New-Onset A-Fib, Chronic Kidney Disease Are Risk Factors For Stroke After TAVR, Meta-Analysis Shows

When it comes to the prevention of cerebrovascular events after TAVR, there are many unknowns, but data from a new meta-analysis has identified multiple risk factors—including chronic kidney disease and new-onset A-fib—that researchers hope will lead to more tailored patient care.

Although much has been reported on the diminishing stroke rate after TAVR, as well as the risks and benefits of embolic protection, cerebrovascular events still remains one of the “most dreadful complications of TAVR,” write study author Vincent Auffret, MD (Laval University, Quebec City, Canada), and colleagues.

For the meta-analysis, which was published online August 8, 2016, in the Journal of the American College of Cardiology, the researchers looked at 64 studies—all but three were observational registries—involving 72,318 patients who underwent TAVR between 2005 and 2014. Overall, 2,385 patients experienced a cerebrovascular event within 30 days, with a median rate of 4% (range 1% to 11%). There were no differences between single and multicenter studies or according to event adjudication availability.

While men were found to be at lower risk of developing a cerebrovascular event compared with women (RR 0.82; 95% CI 0.70-0.97), those with chronic kidney disease (RR 1.29; 95% CI 1.03-1.63) and new-onset A-fib (RR 1.85; 95% CI 1.20-2.84) as well as those treated in the first half of a study (RR 1.55; 95% CI 1.16-2.08) were at higher risk.

There was a trend toward lower risk in obese patients (RR 0.66; 95% CI 0.40-1.07), but there were no associations between the risk of cerebrovascular events and either valve type or approach.

These findings may help enable tailored care, the authors say. Specifically, “identifying the risk factors of [cerebrovascular events] is of paramount relevance in clinical practice to implement preventive strategies, either instrumental (embolic protection devices) or pharmacological in high-risk patients,” senior study author Josep Rodés-Cabau, MD (Laval University), told TCTMD in an email.

In an accompanying editorial, Anthony Bavry, MD, MPH, and Islam Elgendy, MD (University of Florida, Gainesville), say the “study provides important speculations that chronic kidney disease and new-onset atrial fibrillation could be associated with future cerebrovascular events post-TAVR.” Yet they note that because the “vast majority of included studies are observational in nature,” bias might play a role in the final results. Bavry and Elgendy also point out that the “definition of cerebrovascular events was variable among the studies.”

New-Onset A-Fib an Ongoing Issue

Regardless of its limitations, the study’s findings with regard to chronic kidney disease and new-onset A-fib are “important issues we need to pay attention to,” said Peter Block, MD (Emory University School of Medicine, Atlanta, GA), commenting on the study for TCTMD. New-onset A-fib has been an “ongoing issue with cardiac surgery for many years,” he said. “We have tried all kinds of ways to limit [it] and have come up empty.”

The new data indicate that patients need to be even more closely monitored after TAVR, especially as hospital stays get shorter, Block commented. This will be easier with new technology and monitoring devices, he said, but potentially the medical community could also make use of the information provided by “nonmedical fitness bracelets” currently available. “There is likely more nuance than we think,” Block added, and “it will be important for us to figure out more and treat it.”

As the “procedure is expanded to involve patients with lower surgical risk, minimizing cerebrovascular events is of critical importance,” note the editorialists. But “the role of embolic protection devices, which add to procedural complexity and potential risk, remains an area of ongoing research,” they say.

Block agreed, adding that embolic protection devices have been “understudied” and the designs of current models are “not without their own risk.”

Future studies should “aim at defining more precisely which TAVR recipients are most likely to benefit from tailored therapies,” Rodés-Cabau said. These may include not only embolic protection devices, he suggested, but also “optimizing antithrombotic therapy post-TAVR, while taking into account the bleeding risks.”

Additionally, he noted, “the relationship between enrollment date and poorer outcomes post-TAVR is likely multifactorial,” and it is likely “hospital volume will probably play a lesser role going forward as TAVR experience goes up.”

For centers new to TAVR, Rodés-Cabau recommended “careful training with experienced operators and the help of proctors during their first procedures. Predefined protocols especially regarding periprocedural antithrombotic therapy should also be implemented in each center. Finally, as suggested by our analysis, special attention should be paid to atrial arrhythmias post-TAVR.”

Be ‘Especially Vigilant’

According to Block, the study, though important and helpful, only “guides us toward the goal rather than tells us what the issues are.” That goal is zero cerebrovascular events after TAVR, he added. “For anyone who has TAVR, stroke is the most devastating thing that they can hear. If we politely say 1-2% is okay, I would argue we need to decrease that rate to zero.”

For now, clinicians should “keep an eye on [patients] and be more aware” about risk factors, Block continued. “We can’t change chronic kidney disease and female sex and early enrollment, but certainly there are a whole host of things we also have to look at that are potential risk factors . . . that aren’t usually listed in the trials and reports that are published on TAVR.” He cited severe calcification of the proximal aorta as an example.

Bavry and Elgendy conclude that physicians should be “especially vigilant” in being aware of potential risk factors even though “much remains to be learned regarding the pathogenesis of cerebrovascular events with TAVR.” Block gave his peers credit for already being “vigilant about everything we can think of,” but he noted that even closer attention can always be paid.

Related Stories:

• Cerebrovascular Event Risk Highest in First 24 Hours After TAVR
• ADVANCE Published: Stroke Rate Diminishing as TAVR Evolves
• Embolic Protection in TAVR: If, When, What, and How Debated as Trials Wrap Up