There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Background Many patients with severe aortic stenosis and coexisting conditions are not candi dates for surgical replacement of the aortic valve. Recently, transcatheter aortic-valve implantation (TAVI) has been suggested as a less invasive treatment for high-risk patients with aortic stenosis. Methods We randomly assigned patients with severe aortic stenosis, whom surgeons considered not to be suitable candidates for surgery, to standard therapy (including balloon aortic valvuloplasty) or transfemoral transcatheter implantation of a balloon-expandable bovine pericardial valve. The primary end point was the rate of death from any cause. Results A total of 358 patients with aortic stenosis who were not considered to be suitable candidates for surgery underwent randomization at 21 centers (17 in the United States). At 1 year, the rate of death from any cause (Kaplan–Meier analysis) was 30.7% with TAVI, as compared with 50.7% with standard therapy (hazard ratio with TAVI, 0.55; 95% confidence interval [CI], 0.40 to 0.74; P<0.001). The rate of the composite end point of death from any cause or repeat hospitalization was 42.5% with TAVI as com pared with 71.6% with standard therapy (hazard ratio, 0.46; 95% CI, 0.35 to 0.59; P<0.001). Among survivors at 1 year, the rate of cardiac symptoms (New York Heart Association class III or IV) was lower among patients who had undergone TAVI than among those who had received standard therapy (25.2% vs. 58.0%, P<0.001). At 30 days, TAVI, as compared with standard therapy, was associated with a higher incidence of major strokes (5.0% vs. 1.1%, P = 0.06) and major vascular complications (16.2% vs. 1.1%, P<0.001). In the year after TAVI, there was no deterioration in the functioning of the bioprosthetic valve, as assessed by evidence of stenosis or regurgitation on an echocardiogram. Conclusions In patients with severe aortic stenosis who were not suitable candidates for surgery, TAVI, as compared with standard therapy, significantly reduced the rates of death from any cause, the composite end point of death from any cause or repeat hospitalization, and cardiac symptoms, despite the higher incidence of major strokes and major vascular events. (Funded by Edwards Lifesciences; ClinicalTrials.gov number, NCT00530894.)

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Transcatheter Aortic-Valve Implantation for Aortic Stenosis in Patients Who Cannot Undergo Surgery

Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

A b s t r ac t Background The use of transcatheter aortic-valve replacement has been shown to reduce mortality among high-risk patients with aortic stenosis who are not candidates for surgical replacement. However, the two procedures have not been compared in a randomized trial involving high-risk patients who are still candidates for surgical replacement. Methods At 25 centers, we randomly assigned 699 high-risk patients with severe aortic stenosis to undergo either transcatheter aortic-valve replacement with a balloon-expandable bovine pericardial valve (either a transfemoral or a transapical approach) or surgical replacement. The primary end point was death from any cause at 1 year. The primary hypothesis was that transcatheter replacement is not inferior to surgical replacement. Results The rates of death from any cause were 3.4% in the transcatheter group and 6.5% in the surgical group at 30 days (P = 0.07) and 24.2% and 26.8%, respectively, at 1 year (P = 0.44), a reduction of 2.6 percentage points in the transcatheter group (upper limit of the 95% confidence interval, 3.0 percentage points; predefined margin, 7.5 percentage points; P = 0.001 for noninferiority). The rates of major stroke were 3.8% in the transcatheter group and 2.1% in the surgical group at 30 days (P = 0.20) and 5.1% and 2.4%, respectively, at 1 year (P = 0.07). At 30 days, major vascular compli- cations were significantly more frequent with transcatheter replacement (11.0% vs. 3.2%, P<0.001); adverse events that were more frequent after surgical replacement included major bleeding (9.3% vs. 19.5%, P<0.001) and new-onset atrial fibrillation (8.6% vs. 16.0%, P = 0.006). More patients undergoing transcatheter replacement had an improvement in symptoms at 30 days, but by 1 year, there was not a significant between-group difference. Conclusions In high-risk patients with severe aortic stenosis, transcatheter and surgical proce- dures for aortic-valve replacement were associated with similar rates of survival at 1 year, although there were important differences in periprocedural risks. (Funded by Edwards Lifesciences; Clinical Trials.gov number, NCT00530894.)

/pdf/transcatheter-versus-surgical-aortic-valve-replacement-in-1g5w8nl0h8.pdf

Transcatheter versus Surgical Aortic-Valve Replacement in High-Risk Patients

2018 ESC/EACTS Guidelines on myocardial revascularization.

Out of the various applications of intraoperative echocardiography, the transesophageal approach in particular has become important for surgeons in reconfirming the patient’s disease and making appropriate decisions [12]. The usefulness of this method will increase further when technical facilities and surgeons’ understanding of echocardiographic imaging enable them routinely to examine patients pre- and postoperatively and to recognize irregularities in their procedures [8].

Intraoperative Transesophageal Echocardiography (TEE): The Surgeon’s Perspective

Purpose. Transcatheter aortic valve implantation (TAVI) results in the dislodgement of debris with risk of cerebral lesions or stroke. The EMBOL-X protection device (Edwards Lifesciences, Irvine, CA) is positioned within the ascending aorta to capture such debris. Description. Between July 2012 and April 2014 we randomly assigned 30 high-risk patients to undergo transaortic TAVI with the SAPIEN XT prosthesis (Edwards Lifesciences) combined with either the EMBOL-X device (group-1, n [ 14) or without (group-2, n [ 16). Periprocedural cerebral lesions were assessed by diffusion-weighted magnetic resonance imaging (DW-MRI) at baseline and within 7 days post-procedurally. Evaluation. New foci of restricted diffusion on cerebral DW-MRI were found in 69% in group-2 and 50% in group-1. Lesion size was smaller in patients treated with the EMBOL-X device than in those without (88 ± 60 vs 168 ± 217 mm 3 , p [ 0.27, t [ 1.2, degrees of freedom [ 10). Transaortic TAVI patients treated with the EMBOL-X device had significantly smaller lesion volumes in the supply region of the middle cerebral artery (33 ± 29 vs 76 ± 67 mm 3 , p [ 0.04). There were no neurologic events after transaortic TAVI. Conclusions. The intraaortic protection device seems to reduce both the incidence and the volume of new cerebral lesions (ClinicalTrials.gov number, NCT01735513).

https://www.annalsthoracicsurgery.org/article/S0003-4975(15)00669-4/pdf

Intraaortic Protection From Embolization in Patients Undergoing Transaortic Transcatheter Aortic Valve

Time for synchronizing international efforts to jointly develop a consensus and strategy for treatment variations in acute type A aortic dissection.

We thank Dr Urbanski for his kind comments and demonstration of his personal results [1]. There is an obvious misunderstanding in the interpretation of our surgical principles in assuming that a complete resection of all dissected aortic walls was not performed in all patients. On the contrary, all dissected aortic walls were removed in all Type II patients according to our modification of DeBakey’s original classification with extension to the end of the aortic arch, as indicated in the ‘Surgical management’ section [2]. This means that, in 44 patients with Type II dissection, complete removal of the dissected aortic wall was achieved by the sole ascending aortic replacement in 12 (27%), by hemiarch in 16 (36%) and total arch replacement in another 16 (36%) patients. Beyond this, the intention of our article is to demonstrate, that after removal of all dissected tissue, none of the survivors faced any late complications of the downstream aorta. Reiteration of the data pool of the presented Type II patients by January 2012, with continuing complete follow-up from now up to 10 years (mean ± SD 2.8 ± 2 years), confirms the observation from our article that none of the patients developed later downstream aortic dissection or associated pathologies, besides one isolated, infrarenal aortic aneurysm. This indicates that DeBakey’s original assumption that ‘complete resection of the dissected (ascending) aorta could be curative’ holds true for the aortic arch as well [3]. Dr Urbanski’s plea for a different classification, taking into consideration the extent of dissection and the location of the intimal tear, is in good company with several historic attempts to better conceive the anatomical and pathophysiological situation, as described by Dr Kirsch in his thoughtful editorial comment on our article [4]. What all those alternative classifications have in common is their complexity or even impracticability for daily use. In our opinion, the Stanford classification remains the keystone classification in fast clinical decision making, and the DeBakey classification, in its upgraded version based on today’s knowledge and imaging capacities, is the best tool for prognostic judgement after surgical repair. The major intention of our article is to provoke other established groups in the field of thoracic aortic surgery to check with their data bases and ascertain whether or not our, as well as Dr Urbanski’s, observation holds true, that the resection of all dissected aortic tissue renders a very favourable prognosis in regard to cure of the aortic disease. Since up to 40% of all thoracic aortic dissection cases are included in this subgroup, long-term follow-up studies should be undertaken by separating this large subgroup from the Type A patients, which represent the vast preponderance of all publications worldwide. This, however, would mean that up to 40% of those Type A patients would not expect late complications like patients with Type I dissection and persisting false lumen. The consequence would be that there is an enormous underestimation of late risk for downstream complications as judged today. Attempts to treat a dissected descending aorta simultaneously with the ascending aorta and/or arch would be even more justified than today.

Heinz Jakob

Papers

Intraoperative Transesophageal Echocardiography (TEE): The Surgeon’s Perspective

Intraaortic Protection From Embolization in Patients Undergoing Transaortic Transcatheter Aortic Valve

Time for synchronizing international efforts to jointly develop a consensus and strategy for treatment variations in acute type A aortic dissection.

Reply to Urbanski