4D flow CMR analysis comparing patients with anatomically shaped aortic sinus prostheses, tube prostheses and healthy subjects introducing the wall shear stress gradient: a case control study.

BACKGROUND: Anatomically pre-shaped sinus prostheses (SP) were developed to mimic the aortic sinus with the goal to preserve near physiological hemodynamic conditions after valve-sparing aortic root replacement. Although SP have shown more physiological flow patterns, a comparison to straight tube prosthesis and the analysis of derived quantitative parameters is lacking. Hence, this study sought to analyze differences in aortic wall shear stress (WSS) between anatomically pre-shaped SP, conventional straight tube prostheses (TP), and age-matched healthy subjects) using time-resolved 3-dimensional flow cardiovascular magnetic resonance (4D Flow CMR). Moreover, the WSS gradient was introduced and analyzed regarding its sensitivity to detect changes in hemodynamics and its dependency on the expression of secondary flow patterns. METHODS: Twelve patients with SP (12 male, 62 ± 9yr), eight patients with TP (6 male, 59 ± 9yr), and twelve healthy subjects (2 male, 55 ± 6yr) were examined at 3 T with a 4D Flow CMR sequence in this case control study. Six analysis planes were placed in the thoracic aorta at reproducible landmarks. The following WSS parameters were recorded: WSSavg (spatially averaged over the contour at peak systole), max. WSSseg (maximum segmental WSS), min. WSSseg (minimum segmental WSS) and the WSS Gradient, calculated as max. WSSseg - min. WSSseg. Kruskal-Wallis- and Mann-Whitney-U-Test were used for statistical comparison of groups. Occurrence and expression of secondary flow patterns were evaluated and correlated to WSS values using Spearman's correlation coefficient. RESULTS: In the planes bordering the prosthesis all WSS values were significantly lower in the SP compared to the TP, approaching the physiological optimum of the healthy subjects. The WSS gradient showed significantly different values in the four proximally localized contours when comparing both prostheses with healthy subjects. Strong correlations between an elevated WSS gradient and secondary flow patterns were found in the ascending aorta and the aortic arch. CONCLUSION: Overall, the SP has a positive impact on WSS, most pronounced at the site and adjacent to the prosthesis. The WSS gradient differed most obviously and the correlation of the WSS gradient with the occurrence of secondary flow patterns provides further evidence for linking disturbed flow, which was markedly increased in patients compared to healthy sub jects, to degenerative remodeling of the vascular wall.

New Device for the Treatment of Functional Ischemic Mitral Regurgitation: Proof of Concept in an In Vitro Model.

BACKGROUND: Optimal surgical treatment of functional ischemic mitral regurgitation (FIMR) is still controversy. Due to the underlying pathophysiology, stand-alone ring annuloplasty is assumed with a high recurrence rate of mitral regurgitation, thus additional subvalvular repair techniques might improve the results. This in vitro study introduces a new device for subvalvular mitral valve repair. METHODS: We developed a new device for subvalvular mitral valve repair, consisting of two frames for papillary muscle (PM) attachment, which are connected with two holding bars serving for fixation of the device on an annuloplasty ring. In the first experimental run, porcine mitral valves including the chordae tendineae and PMs were fixated on a holding device, consisting of a holding ring simulating mitral annulus dilation and height-adjustable frames for PM attachment simulating leaflet tethering. In vitro regurgitant volume was determined in a pulse duplicator. Afterward, the frames for PM attachment were replaced by our newly developed device and the measurements were repeated. RESULTS: In the model simulating FIMR, the regurgitant volume was 44.3 ± 12.38 mL/stroke. After subvalvular reconstruction with our new device, the regurgitant volume was significantly reduced to 33.1 ± 11.68 mL/stroke (p = 0.009). CONCLUSION: In this specific in vitro model, our new device for subvalvular mitral valve reconstruction led to a significant reduction of the regurgitant volume, thus representing a promising technique to potentially improve the results of mitral reconstruction in ischemic functional mitral valve regurgitation. Additional studies are required to further investigate and improve our device.

In vitro 4D Flow MRI evaluation of aortic valve replacements reveals disturbed flow distal to biological but not to mechanical valves.

BACKGROUND AND AIM OF THE STUDY: Aortic hemodynamics influence the integrity of the vessel wall and cardiac afterload. The aim of this study was to compare hemodynamics distal to biological (BV) and mechanical aortic valve (MV) replacements by in vitro 4D Flow MRI excluding confounding factors of in-vivo testing potentially influencing hemodynamics. METHODS: Two BV (Perimount MagnaEase [Carpentier-Edwards], Trifecta [Abbott]) and two MV (On-X [CryoLife], prototype trileaflet valve) were scanned in a flexible aortic phantom at 3T using a recommended 4D Flow MR sequence. A triphasic aortic flow profile with blood-mimicking fluid was established. Using GTFlow (Gyrotools), area and velocity of the ejection jet were measured. Presence and extent of sinus vortices and secondary flow patterns were graded on a 0 to 3 scale. RESULTS: A narrow, accelerated central ejection jet (Area = 27 ± 7% of vessel area, Velocity = 166 ± 13 cm/s; measured at sinotubular junction) was observed in BV as compared to MV (Area = 53 ± 13%, Velocity = 109 ± 21 cm/s). As opposed to MV, the jet distal to BV impacted the outer curvature of the ascending aorta and resulted in large secondary flow patterns (BV: n = 4, grades 3, 3, 2, 1; MV: n = 1, grade 1). Sinus vortices only formed distal to MV. Although physiologically configured, they were larger than normal (grade 3). CONCLUSIONS: In contrast to mechanical valves, biological valve replacements induced accelerated and increased flow patterns deviating from physiological ones. While it remains speculative whether this increases the risk of aneurysm formation through wall shear stress changes, findings are contrasted by almost no secondary flow patterns and typical, near-physiological sinus vortex formation distal to mechanical valves.

Long-Term (up to 21 Years) Follow Up after Biological and Mechanical Aortic Valve Replacement in Younger Patients.

BACKGROUND: Despite the limited durability of biological aortic valves, increasing numbers of younger patients are choosing to receive them, due mainly to the lack of a need for permanent anticoagulation. Few data exist, however, regarding the outcomes of valve replacement in patients aged <55 years, and additional data are required in this patient population. METHODS: Between 1993 and 2014, at the authors' institution, a total of 448 patients (237 males, 101 females; mean age 45.8 ± 8.0 years) underwent aortic valve replacement (AVR) with either a mechanical prosthesis (M1 group, n = 318) or a biological prosthesis (B1 group, n = 130). The mean follow up was 8.5 ± 5.8 years (range: 4 days to 20.8 years) in the M1 group, and 4.9 ± 4.6 years (range: 2 days to 21 years) in the B1 group. The entire collective (EC) (n = 448 patients) was compared and analyzed with a selective collective (SC) (n = 109 patients) after exclusion of patients with concomitant procedures or comorbidities (M2 group, n = 74; B2 group, n = 35). RESULTS: Early mortality was greater after biological AVR in the EC (6.1% versus 1.9%), but in the SC no early deaths were observed after both primary and redo procedures. The reoperation rate was greater after biological AVR in both collectives. The late mortality, survival and endocarditis rates were comparable in both collectives. Bleeding occurred more often in the EC after mechanical AVR. CONCLUSIONS: Biological AVR in patients aged <55 years provides satisfactory outcomes, whereas reoperations were performed less commonly in patients with mechanical valve substitutes. In selective patients, AVR can be performed with zero mortality.

Does Undersizing of Transcatheter Aortic Valve Bioprostheses during Valve-in-Valve Implantation Avoid Coronary Obstruction? An In Vitro Study.

Background The transcatheter aortic valve-in-valve implantation (TAViVI) is an evolving treatment strategy for degenerated surgical aortic valve bioprostheses (SAVBs) in patients with high operative risk. Although hemodynamics is excellent, there is some concern regarding coronary obstruction, especially in SAVB with externally mounted leaflet tissue, such as the Trifecta (St. Jude Medical Inc., St. Paul, Minnesota, United States). We investigated coronary flow and hydrodynamics before and after TAViVI in a SAVB with externally mounted leaflet tissue (St. Jude Medical, Trifecta) with an undersized transcatheter aortic valve bioprosthesis (Edwards Sapien XT; Edwards Lifesciences LLC, Irvine, California, United States) in an in vitro study. Materials and Methods An aortic root model was constructed incorporating geometric dimensions known as risk factors for coronary obstruction. Investigating the validity of this model, we primarily performed recommended TAViVI with the Sapien XT (size 26 mm) in a Trifecta (size 25 mm) in a mock circulation. Thereafter, hydrodynamic performance and coronary flow (left/right coronary diastolic flow [lCF/rCF]) after TAViVI with an undersized Sapien XT (size 23 mm) in a Trifecta (size 25 mm) were investigated at two different coronary ostia heights (COHs, 8 and 10 mm). Results Validation of the model led to significant coronary obstruction (p < 0.001). Undersized TAViVI showed no significant reduction with respect to coronary flow (lCF: COH 8 mm, 0.90-0.87 mL/stroke; COH 10 mm, 0.89-0.82 mL/stroke and rCF: COH 8 mm, 0.64-0.60 mL/stroke; COH 10 mm, 0.62-0.58 mL/stroke). Mean transvalvular gradients (4-5 mm Hg, p < 0.001) increased significantly after TAViVI. Conclusions In our in vitro model, undersized TAViVI with the balloon-expandable Sapien XT into a modern generation SAVB (Trifecta) successfully avoided coronary flow obstruction.

[Risk Factors for Postoperative Delirium after Cardiac Surgery]. / Risikofaktoren des postoperativen Deliriums in der Herzchirurgie.

Background Delirium is a common psychiatric disorder after cardiac surgery and predisposes patients to increased mortality and morbidity. Its prevention requires knowledge of the risk factors involved. Objective What are preoperative risk factors for postoperative delirium after cardiac surgery? Methods Prospective longitudinal study of 241 elective cardiac surgical patients with preoperative assessment of potential risk factors and delirium assessment twice daily over five postoperative days. Results 13 % of the patients experienced delirium. Reduced cognitive performance (OR: 3.80; 95 % CI: 1.66 - 8.66), higher comorbidity (OR: 1.36; 95 % CI: 1.07 - 1.7) and higher age (OR: 1.08; 95 % CI: 1.02 - 1.13) increased the risk of delirium. Conclusion Delirium after cardiac surgery is common. It occurs in particular in patients with low cognitive performance, higher comorbidity and higher age.

A randomized, parallel group, double-blind study of ticagrelor compared with aspirin for prevention of vascular events in patients undergoing coronary artery bypass graft operation: Rationale and design of the Ticagrelor in CABG (TiCAB) trial: An Investigator-Initiated trial.

BACKGROUND: For patients with coronary artery disease undergoing coronary bypass surgery, acetylsalicylic acid (ASA) currently represents the gold standard of antiplatelet treatment. However, adverse cardiovascular event rates in the first year after coronary artery bypass grafting (CABG) still exceed 10%. Graft failure, which is predominantly mediated by platelet aggregation, has been identified as a major contributing factor in this context. Therefore, intensified platelet inhibition is likely to be beneficial. Ticagrelor, an oral, reversibly binding and direct-acting P2Y12 receptor antagonist, provides a rapid, competent, and consistent platelet inhibition and has shown beneficial results compared with clopidogrel in the subset of patients undergoing bypass surgery in a large previous trial. HYPOTHESIS: Ticagrelor is superior to ASA for the prevention of major cardiovascular events within 1 year after CABG. STUDY DESIGN: The TiCAB trial (NCT01755520) is a multicenter, phase III, double-blind, double-dummy, randomized trial comparing ticagrelor with ASA for the prevention of major cardiovascular events within 12 months after CABG. Patients undergoing CABG will be randomized in a 1:1 fashion to either ticagrelor 90 mg twice daily or ASA 100 mg once daily. The study medication will be started within 24 hours after surgery and maintained for 12 months. The primary end point is the composite of cardiovascular death, myocardial infarction, stroke, and repeat revascularization at 12 months after CABG. The sample size is based on an expected event rate of 13% of the primary end point within the first 12 months after randomization in the control group, a 2-sided α level of .0492 (to preserve the overall significance level of .05 after planned interim analysis), a power of 0.80%, 2-sided testing, and an expected relative risk of 0.775 in the active group compared with the control group and a dropout rate of 2%. According to power calculations based on a superiority design for ticagrelor, it is estimated that 3,850 patients should be enrolled. SUMMARY: There is clinical equipoise on the issue of optimal platelet inhibition after CABG. The TiCAB trial will provide a pivotal comparison of the efficacy and safety of ticagrelor compared with ASA after CABG.

Long-Term Results after Aortic Valve-Sparing-Reimplantation Operation (David) in Bicuspid Aortic Valve.

BACKGROUND AND AIM OF THE STUDY: The aortic valve-sparing reimplantation operation (David) is increasingly used in patients with aortic root aneurysm and intact cusps. David's procedure is also feasible in patients with bicuspid aortic valve (BA), though few long-term data are available. METHODS: An analysis was conducted of the long-term echocardiographic data from patients with BAV who had undergone David's procedure at early and long-term follow up (FU) examinations. RESULTS: Between 1994 and 2010, a total of 30 patients with BAV underwent David's procedure at the authors'institution. There were no in-hospital or late deaths, and the mean long-term FU was 6.64 ± 3.54 years (range: 3.2-20.1 years). The mean aortic regurgitation (AR) grade was increased from 0.26 ± 0.37 at early FU to 0.70 ± 0.80 at long-term FU (p = 0.013). Four patients (13%) had to be reoperated after 10.00 ± 4.74 years (range: 5.49-17.06 years) due to aortic stenosis (n = 1) and aortic insufficiency (n = 3); the latter three patients had a significant prolapse of both the fused and the non-coronary cusp of reconstruction. CONCLUSION: The mean AR grade was increased significantly but was ≤ I-II in 59% of patients and ≤ II in 93% of patients after a mean FU of 6.6 years. Patients with prolapsing non-coronary leaflet at reconstruction seemed vulnerable to recurrent AR. Among patients, survival was excellent, and the reoperation rate and hemodynamics acceptable. Long-term follow up data are necessary to further refine the surgical techniques employed and to improve the results achieved.

Age-related reoperation rate after the Ross procedure: a report from the German Ross Registry.

BACKGROUND AND AIM OF THE STUDY: An increasing number of young adult patients are choosing bioprostheses for aortic valve replacement (AVR). In this context, the Ross operation deserves renewed consideration as an alternative biological substitute. After both the Ross procedure and bioprosthetic AVR, reoperation rates remain a concern and may be related to age at surgery. Herein are reported details of freedom from reoperation after the Ross procedure for different age groups. METHODS: The reoperation rates of 1,925 patients (1,444 males, 481 females; mean age 41.2 ± 15.3 years) from the German Ross registry with a mean follow up of 7.4 ± 4.7 years (range: 0.00-18.51 years; total 12,866.6 patient-years) were allocated to three age groups: group I < 40 years; group II 40-60 years; and group III > 60 years. RESULTS: At 10 years (respectively 15 years) of follow up, freedom from reoperation was 86% (76%) in group I, 93% (85%) in group II, and 89% (83%) in group III. CONCLUSION: There is some evidence that, at least during the first 10 and 15 years after AVR, the Ross procedure provides a significantly lower reoperation rate in young adult and middle-aged patients aged < 60 years. This information may be of interest to the patients' or physicians' decision-making for aortic valve surgery.

Atrial fibrillation burden estimates derived from intermittent rhythm monitoring are unreliable estimates of the true atrial fibrillation burden.

BACKGROUND: Estimates of atrial fibrillation (AF) burden (AFB) derived from intermittent rhythm monitoring (IRM) are increasingly being used as an outcome measure after therapeutic interventions; however, their accuracy has never been validated. The aim of this study was to compare IRM-derived AFB estimates to the true AFB as measured by implantable continuous monitoring (CM) devices. METHODS: Rhythm histories from 647 patients (mean AFB: 12 ± 22%; 687 patient·years) with CM devices were analyzed. IRM of various frequencies and durations were simulated and the obtained IRM-derived AF burdens were compared to the true AFB measured by CM. RESULTS: The relative error of the IRM burden estimates was dependent on the IRM length (P < 0.001), frequency of IRM (P < 0.001), the true AFB (P < 0.001), and its temporal aggregation (AF density, P < 0.001). In paroxysmal AF patients, the relative error even with aggressive IRM strategies was >80% of the true AFB. The relative error decreased with higher true AF burdens, lower AF densities, and higher IRM frequency or duration (P < 0.001). However, even in patients with high AF burdens and/or low AF densities, IRM estimates of AFB significantly deviated from the true AFB (relative error >20%, P < 0.001) and resulted in a substantial measurement error. CONCLUSION: IRM-derived AFB estimates are unreliable estimators of the true AFB. Particularly for paroxysmal AF patients, IRM-derived AFB estimates should not be used to evaluate outcomes after AF interventions.

Clinical outcomes and lessons learned with aortic valve repair in 508 patients.

BACKGROUND AND AIM OF THE STUDY: Aortic valve repair is an attractive alternative to valve replacement. Herein is presented the authors' single-center experience and lessons learned from 508 patients undergoing AVR, in three different groups. METHODS: Between 1993 and 2010, a total of 508 patients (148 females, 360 males; mean age 54 ± 17 years) underwent aortic valve repair. Operations included valve-sparing surgery (n = 253), isolated leaflet intervention (n = 158), and sinotubular junction (STJ) remodeling (n = 97). Aortic valve repair was defined as any primary or concomitant procedure performed at the level of the aortic valve or root for the restoration of function and/or anatomy of the valve. The mean follow up was 6.9 ± 3.8 years (range: 0-18 years; median: 6.3 years; total: 3,477 patient-years). The completeness of clinical follow up was 95%. RESULTS: The 30-day mortality with and without dissection was 4.4% (8/180) and 1.8% (6/328), respectively. Late survival without dissection, although statistically inferior, followed closely the expected general population. In total, 53 patients required a cardiac, valve-related reoperation. Among the valve-sparing group, no significant difference in freedom from reoperation at 10 years was observed between the David and Yacoub types (n = 147 (89%) versus n = 113 (79%); p = 0.373, respectively). Among patients who underwent isolated leaflet interventions, the number required to restore valve function (repair score) significantly affected the durability and incidence of reoperations (hazard ratio 1.47; 95% CI 1.1-2.0; p = 0.01), with the risk for failure being higher early after the operation. Patients with functional aortic insufficiency (AI) requiring only STJ remodeling resulted in the most durable outcome (freedom from reoperation 97.5% at 10 years). At the latest echocardiographic follow up (448 patients; total: 2,755 pt-yr; mean: 6.4 ± 3.7 years; completeness 88%), 97% of patients had AI of grade ≤ 2. CONCLUSION: Aortic valve repair is an attractive alternative to conventional replacement in many patients and pathologies. In particular, pathologies requiring multiple leaflet interventions and repair techniques may lead to suboptimal results. Leaflet quality and leaflet-adjusted root stabilization/reconstruction are key elements for durable results.

A comprehensive evaluation of rhythm monitoring strategies for the detection of atrial fibrillation recurrence: insights from 647 continuously monitored patients and implications for monitoring after therapeutic interventions.

BACKGROUND: Intermittent rhythm monitoring (IRM) to detect atrial fibrillation (AF) recurrence is employed to evaluate the success of therapeutic interventions. In a large population of patients with continuous monitoring (CM), we investigated the sensitivity of various frequencies and durations of IRM strategies on the detection of AF recurrence, the dynamics behind AF recurrence detection, and we describe measures to evaluate temporal AF recurrence. METHODS AND RESULTS: Rhythm histories of 647 patients (mean AF burden, 0.12±0.22; median, 0.014; 687 patient-years) with implantable CM devices were reconstructed and analyzed. With the use of computationally intensive simulation, the sensitivity of IRM of various frequencies and durations on the identification of AF recurrence was evaluated. Prolonged-duration IRM was superior to shorter IRM (P<0.0001). However, even with aggressive IRM strategies, AF recurrence was not detected in a great proportion of patients. The temporal AF burden aggregation (AF density) was directly related to IRM sensitivity (P<0.0001). Even at similar AF burdens, patients with high-density AF required higher-frequency or prolonged-duration IRM to achieve the same sensitivity as in low-density AF (P<0.0001). Patients with high-density, low-burden AF benefit the most from CM for detection of AF recurrence. CONCLUSIONS: IRM follow-up is significantly inferior to CM. IRM strategies will not identify AF recurrence in a great proportion of patients at risk. Temporal AF characteristics play a significant role in AF recurrence detection with the use of IRM. For the scientific, evidence-based evaluation of AF treatments, CM should be strongly recommended. Prospective studies are required to evaluate whether CM to guide clinical management can also improve patient outcomes. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00806689.

Living Longer or Better-Patient's Choice in Cardiac Surgery Is Gender-Dependent-A Multicenter Study.

In view of the increasing age of cardiac surgery patients, questions arise about the expected postoperative quality of life and the hoped-for prolonged life expectancy. Little is known so far about how these, respectively, are weighted by the patients concerned. This study aims to obtain information on the patients' preferences. Between 2015 and 2017, data were analyzed from 1349 consecutive patients undergoing cardiac surgery at seven heart centers in Germany. Baseline data regarding the patient's situation as well as a questionnaire regarding quality of life versus lifespan were taken preoperatively. Patients were divided by age into four groups: below 60, 60-70, 70-80, and above 80 years. As a result, when asked to decide between quality of life and length of life, about 60% of the male patients opted for quality of life, independent of their age. On the other hand, female patients' preference for quality of life increased significantly with age, from 51% in the group below sixty to 76% in the group above eighty years. This finding suggests that female patients adapt their preferences with age, whereas male patients do not. This should impact further the treatment decisions of elderly patients in cardiac surgery within a shared decision-making process.

Survival comparison of the Ross procedure and mechanical valve replacement with optimal self-management anticoagulation therapy: propensity-matched cohort study.

BACKGROUND: It is suggested that in young adults the Ross procedure results in better late patient survival compared with mechanical prosthesis implantation. We performed a propensity score-matched study that assessed late survival in young adult patients after a Ross procedure versus that after mechanical aortic valve replacement with optimal self-management anticoagulation therapy. METHODS AND RESULTS: We selected 918 Ross patients and 406 mechanical valve patients 18 to 60 years of age without dissection, aneurysm, or mitral valve replacement who survived an elective procedure (1994 to 2008). With the use of propensity score matching, late survival was compared between the 2 groups. Two hundred fifty-three patients with a mechanical valve (mean follow-up, 6.3 years) could be propensity matched to a Ross patient (mean follow-up, 5.1 years). Mean age of the matched cohort was 47.3 years in the Ross procedure group and 48.0 years in the mechanical valve group (P=0.17); the ratio of male to female patients was 3.2 in the Ross procedure group and 2.7 in the mechanical valve group (P=0.46). Linearized all-cause mortality rate was 0.53% per patient-year in the Ross procedure group compared with 0.30% per patient-year in the mechanical valve group (matched hazard ratio, 1.86; 95% confidence interval, 0.58 to 5.91; P=0.32). Late survival was comparable to that of the general German population. CONCLUSIONS: In comparable patients, there is no late survival difference in the first postoperative decade between the Ross procedure and mechanical aortic valve implantation with optimal anticoagulation self-management. Survival in these selected young adult patients closely resembles that of the general population, possibly as a result of highly specialized anticoagulation self-management, better timing of surgery, and improved patient selection in recent years.

Preoperative cerebral oxygen saturation and clinical outcomes in cardiac surgery.

BACKGROUND: The current study was designed to determine the relation between preoperative cerebral oxygen saturation (Sco2), variables of cardiopulmonary function, mortality, and morbidity in a heterogeneous cohort of cardiac surgery patients. METHODS: In this study, 1,178 consecutive patients scheduled for on-pump surgery were prospectively studied. Preoperative Sco2, demographics, N-terminal pro-B-type natriuretic peptide, high-sensitive troponin T, clinical outcomes, and 30-day and 1-yr mortality were recorded. RESULTS: Median additive EuroSCORE was 5 (range: 0-19). Thirty-day and 1-yr mortality and major morbidity (at least two major complications and/or a high-dependency unit stay of at least 10 days) were 3.5%, 7.7%, and 13.3%, respectively. Median minimal preoperative oxygen supplemented Sco2 (Sco2min-ox) was 64% (range: 15-92%). Sco2min-ox was correlated (all: P value <0.0001) with N-terminal pro-B-type natriuretic peptide (ρ: -0.35), high-sensitive troponin T (ρ: -0.28), hematocrit (ρ: 0.34), glomerular filtration rate (ρ: 0.19), EuroSCORE (τ: 0.20), and left ventricular ejection fraction class (τ: 0.12). Thirty-day nonsurvivors had a lower Sco2min-ox than survivors (median 58% [95% CI, 50.7-62%] vs. 64% [95% CI, 64-65%]; P < 0.0001). Receiver-operating curve analysis of Sco2min-ox and 30-day mortality revealed an area-under-the-curve of 0.71 (95% CI, 0.68-0.73%; P < 0.0001) in the total cohort and an area-under-the-curve of 0.77 (95% CI, 0.69-0.86%; P < 0.0001) in patients with a EuroSCORE more than 10. Logistic regression based on different EuroSCORE categories (0-2; 3-5, 6-10, >10), Sco2min-ox, and duration of cardiopulmonary bypass showed that a Sco2min-ox equal or less than 50% is an independent risk factor for 30-day and 1-yr mortality. CONCLUSIONS: Preoperative Sco2 levels are reflective of the severity of cardiopulmonary dysfunction, associated with short- and long-term mortality and morbidity, and may add to preoperative risk stratification in patients undergoing cardiac surgery.

Pulmonary homograft morphology after the Ross procedure: a computed tomography study.

BACKGROUND AND AIM OF THE STUDY: In patients undergoing the Ross procedure the autograft morphological characteristics have been well studied, but those of the homograft are less clear. The study aim was to describe the radiomorphological homograft characteristics in Ross patients, and to compare them with such characteristics in normal (control) subjects. METHODS: A total of 79 Ross patients (68 males, 11 females; mean age 43 +/- 12.3 years) underwent a computed tomography (CT) scan at a mean of 31 +/- 26 months after surgery. A group of 123 patients without cardiovascular disease served as controls. Cryopreserved homografts were implanted in all Ross patients, with the majority being obtained from a single source. RESULTS: The mean donor age was 47 +/- 11 years, and the mean homograft diameter 25.4 +/- 1.3 mm (as provided at source). Electrocardiographic-gated CT reconstructions were used for the measurements. The smallest diameters were at the proximal anastomosis, and maximum diameters at the distal anastomosis (p <0.001). In controls, the minimum diameter was just proximal to the pulmonary valve annulus. In Ross patients, the homograft diameters were significantly smaller at all levels compared to controls. This effect persisted after taking into consideration patient age, height, gender, body surface area, and time since surgery. Notably, the measured homograft diameters were significantly smaller than those provided at source. CONCLUSION: The study results provided evidence of homograft shrinkage at all levels after the Ross procedure but, most prominently, at the level of the proximal suture line. This may have implications for novel preservation methods, as well as homograft size selection and implantation techniques.

State-of-the-art: Insights from the Ross Registry.

The treatment of aortic valve disease in young patients is still a major clinical challenge, as the pre-eminent emphasis is on durability and long-term outcomes beyond 10 to 15 years, sometimes >20 to 30 years. The Ross procedure uses the autologous pulmonary valve as an aortic valve substitute and aims to improve valve durability while avoiding anticoagulation and therefore achieve a sustained long-term result with regard to survival, valve functionality, and quality of life. However, this procedure is technically demanding and only performed at a low frequency. Data investigating the Ross procedure are mostly limited to observational studies from single expert centers, while sufficient randomized data are almost completely lacking. Therefore, to create a clinically relevant database of this therapy, the multicenter Ross Registry was founded in 2001. New patients were included, follow-up of past patients continuously updated, and outcomes regularly reported. Throughout recent years, numerous analyses have been performed to characterize this patient population, surgical techniques, risk factors for morbidity and mortality, and most importantly survival outcomes. Currently, more than 2500 patients are included, and the long-term follow-up has reached >25 years in the very first patients who were included. In the most recent study, 2444 adult patients with a mean age of 44.1 ± 11.7 years were analyzed, and it showed that excellent mid-term survival is maintained after 25 years. In addition, the rate of reintervention was lower than reported in patients with xenografts and anticoagulation-related morbidity lower than reported in patients with mechanical valves. In the absence of robust randomized controlled trials, registry data are very important to monitor outcomes and mirror the quality of current practice. Therefore, the Ross Registry provides a unique and important data base regarding treatment of aortic valve disease in young patients.

Aortic valve replacement in sheep with a novel trileaflet mechanical heart valve prosthesis without anticoagulation.

Background: Even after decades of intensive research, an ideal heart valve prosthesis remains elusive. Shortcomings of conventional devices include reduced durability of bioprostheses and the thrombogenicity of mechanical substitutes, necessitating anticoagulation and resulting in imperfect hemodynamics. Here we present in vivo results of a novel mechanical heart valve prosthesis aiming for freedom from anticoagulation. Methods: Four female sheep had their aortic valves replaced using the novel mechanical heart valve (size 21 mm), with no postoperative anticoagulation treatment. This trileaflet heart valve was designed with the pivots in the systolic central flow. Hemodynamics, biochemistry, hematology, and macroscopy and microscopy were studied at 90 days in 2 sheep and at 1 year in the other 2 sheep. Results: Mean (<6 mm Hg) and peak (<10 mm Hg) aortic transvalvular gradients remained low during the study period. Aortic regurgitation was trivial, and central traces were only rarely observed. The rate of thrombotic events was very low, with none macroscopically and microscopically visible thrombotic material on the device. Biochemistry and hemotology were unchanged without hemolysis. In 3 sheep, the fibrous pannus and mitral leaflet were partially folded over the edge of the annular body. Apart from organic/inorganic deposits on the leaflets after 1 year, the ultrastructurally evaluated leaflets were similar to those of nonimplanted controls. Conclusions: The preliminary in vivo results of this novel anticoagulation-free aortic mechanical heart valve are promising with excellent hemodynamics and a very low risk of thrombotic events.

Reduced left ventricular contractility, increased diastolic operant stiffness and high energetic expenditure in patients with severe aortic regurgitation without indication for surgery.

OBJECTIVES: Recent mortality studies showed worse prognosis in patients (ARNS) with severe aortic regurgitation and preserved ejection fraction (EF) not fulfilling the criteria of current guidelines for surgery. The aim of our study was to analyse left ventricular (LV) systolic and diastolic function and mechanical energetics to find haemodynamic explanations for the reduced prognosis of these patients and to seek a new concept for surgery. METHODS: Global longitudinal strain (GLS) and echo-based single-beat pressure-volume analyses were performed in patients with ARNS (LV end-diastolic diameter <70 mm, EF >50%, GLS > -19% n = 41), with indication for surgery (ARS; n = 19) and in mild hypertensive controls (C; n = 20). Additionally, end-systolic elastance (LV contractility), stroke work and total energy (pressure-volume area) were calculated. RESULTS: ARNS demonstrated significantly depressed LV contractility versus C: end-systolic elastance (1.58 ± 0.7 vs 2.54 ± 0.8 mmHg/ml; P < 0.001), despite identical EF (EF: 59 ± 6% vs 59 ± 7%). Accordingly, GLS was decreased [-15.7 ± 2.7% (n = 31) vs -21.2 ± 2.4%; P < 0.001], end-diastolic volume (236 ± 90 vs 136 ± 30 ml; P < 0.001) and diastolic operant stiffness were markedly enlarged, as were pressure-volume area and stroke work, indicating waste of energy. The correlation of GLS versus end-systolic elastance was good (r = -0.66; P < 0.001). ARNS and ARS patients demonstrated similar haemodynamic disorders, whereas only GLS was worse in ARS. CONCLUSIONS: ARNS patients almost matched the ARS patients in their haemodynamic and energetic deterioration, thereby explaining poor prognosis reported in literature. GLS has been shown to be a reliable surrogate for LV contractility, possibly overestimating contractility due to exhausted preload reserve in aortic regurgitation patients. GLS may outperform conventional echo parameters to predict more precisely the timing of surgery.