Use of thrombocyte count dynamics after aneurysmal subarachnoid hemorrhage to predict cerebral vasospasm and delayed cerebral ischemia: a retrospective monocentric cohort study

Abstract

Cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) are critical complications following aneurysmal subarachnoid hemorrhage (aSAH), contributing to substantial morbidity and mortality. This retrospective cohort study investigated thrombocyte count (TC) dynamics as a potential marker for predicting CVS and DCI in 233 adult patients with aSAH. Parameters including TC, C-reactive protein, hematocrit, CVS, and DCI were analyzed using logistic regression, Spearman correlation, and time-to-event analysis. CVS and DCI occurred in 71.1% and 41.2% of patients, respectively. A relative thrombocyte count decrease greater than 12.6% within the early post-aSAH period was significantly associated with increased risks of CVS (p < 0.001; 95% CI 4.74-25.3) and DCI (p = 0.003; 95% CI 1.39-5.43). Temporal analysis revealed that greater TC decrease correlated with earlier CVS onset (p = 0.00016; R=-0.28), with a median of three days from the minimum TC to CVS onset. This association suggests a potential diagnostic window for early detection and intervention if validated in prospective studies.

Keywords: Aneurysmal subarachnoid hemorrhage; Cerebral vasospasm; Delayed cerebral ischemia; Thrombocyte dynamics.

Fig. 1

Flow chart of patient selection process. ICD international classification of diseases, SAH subarachnoid hemorrhage, CVS cerebral vasospasm.

Fig. 2

The figure displays the ROC curves for the TC decrease > 12.6% in predicting CVS and DCI. The red curve represents CVS with an AUC of 0.76, sensitivity of 81.87%, and specificity of 70.59%. The teal curve represents DCI with an AUC of 0.61, sensitivity of 83.33%, and specificity of 38.69%. The dotted diagonal line represents no discrimination. ROC receiver operating curves, AUC area under the curve, CVS cerebral vasospasm, DCI delayed cerebral ischemia.

Fig. 3

(A): Box plots depicting the results of Wilcoxon matched pair test showing significant differences in percentual changes of all three laboratory parameters grouped by CVS presence (no CVS = blue, CVS = red). Median, IQR with 25th and 75^Th quartile and maximums without outliers are presented. This suggests heterogeneity between patients with and without CVS in these parameters. This was most distinct for the changes in TC. (B): Box plots depicting the results of Wilcoxon matched pair test showing differences in percentual changes of laboratory parameters grouped by DCI presence (no DCI = blue, DCI = red). Median, IQR with 25th and 75^Th quartile and maximums without outliers are presented. Only Hct and TC values showed significant differences, with TC showing the most significant distinction.(C): Temporal follow-up [days after aSAH] of median TC values [/nl] with 95% CI grouped by CVS and DCI presence (no CVS/DCI = blue line, CVS/DCI = red line; line represents median) showing steeper decrease of TC during the first two days after aSAH in patients with CVS and DCI. In patients with CVS and DCI overall lower TC values were reached. CRP C-reactive protein, Hct hematocrit, TC thrombocyte count, CVS cerebral vasospasm, CI confidence interval, IQR interquartile range, DCI delayed cerebral ischemia.

Fig. 4

Left: Kaplan-Meier curve showing significantly lower probability (p < 0.0001) of CVS-free interval in aSAH patients with TC decrease > 12.6% (red line) as compared to patients with TC decrease ≤ 12.6% (blue line). * marks significant results.

Fig. 5

Subgroup analysis of patients with CVS on DCI presence Left: Box plots depicting results of Wilcoxon matched pair test showing differences in percentual changes of laboratory parameters grouped by DCI presence in CVS patients (no DCI = blue, DCI = red). Median, IQR with 25th and 75^Th quartile and maximums without outliers are presented. Only Hct and TC values showed significant differences, with Hct showing the most significant distinction as a sign of heterogeneity in hydration status between CVS patients with and without DCI. Right: Temporal follow-up [days after aSAH] of median TC values [/nl] with 95% CI in CVS patients grouped by DCI presence (no DCI = blue line, DCI = red line; line represents median) showing similar rate of TC decrease at the disease onset but overall lower TC reached in patients with DCI confirming the observations from the initial analysis. CRP C-reactive protein, Hct hematocrit, TC thrombocyte count, DCI delayed cerebral ischemia, IQR interquartile range, CI confidence interval.