This study investigated a population of Iranian ischemic stroke cases treated with IVT registered in SITS Registry. It followed their outcomes as three-month mortality, excellent outcome, functional independence, and local hemorrhage. It mainly aimed to compare outcomes in the two categories of PCS and ACS in three months and examine the other most important factors influencing three-month outcomes in IVT-treated stroke patients.
The results showed lower baseline NIHSS in PCS patients than ACS cases.
The NIHSS baseline score was significantly higher in ACS cases than PCS cases in the present work, similar to Macha, Kim, De Marchis, and Forster’s study (on NIHSS baseline that was lower in PCS cases) and dissimilar to Tong’s study4,5,8,13,14.
NIHSS has a weak point due to insensitivity to PCS signs, such as vertigo and imbalance, and could be untruly low in PCS cases compared to those of ACS. Thus, the severity of strokes in PCS and ACS cases is not accurate to the NIHSS score similarly. Accordingly, the findings about the severity of ACS and PCS may not be accurate.
Blood glucose level, WBC count, and AF history were not significantly different between the two circulations in our research as in Tong’s study3.
Diabetes was less in PCS cases than ACS, as in Handelsmann et al. study and the opposite is true in Cui et al., Tong et al., and Kim et al. study. There was no difference in diabetes between ACS and PCS in the current study as in De Marchis8,9,13,22.
AF was higher in ACS cases in Cui, Handlesmann, Kim, and De Marchi’s studies in contrary to Tongs’ study, with higher prevalence in PCS cases. On the other hand, Macha et al. was as ours in that no difference was observed between the two circulation strokes1,4,5,8,22,23.
In Tong et al., the outcome of 3 months was better in PCS cases, and mortality was not significantly different compared to ACS. Still, a lower rate of hemorrhage was seen in PCS cases4.
Kim et al. showed that minor PCS had worse functional independence after three months than minor ACS, especially in vertebrobasilar large vessel disease. On the other hand, we did not find a similar result in our cases (p-value = 0.618)8.
Sommer et al. showed a worse prognosis in PCS cases compared to ACS cases in unknown onset time or more than 4.5 h, as in KIM et al. in minor strokes, but in cases with arrival in less than 4.5 h, there was no difference between PCS and ACS cases as in our study8,17.
In a study on 18-month follow-up of IVT cases, there was 34.3% mortality, possibly making acceptable a mortality rate of 17.75% after a 3-month follow-up in the present work. PCS cases were about 7.00% of IVT therapy cases in this study, while in ours, it was about 4.60%; in other studies, more cases were reported compared to ours4,5,9,20,22. This difference could be due to the delay in diagnosis and admission of our PCS cases and fewer data collection.
Kim et al. found that worse outcomes in three months after minor PCS and ACS were related to baseline NIHSS (P < 0.001), but mortality in three months did not, confirming our results that the major predictor of disability is NIHSS and its increment directly affects 3-months disability8.
Lu et al. showed AF and NIHSS scores to be the primary indicators of poor prognosis in wake-up stroke cases treated with IVT. Local hemorrhage was directly associated with AF, and embolic stroke. On the other hand, it was conversely related to small vessel strokes, NIHSS score, and admission duration24.
Sun et al., in another study about minor strokes without IVT, found the primary NIHSS to be related to three months mRs25. Wang et al., Irvine et al., and Khazaei et al. showed NIHSS to be related directly to early neurologic deterioration26,27,28.
Finally, our research showed that the circulation was not an outcome predictor in ischemic strokes. The most important predictor was baseline NIHSS. The study showed no difference between ACS and PCS cases in the outcome of strokes, and IVT could be used in both circulations cautiously.
This study’s strength was the number of stroke cases and the confidence of information gathered by neurologist supervision in all hospitals. On the other hand, it was the first study about the circulation effect on the outcome of Iranian stroke cases.
The limitations were incompleteness of information about the type of circulation and three months mRS of some cases (which were excluded from the study). Complications were not entirely registered in the registry. Also, some of the confounders as collateral and size of infarction were not collected in the registry.
Another limitation was number of PCS cases that was less than expected, possibly due to less awareness of stroke events in PCS cases both by family and emergency personnel. As registering the type of circulation is an optional item in SITS registry, there was incomplete data about circulation in many cases.
We offer a prospective study that focuses on circulation in IVT cases with or without poor outcome to examine how we could help them prevent the events after thrombolysis and achieve more detailed data about circulation in our cases.