CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 4, July/August 2014
AFRICA
165
Decline in mean platelet volume in patients with patent
foramen ovale undergoing percutaneous closure
Barı
ş
Düzel, Nihan Kahya Eren, Rida Berilgen, U
ğ
ur Kocaba
ş
, Mustafa Gönençer, Cem Nazli, Oktay Ergene
Abstract
Introduction:
The presence of patent foramen ovale (PFO) is
considered a possible cause for cryptogenic stroke. The mech-
anism underlying the ischaemic neurological events in the
presence of PFO has not been firmly established. The purpose
of this study was to compare: (1) the mean platelet volume
levels in PFO patients with and without a cryptogenic stroke,
and (2) pre- and post-procedural mean platelet volumes
(MPV) in patients undergoing percutaneous PFO closure.
Methods:
Sixteen PFO patients undergoing percutaneous
closure to prevent recurrent ischaemic events and 15 asymp-
tomatic patients with PFO were enrolled in the study. Mean
platelet volume was compared between patients with and
without a history of stroke. We also compared pre- and post-
procedural MPV levels in patients undergoing percutaneous
PFO closure.
Results:
Mean platelet volume, which is a marker for platelet
activity, was similar in PFO patients with and without stroke
(9.34
±
1.64 vs 9.1
±
1.34 fl;
p
=
0.526). Interestingly, MPV
decreased significantly after percutaneous closure compared
to pre-procedural levels (9.34
±
1.64 vs 8.3
±
1.12 fl;
p
=
0.001).
Conclusion:
Our findings suggest interatrial communica-
tion through a PFO may be related to increased MPV and
increased platelet activity.
Keywords:
patent foramen ovale, ischaemic stroke, platelets, tran-
scatheter closure
Submitted 22/7/13, accepted 9/5/14
Cardiovasc J Afr
2014;
25
: 165–167
DOI: 10.5830/CVJA-2014-027
Patent foramen ovale (PFO) is a haemodynamically insignificant
communication that is present in 24% of the general population.
1
In 1988 Lechat
et al
. performed transthoracic echocardiography
(TTE) with contrast injection and showed that patients with stroke
of unknown cause had PFOs more frequently than the controls.
2
Since then, many studies have confirmed this association. In 2000,
a meta-analysis summarised the evidence that PFO was more
likely to be found in stroke patients than in stroke-free individuals.
3
In about 50 to 60% of patients younger than 55 years, the
cause of acute ischaemic stroke remains undefined.
4
In this
group, interatrial septal abnormalities are found in 55 to 60% of
cases, which is higher than in the normal population.
In another meta-analysis, Mattle
et al
. reported a higher
prevelance of PFO in patients with cryptogenic stroke than in
patients with a stroke of known causes.
1
The postulated possible
mechanisms underlying the stroke in the presence of PFO are:
paradoxycal embolism, thrombus formation within the conduit
of the PFO, or susceptibility of patients with PFO to atrial
arrhythmias with possible intra-atrial thrombus formation.
4-8
Although paradoxycal embolism, which is associated with
deep-vein thrombosis (DVT), is the favoured hypothesis, DVT in
patients with PFO is usually undetectable.
9
Therefore, increased
platelet activity as well as disorders in the coagulation cascade
may contribute to the association between PFO and stroke.
Mean platelet volume (MPV) is a measure of platelet size and
is a potential marker of platelet reactivity. It has been shown that
larger platelets are metabolically and enzymatically more active
and have greater prothombotic potential.
10,11
The aim of this study was (1) to compare MPVs of PFO
patients with and without a history of cryptogenic stroke, and (2)
to determine the effect of percutaneous PFO closure on MPV.
Methods
Between January 2008 and June 2012, 16 consecutive patients
who had suffered cryptogenic stroke and underwent percutaneous
PFO closure to prevent recurrent cerebral ischaemic events, and
15 consecutive patients with a diagnosis of PFO but without a
history of stroke were recruited into the study. The diagnosis
of PFO was established if any microbubble was seen in the
left-sided cardiac chambers within three cardiac cycles from
the maximum right atrial opacification after contrast injection
during transoesophageal echocardiography (TEE).
Demographic data and history of conventional risk factors
such as smoking habits, hypertension, diabetes mellitus,
hyperlipidaemia, history of vascular disease (stroke, coronary
artery disease, peripheral artery disease) and medications were
recorded for every patient.
Non-fasting blood samples were taken from each patient
to assess mean platelet volume and standard blood tests.
In patients who underwent percutaneous PFO closure, mean
platelet volume was measured before percutaneous PFO closure
and at the six-month follow up after the intervention. In patients
with PFO without a history of stroke, MPV was measured once
at the time of enrollment.
Mersin State Hospital, Mersin, Turkey
Bari
ş
Düzel, MD
Izmir Katip Çelebi University, Cardiology Clinic, Atatürk
Research and Education Hospital, Turkey
Nihan Kahya Eren, MD,
U
ğ
ur Kocaba
ş
, MD
Mustafa Gönençer, MD
Cem Nazli, MD
Oktay Ergene, MD
Mardin Kiziltepe State Hospital, Mardin, Turkey
Rida Berilgen, MD
