Pierpaolo Chivasso

Impact of multiple arterial grafts in off-pump and on-pump coronary artery bypass surgery

Objectives: There is growing concern that off‐pump coronary artery bypass (OPCAB) is associated with reduced long‐term survival compared with traditional on‐pump coronary artery bypass (ONCAB); however, most of available comparisons between OPCAB and ONCAB focus on single‐artery (SA) revascularization. We sought to investigate the impact of using multiple arterial (MA) conduits in the comparison between OPCAB versus ONCAB by performing a single‐center, long‐term propensity score base analysis. Methods: The study population included 5195 SA‐ONCAB, 1208 MA‐ONCAB, 4412 SA‐OPCAB, and 1818 MA‐OPCAB procedures. Late survival was available for all cases (100%). Inverse propensity score weighting and a time‐segmented Cox model were used for multiple treatments comparison. Results: No significant differences were found between the 4 groups in terms of 30‐day mortality, postoperative cerebrovascular accident, and renal replacement therapy. After a mean follow‐up time of 8.2 ± 4.7 years, in the propensity score−weighted sample, survival probabilities at 10 years were 74.5 ± 0.4, 79.7 ± 0.4, 73.4 ± 0.5, and 79.0 ± 0.5 in the SA‐ONCAB, MA‐ONCAB, SA‐OPCAB, and MA‐OPCAB groups respectively. Propensity‐weighted analysis confirmed that MA‐OPCAB (hazard ratio, 0.81; 95% confidence interval, 0.69‐0.98) and MA‐ONCAB (hazard ratio, 0.81; 95% confidence interval, 0.65‐0.99) were associated with a lower late mortality compared with standard SA‐ONCAB. Conclusions: OPCAB with multiple arterial grafts is as safe as the conventional ONCAB and achieves excellent long term survival rates which are superior to those observed after standard SA‐ONCAB and comparable with MA‐ONCAB.

Gentamicin-Impregnated Collagen Sponge

Sternal wound infections represent one of the most frequent complications after cardiac surgery and are associated with high postoperative mortality. Several preventive methods have been introduced, and recently, gentamicin-impregnated collagen sponges (GICSs) have shown a promising effect in reducing the incidence of this type of complications. Gentamicin is an aminoglycoside antibiotic that has been widely used to treat infections caused by multiresistant bacteria; despite its effectiveness, its systemic use carries a risk of toxicity. GICSs appear to overcome this side effect, topically delivering high antibiotic concentrations to the wound and thus reducing the toxic-related events. Although several retrospective analyses and randomized controlled trials have studied the use of GICSs in cardiac surgery, conclusions regarding their efficacy in preventing sternal wound infection are inconsistent. We have reviewed the current literature focusing on high-risk patients.

Predictors of survival in octogenarians after mitral valve surgery for degenerative disease: The Mitral Surgery in Octogenarians study

Objectives: An increasing number of octogenarians are referred to undergo mitral valve surgery for degenerative disease, and percutaneous approaches are being increasingly used in this subgroup of patients. We sought to determine the survival and its predictors after Mitral Valve Surgery in Octogenarians (MiSO) in a multicenter UK study of high‐volume specialized centers. Methods: Pooled data from 3 centers were collected retrospectively. To identify the predictors of short‐term composite outcome of 30 days mortality, acute kidney injury, and cerebrovascular accident, a multivariable logistic regression model was developed. Multiple Cox regression analysis was performed for late mortality. Kaplan–Meier curves were generated for long‐term survival in various subsets of patients. Receiver operating characteristic analysis was done to determine the predictive power of the logistic European System for Cardiac Operative Risk Evaluation. Results: A total of 247 patients were included in the study. The median follow‐up was 2.9 years (minimum 0, maximum 14 years). A total of 150 patients (60.7%) underwent mitral valve repair, and 97 patients (39.3%) underwent mitral valve replacement. Apart from redo cardiac surgery (mitral valve repair 6 [4%] vs mitral valve replacement 11 [11.3%], P = .04) and preoperative atrial fibrillation (mitral valve repair 79 [52.6%] vs mitral valve replacement 34 [35.1%], P < .01), there was no significant difference in terms of any other preoperative characteristics between the 2 groups. Patient operative risk, as estimated by logistic European System for Cardiac Operative Risk Evaluation, was lower in the mitral valve repair group (10.2 ± 11.8 vs 13.7 ± 15.2 in mitral valve replacement; P = .07). No difference was found between groups for duration of cardiopulmonary bypass and aortic crossclamp times. The 30‐day mortality for the whole cohort was 13.8% (mitral valve repair 4.7% vs mitral valve replacement 18.6%; P < .01). No differences were found in terms of postoperative cerebrovascular accident (2% vs 3.1%; P = .9), acute kidney injury requiring dialysis (6.7% vs 13.4%; P = .12), and superficial or deep sternal wound infection (10% vs 16.5%, P = .17; 2% vs 3.1%, P = .67, respectively). The final multiple regression model for short‐term composite outcome included previous cardiac surgery (odds ratio [OR], 4.47; 95% confidence interval [CI], 1.37‐17.46; P = .02), intra‐aortic balloon pump use (OR, 4.77; 95% CI, 1.67‐15.79; P < .01), and mitral valve replacement (OR, 7.7; 95% CI, 4.04‐14.9; P < .01). Overall survival for the entire cohort at 1, 5, and 10 years was 82.4%, 63.7%, and 45.5% (mitral valve repair vs mitral valve replacement: 89.9% vs 70.7% at 1 year, 69.6% vs 54% at 5 years, and 51.8% vs 35.5% at 10 years; P = .0005). Cox proportional hazard model results showed mitral valve replacement (hazard ratio, 1.88; 95% CI, 1.22‐2.89; P < .01) and intra‐aortic balloon pump use (hazard ratio, 2.54; 95% CI, 1.26‐5.13; P < .01) to be independent predictor factors affecting long‐term survival. Logistic European System for Cardiac Operative Risk Evaluation did not perform well in predicting early mortality (area under the curve, 0.57%). Conclusions: In octogenarians, mitral valve repair for degenerative disease is associated with good survival and remains the gold standard, whereas mitral valve replacement is still associated with significant mortality. Logistic European System for Cardiac Operative Risk Evaluation was unable to predict early mortality in our cohort of patients. Larger international multicenter registries are required to optimize the decision‐making process in such a high‐risk subgroup.

Gentamicin-Impregnated Collagen Sponge: Effectiveness in Preventing Sternal Wound Infection in High-Risk Cardiac Surgery

Sternal wound infections represent one of the most frequent complications after cardiac surgery and are associated with high postoperative mortality. Several preventive methods have been introduced, and recently, gentamicin-impregnated collagen sponges (GICSs) have shown a promising effect in reducing the incidence of this type of complications. Gentamicin is an aminoglycoside antibiotic that has been widely used to treat infections caused by multiresistant bacteria; despite its effectiveness, its systemic use carries a risk of toxicity. GICSs appear to overcome this side effect, topically delivering high antibiotic concentrations to the wound and thus reducing the toxic-related events. Although several retrospective analyses and randomized controlled trials have studied the use of GICSs in cardiac surgery, conclusions regarding their efficacy in preventing sternal wound infection are inconsistent. We have reviewed the current literature focusing on high-risk patients.

How Safe Is it to Train Residents to Perform Coronary Surgery With Multiple Arterial Grafting? Nineteen Years of Training at a Single Institution

The learning curve of coronary artery bypass grafting (CABG) with multiple arterial grafting (MAG) is perceived to be associated with increased surgical morbidity and potentially poorer long-term outcomes. We compared short-term outcomes and long-term survival in patients who underwent CABG with MAG performed by attending surgeons or resident trainees at a single institution over a period of 19 years. Using our institutional database, we identified 3039 patients undergoing MAG from 1996-2015. Of those, 958 (32%) were operated on by residents and 2081 (68%) by attending surgeons. Propensity score matching and mixed-effects models were used to compare the 2 groups. Operative mortality rate was 0.3% and 0.4% among patients operated by residents and attending surgeons, respectively (P = 0.71), with no significant differences among the groups in postoperative complications. After a mean follow-up time of 11 ± 4 years, survival probability at 5, 10, and 15 years was 95.1% ± 0.7% vs 96.4% ± 0.6%, 87.0% ± 1.1% vs 87.8% ± 1.1%, and 76.6.% ± 1.8% vs 77.6% ± 1.8% in the resident and attending surgeon group, respectively. Resident and attending surgeon cases showed comparable risk of death (hazard ratio [HR] = 1.01; 95% CI: 0.80-1.28; P = 0.92). The equipoise between the 2 groups was confirmed among cases receiving bilateral internal thoracic arteries only (HR = 0.88; 95% CI: 0.54-1.43; P = 0.61), radial artery (HR = 1.22; 95% CI: 0.92-1.61; P = 0.15), or their combination (HR = 0.74; 95% CI: 0.33-1.65; P = 0.47). The present analysis confirms that adequately supervised trainees can perform CABG with MAG without compromising patient safety and long-term survival.

Early health outcome and 10-year survival in patients undergoing redo coronary surgery with or without cardiopulmonary bypass: a propensity score-matched analysis

Abstract OBJECTIVES To investigate the in-hospital health outcome and 10-year survival in patients undergoing redo coronary surgery with (redo-CABG) or without (redo-OPCAB) cardiopulmonary bypass. METHODS A total of 349 redo coronary surgery patients were identified from our registry. Of these, 143 redo-OPCAB patients (40.97%) were compared with 206 redo-CABG patients. To minimize the bias, we also conducted propensity score matching. In Matched Analysis A, 111 redo-OPCAB patients with any type of primary cardiac operation were compared with 111 redo-CABG cases. In Matched Analysis B, 84 redo-OPCAB patients with isolated coronary surgery as their primary operation were compared with 84 redo-CABG patients. We assessed for all 3 analyses a composite of in-hospital mortality, acute kidney injury, stroke and severe low cardiac output requiring intra-aortic balloon pump. In addition, we assessed 1-, 5-, and 10-year survival. RESULTS In the unmatched analysis, redo-CABG was associated with higher usage of intra-aortic balloon pump (10 vs 3%, P = 0.01) and composite compared with redo-OPCAB (25 vs 16%, P = 0.06) and similar 10-year survival (67.2 vs 68.5%, log-rank test: P = 0.78). Matched Analysis A showed similar rates of composite (15 vs 21%, P = 0.25) and 10-year survival (65.1 vs 60.8%, log-rank test: P = 0.5). Matched Analysis B showed reduction of the composite (19 vs 8%, P = 0.04), less in-hospital mortality (5 vs 0%, P = 0.13), 4.5 times less need for intra-aortic balloon pump (2 vs 11%, P = 0.02) favouring redo-OPCAB and a similar 10-year survival (71.6 vs 71.7%, log-rank test: P = 0.61). CONCLUSIONS Redo-OPCAB surgery is feasible, safe and effective with improved in-hospital outcome and similar 10-year survival compared to redo-CABG.

Surgical repair of Stanford type A aortic dissection in elderly patients: a contemporary systematic review and meta-analysis

BACKGROUND The results of surgical treatment of type A aortic dissection (AAD) in the elderly are controversial and aggravated by a higher operative mortality rate. The studies published in this subset of patients are mainly retrospective analyses or small samples from international registries. We sought to investigate this topic by conducting a contemporary meta-analysis of the most recent observational studies. METHODS A systematic literature search was conducted for any study published in the last five years on aortic dissection treated surgically in patients 70 years and older. A pooled risk-ratio meta-analysis has been conducted three main post-operative outcomes: short-term mortality, stroke and acute kidney injury. RESULTS A total of 11 retrospective observational studies have been included in the quantitative meta-analysis. Pooled meta-analysis showed an increased risk of short term mortality for the elderly population [relative risk (RR) =2.25; 95% CI, 1.79-2.83; I (2)=0%; P<0.0001], and this has been confirmed in a sub-analysis of patients 80 years and older. The risk of having stroke (RR =1.15; 95% CI, 0.89-1.5; I (2)=0%; P=0.28) and acute kidney injury (RR =0.79; 95% CI, 0.5-1.25, I (2)=14%, P=0.31) after surgery were comparable to the younger cohort of patients. CONCLUSIONS Although affected by an increased risk of short-term mortality in the elderly, surgical repair remains the treatment of choice for AAD. The main post-operative outcomes are comparable to younger patients and the mid-term survival rates are acceptable.

Enlightening the Association between Bicuspid Aortic Valve and Aortopathy

Bicuspid aortic valve (BAV) patients have an increased incidence of developing aortic dilation. Despite its importance, the pathogenesis of aortopathy in BAV is still largely undetermined. Nowadays, intense focus falls both on BAV morphology and progression of valvular dysfunction and on the development of aortic dilation. However, less is known about the relationship between aortic valve morphology and aortic dilation. A better understanding of the molecular pathways involved in the homeostasis of the aortic wall, including the extracellular matrix, the plasticity of the vascular smooth cells, TGFβ signaling, and epigenetic dysregulation, is key to enlighten the mechanisms underpinning BAV-aortopathy development and progression. To date, there are two main theories on this subject, i.e., the genetic and the hemodynamic theory, with an ongoing debate over the pathogenesis of BAV-aortopathy. Furthermore, the lack of early detection biomarkers leads to challenges in the management of patients affected by BAV-aortopathy. Here, we critically review the current knowledge on the driving mechanisms of BAV-aortopathy together with the current clinical management and lack of available biomarkers allowing for early detection and better treatment optimization.

Propensity-matched analysis of outcomes after mitral valve surgery between trainees and consultants (institutional report)

OBJECTIVES We aimed to determine whether early outcomes and long-term survival after mitral valve surgery performed by trainee residents are equivalent in terms of safety and efficacy when compared with consultant surgeons. METHODS Between January 2000 and December 2015, a total of 1742 patients who underwent mitral valve surgery were identified. Of these, 1622 operations were performed by consultants (Group I) and 120 operations were performed by trainees (Group II). A propensity score-matched analysis has been used to minimize selection bias. Early postoperative outcomes were defined as in-hospital mortality, cerebrovascular accident, postoperative requirement of renal replacement therapy, reoperation for bleeding and postoperative length of hospital stay. Long-term outcomes were evaluated using late survival data after discharge. RESULTS Before matching, the 2 groups differed significantly in terms of gender and reduced left ventricular ejection fraction, but these differences were solved after matching. Also, Group I included significantly more patients with mitral regurgitation (83% vs 62%; P < 0.01), but after matching, this difference was corrected (62% vs 59%; P = 0.71). Consultant group was associated with a higher in-hospital mortality (6% vs 2%; P = 0.04) in the unmatched population. Moreover, in the unmatched cohort, this group had longer cross-clamp time compared with the trainees group (91 ± 38 vs 89 ± 26 min; P = 0.47) and longer cardiopulmonary bypass time (132 ± 58 vs 121 ± 33 min; P = 0.27); these differences were not statistically significant. There were no significant differences in postoperative dialysis, cerebrovascular accident, reoperation for bleeding and length of hospital stay. Even after matching, no significant differences were found in terms of perioperative complications. The Kaplan-Meier survival curves at 1, 5 and 10 years were similar between the 2 groups. CONCLUSIONS Mitral valve surgery can be safely performed by trainees and provides similar short- and long-term results compared with consultant surgeons.

Effectiveness and Safety of Aprotinin Use in Thoracic Aortic Surgery

OBJECTIVE To determine the effectiveness and safety of aprotinin use in adult patients undergoing thoracic aortic surgery. DESIGN Single-center, retrospective study. SETTING All cases performed at a single university hospital. PARTICIPANTS Between January 2004 and December 2014, 846 adult patients underwent thoracic aortic surgery. Due to missing or duplicated data on primary outcomes, 314 patients were excluded. The final sample of 532 patients underwent surgery on the thoracic aorta. INTERVENTIONS The patients were divided in the following 2 groups: 107 patients (20.1%) received aprotinin during the surgery, which represented the study group, whereas the remaining 425 patients (79.9%) underwent surgery without the use of aprotinin. MEASUREMENTS AND MAIN RESULTS To adjust for patient selection and preoperative characteristics, a propensity score-matched analysis was conducted. Mean total blood loss at 12 hours after surgery was similar between the 2 groups. The blood product transfusion rates did not differ in the 2 groups, except for the rate of fresh frozen plasma transfusion being significantly higher in the aprotinin group. Re-exploration for bleeding and the incidence of a major postoperative bleeding event were similar between the groups. Rates of in-hospital mortality, renal failure, and cerebrovascular accidents did not show any statistically significant difference. Aprotinin did not represent a risk factor for mortality over the long term (hazard ratio 1.14, 95% confidence interval 0.62-2.08, p = 0.66). CONCLUSIONS The use of aprotinin demonstrated a limited effect in reducing postoperative bleeding and prevention of major bleeding events. Aprotinin did not adversely affect early outcomes and long-term survival.