CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013
252
AFRICA
ventricular hypertrophy (LVH) (HCM-risk: z-score for IVS and/or
PW
<
2.5 SD;
n
=
10) and HCM-patients with LVH (HCM: z-score
>
2,5 SD;
n
=
10), and compared to age- and gender-matched healthy
controls (
n
=
20) and athletes (
n
=
10, endurance physical exercise
>
10 hours/week, z score
>
2 SD). Conventional ECHO, TD, advanced
12-lead ECG (A-ECG) for calculation of spatial mean QRS-T angle
by Kors (Cardiax
®
, IMED Co Ltd, Budapest/Hungary and Houston/
USA) were used. Cutaneous microvascular responses to acetylcho-
line (Ach) and sodium nitroprusside were assessed by laser Doppler
with iontophoresis.
Results:
As compared to controls and athletes, the micro-vascular
responses to Ach were increased in patients with HCM and LVH, and
also in those at risk for HCM (i.e. HCM heredity without LVH;
p
=
0.09). In this latter group, micro-vascular responses to Ach correlated
significantly with both spatial mean QRS/T angle by Kors and E/E´
ratio by TD (
p
<
0.05,
r
>
0.3). With the exception of left ventricular
mass (LVM) and myocardial thickness, which were increased in both
athletes and HCM patients, there were no differences in any other
measured variable between controls and athletes.
Conclusion:
Independent to the presence of LVH the presymptomat-
ic HCM-risk individuals and HCM patients demonstrated enhanced
peripheral micro-vascular reactivity, probably reflecting compensa-
tory vasoactive mechanisms in response to HCM-related noxious
factors. The enhanced peripheral micro-vascular reactivity is present
in both presymptomatic HCM-risk individuals and HCM patients,
but not in athletes or normal controls, and seem to be associated with
fine abnormalities in myocardial electrophysiology and function.
1575: COMPLICATION CAPTURE TO ENHANCE PAEDIAT-
RIC CARDIAC SURGERY OUTCOMES
David Maldonado
1,2
, Hayley Burton
2
, Andrew Warren
1,2
, Stacy
O’Blenes
1,2
, Camille Hancock Friesen
1,2
1
Dalhousie University, Halifax, Canada
2
IWK Health Centre, Halifax, Canada
Background:
With current low mortality rates in paediatric cardiac
surgery, we can now focus on reducing complications to enhance
patient outcomes. In the absence of a risk-adjusted score for morbid-
ity, we have developed a system of tracking programme-wide
complications. The system generates a flag at the time of any excess
observed:expected (O:E) complications.
Methods:
Consecutive procedures and 30-day complications have
been recorded prospectively at the IWK Heart Centre since 2009,
using the Multi Institutional Database Committee definitions.
Inclusion criterion was a procedure with an assignable risk adjusted
congenital heart surgery (RACHS) category, which includes 70% of
cases. A morbidity score was generated for each procedure factor-
ing in frequency and severity of complications. Observed outcomes
were collected (2011–12) and expected outcomes were calculated
based on historic complications (2009–2011). An overall O:E plot
was generated case-by-case. Complications were also stratified by
RACHS category and organ-system. Flags were generated to indicate
unexpected complication frequency or severity.
Results:
In 2011–12, 116 procedures were performed on 106
patients, 86 of whom had an assignable RACHS category. The opera-
tive mortality was 5/116 (4.3%). Ninety-two complications occurred
in 31 procedures. The overall O:E plot was flagged 4 times as a
result of 9 complications (arrhythmia, neurologic and pulmonary).
The arrhythmia flags were generated by spontaneously resolving
arrhythmias in 3/4 cases. The single neurologic flag resulted from a
subdural haematoma in a procedure requiring preoperative ECMO.
Pulmonary flags were generated in 4 neonatal procedures (1 reintu-
bation and 4 long-term intubation). There was excess morbidity in
RACHS category 4 and 6.
Conclusions:
This complication capture and stratification system
allows real-time identification of excess complication occurrence.
We anticipate that the ability to detect complications will allow
focused changes to improve patient outcomes.
1576: DUAL ANTIPLATELET THERAPY IN PAEDIATRIC
CARDIOVASCULAR PRACTICE
Srinivas Ananth Narayan
1
, Elizabeth Orchard
2
, Georgina Stepney
1
1
Children’s Hospital, Oxford, UK
2
Oxford Heart Hospital, Oxford, UK
Introduction:
Antiplatelet drugs are increasingly used in paediatric
patients to prevent thromboembolic episodes, as an alternative to
warfarin. Aspirin remains the most frequently used antiplatelet agent;
however there has been an increased interest in the use of newer
agents. Clopidogrel is an antiplatelet drug that acts by irreversibly
modifying the adenosine diphosphate (ADP) purinergic platelet
receptor. Clopidogrel use in children has been reported principally by
American centres, predominantly in patients with congenital cardiac
disease. However, the dosage, duration and indications vary widely.
Experience in the UK remains very limited.
Objective:
The aim of the study was to assess the indication, dosage,
duration of therapy and safety of dual antiplatelet therapy with aspi-
rin and clopidogrel in paediatric patients with cardiovascular disease.
Methods:
The study included 21 consecutive children (with cardio-
vascular disease, presenting over a 2-year period with an indication
for anticoagulation (excluding mechanical valve replacement), who
were treated with aspirin and clopidogrel. Patient demographics
(12 male), median (range) (age 4.08 (0.02-13.61) years), diagnosis,
indication, dose (clopidogrel 0.3 (0.18-1.12) mg/kg; aspirin 4.46
(1.6-9.44) mg/kg), duration of treatment (23.14 (0.57-101.3) weeks)
and adverse events were recorded. Indications for combination use
were systemic-pulmonary artery shunt (7), Fontan (7), Glenn shunt
(3), stent (3) and others (3).
Results:
There were 2 adverse events:
• 4-year-old boy with gastrointestinal bleed, 7 days after starting
clopidogrel at 0.8 mg/kg/day. An endoscopy confirmed a gastric
ulcer. He was also taking aspirin 75 mg (4.17 mg/kg) and has
now been recommenced on warfarin.
• 6.5-year-old girl with haemorrhagic cerebrovascular accident 5
days after starting clopidogrel at 0.2 mg/kg/day. MRI showed
arteriovenous malformations in her brain. Her aspirin was
restarted at 50 mg (2.83 mg/kg) with no further adverse events.
Discussion:
Combined use of aspirin and clopidogrel is increasing
among children
.
Compared with warfarin, dual antiplatelet therapy
has advantage of ease of administration, with no monitoring required.
However there is limited knowledge of the bleeding risks associated
with dual antiplatelet therapy in children. This study highlights the
need for caution and vigilance in treating children with clopidogrel
in combination with aspirin, especially at higher clopidogrel doses.
1578: CHANGES IN MESENTERIC FLOW, HEART RATE
VARIABILITY AND SYSTEMIC MICROVASCULAR FUNC-
TION AFTER TOTAL CAVOPULMONARY CONNECTION-
RELATIONSHIP TO PULMONARY HAEMODYNAMICS
AND POSTOPERATIVE PLEURAL EFFUSION
Mikaela Dolk
1
, Katarina Hanseus
1
, Jens Johansson
2
, Thomas Higgins
1
,
Annika Maxedius
1
, Petru Liuba
1
1
Cardiology, Pediatric Heart Center, Skåne University Hospital,
Lund, Sweden
2
Cardiac Surgery, Pediatric Heart Center, Skåne University Hospital,
Lund, Sweden
Background
: Prolonged pleural effusion (PE) after total cavopul-
monary connection (TCPC) remains a serious complication with
important clinical and economic impact. Downstream pulmonary
action of mediators released in response to abnormal circulation in
the gut along with changes in cardiac autonomic nervous activity have
been suggested among possible mechanisms. We aimed to assess this
hypothesis by studying in a prospective manner the profiles of mesen-
teric flow, systemic microvascular function, and cardiac autonomic
function derived from the analysis of heart rate variability (HRV).
Methods:
Fifteen patients (median age at surgery: 2.1 yrs) with
univentricular heart physiology and previous Glenn surgery were
