Long-Term Stroke Rate After TAVR: New Data

March 16, 2020

The largest study to date evaluating late neurological events after transcatheter aortic valve replacement (TAVR) has shown an increased rate of stroke and a very high rate of associated mortality in the years following the procedure compared with what would be expected in the general population of a similar age.

But the authors say they do not think this is related to the valve replacement procedure itself.

"There is no doubt that there is an increase of strokes in the periprocedural period after TAVR, which is thought to be caused by the manipulation of the catheter around the valve. But we don't know much about the longer-term risks of stroke," senior author Josep Rodés-Cabau, MD, Quebec Heart & Lung Institute, Quebec City, Canada, told Medscape Medical News.  

"In our observational study we found a stroke rate of about 5% over a median follow-up of 2 years," a rate higher than the stroke rate that would be expected in the general population of the same age but not "exceptionally higher," he said. 

"Because the median time of stroke occurrence was 16 months we do not believe these strokes are directly related to the TAVR procedure. It is not usual to have clinical or subclinical thrombosis so long after the TAVR procedure. In addition, many of our patents underwent cardiac echo around the time of the stroke, and this did not show evidence of valve thrombosis and very few had valve degeneration," Rodés-Cabau said. He called these echo findings "reassuring."

"So we think these strokes are related to the characteristics of the patients in this cohort," he added. This group of patients were high risk in that they were considered not suitable for valve surgery; they were older with comorbidities, prior strokes, and highly calcified valves before the TAVR procedure.

"I think the stroke rate we saw is probably representative of this type of population, but we didn't have a control group who did not undergo TAVR so we cannot say anything for sure," he commented.  

The study was published online March 11 in JACC: Cardiovascular Interventions.

However, in the article the researchers note, "Most late stroke events were disabling and associated with very high early and late mortality rates, further highlighting the importance of future efforts to both reduce their occurrence and implement the most appropriate therapies to improve outcomes."

The current multicenter study included 3750 consecutive patients from seven centers in Canada, France, and Spain who underwent TAVR and survived the periprocedural (30-day) period. Procedural aspects, valve type, access, and post-procedural management were at the discretion of the heart team in each center. Baseline, procedural, and follow-up data were prospectively collected in each center.

Baseline data showed that the mean age of patients was 80 years, and the mean STS-PROM score (the predicted risk of surgical mortality) was 4.9%.

In-hospital stroke occurred in 2% of patients, and 34.6% of patients were discharged on anticoagulation therapy.

Long-term results showed that after a median follow-up of 2 years, a total of 192 (5.1%) patients had had a late cerebrovascular event. These events occurred at a median of 16 months post-TAVR, and the annual incidence (up to 4-year follow-up) ranged from 1.5% to 2.1% (2.14 per 100 person-years).

The cerebrovascular events consisted of stroke in 80.2% of cases and transient ischemic attack in 19.8% of cases. Strokes were of ischemic origin in 80.5% of cases, hemorrhagic in 18.8%, and undetermined in 0.7%.

Late stroke was disabling in 69% of cases and associated with a very high in-hospital mortality rate of 29%. Among patients with hemorrhagic stroke, disabling status and in-hospital mortality rates increased up to 79% and 66%, respectively, which the researchers describe as "particularly dreadful."

Factors associated with an increased risk of stroke were older age, history of cerebrovascular disease, higher mean aortic gradient, periprocedural stroke at the time of the TAVR procedure, and lack of anticoagulation therapy at hospital discharge.

Whereas most patients who had an ischemic stroke were on single antiplatelet therapy, anticoagulation treatment was more frequent in patients who had a hemorrhagic stroke (48.3%) than in those who had an ischemic stroke (27.2%).

Among the 14 patients on anticoagulation therapy who suffered a hemorrhagic stroke, five (36%) were also receiving antiplatelet treatment at the time of the event.

"TAVR patients are not given routine anticoagulation after the procedure; whether this should occur is currently under investigation in clinical trials," Rodés-Cabau noted.

"There is a delicate balance between preventing future ischemic strokes and causing future hemorrhagic strokes. These results will help inform about the use of anticoagulants in this population," he added.

"Devastating" Stroke Outcomes 

In an accompanying editorial, Paul Sorajja, MD, and Santiago Garcia, MD, Minneapolis Heart Institute Foundation, Minnesota, note that the frequency of periprocedural stroke for TAVR has been found to be comparable to surgery and has improved steadily because of a combination of device and procedural enhancements and expansion to lower-risk patients, though its occurrence still remains a significant concern.

They say that although stroke rates reported in the current study "may seem infrequent by some measures, the clinical outcomes were devastating, with an in-hospital mortality of 29% and disabling stroke occurring in 69%."

"The use of anticoagulation, likely a surrogate for treated atrial fibrillation, coupled with the finding of increased hemorrhagic stroke among these patients may suggest that nonpharmacological alternatives such as left atrial appendage closure may be preferred in some TAVR patients with atrial fibrillation at increased risk of bleeding," the editorialists comment.

"These data highlight the persistent susceptibility of our patients and emphasize the need for longitudinal viewpoints in terms of gauging successful patient outcomes," they state.

They recommend that further study on the implications of these data for patient management are needed, including further quantification of the degrees of increased risk to inform changes in care, such as use of diagnostic imaging, alterations in medical management, and perhaps even affecting prosthetic valve choice or its method of placement.

"Taken together, these steps will help our patients survive not only the acute TAVR procedure, but also attain the long-term health we may desire," they conclude.

Rodés-Cabau has reported receiving institutional research grants from Edwards Lifesciences, Medtronic, and Boston Scientific. Sorajja has reported consulting for Abbott Structural, Medtronic, Boston Scientific, Edwards Lifesciences, Admedus, W.L. Gore; and receiving institutional research grants from for Abbott Structural, Medtronic, and Boston Scientific. Garcia has reported consulting for Abbott Structural, Medtronic, Edwards Lifesciences, and receiving institutional research grants from for Abbott Structural, Medtronic, Boston Scientific, and W.L. Gore

JACC: Cardiovasc Interv. Published online March 11, 2020. Abstract, Editorial

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