Permanent Pacemaker After TAVR Does Not Worsen Hard Outcomes

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In patients undergoing transcatheter aortic valve replacement (TAVR), need for a permanent pacemaker does not raise the risk of all-cause death or other adverse outcomes by 1 year. Irrespective of pacemaker implantation, however, TAVR patients carry a poorer prognosis than matched controls from the general population, according to findings published online June 20, 2012, ahead of print in the Journal of the American College of Cardiology.

Researchers led by Stephan Windecker, MD, of Bern University Hospital (Bern, Switzerland), enrolled 353 consecutive patients with severe aortic stenosis treated with transfemoral TAVR at 2 centers between 2007 and 2010. Patients were divided into 3 groups based upon whether they:

  • Already had a permanent pacemaker prior to TAVR (13.6%)
  • Required pacemaker implantation after TAVR (27.8%)
  • Did not need a permanent pacemaker at any point (58.6%)

Most patients (90.4%) underwent TAVR using the CoreValve prosthesis (Medtronic, Minneapolis, MN), with the remainder receiving either the Sapien or Sapien XT prostheses (Edwards Lifesciences, Irvine, CA). CoreValve use was more common in those requiring a pacemaker before TAVR (95.8%) and after TAVR (94.9%) than in those who did not need a pacemaker (87.0%; P = 0.03).

At 30 days, all-cause mortality and other adverse outcomes were equivalent across all 3 groups. The lack of difference persisted at 12 months (table 1).

Table 1. Clinical Outcomes According to Need for Permanent Pacemaker

 

None
(n = 207)

Before TAVR
(n = 48)

After TAVR
(n = 98)

P Value Among Groups

At 30 Days
All-Cause Death
MI
Stroke
TIA

 

6.8%|
1.0%
3.9%
0.5%

 

4.2%
0
0
2.1%

 

7.1%
0
2.0%
0

 

0.77
1.00
0.48
0.33

At 12 Months
All-Cause Death
MI
Stroke
TIA

 

18.0%
2.4%
3.9%
1.0%

 

22.9%
0
0
2.1%

 

19.4%
1.0%
2.0%
1.0%

 

0.77
0.6
0.48
0.8


Despite this similarity, patients in all 3 groups were more than twice as likely to die by 12 months compared with age-, sex-, and region-matched controls in the general population (table 2).

Table 2. Risk of Death Stratified by Pacemaker Use vs. Standardized Population

 

Adjusted HR

95% CI

None

2.24

1.62-3.09

Before TAVR

2.75

1.52-4.97

After TAVR

2.37

1.51-3.72


Other studies have reported permanent pacemaker use ranging from 5% to 40%, the paper notes, with higher incidence seen in patients treated with the self-expanding CoreValve vs. the balloon-expandable Sapien/Sapien XT. “Differences in device designs may explain this finding, such as a deeper extension of the stent frame into the left ventricular outflow tract and the self-expanding properties of the [CoreValve] prosthesis, maintaining a steady radial force on the annular and subendocardial tissue,” Dr. Windecker and colleagues write, adding that there are no established or uniformly applied criteria for TAVR-related permanent pacemaker use. TAVR techniques are also “heterogeneous,” they say, with differences in “intended target depth of prosthesis implant, balloon and device sizing, and so on.”

But Pacemaker Not Without Consequences

Despite having no influence on adverse event risk, several consequences of TAVR-related pacemaker use still “deserve consideration,” the investigators say. “[Pacemaker] implantation adds technical complexity and considerable cost and may result in prolonged hospitalization. Apart from this, the impact of [such implantations] on outcomes such as functional patient status, atrial and ventricular remodeling, and rhythm profile deserves further detailed evaluation.” Elderly patients may be particularly vulnerable when receiving single lead pacemakers with ventricular pacing modes, they add.

In telephone interviews with TCTMD, outside physicians strongly agreed that the results in no way suggest that permanent pacemaker implantation after TAVR is trivial.

Peter C. Block, MD, of Emory University Hospital (Atlanta, GA), said that “one of the things this tells us is that, particularly for self-expanding valves, the pacemaker issue has not gone away.”

Similarly, Josep Rodés-Cabau, MD, of Laval University (Quebec City, Canada), said, “The paper is interesting because . . . it doesn’t seem that the need for pacemaker implantation plays a major prognostic role in these patients.

“This being said, we all know there are complications associated with the implantations of pacemakers. There’s morbidity. There’s infection that can even be life threatening. Also, for some patients, losing sinus rhythm can have a deleterious effect on ventricular function,” he commented.

Somewhere around 25% to 40% of TAVR patients need pacemakers, though the definition is difficult to pin down, Dr. Block noted, explaining that “[m]any of these patients have pacemakers implanted prophylactically if they have atrioventricular conduction defects immediately after their valve placement rather than true heart block, and many of the pacemakers implanted are never actually used by the patient.”

The effect of a pacemaker on outcomes appears “moot,” he said. “But candidly, that’s not surprising, because if you need a pacer and you get a pacer, then your outcomes are good. The problem with this is . . . that pacemakers are expensive and a continued need for pacemakers with self-expanding valves is an ongoing troublesome issue.”

And had the study uncovered any differences in outcomes, “that would have been critical to learn,” Dr. Block stressed.

Looking Forward

But Dr. Rodés-Cabau urged that, given the small size of each subgroup within the current study, additional series are needed to establish that implanting a permanent pacemaker “is not a big issue.”

Dr. Windecker concurred via an e-mail communication, noting that the “findings require confirmation in larger, prospectively defined patient cohorts. In addition, other factors such as postprocedural monitoring, prolongation of hospital stay, and cost related to pacemaker implantation remain important considerations.”

In the meantime, certain practices may help minimize pacemaker use, the physicians suggested, including the use of second-generation TAVR devices.

A patient experiencing right bundle branch block (RBBB) might be more suitable for surgery if operable, Dr. Rodés-Cabau said. Dr. Windecker also emphasized “careful preprocedural assessment,” pointing out that RBBB is associated with “a very high rate of pacemaker implantation.” Moreover, he advised correct TAVR device positioning that avoids “deep seating of the prosthesis in the left ventricular outflow tract.”

Study Details

As might be expected, patients who had received permanent pacemakers before TAVR had more baseline risk factors than those who needed pacemakers later or not at all. These included hypertension, CAD, renal failure, prior MI, and atrial fibrillation. Mean logistic EuroSCORE was 28.37 in the pre-TAVR group compared with 27.76 in the post-TAVR group and 22.77 in the no-pacemaker group (P < 0.01).

 


Source:
Buellesfeld L, Stortecky S, Heg D, et al. Impact of permanent pacemaker implantation on clinical outcome among patients undergoing transcatheter aortic valve implantation. J Am Coll Cardiol. 2012;Epub ahead of print.

 

 

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Disclosures
  • Dr. Windecker reports receiving honoraria and consulting fees from Edwards Lifesciences and Medtronic.
  • Dr. Block reports no relevant conflicts of interest.
  • Dr. Rodés-Cabau reports serving as a consultant to Edwards Lifesciences and St. Jude Medical.

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