Persistent Long-Term Stroke Risk After TIA or Minor Stroke

Patients who suffer transient ischemic attack (TIA) or minor stroke have a persistently elevated risk for subsequent stroke over the next 10 years, results of a systematic review and meta-analysis indicated.

“The magnitude of the long-term risk is considerable, with 1 in every 5 patients expected to experience a subsequent, more severe stroke within 10 years of experiencing a TIA or minor stroke,” first author Faizan Khan, PhD, with Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada, told Medscape Medical News.

“Of all the subsequent strokes within the 10 year follow-up period, half occurred after the first year emphasizing that the high risk of stroke in these patients persists beyond 1 year after presentation,” Khan noted.

This finding has implications for care, Khan said.

“As most secondary prevention clinics only follow these patients for the first 90 days, I hope our findings raise attention to the persistently high risk and provide a benchmark upon which to improve long-term stroke prevention. We need to pay attention as there is certainly room for improvement in stroke prevention care,” Khan told Medscape Medical News.

The study was published online on March 26 in JAMA.

Harbinger of Future Events

TIA or minor stroke is often treated as a warning of potentially more a serious cerebrovascular event. While the immediate risk for subsequent stroke, typically in the first 90 days after a TIA or minor stroke, is well recognized and managed aggressively, the long-term risk for stroke is not well known.

This systematic review and meta-analysis filled a critical gap by assessing stroke incidence up to 10 years after TIA or minor stroke.

The study team pooled data from 171,068 patients across 38 relevant studies. The cohort had a median age of 69 years, the median percentage of men was 57%, and 95% were discharged on antithrombotic medication.

The pooled rate of stroke (per 100 person-years) decreased from 5.94 events in the first year to 1.80 events annually in years 2-5 and 1.72 in years 6-10.

Nearly two thirds (62%) of subsequent stroke events occurred in the first 90 days after TIA or minor stroke, confirming the high early risk.

“Notably, half of all subsequent stroke events occurred after the first year, underscoring that the elevated risk of stroke in this patient population persists for more than 1 year after presentation,” the authors wrote.

The cumulative risk for stroke was 12.5% at 5 years and 19.8% at 10 years. The case-fatality rate of subsequent stroke was 10.4%.

Long-term disability and mortality from TIA or minor stroke were also significant. 

Among patients without a subsequent stroke during follow-up, nearly 1 in 3 had some neurologic disability at 5 years, increasing to 2 in 5 at 10 years, and one third were likely to die from any cause within 10 years.

“Crucially, nearly 90% of all-cause deaths occurred for causes other than fatal stroke. This further highlights the significance of effectively managing comorbid illnesses associated with stroke to decrease the considerable long-term mortality burden in this population,” the authors said.

Long-Term Risk Factor Management Key

Reached for comment, Hardik Amin, MD, national volunteer expert with the American Stroke Association, told Medscape Medical News the “continued long-term risk of recurrent stroke may be because follow-up tends to be the most intense in the months following a first-time stroke/TIA and less frequent over time. If a patient remains stable for an extended period, treatment inertia may set in where risk factor control and medication adherence can lag. Long-term management of risk factors is crucial for preventing subsequent strokes, even years later.

Amin also highlighted the importance of early comprehensive evaluation, ideally by a stroke specialist, after TIA or minor stroke.

“Strokes and TIAs occur because of underlying risk factors. A stroke specialist can identify which risk factors caused the stroke, test for previously unknown risk factors, and recommend evidence-based treatment plans,” said Amin, co-director, Hartford Hospital Comprehensive Stroke Center in Hartford, Connecticut.

Identifying the cause of a patient’s first stroke is crucial for preventing future events. Once the underlying risk factors are recognized, a collaborative effort among healthcare professionals — including primary care providers, stroke specialists, cardiologists, endocrinologists, and surgeons — is essential to manage and reduce the risk for recurrence, Amin added.

Ongoing follow-up with a primary care provider is important for all stroke survivors, with specialist involvement continuing as needed. The frequency of follow-up should be personalized: Patients with multiple or poorly controlled risk factors require more frequent visits, while those with stable, well-managed conditions may need less frequent monitoring, he added. 

The study had no commercial funding. The complete list of author disclosures is available with the original article. Amin had no relevant disclosures.