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PE and the epidemiology of CTEPH

CTEPH may be more common than previously estimated

CTEPH is a rare and often underdiagnosed form of pulmonary hypertension (PH). CTEPH is a complex condition and underdiagnosis may be due to a number of factors, including1:

  • Nonspecific symptoms

  • Variable rates of previous history of acute pulmonary embolism (PE)

  • Expertise required to read computed tomography pulmonary angiography (CTPA)

  • Infrequent use of ventilation/perfusion scintigraphy (V/Q scan) for accurate diagnosis, despite guideline recommendations


Prompt and accurate diagnosis of CTEPH is critical. In a prospective international registry, the 3-year survival rate has been estimated at only 70% in patients that do not have surgery.2


Data from multiple observational studies suggest that as many as 0.57% to 3.8% of patients may go on to develop CTEPH within 2 years after a first acute PE.3 Applying even the lower end of that range to the estimated 600,000 cases of acute PE per year in the US suggests the actual number of CTEPH cases developing each year may be substantially greater than diagnosed cases suggest.4

Thromboembolic model of CTEPH progression

CTEPH in patients who experience PE

Pengo et al. conducted a prospective, observational, long-term follow-up study to evaluate the incidence of symptomatic CTEPH in 314 patients with an acute episode of PE without prior venous thromboembolism. CTEPH was considered to be present if: systolic and mean pulmonary artery pressures exceeded 40 mm Hg and 25 mm Hg, respectively; if pulmonary-capillary wedge pressure was normal; and if there was angiographic evidence of disease.5


The figure below shows the cumulative incidence of symptomatic CTEPH over follow-up of as long as 10 years5:

  • 1% at 6 months (95% CI, 0.0 to 2.4)

  • 3.1% at 1 year (95% CI, 0.7 to 5.5)

  • 3.8% at 2 years (95% CI, 1.1 to 6.5)

  • CTEPH did not develop after 2 years with a median follow-up of ~8 years


Results from this study illustrate the importance of awareness to the possibility of CTEPH in patients who experience a PE, especially in the first 2 years following PE diagnosis.5

Incidence of CTEPH after PE chart

CTEPH does not always include history of documented PE

A European registry that published results in 2011 demonstrated that 74.8% of patients with CTEPH presented with previous acute PE, while 56.1% presented with previous deep vein thrombosis.6


However, as many as 30% of patients who have CTEPH may never have had an overt PE.7 The true incidence of CTEPH may be underestimated, because postembolism observational studies do not include patients who have no history of venous thromboembolism.8


Without intervention, survival with CTEPH is poor. To define the true epidemiology and natural history of CTEPH, further studies are needed.4


30 percent


1. Kim NH, Delcroix M, Jais X, et al. Chronic thromboembolic pulmonary hypertension. Eur Respir J. 2019;53:1801915. 2. Delcroix M, Lang I, Pepke-Zaba J, et al. Long-term outcome of patients with chronic thromboembolic pulmonary hypertension. Results from an international prospective registry. Circulation. 2016;133:859-871. 3. Fedullo P, Kerr KM, Kim NH, Auger WR. Chronic thromboembolic pulmonary hypertension. Am J Respir Crit Care Med. 2011;183(12):1605-1613. 4. Tapson VF and Humbert M. Incidence and prevalence of chronic thromboembolic pulmonary hypertension: from acute to chronic pulmonary embolism. Proc Am Thorac Soc. 2006;3:564-567. 5. Pengo V, Lensing AWA, Prins MH, et al. Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism. N Engl J Med. 2004;350(22):2257-2264. 6. Pepke-Zaba J, Delcroix M, Lang I, et al. Chronic thromboembolic pulmonary hypertension (CTEPH): results from an international prospective registry. Circulation. 2011;124(18):1973-1981. 7. Jamieson SW, Kapelanski DP, Sakakibara N, et al. Pulmonary endarterectomy: experience and lessons learned in 1,500 cases. Ann Thorac Surg. 2003;76(5):1457-1464. 8. Fedullo P, Kerr KM, Kim NH, Auger WR. Chronic thromboembolic pulmonary hypertension. Am J Respir Crit Care Med. 2011;183(12):1605-1613.