Surgical aortic valve replacements increasingly use bioprosthesis implants rather than mechanical valves.¹ Structural valve deterioration can result in leaflet degeneration and failure, as evidenced by valve stenosis, regurgitation, or a combination of both.^2-4 Owing to a considerable shift toward bioprosthesis implantation, it is expected that patients will increasingly present with degenerated bioprostheses. Treatment of patients with failed bioprostheses is a clinical challenge. Although reoperation is considered the standard of care, these patients are frequently elderly, and repeat cardiac surgery carries significant morbidity and mortality risks.^5,6

There are limited data on coronary obstruction following transcatheter valve-in-valve (ViV) implantation inside failed aortic bioprostheses. The objectives of this study were to determine the incidence, predictors, and clinical outcomes of coronary obstruction in transcatheter ViV procedures. A total of 1612 aortic procedures from the Valve-in-Valve International Data (VIVID) Registry were evaluated. Data were subject to centralized blinded corelab computed tomography (CT) analysis in a subset of patients. The virtual transcatheter valve to coronary ostium distance (VTC) was determined. A total of 37 patients (2.3%) had clinically evident coronary obstruction. Baseline clinical characteristics in the coronary obstruction patients were similar to controls. Coronary obstruction was more common in stented bioprostheses with externally mounted leaflets or stentless bioprostheses than in stented with internally mounted leaflets bioprostheses (6.1% vs. 3.7% vs. 0.8%, respectively; P < 0.001). CT measurements were obtained in 20 (54%) and 90 (5.4%) of patients with and without coronary obstruction, respectively. VTC distance was shorter in coronary obstruction patients in relation to controls (3.24 ± 2.22 vs. 6.30 ± 2.34, respectively; P < 0.001). Using multivariable analysis, the use of a stentless or stented bioprosthesis with externally mounted leaflets [odds ratio (OR): 7.67; 95% confidence interval (CI): 3.14–18.7; P < 0.001] associated with coronary obstruction for the global population. In a second model with CT data, a shorter VTC distance predicted this complication (OR: 0.22 per 1 mm increase; 95% CI: 0.09–0.51; P < 0.001), with an optimal cut-off level of 4 mm (area under the curve: 0.943; P < 0.001). Coronary obstruction was associated with a high 30-day mortality (52.9% vs. 3.9% in the controls, respectively; P < 0.001). Coronary obstruction following aortic ViV procedures is a life-threatening complication that occurred more frequently in patients with prior stentless or stented bioprostheses with externally mounted leaflets and in those with a short VTC.

In animal models of conotruncal heart defects, an abnormal calcium sensitivity of the contractile apparatus and a depressed L-type calcium current have been described. Sarcoplasmic reticulum (SR) Ca(2+) ATPase (SERCA) is a membrane protein that catalyzes the ATP-dependent transport of Ca(2+) from the cytosol to the SR. The activity of SERCA is inhibited by phospholamban (PLN) and sarcolipin (SLN), and all these proteins participate in maintaining the normal intracellular calcium handling. Ryanodine receptors (RyRs) are the major SR calcium-release channels required for excitation-contraction coupling in skeletal and cardiac muscle. Our objective was to evaluate SERCA2a (i.e., the SERCA cardiac isoform), PLN, SLN, and RyR2 (i.e., the RyR isoform enriched in the heart) gene expression in myocardial tissue of patients affected by tetralogy of Fallot (TOF), a conotruncal heart defect. The gene expression of target genes was assessed semiquantitatively by RT-PCR using the calsequestrin (CASQ, a housekeeping gene) RNA as internal standard in the atrial myocardium of 23 pediatric patients undergoing surgical correction of TOF, in 10 age-matched patients with ventricular septal defect (VSD) and in 13 age-matched children with atrial septal defect (ASD). We observed a significantly lower expression of PLN and SLN in TOF patients, while there was no difference between the expression of SERCA2a and RyR2 in TOF and VSD. These data suggest a complex mechanism aimed to enhance the intracellular Ca(2+) reserve in children affected by tetralogy of Fallot.

Life-threatening complications occur during transcatheter aortic valve implantation (TAVI) which can require emergent cardiac surgery (ECS). Risks and outcomes of patients needing ECS during or immediately after TAVI are still unclear. Incidence, risk factors, management, and outcomes of patients requiring ECS during transfemoral (TF)-TAVI were analysed from a contemporary real-world multicentre registry. Between 2013 and 2016, 27 760 patients underwent TF-TAVI in 79 centres. Of these, 212 (0.76%) patients required ECS (age 82.4 ± 6.3 years, 67.5% females, logistic EuroSCORE: 17.1%, STS-score 5.8%). The risk of ECS declined from 2013 (1.07%) to 2014 (0.70%) but remained stable since. Annual TF-TAVI numbers have more than doubled from 2013 to 2016. Leading causes for ECS were left ventricular perforation by the guidewire (28.3%) and annular rupture (21.2%). Immediate procedural mortality ( 85 years [odds ratio (OR) 1.87, 95% confidence interval (95% CI) (1.02–3.45), P = 0.044], annular rupture [OR 1.96, 95% CI (0.94–4.10), P = 0.060], and immediate ECS [OR 3.12, 95% CI (1.07–9.11), P = 0.037]. One year of survival of the 114 patients surviving the in-hospital period was only 40.4%. Between 2014 and 2016, the need for ECS remained stable around 0.7%. Left ventricular guidewire perforation and annular rupture were the most frequent causes, accounting for almost half of ECS cases. Half of the patients could be salvaged by ECS—nevertheless, 1 year of all-cause mortality was high even in those ECS patients surviving the in-hospital period.

Recent studies have suggested an increased risk of stroke in patients undergoing minimally invasive mitral-valve surgery with retrograde perfusion when compared with antegrade perfusion. The aim of the present study was therefore to evaluate the impact on early outcome of retrograde arterial perfusion (RAP) strategy vs antegrade arterial perfusion strategy in a consecutive large cohort of patients who underwent minimally invasive mitral-valve surgery through a right minithoracotomy. Between 2003 and 2012, 1280 consecutive patients underwent first-time minimally invasive mitral-valve surgery at our institution. A total of 167 (13%) of these patients received a retrograde perfusion, while 1113 (87%) received antegrade perfusion. Logistic analysis was used to evaluate outcomes and risk factors for stroke. Treatment selection bias was controlled by constructing a propensity score from core patient characteristics. The propensity score was the probability of receiving retrograde perfusion and was included along with the comparison variable in the multivariable analyses of outcome. The overall frequency of in-hospital mortality was 1.1% (14/1280) and postoperative stroke was 1.6% (21/1280). After adjusting for the propensity score, RAP was associated with a higher incidence of stroke (5 vs 1%; P = 0.002), postoperative delirium (14 vs 5%, P = 0.001) and aortic dissection (1.7 vs 0%; P = 0.01). Multivariable regression analysis revealed that the use of retrograde perfusion was an independent risk factor for stroke [odds ratio (OR) 4.28; P = 0.02] and postoperative delirium (OR 3.51; P = 0.001). Minimally invasive mitral valve procedure can be performed with low morbidity and mortality. The use of retrograde perfusion is associated with a higher incidence of neurological complications and aortic dissection when compared with antegrade perfusion. Central aortic cannulation allows the avoidance of complications associated with retrograde perfusion while extending the suitability of minimally invasive mitral procedures also to those patients who have an absolute contraindication to femoral artery cannulation.