Argatroban is a direct thrombin inhibitor that can rapidly inhibit thrombosis, and its safety and effectiveness have been confirmed in many clinical studies [11-15]. Early venous anticoagulation is an important strategy for individualized treatment of AIS.
The relationship between hyperacute BP, BPV, and short-term and long-term functional outcomes in patients with AIS has attracted increasing attention. Until now, no studies have explored the relationship between BP and BPV in the first 24 hours with 90-day functional prognosis in patients with AIS undergoing acute/early anticoagulation therapy (within 24 hours). Our center reviewed BP and BPV and further analyzed the relevance of 90-day functional outcomes, aiming to explore whether BP and BPV-related indicators could be effective prognostic indicators in patients with AIS undergoing acute/early argatroban anticoagulation therapy.
Although a meta-analysis [16] showed that the first 24-hour systolic BPV in patients with AIS was a good predictor of stroke outcome, the greater the systolic BPV, the worse the prognosis. Moreover, data from the VISTA study [17] showed that an elevated 24-hour SBP SD, DBP SD, and MAP SD were associated with 90-day adverse outcomes (mRS score of 3–6). Furthermore, the ECASS-II study [5] showed that 24-hour SBP SV was a risk factor for a poor prognosis at 90 days. Despite these previous observations, the results of our study suggest that systolic BPV, diastolic BPV, and MAP BPV indices (SD, CV, SV, and ARV) are not associated with prognosis. The results of this study are consistent with the results of Graff et al. [18] and the Samurai rt-PA registration study [19]. In an attempt to explain such discrepancies, Manning et al. [3] suggested that different BP detection methods might lead to different results. Different from the beat-to-beat finger BP detection method used by Graff et al. [18], our study and the Samurai rt-PA registration study [19] adopted fixed-interval and random cuff BP detection methods. Although the BP detection methods were different, the study results were consistent, which further suggests that 24-hour SD, CV, SV, and ARV have little predictive value for the prognosis of patients with AIS at 3 months. In this study, patients admitted to hospital had an average NIHSS score of 6 points, which means their condition was relatively mild with only slight BPV. To avoid interference of antihypertensive drugs on BPV, all patients who underwent intravenous thrombolysis and bridging therapy and all patients with related complications requiring emergency antihypertensive drug treatment were excluded. Moreover, early anticoagulant therapy can inhibit thrombus enlargement and cause partial dissolution of the thrombus, which can improve cerebral perfusion and reduce brain edema. Furthermore, anticoagulant therapy causes little fluctuation in various indicators of BPV among groups, and it has no significant effect on functional prognosis at 3 months. Both Graff et al.’s study [18] and our study had a small sample size (n = 75 and n = 214, respectively), and our study population underwent early intravenous argatroban anticoagulation therapy, so the three studies could not be analyzed in combination. Although the SD, CV, SV, and ARV of our study did not show significant differences between groups, more pronounced BPV was observed in the poor prognosis group than in the good prognosis group in this study.
Mean-SBP (OR = 1.068; 95% CI 1.008–1.131) showed some predictive value at 90 days, which is consistent with Yasuhiro’s study [20] (OR = 1.92; 95% CI 1.15–3.68) and the VISTA study [17] (OR = 1.24; 95% CI 1.10–1.38). The predictive value of max-SBP was second to mean-SBP, but min-SBP did not show predictive value.
It is worth mentioning that in our study, all DBP indicators (mean-DBP, max-DBP, min-DBP, and the corresponding SD, CV, SV, and ARV of DBP) showed no correlation with 90-day prognosis, which is consistent with the results of Manning et al. [16]. The reason may be that patients with AIS are older, and SBP has a greater influence on cerebral perfusion. Once stroke occurs, the self-regulation mechanism of cerebral blood flow is affected, and the survival of ischemic penumbra is greatly affected by systemic BP. Similarly, in our study, the predictive value of MAP-related indicators was similar to that of DBP.
Although earlier studies [21-22] showed that patients with a higher initial BP after stroke have a better prognosis, the ECASS-II study [17] and a study by Endo et al. [19] showed no correlation between initial BP and prognosis at 3 months. Our study also showed that initial BP at admission was not related to clinical outcomes at 90 days.
Delado-Mederos et al. [23] found that the influence of BPV on lesion enlargement and 90-day outcomes depends on whether blood vessels are recanalized in patients with AIS undergoing rt-PA thrombolysis. In patients with poor early recanalization, marked systolic BPV is an independent predictor of infarction enlargement and poor prognosis. However, in patients with good recanalization, this predictive value disappears. It is regrettable that our study did not consider infarct size and intracranial and extracranial vascular conditions in patients with AIS. The subtypes of stroke were not differentiated in accordance with Trial of Org 10172 in Acute Stroke Treatment or Oxfordshire Community Stroke Project classifications, but it may be more accurate to evaluate the association between BPV and prognosis by combining relevant imaging examinations and stroke subtypes, which is the direction of our future research.
This study has some limitations that should be noted. First, the study adopted a retrospective design and the sample size was small. Second, we used an electronic cuff to monitor BP, which is different from more accurate methods mentioned in the literature, such as beat-to-beat BP monitoring. Third, we did not consider the effects of heart rate on BP, and BPV was only monitored for 24 hours, rather than for 48–72 hours or 1 week. In addition, the fluctuation in BP in patients with AIS is most pronounced in the first few hours, but we did not perform a more detailed analysis at 0–6 hours of BPV or distinguish between diurnal and diurnal BPV and 90-day outcomes. Future studies are needed to explore the relationship between BPV and prognosis in patients undergoing early intravenous anticoagulation therapy.