Transcatheter Aortic Valve Implantation: Insights into Clinical Complications

__Abstract__ Transcatheter Aortic Valve Implantation (TAVI) has emerged as a viable and safe treatment for patients with severe aortic stenosis (AS) who are considered ineligible or at prohibitive risk for Surgical Aortic Valve Replacement (SAVR)1–4. The aim of the present thesis was to evaluate the in-hospital complications and the determinants or factors associated with outcome after TAVI, thereby, offering insight into the pathophysiology of complications that in turn may help to propose recommendations to improve the planning, execution and follow-up of TAVI

Defective recovery of QT dispersion following transcatheter aortic valve implantation: Frequency, predictors and prognosis

Background: Corrected QT dispersion (cQTD) has been correlated with non-uniform ventricular repolarisation and increased mortality. In patients with aortic stenosis, cQTD has been shown improved after surgical valve replacement, but the effects of transcatheter aortic valve implantation (TAVI) are unknown. Therefore, we sought to explore the frequency, predictors and prognostic effects of defective cQTD recovery at 6 months after TAVI. Methods: A total of 222 patients underwent TAVI with the Medtronic-CoreValve System between November 2005 and January 2012. Patients who were on class I or III antiarrhythmics or on chronic haemodialysis or who developed atrial fibrillation, a new bundle branch block or became pacemaker dependent after TAVI were excluded. As a result, pre-, post- and follow-up ECG (median: 6 months) analysis was available in 45 eligible patients. Defective cQTD recovery was defined as any progression beyond the baseline cQTD at 6 months. Results: In the 45 patients, the mean cQTD was 47 ± 23 ms at baseline, 45 ± 17 ms immediately after TAVI and 40 ± 16 ms at 6 months (15% reduction, P = 0.049). Compared to baseline, cQTD at 6 months was improved in 60% of the patients whereas defective cQTD recovery was present in 40%. cQTD increase immediately after TAVI was an independent predictor of defective cQTD recovery at 6 months (per 10 ms increase; OR: 1.89, 95% CI: 1.15-3.12). By univariable analysis, defective cQTD recovery was associated with late mortality (HR: 1.52, 95% CI: 1.05-2.17). Conclusions: Despite a gradual reduction of cQTD after TAVI, 40% of the patients had defective recovery at 6 months which was associated with late mortality. More detailed ECG analysis after TAVI may

The SURTAVI model: Proposal for a pragmatic risk stratification for patients with severe aortic stenosis

Transcatheter aortic valve implantation (TAVI) is a less invasive alternative to surgical aortic valve replacement (SAVR) for patients with symptomatic severe aortic stenosis (AS) and a high operative risk. Risk stratification plays a decisive role in the optimal selection of therapeutic strategies for AS patients. The accuracy of contemporary surgical risk algorithms for AS patients has spurred considerable debate especially in the higher risk patient population. Future trials will explore TAVI in patients at intermediate operative risk. During the design of the SURgical replacement and Transcatheter Aortic Valve Implantation (SURTAVI) trial, a novel concept of risk stratification was proposed based upon age in combination with a fixed number of predefined risk factors, which are relatively prevalent, easy to capture and with a reasonable impact on operative mortality. Retrospective application of this algorithm to a contemporary academic practice dealing with clinically significant AS patients allocates about one-fourth of these patients as being at intermediate operative risk. Further testing is required for validation of this new paradigm in risk stratification. Finally, the Heart Team, consisting of at least an interventional cardiologist and cardiothoracic surgeon, should have the decisive role in determining whether a patient could be treated with TAVI or SAVR

Aortic annulus dimensions and leaflet calcification from contrast MSCT predict the need for balloon post-dilatation after TAVI with the Medtronic CoreValve prosthesis

Aims: We compared the measurement of aortic leaflet calcification on contrast and non-contrast MSCT and investigated predictors of the need for balloon post-dilatation after TAVI. Methods and results: In 110 patients, who had TAVI with a Medtronic CoreValve prosthesis (MCS) for symptomatic aortic stenosis, calcification of the aortic root was measured on non-contrast MSCT (conventionally) and on contrast MSCT (signal attenuation >450 Houndsfield units). Calcium volume was underestimated on contrast- when compared to non-contrast MSCT: median (IQ-range)=759 (466 to 1295) vs. 2016 (1376 to 3262) and the difference between the two methods increased with higher calcium volumes (correlation coefficient r=0.90). Calcium mass was only slightly underestimated on contrast vs. non-contrast MSCT: median (IQ-range)=441 (268 to 809) vs. 555 (341 to 950) and there was no association between the differences and increasing calcium mass (r=0.17). Balloon post-dilatation was performed for significant aortic regurgitation after TAVI in 11 of 110 patients. When compared to controls, the patients who required balloon post-dilatation had higher aortic leaflet calcium on contrast CT (p0.80 for all), whereas the discriminatory value of aortic annulus dimensions was moderate (area under ROC=0.69) and that of prosthesis to annulus ratio was poor (area under ROC=0.36). Conclusions: Dense aortic leaflet calcification measured on contrast MSCT discerned well the need for balloon post-dilatation after TAVI with an MCS for significant PAR. Non-contrast MSCT may no longer be needed to quantify aortic root calcium before TAVI