Dependent Patients May Benefit From tPA After Stroke

February 04, 2016

Withholding thrombolysis in patients having an acute stroke who were previously dependent on the daily help of others might not be justified, a new study suggests.

The registry-based study found that dependent stroke patients who received tissue plasminogen activator (tPA) had a higher mortality risk than previously independent patients, but the risk for symptomatic intracranial hemorrhage and the likelihood of poor outcome were not specifically influenced by previous dependency. Among survivors, poor outcome was avoided at least as effectively in previously dependent patients.

The study, published in Stroke on January 21, was conducted by the Thrombolysis in Stroke Patients (TriSP) collaborators, led by Henrik Gensicke, MD, University Hospital Basel, Switzerland.

"Concerns of higher complication rates from thrombolysis treatment resulting in a less than favorable risk–benefit ratio for dependent patients might be unjustified and perhaps should be set aside to allow further study," Dr Gensicke said.

The researchers explain that patients who could not live alone without daily help of another person before stroke — those with a modified Rankin Scale (mRS) score of 3 or above — were not eligible for the large randomized trials of tPA in acute stroke. And in clinical practice, some patients with preexisting dependency receive tPA and others do not.

For the current study, researchers analyzed data on 7430 stroke patients who received intravenous thrombolysis at 12 European stroke centers.

Of these 6.6%, were dependent before stroke, with previous stroke, dementia, and heart and bone diseases the most common causes of preexisting dependency. Dependent patients were older, were more often female, had more severe strokes, and were more often prescribed antithrombotic medication than previously independent patients.

Result showed that previously dependent patients were more likely to die than nondependent patients but to have a similar risk for symptomatic intracranial hemorrhage.

Although poor outcome (defined as an mRS score not reaching at least the prestroke score for dependent patients or a of 3 to 6 for previously independent patients) was more frequent in dependent than in independent patients, the adjusted odds ratios were similar.

Among survivors, the proportion of those with poor outcome did not differ between previously dependent and independent patients, but after adjustment for age and stroke severity, previously dependent patients were less likely to have a poor outcome.

Table. Outcomes at 3 Months in Dependent vs Independent Stroke Patients Receiving tPA

Endpoint Dependent (%) Independent (%) Adjusted Odds Ratio (95% Confidence Interval)
Death 38.7 12.2 2.19 (1.70 - 2.84)
Symptomatic intracranial hemorrhage 4.8 4.5 0.66 (0.42 - 11.04)
Poor outcome 60.5 39.6 0.95 (0.75 - 1.21)
Survivors with poor outcome 35.7 31.3 0.64 (0.49 - 0.84)

Of the patients with preexisting disability, almost 40% had died within 3 months of the stroke, and after adjustment for confounding variables, they were twice as likely not to survive compared with previously independent patients. The researchers point out that this doubling in risk for death is almost identical to that previously shown in dependent patients having a stroke and not receiving tPA.

They note that the observed higher mortality is not explained by an excess of bleeds, and possible explanations may include a higher susceptibility for other complications, worsening of preexisting comorbid diseases triggered by the stroke, a higher disease burden caused by preexisting comorbidities, and withdrawal of care according to patient's preferences.

Furthermore, the current results suggest that mortality risk increased with increasing degree of preexisting dependency, with patients with complete dependency almost twice as likely to die as those with only partial dependency.

The researchers say the result showing that previously dependent patients still alive at 3 months had greater chance of a good outcome than previously independent patients was unexpected, and they urge caution in interpreting this observation. One reason for this result may have been the different definitions used for poor outcome in previously dependent and independent patients, they suggest.

They add that while providing outcome data separately for the survivors runs the risk that outcomes might be perceived as inappropriately good, patients and relatives often do fear survival with dependency more than dying after a stroke.

They conclude that a definitive answer to the question of whether tPA is effective and safe in patients with preexisting dependency requires a randomized trial in this population. "At least our results indicate that such a trial would be ethically justified."

This research was partly supported by the Stroke-[Hirnschlag]-Fund Basel and by grants from the Swiss National Foundation and the University of Basel. Author disclosures are provided with the published article.

Stroke. Published online January 21, 2016. Full text

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