Objective: The use of thrombectomy alone (endovascular thrombectomy [EVT]) was found to be noninferior to combination therapy (EVT plus intravenous thrombolysis [IVT] with alteplase before thrombectomy [EVT+IVT]) in the DIRECT-MT (Direct Intra-Arterial Thrombectomy in Order to Revascularize AIS Patients With Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals: A Multicenter Randomized Clinical Trial), yet the economic value of omitting alteplase was unclear. Thus, in this paper the authors assessed the cost-effectiveness of EVT alone versus EVT+IVT in the DIRECT-MT.
Methods: In the context of the Chinese healthcare system, the authors conducted a post hoc economic analysis of the DIRECT-MT based on an intention-to-treat approach. Index stroke costs were collected at the individual level, while costs after discharge were complemented with published literature and government websites. Utility weights assessed at 90 days using the 5-Level EQ-5D questionnaire were prospectively collected. For long-term modeled cost-effectiveness analysis, a Markov model with 7 health states corresponding to the 7 modified Rankin Scale scores was used. Deterministic and probabilistic sensitivity analyses were performed. All costs are expressed in 2019 US dollars, discounted using the annual Consumer Price Index in China.
Results: During the index hospitalization, the mean medication cost in the EVT-alone group was $487 lower than that in the EVT+IVT group ($2453 [95% CI $2205-$2701] vs $2940 [95% CI $2703-$3178], p = 0.01), but the mean overall costs were similar between the groups ($15,565 [95% CI $14,876-$16,254] vs $15,472 [95% CI $14,714-$16,230], p = 0.73). Within 90 days of the trial, there were no significant differences in total costs (difference -$222 [95% CI -$603 to $161], p = 0.06, bootstrapping) or utility values (median 0.84 [IQR 0.48-0.95] vs median 0.85 [IQR 0.26-1.00]; beta coefficient < 0.01 [95% CI -0.06 to 0.07]) between EVT alone and EVT+IVT. Over the lifetime horizon, EVT alone and EVT+IVT yielded comparable lifetime QALYs (2.02 QALYs [95% CI -0.07 to 4.55 QALYs] vs 1.90 QALYs [95% CI -0.09 to 4.55 QALYs]) and costs ($26,795 [95% CI $15,281-$54,463] vs $27,632 [95% CI $14,558-$52,251]).
Conclusions: In this economic analysis based on a trial conducted in China, the authors found that EVT alone was not associated with economic dominance over EVT+IVT in patients with anterior circulation large-vessel occlusion.
The study measured fibrinogen fluorescence at temperatures between 20 and 80 degrees Celsius across different pH levels.
It was found that raising the temperature from 20 to 40 degrees Celsius did not change the structure of fibrinogen in solutions with pH between 4.5 and 9.3.
However, temperatures between 40 to 50 degrees Celsius caused some structural changes in neutral solutions, and temperatures above 50-55 degrees Celsius led to significant denaturation of the fibrinogen molecule.
