SURTAVI Stroke Analysis Published, Confirms Less Early Stroke With TAVR

 

(UPDATED) Full results of the secondary analysis looking at neurological events in the SURTAVI trial affirm that intermediate-risk patients who underwent TAVR with the self-expanding CoreValve (Medtronic) versus surgical aortic valve replacement (SAVR) fared better in the first 30 days of follow-up.

As first revealed at EuroPCR 2017, patients in the TAVR arm had lower rates of stroke (3.3% vs 5.4%; P = 0.031) and encephalopathy (1.6% vs 7.8%; P < 0.001) during that early time period, lead author Andras Durko, MD (Erasmus Medical Center, Rotterdam, the Netherlands), and colleagues report in a study published online ahead of the October 30, 2018, issue of the Journal of the American College of Cardiology. By 1 year, there was no longer a significant difference in stroke (5.2% vs 6.9%; P = 0.136), but the rate of encephalopathy remained lower in the TAVR arm (3.0% vs 8.8%; P < 0.001).

Early occurrence of either stroke or encephalopathy was associated with elevated mortality at 1 year in both arms of the trial, with early strokes also tied to prolonged ICU and hospital stays and a lower likelihood of being discharged home after the procedure.

“Previously the perception was that TAVR may yield higher stroke rates than SAVR, and this study adds to the evidence that TAVR can be as safe as SAVR—if not safer—in terms of stroke,” Durko told TCTMD. “And that’s something that supports the use of TAVR in the intermediate-risk population.”

Durko noted that SURTAVI is the first randomized study to show a lower stroke rate with TAVR versus SAVR, and said it’s not clear why. A combination of factors probably came into play, he said, including the lower-risk patient population compared with prior studies, which would explain the lower overall stroke rate, as well as recent technical advancements in TAVR.

In an accompanying editorial, Josep Rodés-Cabau, MD (Quebec Heart and Lung Institute, Canada), and Ralph Sacco, MD (University of Miami, FL), point out that even though TAVR has become a safer procedure due to growing experience and technological improvements, the 30-day rate of stroke remains at about 3% in the most recent studies with the latest technology, one of the highest rates seen for any procedure in interventional cardiology.

Thus, “neurological complications following AVR remain a major concern,” they conclude. “Continuous efforts to identify modifiable predictors of neurological events and the implementation of protective measures need to remain one of the major research priorities in this field to advance the care of patients who need AVR.”

Commenting for TCTMD, Alexandra Lansky, MD (Yale University School of Medicine, New Haven, CT), indicated that the issue may be even more important as the population of patients treated with TAVR broadens. “The devastating consequences of stroke are likely of greater concern for lower-risk, more-functional patients,” she said in an email.

The relevance of this analysis, Lansky said, “is to reemphasize the importance of stroke detection and prevention rather than stroke management.  While early studies have evaluated the role of cerebral embolic protection, much work remains to be done in this field to reduce stroke risk and optimize outcomes with TAVR.”

Careful Assessment of Neurological Outcomes

The SURTAVI trial, which showed that TAVR was noninferior to SAVR in 1,660 patients with symptomatic severe aortic stenosis and intermediate surgical risk in terms of the 2-year rate of all-cause death or disabling stroke, involved strict protocols for neurological evaluations. All assessments were performed by study-trained neurologists or stroke specialists, and all neurological events were adjudicated by an independent clinical events committee.

Of all strokes identified in the first year of follow-up, 63.6% of those in the TAVR arm and 79.6% of those in the SAVR arm occurred in the first 30 days, with the highest risk seen immediately after the procedures.

Though early stroke and encephalopathy were more frequent in the SAVR arm, there were no differences between groups in late events occurring from 30 days to 1 year. Rates of other neurological events, including disabling stroke, nondisabling stroke, and TIA, did not differ between trial arms at any time point, although there was a nonsignificant trend toward more disabling strokes after SAVR in the first 30 days (2.4% vs 1.2%; P = 0.058).

Study investigators also measured quality of life using the Medical Outcomes Study Short-Form 36, finding that the physical component score at 30 days in patients who had an early stroke was significantly worse in the patients who had undergone SAVR versus TAVR; a discrepancy was no longer seen at 6 and 12 months.

“Although quality of life improved earlier in TAVR patients after early strokes, this is most likely only a consequence of the greater invasiveness of SAVR compared with TAVR,” the authors say.

The researchers searched for independent predictors of early stroke and failed to find any, likely, they say, because of the low overall stroke rates in the trial.

“Further research is needed to identify patient and procedural factors that predispose to neurological complications after aortic valve preplacement and to evaluate the roles of embolism protection and antithrombotic medication in stroke prevention,” Durko et al write.

Room for Improvement

Indeed, Rodés-Cabau and Sacco argue in their editorial, there is a need to lower rates of neurological complications following aortic valve replacement even further.

“Refinement of transcatheter valve systems, reducing the multiplicity of valve repositioning attempts, and decreasing procedural times may help to reduce these early stroke events,” they write.

“Moreover, the use of embolic protection devices (not allowed in the SURTAVI trial) has been associated with some promising results with respect to a reduction in the global burden of ischemic lesions as evaluated by cerebral magnetic resonance imaging,” Rodés-Cabau and Sacco write. “However, no definite evidence exists on the reduction of clinically overt stroke with the use of such devices, and more evidence-based data may be necessary before implementing their systematic application in all TAVR procedures.”

Lansky said, however, that “with no single risk factor or combination of identifiable factors, prevention and embolic protection should be applied broadly.”

Rodés-Cabau and Sacco also say more work needs to be done on appropriate antithrombotic therapy after TAVR, noting that there are multiple ongoing trials that will provide insight in this area..

Though SURTAVI does not provide information on the impact of embolic protection in TAVR or on the most appropriate antithrombotic regimen, “we could say that stroke happens and stroke has a negative influence on outcomes and therefore we have to do anything we can do to prevent it,” according to Durko.

A Centers for Medicare & Medicaid Services (CMS) New Technology Add-on Payment for use of the Sentinel cerebral embolic protection system (Boston Scientific) during TAVR went into effect earlier this month, potentially clearing the way for greater use of the technology in the United States.