第一部分

目的：探讨老年人群握力减弱与静脉血栓栓塞症（VTE）发病风险之间的因果关联。

方法：运用孟德尔随机化（MR）方法，分析握力减弱与VTE发病风险之间的关联，因果效应主要采用逆方差加权法（IVW）进行评估。计算F统计量检验工具变量的稳定性，运用Cochran’s Q统计法进行异质性检验，并运用加权中位数、MR-Egger回归和留一法评估敏感性和多效性。

结果：老年人群握力减弱与VTE发病风险之间无因果关联（OR：1.001，95%CI：0.997-1.005，P= 0.524）。进一步分析老年人群握力减弱与深静脉血栓形成（DVT）和肺栓塞（PE）的因果关联后，老年人群握力减弱与DVT（OR：1.002，95%CI：0.999~1.006，P= 0.254）和PE发病风险之间均无因果关联（OR：0.894，95%CI：0.700~1.141，P= 0.368）。

结论：老年人群的握力减弱与VTE发病风险无因果关联。

第二部分

目的：肺栓塞（PE）残余肺血管阻塞（RPVO）的慢性阻塞可导致持续心肺功能受损和肺动脉高压，本研究通过CT肺血管造影（CTPA）评估PE血栓溶解的影响因素。

方法：基于一项注册的前瞻性PE队列（NCT06073366），对纳入102名经CTPA诊断为急性PE且确诊后3~6个月内完成至少一次CTPA随访的患者进行回顾性分析，采用卡方检验进行单因素分析和采用逻辑回归进行多因素校正。

结果：对102名PE患者的1658支阻塞肺动脉进行分析，其中219支肺动脉完全阻塞，1439支肺动脉部分阻塞。抗栓治疗3~6个月后，部分阻塞肺动脉1268支（88.1%）血栓完全溶解，完全阻塞肺动脉164支（74.9%）血栓完全溶解，完全阻塞血管的血栓完全溶解率显著低于部分阻塞血管，RPVO风险增高118%（OR：2.179，95%CI：1.529~3.105，P<0.001）。药物治疗策略（单纯抗凝治疗与溶栓治疗）、PE危险分层（低危与中危）、血栓部位（中央肺动脉与外周肺动脉）、老年（≥65岁）、性别、肥胖（身体质量指数≥28 kg/m²）和合并深静脉血栓对血栓完全溶解的影响无显著差异。

结论：抗栓治疗后约13.6%的肺动脉具有RPVO，完全阻塞的肺动脉发生RPVO的风险较部分阻塞的肺动脉显著增高，对于血管完全阻塞的PE患者可能需要优化治疗策略，减少远期并发症的发生。

Part I

Objective To investigate the causal association between weak grip strength and the risk of venous thromboembolism (VTE) in the elderly.

Methods The association between weak grip strength and the risk of VTE was analyzed using Mendelian randomization (MR), and the causal effect was mainly assessed with inverse variance weighting (IVW). The F-statistic was calculated to test the stability of instrumental variables, Cochran's Q-statistic was applied to test for heterogeneity, and sensitivity and multiplicity were assessed using weighted median, MR-Egger regression, and leave-one-out methods.

Results There was no causal association between weak grip strength and the risk of VTE in the elderly (OR: 1.001, 95% CI: 0.997-1.005, P= 0.524). In a further analysis of deep vein thrombosis (DVT) and pulmonary embolism (PE), similarly no causal association was found between weak grip strength and the risk of DVT (OR: 1.002, 95% CI: 0.999-1.006, P= 0.254) and PE (OR: 0.894, 95% CI: 0.700-1.141, P= 0.368) in the elderly.

Conclusion There was no causal association between weak grip strength and risk of VTE in the elderly.

Part II

Objective: Chronic obstruction of Chronic obstruction from residual pulmonary vascular obstruction (RPVO) can lead to persistent cardiopulmonary dysfunction and pulmonary hypertension. This study investigated the influence factors on the resolution of pulmonary embolism (PE) by computed tomography pulmonary angiography (CTPA).

Methods: Based on a registered prospective PE cohort (NCT06073366), a retrospective analysis was conducted on 102 patients with acute PE diagnosed by CTPA and followed up with at least one CTPA examination 3~6 months after diagnosis. Chi-square tests were used for univariate analysis, and logistic regression was employed for multivariate corrections.

Results: A total of 1,658 obstructed pulmonary arteries from 102 PE patients were analyzed, including 219 completely obstructed and 1,439 partially obstructed pulmonary arteries. After 3 to 6 months of antithrombotic therapy, 1268 (88.1%) of the partially obstructed pulmonary arteries and 164 (74.9%) of the completely obstructed pulmonary arteries had complete resolution of clots, the complete resolution rate of clots in completely obstructed vessels was significantly lower than that in partially obstructed vessels, increasing the risk of RPVO by 118% (OR: 2.179, 95% CI: 1.529-3.105, P < 0.001). There were no significant differences in the complete resolution of clots with respect to medication strategy (anticoagulation alone vs. thrombolytic therapy), PE risk stratification (low risk vs. high risk), thrombus location (central vs. peripheral pulmonary arteries), age (≥65 years), gender, obesity (BMI ≥28 kg/m²), and concomitant deep vein thrombosis.

Conclusion: About 13.6% of pulmonary arteries had RPVO after antithrombotic therapy, and the risk of RPVO was higher in completely obstructed pulmonary arteries than in partially obstructed pulmonary arteries. For PE patients with complete vascular obstruction, warranting further exploration of treatment strategies to reduce the incidence of long-term complications.