**2.5 Prognosis**

The prognosis of pericardial effusion is related to its etiology and size. Moderate-to-large size effusions are more commonly associated with bacterial infection, systemic inflammatory disease, or malignancy. Idiopathic pericardial effusion has a good prognosis, but effusion related to bacteria, post-radiation, or pericardial injury has a higher rate of developing either early (cardiac tamponade) or late complications (constrictive pericarditis). Large effusion (>3 months) carries a 30–35% risk of progression to cardiac tamponade. The follow-up of pericardial effusion is mainly based on symptomatic evaluation with the follow-up of inflammatory biomarkers and echocardiography [3]. A recent meta-analysis regarding prognosis of pericardial effusion in an elderly population with mean age > 60 reported that pericardial effusion can be considered as a marker of severity of the underlying disease as evidenced by a higher hazard ratio (HR) in patients with pericardial effusion with myocardial infarction (HR 2.65, 95% CI: 1.4–4.99; P = 0.003, 15 months follow-up) versus those with chronic heart failure (HR 1.53, 95% CI: 1.22–1.92; P < 0.0001, 31 months follow-up) [12].

#### **Figure 2.**

*Management algorithm for pericardial effusion with unknown origin.*
