Predictors and incidence of access site complications in transcatheter aortic valve implantation with the use of new delivery systems.

OBJECTIVES: The aim of this single-center study was to assess the incidence and predictors of in-hospital access site complications related to transcatheter aortic valve implantation (TAVI) performed with new delivery systems in our hospital which has the largest case series in Turkey. MATERIALS AND METHOD: We performed successful TAVI with the Edwards Sapien XT valve to 127 (46 male) patients via a transfemoral (121), trans-subclavian (5) and transapical (1) approach. Access site complications were defined according to the Valve Academic Research Consortium (VARC) end-point definitions. RESULTS: Vascular complications occurred in 10.1% of patients. There was negative correlation between vascular complications and diameter of the common femoral artery (r = - 0.301, p=0.004), external iliac artery (r = - 0.327, p=0.004) and common iliac artery (r = - 0.324, p=0.004), but positive correlation between diabetes (r =0.240, p=0.008), sheath to femoral artery ratio (SFAR), sheath to external iliac artery ratio (SEIAR), procedure time, discharge time and the Society of Thoracic Surgeons (STS) score (respectively; r=0.339, 0.001, 0.527, 0.361, 0.289, p=0.003, 0.001, 0.001, 0.001, 0.002). The incidence of vascular complications was significantly higher in patients with diabetes and a high STS score. VARC bleeding complications occurred in 11.7 % of patients. The learning curve pointing out the importance of experience was significantly important in decreasing both bleeding and vascular complications. CONCLUSIONS: In this study, we demonstrated that major vascular complications related to TAVI decrease with the use of smaller delivery systems and experience and increase with high-risk scores (STS) and the presence of diabetes. In addition, VARC major vascular complications, observed mostly in patients with diabete mellitus (DM) and high STS scores, were associated with vascular diameters. These results further underline the importance of experience and a multidisciplinary team in patient selection and management for TAVI.

Central muscarinic M2 cholinoceptors involved in cholinergic hypertension.

Cholinomimetic agents increase blood pressure and heart rate via central muscarinic cholinoceptors in various species. It was reported that i.c.v. injection of the muscarinic M1 and M3 cholinoceptor selective antagonist, 4-DAMP (4-diphenylacetoxy-N-methyl-piperidine methiodide), inhibited the pressor response to physostigmine, while the M1 selective antagonist, pirenzepine, was ineffective. In the present study, the involvement of muscarinic M2 cholinoceptors in central cholinergic hypertension and tachycardia was investigated. Physostigmine (10-80 micrograms/kg i.v.), a cholinesterase inhibitor, and oxotremorine (20-40 micrograms/kg i.v.), a direct muscarinic cholinoceptor agonist, caused a dose-dependent increase in blood pressure. Additionally, physostigmine induced dose-dependent tachycardiac responses. I.c.v. administration of the muscarinic M2 cholinoceptor antagonists, AF-DX 116 and methoctramine, inhibited both physostigmine (60 micrograms/kg) and oxotremorine (20 micrograms/kg)-induced pressor responses at their lower doses used in this study (100 nmol/rat and 10 nmol/rat, respectively). These findings indicate the partial involvement of postsynaptic muscarinic M2 cholinoceptors. The higher doses of the antagonists (AF-DX 116,300 nmol/rat and methoctramine 30 nmol/rat) potentiated the blood pressure increase due to physostigmine but did not affect that due to oxotremorine. The physostigmine-induced tachycardiac responses were influenced similarly by these antagonists. These results suggest the presence and tonic influence of presynaptic inhibitory muscarinic M2 cholinoceptors.