European Registries Show Solid Gains in TAVR Outcomes

Both survival and overall safety outcomes after transcatheter aortic valve replacement (TAVR) have improved as clinicians gain experience and device technology advances, according to a European registry study published online January 2, 2013, ahead of print in the American Heart Journal.

Researchers led by Nicolas M. Van Mieghem, MD, of Erasmus Medical Center (Rotterdam, The Netherlands), analyzed a series of 944 consecutive patients who underwent tranfemoral TAVR at 4 experienced centers in Italy, France, and The Netherlands between November 2005 and August 2011. They divided the cohort into 3 tertiles of 214 propensity score-matched patients based on enrollment date.

Reductions in Adverse Outcomes Seen

In the time period between tertiles 1 and 3, median contrast volume decreased from 195.0 mL to 115.0 mL, while the median radiation time dropped from 25.4 minutes to 19.0 minutes. 

There were fewer instances of major vascular complications, life-threatening bleeding, and major bleeding over time. The number of adverse events related to closure device failure also decreased (table 1).

Table 1. Vascular Complications and Bleeding Events

At 30 days, the combined safety endpoint (defined as all-cause mortality, major stroke, life-threatening or disabling bleeding, stage 3 acute kidney injury, periprocedural MI, major vascular complication, or repeat procedure for valve-related dysfunction) was reduced between tertiles 1 and 3. There also were strong trends toward lower all-cause and cardiovascular mortality (table 2).

Table 2. Clinical Outcomes at 30 Days

 
Risk of major stroke and need for permanent pacemaker remained steady throughout the study period, however. 

Multivariable analysis adjusting for baseline characteristics and sheath size confirmed reductions between tertiles 1 and 3 in 30-day mortality (OR 0.35; 95% CI 0.12-0.96), stage 3 acute kidney injury (OR 0.12; 95% CI 0.29-0.93), and the combined safety endpoint (OR 0.52; 95% CI 0.29-0.93).

Kaplan-Meier analyses, meanwhile, estimated that 1-year survival rose from 79% in tertile 1 to 86% in tertile 3 (adjusted HR 0.52; 95% CI 0.31-0.87; P = 0.016). Cardiovascular mortality risk remained stable.

According to the study authors, there are several explanations for why TAVR results improved so rapidly.

“Growing experience and technological refinements can lead to practice changes in terms of patient selection, procedural execution, postoperative management, and patient follow-up,” Dr. Van Mieghem and colleagues write, adding that patient selection has been enhanced by the growing popularity of dedicated multidisciplinary heart teams. Moreover, the “surge of multimodality imaging with the integration of multislice computed tomography scans, echocardiography, and conventional invasive angiography has provided unprecedented anatomical information refining access strategy selection.”

Dr. Van Mieghem told TCTMD in an e-mail communication that, beyond the factors mentioned above, “I believe these large strides forward illustrate the pedigree of the [pioneering operators and] centers that embraced the TAVR technology at an early stage.”

Room for Improvement

Asked whether similar shifts are occurring in the United States, or if these trends are unique to Europe, Dr. Van Meighem suggested that both regions have their own strengths. 

“From a European academic perspective, I would say a blending of the American and European realities would be ideal. In Europe probably the technology has boomed at an unrealistically fast pace, whereas TAVR practice in the United States was maybe overly scrutinized,” Dr. Van Mieghem commented. On the other hand, he added, momentum is growing in the United States thanks to randomized trials such as PARTNER I and II, the Medtronic CoreValve US Pivotal Trial, and SURTAVI. 

In an e-mail communication with TCTMD, Philippe Généreux, MD, of Columbia University Medical Center (New York, NY), reported that the European population in the current paper is lower risk than patients who took part in PARTNER and those currently being treated in the United States. Because of this difference, and the possibility of bias introduced in observational studies, “it is difficult and unfair at this stage to make the comparison” between US and European outcomes, he explained. 

Overall, the ongoing risks of pacemaker requirement and stroke are areas for improvement, Dr. Généreux said, noting that embolic protection devices for TAVR may ultimately help prevent stroke. 

Dr. Van Mieghem, meanwhile, advised that refinement is needed in terms of patient selection and that many centers are still below optimal volume levels. “I would urge for a more [centralized approach to ensure] that operators who are involved with the TAVR technology do get the opportunity and thus the patient volume to become true experts. For now, TAVR is not a technology that should be available in every hospital,” he said. “As for procedural improvements, more reliable arteriotomy closure and cerebral embolic protection [are] targets for current and future research.” 

Study Details 

Mean patient age was 81 years, and half were male. The median logistic EuroSCORE was 20% (interquartile range [IQR], 12.2-27.8%). Most patients (56.2%) received CoreValve devices (Medtronic, Minneapolis, MN). The rest received a Sapien device (Edwards Lifesciences, Irvine, CA), with the smaller profile Sapien XT (Edwards Lifesciences) being introduced in the latter 2 tertiles. 

 

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Source:
Van Mieghem NM, Chieffo A, Dumontell N, et al. Trends in outcome after transfemoral transcatheter aortic valve implantation. Am Heart J. 2013;Epub ahead of print.

 

 

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