Does the use of Suture-less Prosthesis increase the Risk for Permanent Pacemaker Implantation following Aortic Valve replacement?

Background:
The use of Suturless Aortic Valve replacement (SU-AVR) in aortic valve stenosis is increasing. It is associated with reduced cross clamp (XCL) and cardiopulmonary bypass (CPB) times and easier valve replacement via minimal invasive approach. Recent reports, however, have shown a trend for increasing incidence of post-operative conduction disorders.

Objectives:
We sought to evaluate the incidence and predictors for permanent pacemaker (PPM) implantation following SU-AVR.

Methods:
We compared SU-AVR and conventional -AVR (C-AVR) Between January 2011 and November 2016. 95 patients underwent isolated SU-AVR versus 324 patients isolated C-AVR due to severe aortic stenosis. Propensity score match was performed between the groups. Predictive baseline, procedural variables were equated.

Results:
73 pairs were compared with no difference in the baseline predictors (age 75±6 SU-AVR;75±6 C-AVR [p=0.67], males 36% SU- AVR; 32% C-AVR [p=0.72], logEuroscore 8.5±9.8 SU-AVR; 8.9±9.7 C-AVR [p=0.81]). ECG parameters included atrial fibrillation (7% SU-AVR; 4% C-AVR [p=0.71]), first degree AVB (10% SU-AVR; 4%C-AVR[p=0.32], LBBB (4% SU-AVR; 6%C-AVR [p=1.00], RBBB (6% SU-AVR; 4% C-AVR [p=1.00], Bi-fascicular block (3% SU-AVR; 0% C-AVR [p=0.49], Left Anterior Hemi-block (0% SU-AVR; 1 %C-AVR [p=1.00]). As expected XCL and CPB time was shorter in SU-AVR (45±15 SU-AVR;C-AVR 70±24 [p=0.00],70±27SU-AVR; 93±51 C-AVR [p=0.001] respectively).There was a significantly higher incidence of PPM implantation in the SU-AVR group versus C-AVR (11% vs 1%[p=0.033]). In a univariated analysis significant correlation was found between pre-operative conduction disturbances and PPM implantation (67% PPM group,20% non-PPM;[p=0.004]). In a multi-variate analysis only pre-operative conduction disturbances predicted PPM implantation (95% CI 9.5[1.47-61.87], p=0.018)

Conclusion:
SU-AVR gives advantage of shorter CPB and XCL times. In patients with pre-operative conduction disturbances SU-AVR increases the risk for PPM implantation. The incidence can be reduced by excluding patients with pre-operative conduction disorders.