Cost and Outcome of PPM Implantation
Cost
Patients with AV conduction disturbances after TAVR are disposed to prolonged hospitalisation and use of in-hospital continuous telemetry43, both of which result in a considerable increase of overall cost of the TAVR procedure. Data from the FRANCE registry found that receiving a pacemaker was associated with a 36 % increase in cost44. Gutmann et al. assessed elevated procedural costs of €1,946 in case of PPM implantation in a German healthcare analysis45. Compared with surgical aortic valve replacement (SAVR), in-hospital costs were higher in TAVR patients than in SAVR patients (€40,802 versus €33,354, respectively; p=0.010)46). Reducing PPM rate would have an impact on the cost-effectiveness of TAVR relative to that of SAVR.
Outcome
The impact of new-onset LBBB, with or without need for PPM implantation, on patient outcome after TAVR is still under debate. Houthuizen et al. found negative effects of a procedure-related LBBB on survival in a group of 679 patients after TAVR. They described an all-cause mortality of 37.8 % (n=88) in 233 patients with new-onset LBBB and 24.0 % (n=107) in patients without LBBB (p=0.002) after a median follow-up of 450 days. Consecutively, a procedure-related LBBB was an independent predictor for all-cause mortality (hazard ratio: 1.54; confidence interval (CI): 1.12–2.10) in this cohort47.
Schymik et al. confirmed that a persistent new-onset LBBB was associated with increased mortality in a cohort of 634 patients who were treated by either an MCP or ESV prosthesis. The one-year all-cause mortality rate was also higher in patients with persistent new-onset LBBB (20.8 %, n=41) than in patients without LBBB (13.0 %, n=57; p=0.010). Multivariate regression analysis revealed again that persistent new-onset LBBB was an independent predictor of all-cause mortality at one year (HR 1.84, 95 % CI 1.35–2.02).
However, Buellesfeld et al. recently published data on 353 patients undergoing TAVR with the CoreValve prosthesis and found that PPM implantation had no impact on major adverse cardiac and cerebrovascular events or mortality outcome one year after TAVR48. Other study groups found no difference in mortality regarding LBBB or PPM49–51. Hoffmann et al. found a significantly higher left ventricular ejection fraction in patients after TAVR without LBBB (59±10 %) as compared with those with LBBB during 12 months of follow-up (51±12 %; p=0.052), but found no difference in clinical outcome52. These findings were confirmed by Nazif et al. who presented the one-year results of the PARTNER trial and focused on new-onset LBBB which was not associated with significant differences in
one-year mortality, cardiovascular mortality or repeat hospitalisation. However, it was associated with increased PPM implantation during hospitalisation (8.3 % versus 2.8 %, p=0.005) and the ejection fraction failed to improve after TAVR in patients with new LBBB and remained lower at six months to one year (52.8 % versus 58.1 %, p=0.001)53. The independent predictors of the outcome in patients with new-onset LBBB (including the protective or detrimental effect of pacemaker implantation after TAVR) are currently unclear and still need further investigation.
Clinical Implication
Temporarily inserted pacing leads are mandatory for rapid pacing during the procedure as well for at least 24 hours after TAVR for therapy of delayed bradycardia. Patients with self-expanding valves like the MCP should be monitored for at least 48 hours after TAVR54. In case of new-onset LBBB or AV block, ECG monitoring should be continued for five days. In particular, those patients with pre-existing conduction disturbances such as RBBB or first-degree AV block should be carefully monitored with daily ECG. Pacemaker rates after TAVR may be safely decreased by avoiding pre-dilatation or use of undersized balloons31, as well as correct positioning of the prosthesis37.
Future Considerations
Increasing data from observational studies involving new valve technologies, such as the Direct Flow Medical (Santa Rosa, CA, USA), the Lotus Aortic Valve prosthesis (Boston Scientific Corporation, Marlborough, Massachusetts), the JenaValve™ system (JenaValve Technology GmbH, Munich, Germany), the transfemoral Medtronic Evolut R, and the transapical Medtronic Engager (Medtronic, Minneapolis, Minnesota) show promising results and improve outcomes by minimising procedure-related complications. Future studies might give new answers on predictors and outcome after TAVR regarding PPM.