Emergency treatment of decompensated aortic stenosis.

OBJECTIVE: The optimal treatment of patients with acute and severe decompensation of aortic stenosis is unclear due to recent advances in transcatheter interventions and supportive therapies. Our aim was to assess the early outcome of emergency transcatheter aortic valve implantation (eTAVI) versus emergency balloon aortic valvuloplasty (eBAV) followed by TAVI under elective circumstances. METHODS: Emergency conditions were defined as: cardiogenic shock with requirement of catecholamine therapy, severe acute dyspnoea (NYHA IV), cardiac resuscitation or mechanic respiratory support. The data were collected according to the Valve Academic Research Consortium 2 (VARC-2) criteria. RESULTS: In five German centres, 23 patients (logistic Euroscore 37.7%±18.1) underwent eTAVI and 118 patients underwent eBAV (logistic Euroscore 35.3%±20.8). In the eTAVI group, immediate procedural mortality was 8.7%, compared with 20.3% for the eBAV group (p=0.19). After 30 days, cardiovascular mortality for the eTAVI group was 23.8% and for the eBAV group 33.0% (p=0.40). Analyses adjusting for potential confounders did not provide evidence of a difference between groups. Of note, the elective TAVI performed after eBAV (n=32, logistic Euroscore 25.9%±13.9) displayed an immediate procedural mortality of 9.4% and a cardiovascular mortality after 30 days of 15.6%. Major vascular complications were significantly more likely to occur after eTAVI (p=0.01) as well as stroke (p=0.01). CONCLUSION: In this multicentre cohort, immediate procedural and 30-day mortality of eTAVI and eBAV were high, and mortality of secondary TAVI subsequent to eBAV was higher than expected. Randomised study data are required to define the role of emergency TAVI in tertiary care centres with current device generations.

Transaortic transcatheter aortic valve implantation: experience from the Kiel study.

OBJECTIVES: To evaluate the efficacy and safety of Edwards SAPIEN-XT or SAPIEN-3 transcatheter heart valves via transaortic (TAo) access. METHODS: A total of 100 consecutive patients with severe symptomatic aortic stenosis undergoing TAo-transcatheter aortic valve implantation (TAVI) were included in this observational registry (November 2012-December 2014). Periprocedural and post-procedural outcomes were assessed. RESULTS: Of these 100 patients, 1 received a Medtronic CoreValve. Therefore, this patient was subsequently removed from the analysis. Ninety-nine consecutive TAo-TAVI patients received a balloon-expandable transcatheter heart valve (Sapien). The SAPIEN-XT valve was implanted in 53 patients and the SAPIEN-3 valve in 46 patients. Fluoroscopy time was shorter in the SAPIEN-3 cases (5.6 ± 2.5 vs 8.1 ± 5.1 min, SAPIEN-XT; P = 0.004), with fewer patients requiring dilatation after the operation (20.5% SAPIEN-3 vs 64.2% SAPIEN-XT; P < 0.0001). There were no other significant differences in procedural characteristics between the two valves. All-cause 30-day mortality was 5.1% overall, with comparable outcomes for the two valves (5.7 and 4.4% for SAPIEN-XT and SAPIEN-3 valves, respectively; OR: 1.32; 95% CI: 0.21-8.27; P = 1.0). New atrial fibrillation (13.1%) and acute kidney injury (11.1%) were the most common complications during the 30 days post-procedure. The number of new pacemakers was low (6.1%), with no differences found between the two valve groups. A comparison of 100 TAo- and 42 TA-TAVI implanted in the same period demonstrated similar results in short- (P = 0.31) and long-term (P = 0.99) mortality rates. CONCLUSIONS: The efficacy and safety of the Edwards SAPIEN-XT or SAPIEN-3 heart valves via TAo access were demonstrated by high procedural success and low complication rates. The data indicate that this approach is a viable alternative to established access routes.

Dyrk1a regulates the cardiomyocyte cell cycle via D-cyclin-dependent Rb/E2f-signalling.

AIMS: Down syndrome-associated dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1A (DYRK1A) is a ubiquitously expressed protein kinase. Up to date a variety of targets have been identified, establishing a key role for Dyrk1a in selected signalling pathways. In cardiomyocytes, Dyrk1a acts as a negative regulator of hypertrophy by phosphorylating transcription factors of the NFAT family, but its mechanistic function in the heart remains poorly understood. This study was designed to investigate a potential protective role of Dyrk1a in cardiac hypertrophy in vivo. METHODS AND RESULTS: We generated transgenic mice with cardiac-specific overexpression of Dyrk1a. Counterintuitively, these mice developed severe dilated cardiomyopathy associated with congestive heart failure and premature death. In search for the cause of this unexpected phenotype, we found that Dyrk1a interacts with all members of the D-cyclin family and represses their protein levels in vitro and in vivo. Particularly, forced expression of Dyrk1a leads to increased phosphorylation of Ccnd2 on Thr280 and promotes its subsequent proteasomal degradation. Accordingly, cardiomyocytes overexpressing Dyrk1a display hypo-phosphorylated Rb1, suppression of Rb/E2f-signalling, and reduced expression of E2f-target genes, which ultimately results in impaired cell cycle progression. CONCLUSIONS: We identified Dyrk1a as a novel negative regulator of D-cyclin-mediated Rb/E2f-signalling. As dysregulation of this pathway with impaired cardiomyocyte proliferation leads to cardiomyopathy, dose-specific Dyrk1a expression and activity appears to be critical for the hyperplastic and hypertrophic growth of the developing heart.

Coculture with hematopoietic stem cells protects cardiomyocytes against apoptosis via paracrine activation of AKT.

BACKGROUND: Previous experimental studies concluded that stem cells (SC) may exert their beneficial effects on the ischemic heart by paracrine activation of antiapoptotic pathways. In order to identify potential cardioprotective mediators, we performed a systematic analysis of the differential gene expression of hematopoietic SC after coculture with cardiomyocytes (CM). METHODS: After 48 h of coculture with neonatal rat ventricular CM (NRVCM), two consecutive cell sorting steps generated a highly purified population of conditioned murine hematopoietic SC (>99%). Next, a genome-wide microarray analysis of cocultured vs. monocultured hematopoietic SC derived from three independent experiments was performed. The analysis of differentially expressed genes was focused on products that are secretable and/or membrane-bound and potentially involved in antiapoptotic signalling. RESULTS: We found CCL-12, Macrophage Inhibitory Factor, Fibronectin and connexin 40 significantly upregulated in our coculture model. An ELISA of cell culture supernatants was performed to confirm secretion of candidate genes and showed that coculture supernatants revealed markedly higher CCL-12 concentrations. Moreover, we stimulated NRVCM with concentrated coculture supernatants which resulted in a significant reduction of apoptosis compared to monoculture-derived supernatant. Mechanistically, NRVCMs stimulated with coculture supernatants showed a higher level of AKT-phosphorylation, consistent with enhanced antiapoptotic signaling. CONCLUSION: In summary, our results show that the interaction between hematopoietic SC and NRVCM led to a modified gene expression and induction of antiapoptotic pathways. These findings may thus at least in part explain the cardioprotective effects of hematopoietic SC.