Although
the efficacy of intravenous thrombolysis to increase the chance of alive and
independency among stroke patients has been proven with numerous evidences from
randomized trials and meta-analyses, the safety and effectiveness of
thrombolysis in the real world setting sometimes remains controversial.
According
to the results of the multi-country INTERSTROKE study recently published in the
Lancet, thrombolysis for infarct was
neither associated with alive without severe disability (odds ratio [OR]: 0.90;
95% CI: 0.68-1.18) nor alive (OR: 0.85; 95% CI: 0.55-1.31). On the contrary,
the authors concluded that “across all countries, irrespective of economic
level, access to a stroke unit was associated
with improved use of investigations and treatments, access to other
rehabilitation services, and improved survival without severe dependency (OR:
1.29; 95% CI: 1.14–1.44), which was independent of patient casemix
characteristics and other measures of care. Use of acute antiplatelet treatment was associated with improved
survival (OR: 1.39; 95% CI: 1.12–1.72) irrespective of other patient and
service characteristics.”
The
authors did not discuss the lack of benefit for thrombolysis, in contrast to
stroke unit care and antiplatelet treatment in the article. Of course, the
INTERSTROKE study is an observational study. Although several patient-,
hospital-, and health care system-level factors have been adjusted in the
multivariate analysis, unmeasured confounders and selection bias may still
exist and cause the different results from the ones in the RCTs. In this study,
intravenous thrombolysis was given in 4% and 3% of patients in the
upper-middle-income countries and low middle-income countries, compared to 20%
of patients in the high income countries. It should be explained by the drug
price, i.e., the thrombolytic agents (e.g. alteplase) is expansive and may
equal one household income for several months in the low income countries.
My
reflection is: thrombolysis should not be over-emphasized when we are trying to
improve stroke care in the low income countries. The expensive thrombolytic
agent or even the so-called “state-of-art” thrombectomy devices may largely
consume the limited healthcare resources in low income countries. On the
contrary, the use of antiplatelet treatment (e.g. aspirin) and the set-up of
more stroke units may be more cost-effective. Besides, both of them do not have
a narrow time window as thrombolysis does. Thus, more patients may get benefit.
Somebody
has calculated the number needed to treat (NNT) and potential target population
of thrombolysis, aspirin, and stroke unit care. The NNT was 16, 83, and 18,
respectively. However, 10%, 40%, and 80% of stroke patients, respectively, can
get benefit from those treatment.
However,
if you attend any large international stroke conferences, the major focuses are
still always thrombolysis and thrombectomy, rather than stroke unit care.
Roughly, even in high-income country like Taiwan, 80-90% stroke patients cannot
receive those high-tech treatment, mostly because they fail to arrive hospitals
within the therapeutic time window.
Lest
we forget them!
