Ex vivo lung perfusion: a procedural guide.

Available donor organs for lung transplantation are scarce. Ex vivo lung perfusion provides a platform to preserve, assess, and recondition donor lungs and can thereby aid in enlarging the donor pool. This video tutorial discusses the indications, preparation, and surgical technique for and the initiation, maintenance and termination of the ex vivo lung perfusion procedure.

Comparative study of male and female patients undergoing surgical aortic valve replacement.

BACKGROUND: Sex does have an effect on disease perception and outcomes after cardiac surgery. OBJECTIVES: The aim of this study was to quantify the differences in cardiovascular risk profiles within an age-matched cohort and assess the long-term survival differences in males and females who underwent surgical aortic valve replacement (SAVR) with or without concomitant coronary artery bypass surgery. METHODS: All-comers patients who underwent SAVR with or without coronary artery bypass surgery were included. Characteristics, clinical features and survival up to 30 years were compared between female and male patients. Propensity matching and age matching using propensity scores were used to compare both groups. RESULTS: During the total study period between 1987 and 2017, there were 3462 patients {mean age 66.8 [standard deviation (SD): 11.1] years, 37.1% female} who underwent SAVR with or without coronary artery bypass surgery at our institution. In general, female patients were older than male patients (69.1 (SD : 10.3) versus 65.5 (SD : 11.3), respectively). In the age-matched cohort, female patients were less likely to have multiple comorbidities and undergo concomitant coronary artery bypass surgery. Twenty-year survival following the index procedure was higher in age-matched female patients (27.1%) compared to male patients (24.4%) in the overall cohort (P = 0.018). CONCLUSIONS: Substantial sex differences in cardiovascular risk profile exist. However, when SAVR with or without coronary artery bypass surgery is performed, extended long-term mortality is comparable between males and females. More research regarding sex-dimorphic mechanisms of aortic stenosis and coronary atherosclerosis would promote more awareness in terms of sex-specific risk factors after cardiac surgery and contribute to more guided personalized surgery in the future.

Redo Surgical Aortic Valve Replacement versus Valve-In-Valve Transcatheter Aortic Valve Implantation: A Systematic Review and Reconstructed Time-To-Event Meta-Analysis.

Objective. Valve-in-valve transcatheter aortic valve implantation (ViV-TAVI) has emerged as a useful alternative intervention to redo-surgical aortic valve replacement (Redo-SVAR) for the treatment of degenerated bioprosthesis valve. However, there is no robust evidence about the long-term outcome of both treatments. The aim of this meta-analysis was to analyze the long-term outcomes of Redo-SVAR versus ViV-TAVI by reconstructing the time-to-event data. Methods. The search strategy consisted of a comprehensive review of relevant studies published between 1 January 2000 and 30 September 2022 in three electronic databases, PubMed, Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE. Relevant studies were retrieved for the analysis. The primary endpoint was the long-term mortality for all death. The comparisons were made by the Cox regression model and by landmark analysis and a fully parametric model. A random-effect method was applied to perform the meta-analysis. Results. Twelve studies fulfilled the eligibility criteria and were included in the final analysis. A total of 3547 patients were included. Redo-SAVR group included 1783 patients, and ViV-TAVI included 1764 subjects. Redo-SAVR showed a higher incidence of all-cause mortality within 30-days [Hazard ratio (HR) 2.12; 95% CI = 1.49−3.03; p < 0.0001)], whereas no difference was observed between 30 days and 1 year (HR = 1.03; 95% CI = 0.78−1.33; p = 0.92). From one year, Redo-SAVR showed a longer benefit (HR = 0.52; 95% CI = 0.40−0.67; p < 0.0001). These results were confirmed for cardiovascular death (HR = 2.04; 95% CI = 1.29−3.22; p = 0.001 within one month from intervention; HR = 0.35; 95% CI = 0.18−0.71; p = 0.003 at 4-years follow-up). Conclusions. Although the long-term outcomes seem similar between Redo-SAVR and ViV-TAVI at a five-year follow-up, ViV-TAVI shows significative lower mortality within 30 days. This advantage disappeared between 30 days and 1 year and reversed in favor of redo-SAVR 1 year after the intervention.

The impact of coronary artery bypass grafting added to aortic valve replacement on long-term outcomes in octogenarian patients: a reconstructed time-to-event meta-analysis.

The long-term results in studies comparing octogenarian patients who received either isolated surgical aortic valve replacement (i-SAVR) or coronary artery bypass grafting (CABG) in addition to SAVR are still debated. We performed a reconstructed time-to-event data meta-analysis of studies comparing i-SAVR and CABG+SAVR to evaluate the impact of CABG and to analyse the time-varying effects on long-term outcome. We performed a systematic review of the literature from January 2000 through November 2021, including studies comparing i-SAVR and CABG+SAVR, which reported at least 3-year follow-up and that plotted Kaplan-Meier curves of overall survival. The primary endpoint was overall long-term survival; secondary endpoints were in-hospital/30-day mortality and postoperative outcomes. The pooled hazard ratio (HR) and odds ratio) with 95% confidence interval (CI) were calculated for primary and secondary endpoints, respectively. Random-effect model was used in all analyses. Sixteen retrospective studies were included (5382 patients, i-SAVR = 2568 and CABG+SAVR = 2814). I-SAVR showed a lower incidence of in-hospital mortality compared to CABG+SAVR (odds ratio = 0.73; 95% CI= 0.60-0.89; P = 0.002). Landmark analyses showed a significantly higher all-cause mortality within 1 year from surgery in CABG+SAVR (HR = 1.17; 95% CI = 1.01-1.36; P = 0.03); after 1 year, no significant difference was observed (HR = 0.95; 95% CI = 0.87-1.04; P = 0.35). Landmark analysis was confirmed by time-varying trend of HR. Late survival of octogenarians did not differ significantly between the 2 interventions. Interestingly, CABG added to SAVR was associated with both higher in-hospital and within 1-year mortality after surgery, whereas this difference was statistically non-significant at long-term follow-up.

Outcomes of surgical aortic valve replacement over three decades.

OBJECTIVE: The study objective was to analyze temporal changes in baseline and procedural characteristics and long-term survival of patients undergoing surgical aortic valve replacement over a 30-year period. METHODS: A retrospective analysis of patients undergoing surgical aortic valve replacement between 1987 and 2016 in the Erasmus Medical Center (Rotterdam, The Netherlands) was conducted. Patient baseline and procedural characteristics were analyzed in periods according to the date of surgical aortic valve replacement (period A: 1987-1996; B: 1997-2006; C: 2007-2016). Survival status was determined using the Dutch National Death Registry. Relative survival was obtained by comparing the survival after surgical aortic valve replacement with the survival of the age-, sex-, and year-matched general population. RESULTS: Between 1987 and 2016, 4404 patients underwent SAVR. From period A to C, the mean age increased from 63.9 ± 11.2 years to 66.2 ± 12.3 years (P < .001), and the prevalence of diabetes mellitus, hypertension, hypercholesterolemia, previous myocardial infarction, and previous stroke at baseline increased (P values for trend for all < .001). The prevalence of concomitant procedures increased from 42.4% in period A to 48.3% in period C (P = .004). Bioprosthesis use increased significantly (18.8% in period A vs 67.1% in period C, P < .001). Mean survival after surgical aortic valve replacement was 13.8 years. Relative survival at 20 years in the overall cohort was 60.4% (95% confidence interval, 55.9-65.2) and 73.8% (95% confidence interval, 67.1-81.1) in patients undergoing isolated primary surgical aortic valve replacement. CONCLUSIONS: Patient complexity has been continuously increasing over the last 30 years, yet long-term survival after surgical aortic valve replacement remains high compared with the age-, sex-, and year-matched general population.

Weaning from cardiopulmonary bypass, decannulation, and closure.

In 1952, John Gibbon performed the first successful cardiac procedure using cardiopulmonary bypass, which turned out to be one of the most important clinical advances of that year. Cardiopulmonary bypass has also been described as "One of the most impressive evidences of the role of investigative surgery in the history of medicine in the persevering efforts of Dr. Gibbon for more than 20 years, which finally culminated in a practical heart-lung machine," at the first John H. Gibbon, Jr, Lecture at the annual meeting of the American College of Surgeons [1]. Due to the subsequent advancement of cardiopulmonary bypass, many patients with complex heart disease requiring surgical care undergo cardiac surgery while the other organs remain adequately oxygenated and perfused.

Surgical setup for cardiopulmonary bypass through central cannulation.

The introduction of cardiopulmonary bypass was one of the most important clinical advances of 1952. In that year, John Gibbon performed the first successful cardiac surgery using cardiopulmonary bypass. The procedure has been described as "One of the most impressive evidences of the role of investigative surgery in the history of medicine in the persevering efforts of Dr. Gibbon for more than 20 years, which finally culminated in a practical heart-lung machine", at the first John H. Gibbon, Jr. Lecture at the annual meeting of the American College of Surgeons. Due to on-going advancements in cardiopulmonary bypass, many patients with complex heart disease requiring surgical care undergo cardiac surgery while the other organs remain adequately oxygenated and perfused. This tutorial discusses the access, surgical technique, and initiation of cardiopulmonary bypass through central cannulation and describes the safeguards and pitfalls.

Asymptomatic Patients with Severe Aortic Stenosis and the Impact of Intervention.

Objectives the exact timing of aortic valve replacement (AVR) in asymptomatic patients with severe aortic stenosis (AS) remains a matter of debate. Therefore, we described the natural history of asymptomatic patients with severe AS, and the effect of AVR on long-term survival. Methods: Asymptomatic patients who were found to have severe AS between June 2006 and May 2009 were included. Severe aortic stenosis was defined as peak aortic jet velocity Vmax ≥ 4.0 m/s or aortic valve area (AVA) ≤ 1 cm2. Development of symptoms, the incidence of AVR, and all-cause mortality were assessed. Results: A total of 59 asymptomatic patients with severe AS were followed, with a mean follow-up of 8.9 ± 0.4 years. A total of 51 (86.4%) patients developed AS related symptoms, and subsequently 46 patients underwent AVR. The mean 1-year, 2-year, 5-year, and 10-year overall survival rates were higher in patients receiving AVR compared to those who did not undergo AVR during follow-up (100%, 93.5%, 89.1%, and 69.4%, versus 92.3%, 84.6%, 65.8%, and 28.2%, respectively; p < 0.001). Asymptomatic patients with severe AS receiving AVR during follow-up showed an incremental benefit in survival of up to 31.9 months compared to conservatively managed patients (p = 0.002). Conclusions: The majority of asymptomatic patients turn symptomatic during follow-up. AVR during follow-up is associated with better survival in asymptomatic severe AS patients.

Surgical Aortic Valve Replacement with Concomitant Aortic Surgery in Patients with Purely Bicuspid Aortic Valve and Associated Aortopathy.

The bicuspid aortic valve (BAV) is the most common congenital cardiac malformation associated with aortopathy. The current study provides surgical clinical data on the patient characteristics and long-term survival of this less common adult purely BAV population undergoing surgical aortic valve replacement (SAVR) with concomitant aortic surgery. Adult patients with purely BAV who underwent SAVR and concomitant aortic surgery were included. Prevalence, predictors of survival, and outcomes for this patient population were analyzed. A total of 48 patients (mean age 58.7 ± 13.2 years, 33% female) with purely BAV underwent SAVR and concomitant aortic surgery between 1987 and 2016. The majority (62%) of the patients had pure aortic stenosis (AS). A total of 12 patients died. Survival was 92%, 73%, and 69% at 1, 5, and 20 years of follow-up. At 15 years of follow-up, the survival was close to that of the Dutch population, with a relative survival of 77%. Adult patients with a purely bicuspid aortic valve morphology undergoing SAVR and concomitant aortic root and/or ascending aorta present with excellent survival.

Differences in baseline characteristics and outcomes of bicuspid and tricuspid aortic valves in surgical aortic valve replacement.

OBJECTIVES: Patients with bicuspid aortic valve (BAV) comprise a substantial portion of patients undergoing surgical aortic valve replacement (SAVR). Our goal was to quantify the prevalence of BAV in the current SAVR ± coronary artery bypass grafting (CABG) population, assess differences in cardiovascular risk profiles and assess differences in long-term survival in patients with BAV compared to patients with tricuspid aortic valve (TAV). METHODS: Patients who underwent SAVR with or without concomitant CABG and who had a surgical report denoting the relevant valvular anatomy were eligible and included. Prevalence, predictors and outcomes for patients with BAV were analysed and compared to those patients with TAV. Matched patients with BAV and TAV were compared using a propensity score matching strategy and an age matching strategy. RESULTS: A total of 3723 patients, 3145 of whom (mean age 66.6 ± 11.4 years; 37.4% women) had an operative report describing their aortic valvular morphology, underwent SAVR ± CABG between 1987 and 2016. The overall prevalence of patients with BAV was 19.3% (607). Patients with BAV were younger than patients with TAV (60.6 ± 12.1 vs 68.0 ± 10.7, respectively). In the age-matched cohort, patients with BAV were less likely to have comorbidities, among others diabetes (P = 0.001), hypertension (P < 0.001) and hypercholesterolaemia (P = 0.003), compared to patients with TAV. Twenty-year survival following the index procedure was higher in patients with BAV (14.8%) compared to those with TAV (12.9%) in the age-matched cohort (P = 0.015). CONCLUSIONS: Substantial differences in the cardiovascular risk profile exist in patients with BAV and TAV. Long-term survival after SAVR in patients with BAV is satisfactory.

Technique of surgical aortic valve implantation using single interrupted annular sutures.

The introduction of the first surgical prosthetic heart valves in the early 1960s made effective treatment of aortic valve disease possible. The goal of surgical aortic valve replacement is to replace the diseased aortic valve with a properly functioning, sufficiently large prosthesis while avoiding intraoperative complications such as conduction disturbances, coronary artery occlusion, or paravalvular leaks. Although most commonly, non-everting pledgeted mattress sutures are used to implant the prosthesis during surgical aortic valve replacement , interrupted single sutures without pledgets can be a useful alternative, especially in patients with a small tissue annulus, because they theoretically maximize the orifice available for flow. This tutorial discusses the surgical technique of surgical aortic valve replacement using interrupted single annular sutures.

Mortality in low-risk patients with aortic stenosis undergoing transcatheter or surgical aortic valve replacement: a reconstructed individual patient data meta-analysis.

OBJECTIVES: Although the standard of care for patients with severe aortic stenosis at low-surgical risk has included surgical aortic valve replacement (SAVR) since the mid-1960s, many clinical studies have investigated whether transcatheter aortic valve implantation (TAVI) can be a better approach in these patients. As no individual study has been performed to detect the difference in mortality between these 2 treatment strategies, we did a reconstructive individual patient data analysis to study the long-term difference in all-cause mortality. METHODS: Randomized clinical trials and propensity score-matched studies that included low-risk adult patients with severe aortic stenosis undergoing either SAVR or TAVI and with reports on the mortality rates during the follow-up period were considered. The primary outcome was all-cause mortality of up to 5 years. RESULTS: In the reconstructed individual patient data analysis, there was no statistically significant difference in all-cause mortality between TAVI and SAVR at 5 years of follow-up [30.7% vs 21.4%, hazard ratio (HR) 1.19, 95% confidence interval (CI) 0.96-1.48; P = 0.104]. However, landmark analyses in patients surviving up to 1 year of follow-up showed significantly higher all-cause mortality at 5 years of follow-up (27.5% vs 17.3%, HR 1.77, 95% CI 1.29-2.43; P < 0.001) in patients undergoing TAVI compared to patients undergoing SAVR, respectively. CONCLUSIONS: This reconstructed individual patient data analysis in low-risk patients with severe aortic stenosis demonstrates that the 5-year all-cause mortality rates are higher after TAVI than after SAVR, driven by markedly higher mortality rates between 1 and 5 years of follow-up in the TAVI group. The present results call for caution in expanding the TAVI procedure as the treatment of choice for the majority of all low-risk patients until long-term data from contemporary randomized clinical trials are available.

Natural History of Asymptomatic Severe Aortic Stenosis and the Association of Early Intervention With Outcomes: A Systematic Review and Meta-analysis.

Importance: Whether intervention should be performed in patients with asymptomatic severe aortic stenosis (AS) remains debated. Objective: To meta-analyze the natural history of asymptomatic severe AS and examine the association of early intervention with survival. Data Sources: PubMed, Embase, and Cochrane databases were searched from inception to February 1, 2020. Study Selection: Observational studies of adult patients with asymptomatic severe AS. Data Extraction and Synthesis: Two investigators independently extracted study and patient characteristics, follow-up time, events, and prognostic indicators of events. Random-effects models were used to derive pooled estimates. Main Outcomes and Measures: The meta-analysis on natural history was performed on the primary end point of all-cause death occurring during a conservative treatment period, with secondary end points consisting of cardiac death, death due to heart failure, sudden death, development of symptoms, development of an indication for aortic valve intervention, and aortic valve intervention. The primary end point for the meta-analysis of early intervention vs a conservative strategy was all-cause death during long-term follow-up. Finally, meta-analysis was performed on the association of prognostic indicators with the composite of death or aortic valve intervention found in multivariable models. Results: A total of 29 studies with 4075 patients with 11 901 years of follow-up were included. Pooled rates per 100 patients per year were 4.8 (95% CI, 3.6-6.4) for all-cause death, 3.0 (95% CI, 2.2-4.1) for cardiac death, 2.0 (95% CI, 1.3-3.1) for death due to heart failure, 1.1 (95% CI, 0.6-2.1) for sudden death, 18.1 (95% CI, 12.8-25.4) for an indication for aortic valve intervention, 18.5 (95% CI, 13.4-25.5) for development of symptoms, and 19.2 (95% CI, 15.5-23.8) for aortic valve intervention. Early intervention was associated with a significant reduction in long-term mortality (hazard ratio, 0.38; 95% CI, 0.25-0.58). Factors associated with worse prognosis were severity of AS, low-flow AS, left ventricular damage, and atherosclerotic risk factors. Conclusions and Relevance: Data from observational studies and a recent randomized clinical trial suggest that many patients with asymptomatic severe AS develop an indication for aortic valve intervention, and their deaths are mostly cardiac but not only sudden. Other end points besides sudden death should be considered during the decision to perform early intervention that are associated with improved survival.

Coronary revascularization after surgical aortic valve replacement.

Objective: It remains unclear how often coronary revascularization is necessary after aortic valve interventions, either by surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement. However, these data are relevant for treatment and prosthesis choice. The authors sought to analyze the incidence and characteristics of coronary revascularization after SAVR during follow-up. Methods: Of 2256 patients undergoing isolated SAVR between 1987 and 2015, 420 patients (mean age 56.9 ± 15.5 years, 66.9% male) were followed at the Erasmus Medical Center. Incidence, predictors, and characteristics of coronary revascularization were analyzed. Cumulative incidence of revascularization was assessed using a competing risk approach. Results: Mean follow-up after SAVR was 17.2 years (total of 4541 patient-years). A total of 24 patients underwent 28 procedures of revascularization. The cumulative incidence of revascularization after SAVR was 0.5%, 2.2%, 4.1%, and 6.9% at 1, 5, 10, and 20 years, respectively. The linearized rate of revascularization was 6.2 per 1000 patient-years. Percutaneous coronary intervention was the most common revascularization method (64%; N = 18/28). Revascularization before SAVR (N = 36/420; of whom 27 percutaneous coronary intervention) was an independent predictor of revascularization during follow-up (hazard ratio, 6.6; 95% confidence interval, 2.6-17.1; P < .001). Conclusions: After SAVR, the rate of coronary revascularization was 6.9% (N = 24/420) at 20-year follow-up. Patients were at particular risk if they had undergone previous revascularization before SAVR. These data may furthermore be relevant to the transcatheter aortic valve replacement population.

Mechanical versus bioprosthetic aortic valve replacement.

Mechanical valves used for aortic valve replacement (AVR) continue to be associated with bleeding risks because of anticoagulation therapy, while bioprosthetic valves are at risk of structural valve deterioration requiring reoperation. This risk/benefit ratio of mechanical and bioprosthetic valves has led American and European guidelines on valvular heart disease to be consistent in recommending the use of mechanical prostheses in patients younger than 60 years of age. Despite these recommendations, the use of bioprosthetic valves has significantly increased over the last decades in all age groups. A systematic review of manuscripts applying propensity-matching or multivariable analysis to compare the usage of mechanical vs. bioprosthetic valves found either similar outcomes between the two types of valves or favourable outcomes with mechanical prostheses, particularly in younger patients. The risk/benefit ratio and choice of valves will be impacted by developments in valve designs, anticoagulation therapy, reducing the required international normalized ratio, and transcatheter and minimally invasive procedures. However, there is currently no evidence to support lowering the age threshold for implanting a bioprosthesis. Physicians in the Heart Team and patients should be cautious in pursuing more bioprosthetic valve use until its benefit is clearly proven in middle-aged patients.