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Suspecting and Screening for PH
After PE …It May Be CTEPH
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Acute pulmonary embolism can become chronically complicated
presented by
Raymond L. Benza, MD
Raymond L. Benza, MD, is a Professor of Medicine at Temple University, College of Medicine, in Philadelphia,
Pennsylvania, and Program Director for the Advanced Heart Failure, Transplantation, Mechanical Circulatory
Support and Pulmonary Vascular Diseases group of the Division of Cardiovascular Diseases at Allegheny General
Hospital, Allegheny Health Network in Pittsburgh.
He holds the James Magovern Chair for Cardiovascular Research.
I
t has been estimated that there may be as many as 600,000
episodes of acute PE in the US each year.1 For as many
as a quarter of patients who experience an acute PE, the
initial clinical presentation is sudden death owing to right
ventricular failure.2,3 For those patients who survive an acute
PE, the symptoms include shortness of breath, pleuritic pain,
and cough.3 Patients with a first episode of acute PE who
have stable hemodynamics can have good survival rates
when they are anticoagulated for at least 3 months.3,4
But even with adequate anticoagulation, some
survivors of acute PE have lasting complications and
associated symptoms.5 Recently, Klok et al have coined the
term “post-pulmonary embolism syndrome” to describe
chronic complications of PE, involving permanent changes
in pulmonary hemodynamics (artery flow, pulmonary gas
exchange and/or cardiac function) which are associated
with shortness of breath and decreased exercise capacity.6
The most serious manifestation of this syndrome—and the
most serious complication of acute PE—is chronic thromboembolic pulmonary hypertension, or CTEPH.2,6
HOW COMMON IS CTEPH?
Based on data from small observational studies that
followed survivors of acute PE, incidence of CTEPH has
been estimated to be 0.57% (N=866 survivors of acute
PE observed) to 3.8% (N=314 survivors of acute PE
observed).5,7 A more recent, but smaller (N=146 acute
PE survivors followed for 26 months), study found that 8
survivors of acute PE were suspected to have CTEPH, and
7 of these patients were confirmed to have CTEPH.8 Yet
another study of survivors of acute PE (N=104) saw 5.8%
of patients develop CTEPH within 2 years. Further
follow-up saw an additional 4 cases develop beyond 2
years (time period not specified) for a total of 9.1% of the
original study population.9
The absence of prior acute PE does not
exclude a diagnosis of CTEPH10-12
Applying even the lower end of this range of
estimates to the annual population of survivors of acute
PE suggests there could be thousands of incident cases of
CTEPH each year in the US. Further, though CTEPH is a
complication of a single or recurrent PE, as many as 25%
to 30% of patients who have CTEPH may never have had
an overt PE or a history suggestive of PE.10-12 The true
incidence of CTEPH may, therefore, be underestimated,
because postembolism observational studies do not include
patients without a history of PE.5
CTEPH IS A FORM OF PULMONARY
HYPERTENSION
Chronic thromboembolic pulmonary hypertension is
a form of pulmonary hypertension (PH), designated by
the World Health Organization as Group 4 PH. There are
5 WHO Groups of PH:13
1: Pulmonary arterial hypertension
2: PH due to left heart disease
3: PH due to lung diseases and/or