Original title: Pacemaker implantation following transcatheter aortic valve implantation: Impact on late clinical outcomes and left ventricular function. Reference: Urena M et al. Circulation. 2014 Mar 18;129(11):1233-43.
The need for permanent pacemaker implantation (PPI) is one of the most frequent complications associated with TAVI. Although data suggest that right ventricle stimulation has a potential negative impact, the evidence on the clinical impact of the PPI post TAVI remains weak and is based on small studies. Urena and colleagues conducted a multicentre study with a large cohort of patients undergoing TAVI (with self-expanding and balloon expandable valves, SEV or BEV, respectively), with the objective of evaluating the impact of the new placement of a pacemaker in the final results over the left ventricular function and functional status.
The study population consisted of 1556 patients, 239 (15.4%) received a PPI within 30 days after TAVI (25.5% of patients treated with SEV and 7.1% of those treated with BEV). There were no differences between groups PPI versus no PPI in terms of 30-day mortality or to major complications after TAVI (p> 0.20 for all). No differences between groups were observed regarding death or readmission for heart failure (34.1% versus 31.8%, HR: 1.00, CI 95%: 0.77 to 1.30, p = 0.98). A lower rate of sudden death (sudden or unknown) among patients who had a PPI within 30 days after TAVI (HR: 0.31, CI 95%: 0.11 to 0.85; p = 0,023) was observed. The permanent atrial fibrillation (HR: 1.76, CI 95%: 1.09 to 2.86, p = 0.021) and lack of placement of PPI post TAVI (HR: 3.22, CI 95%: 1.16 to 9.9; p = 0.024) were independent predictors of sudden death. The advent of new left bundle branch block (LBBB) (HR: 2.77, CI 95%: 1.9 to 7.7, p = 0.033) and reduced LV ejection fraction (EF) at baseline (5.25 per 5% EF decrease, CI 95%: 5.15 to 5.45, P = 0.001) were independent predictors of sudden cardiac death. In the resting ECG, pacemaker rhythm was observed in 66.9% of patients and was more frequent in patients who had received SEV (72.8% versus 46.7% in patients with BEV, p = 0.007). The LVEF increased significantly in the general population in the 12 months follow-up (p <0.001). While LVEF increased over the time in patients without PPI, the LVEF decreased during follow-up in patients with PPI after TAVI (p = 0.017), with no difference between SEV and BEV groups (p = 0.668). A worse outcome of the LVEF in patients who received bi-cameral PPI was observed. The baseline LVEF and the need for PPI at 30 days were the only independent predictors of decreased LVEF over the time (estimated coefficient: -3.44 CI -4.11 to -2.26, CI 95%: -4.07 to -0.44, P = 0.013 and R2: 0.121, respectively). A marked improvement in NYHA functional class was found in patients with and without PPI (p <0.001).
Conclusion
The need for permanent pacemaker is a common complication after percutaneous aortic valve implantation but is not associated with increased total mortality, cardiovascular mortality, or re-hospitalization for heart failure at 2 years follow-up. Indeed, pacemaker implantation within 30 days post procedure was a protective factor for the occurrence of unexpected death (sudden or unknown) but was associated with impaired ventricular function over the time.
Editorial comment:
The study of Urena et al. showed that in a large cohort of patients undergoing TAVI the need for PPI immediately post procedure has no impact on overall and cardiovascular mortality, functional status, or new decompensation by heart failure. Interestingly, the authors showed that the PPI to 30 days was a protective factor for the occurrence of unexpected death. This finding, as suggested by the authors, indirectly raises questions about the proper conduct of the new conduction disorders that do not meet the criteria for PPI post TAVI. The authors demonstrated that PPI had a negative impact on LVEF and that this adverse effect was more pronounced in those patients receiving a dual-chamber pacemaker. However, this decline in LVEF did not influence the NYHA functional class or the re-occurrence of hospitalizations for heart failure, although these results should be confirmed in studies with longer follow-up. Another key point of this study is the observation that over a third of patients with PPI post TAVI had no stimulating activity for monitoring and stimulatory rhythm was observed more frequently with the auto expandable valve (72.8% versus 46.7%, P = 0.007). These findings suggest that a significant proportion of atrioventricular blocks usually resolve over time.
Courtesy Dr. Matias Sztejfman
Dr. Matías Sztejfman