 6 weeks, an endothelium-remodeling layer associated with an increase of wall thickness was observed in each group. Endothelium-dependent tone was reduced in the vein graft regardless of the group. No difference was observed concerning the ROS in vein graft between the different groups. In distal aortic sections, ROS levels were increased in HS and GALA groups. CONCLUSIONS: Storage solutions used in this experimental model of vein graft implanted in arterial position cause graft injury and a complete disappearance of vascular reactivity. GALA solution did not reduce intimal risk hyperplasia when the vein graft was exposed to arterial flow in a rat model.

Which echocardiographic parameters improve the risk prediction for peri-operative outcomes in patients undergoing coronary bypass surgery: a prospective study.

OBJECTIVE: To assess the performance of transthoracic echocardiographic parameters to predict operative mortality and morbidity in patients undergoing coronary artery bypass grafting, and to assess its incremental prognostic value as compared to the Society of Thoracic Surgeons (STS) score. MATERIALS AND METHODS: We prospectively collected the clinical and biological data required to calculate the STS score in patients hospitalised for coronary artery bypass grafting. Preoperative transthoracic echocardiography was performed for each patient. The primary endpoint was 30-day mortality or major morbidity (i.e. stroke, renal failure, prolonged ventilation, deep sternal wound infection, reoperation) as defined by the STS. The secondary endpoint was prolonged hospitalisation for over 14 days. RESULTS: A total of 172 patients was included (mean age 66.1±10.2 years, 12.2% were women). The primary endpoint occurred in 33 patients (19.2%), and 28 patients (16.3%) had a prolonged hospital stay. Independent predictive factors for the primary endpoint were an increased left atrial volume (>31 mL/m²; odds ratio (OR) 3.55, 95% confidence interval (CI) 1.38-9.12; P=0.004) and a decreased tricuspid annular plane systolic excursion (<20 mm; OR 3.45, 95% CI 1.47-8.21; P=0.008). The predictive value of the multivariate model increased when the two echocardiographic parameters were added to the STS score (area under the curve 0.598 vs. 0.695, P=0.001; integrated discrimination improvement 7.44%). CONCLUSION: In patients undergoing coronary artery bypass grafting, preoperative assessment of left atrial size and tricuspid annular plane systolic excursion should be performed systematically, as it provides additional prognostic information to the STS score.

The intrinsic prognostic value of the ankle-brachial index is independent from its mode of calculation.

The object of this study was to compare the prognostic value of different methods of ankle-brachial index (ABI) calculation. From April 1998 to September 2008, we calculated the ABI in 1223 patients before coronary artery bypass grafting. The ABI was calculated according to five different calculation modes of the numerator. The patients were classified into three groups: clinical peripheral artery disease (PAD), subclinical PAD if no clinical history but abnormal ABI (< 0.90 or > 1.40), and no PAD. The primary outcome was total mortality. During a follow-up of 7.6 years (0.1-15.9), 406 patients (33%) died. The prevalence of the subclinical PAD varied from 22% to 29% according to the different modes of ABI calculation. Areas under the ROC curve to predict mortality according to different calculation modes varied from 0.608 ± 0.020 to 0.625 ± 0.020 without significant differences. The optimal ABI threshold to predict mortality varied for every method, ranging from 0.87 to 0.95. In multivariate models, ABI was significantly and independently associated with total mortality (hazard ratio (HR) = 1.46, 95% CI: 1.15-1.85, p = 0.002); however, this association was not significantly different between the various methods (HRs varying from 1.46 to 1.67). The use of the optimal ABI threshold for each calculation mode (rather than standard 0.90) allowed a slight improvement of the model. In conclusion, the ABI prognostic value to predict mortality is independent from its method of calculation. The use of different optimal thresholds for each method enables a comparable prognosis value.

Mid- and long-term prognosis of off- vs. on-pump coronary artery bypass graft in patients with multisite artery disease.

BACKGROUND: Among patients with coronary artery disease (CAD), around 25% have multisite artery disease (MSAD). Patients with CAD and MSAD are at higher risk of peri-operative and long-term cardiovascular events. Whether off-pump coronary bypass grafting (CABG) can improve their prognosis is unknown. We aimed to assess the benefits of off- vs. on-pump cardiac surgery in patients undergoing CABG, according to coexistence of extra-cardiac artery disease. METHODS: Between April 1998 and September 2008, 1221 patients undergoing CABG without any other intervention were enrolled. Overall death and major cardiovascular events were recorded at 1-month and during long-term follow-up. A propensity score (PS), derived from all relevant variables (P<0.25) associated with on-pump as compared to off-pump CABG, and representing the likelihood for each individual patient to receive off-pump CABG, was calculated. RESULTS: MSAD was observed in 279 patients (23%). Off-pump CABG was performed in 208 (17%) patients. The median follow-up was 7.6 years. The 10-year mortality was significantly lower in off- vs. on-pump CABG group (74±4% vs. 68±2%, P=0.024). In patients with MSAD, there was a trend for better survival for off- vs. on-pump CABG (63±8% vs. 50±4%, P=0.078). After adjustment for PS, we found no further difference between on- and off-pump CABG both in the whole cohort (HR=1.30, P=0.10), as well as in MSAD patients (HR=1.51, P=0.14). CONCLUSIONS: Patients with MSAD receiving CABG are at worst prognostic than those with isolated CAD. In these patients, we found no significant difference in the long-term mortality and cardiovascular events between on- and off-pump CABG.

Clampless myocardial revascularization on a healed iatrogenic aortic dissection.

Iatrogenic aortic dissection is an infrequent complication of cardiac catheterization (0.03-0.06%) associated with up to 19% of mortality at 30 days. It was reported to mostly occur when using a 6-Fr guiding catheter to cannulate the right coronary artery. This life-threatening complication usually requires early surgical management and close imaging monitoring and control of systolic blood pressure. This case report describes a patient with iatrogenic aortic dissection during cardiac catheterization in symptomatic coronary artery disease. Conservative management of the limited non-progressive aortic dissection was chosen followed by surgical revascularization with a clampless technique, despite the recent aortic injury.

Fate of aortic bioprostheses: An 18-year experience.

OBJECTIVE: To report our experience in aortic valve replacement with the Mitroflow (Sorin, Vancouver, Canada) aortic bioprosthesis. METHODS: We retrospectively reviewed all patients who underwent aortic valve replacement with a Mitroflow bioprosthesis at our institution from January 1994 to December 2011. No exclusion criteria were retained. Patients were followed yearly. Echocardiography follow-up was performed systematically before the hospital discharge and annually by patients' cardiologists. RESULTS: Seven hundred twenty-eight patients (mean age, 76 ± 6 years; range, 33-91 years) underwent aortic valve replacement with Mitroflow 12A or LX model and were included in this analysis. 30-day mortality for nonemergent isolated aortic valve replacement was 5.5%. Eight patients (1%) underwent reoperation for structural valve deterioration (SVD) and 30 patients (5.8%) presented echocardiographic signs of SVD. Actuarial freedom from reoperation for SVD was 99% ± 0.5% and 95% ± 5% at 10 and 15 years. Actuarial freedom from echocardiographic signs of SVD was 77% ± 5% and 56% ± 11% at 10 and 15 years, respectively. At the univariate analysis, only the mean gradient at discharge (P = .0200), the prevalence of size 19 (P = .0273), and severe patient-prosthesis mismatch (P = .0384) were significantly different in patients developing SVD at follow-up. Freedom from echocardiographic signs of SVD at 8 years were 88% ± 4% and 64% ± 13% in patients with a Mitroflow > 19 and Mitroflow 19, respectively (log-rank test, P = .0056; Wilcoxon test, P = .0589). CONCLUSIONS: Overall outcomes were satisfactory. However the risk of early SVD seems higher for the Mitroflow size 19. This size should be reserved for applications when annulus enlargement is risky or there is an anatomic contraindication to sutureless or stentless valve.