Predisposition to Thrombophilia and Hypofibrinolysis in Pulmonary Embolism: Analysis of Inherited Factors

Pulmonary embolism (PE) is a relatively common cardiovascular emergency, though its exact incidence is difficult to assess. Accurate diagnosis is critical because of the high 30-day mortality in patients in whom the diagnosis is missed on admission. Doubt for PE is often raised by the presence of risk factors for venous thromboembolism (VTE), which are categorized into inherited and acquired. Among these, the importance of inherited/genetic thrombophilic factors is increasingly recognized. The most frequent markers of inherited thrombophilia are Factor V Leiden (FVL) and G2021OA prothrombin gene mutation. Among the inherited factors causal to thrombophilia, the C677T variant in methylentetrahydrofolate reductase (MTHFR) gene as well as factors like P1A1/P1A2 polymorphism in platelet glycoprotein Ilb/IIIa (P1A2) and hypofibrinolytic polymorphism 4G/4G in PAI-1 gene are discussed with controversial results. In our study, thrombophilic and hypofibrinolytic genetic variants were identified in 54.2% of 115 patients with PE. The most common significant genetic defects were FVL- 16.5% in patients versus 6.2% in controls (OR=3.102; p=0.05), G20210A PT 5.7% versus 2.1% (OR=2.983; p>0.05). P1A2 was found in 27.3% patients versus 19.9% in controls (OR= 1.523, p>0.05) and PAM 27.8% versus 22.6% (OR =1.501 p>0.05). MTHFR C677T carriage was inverse: 6.7% in patients versus 13.4% in controls. (OR=0.461 p=0.05). Of all the patients studied, 15.65% had a history of recurrent embolic incidents. The risk of recurrence was higher for the carriers of FVL and G20210A prothrombin gene mutation. The association between carriage of thrombophilic genetic factor and the early onset of the first embolic episode was found in the patients with PE. The awareness of risk factors and risk stratification is a critical issue in treatment and prevention policy. Preventive measures should be taken in particular medical conditions.