Multicenter Study on Coronary Anomalies in The Netherlands

Anomalous coronary arteries originating from the opposite sinus of Valsalva or
opposite coronary artery (ACAOS), anomalous left or right coronary artery from
the pulmonary artery (resp. ALCAPA, ARCAPA) and coronary arteriovenous fistulas
(CAVF) are rare congenital conditions. In the *ESC guidelines for the
management of grown-up congenital heart disease* ACAOS, ALCAPA, ARCAPA and CAVF
are not even included for patients without concomitant congenital heart
defects1. The existing guidelines that do discuss these defects in adults are
mainly based on expert consensus and small or few trials1-3. For example, for
interarterial courses of an ACAOS there is a class I, level B-NR indication for
surgery in the new 2018 ACC/AHA guidelines2. The guideline states *surgery is
recommended for AAOCA (=ACAOS) from the left sinus or AAOCA from the right
sinus for symptoms or diagnostic evidence consistent with coronary ischemia
attributable to the anomalous coronary artery*. They only speak of a
recommendation and it is unclear what examinations have the most value in
requiring the evidence of ischemia and thus making the decision to operate or
not. So there is a need for a standardized work up and treatment protocol based
on evidence from a larger study, especially for ACAOS with an interarterial
course.

No protocol exists regarding the work-up, treatment and follow-up of our
patient group. Many hospitals use different tools for diagnosis, possibly
leading to different ways of treatment. We aim to create one national protocol
using only the most important diagnostic tools for decision making. To decide
which examinations are the most valuable in the diagnostic process we need to
be able to compare the outcomes of different diagnostics per patient. This will
provide for future patients a clear treatment path, thus keeping hospitals
visits and hospital stays to a minimum and provide for clinicians an aid in
caring for these rare anomalies.

- Create a protocol including work-up, treatment and follow-up of ACAOS
- Give an overview of the current practices involving ALCAPA, ARCAPA and CAVF

This part of the larger MuSCAT study will be in a prospective setting. All
referred patients with an ACAOS will receive work-up and follow-up according
to a standard protocol created for this this study. For patients with ALCAPA,
ARCAPA or CAVF only registry of hospital visits and events will take place.
Inclusion will take place during 3 years with at least 2 years of follow-up.

All examinations that will be done are currently routinely used for diagnostic
purposes of ACAOS. Though, different hospitals use different examinations. All
tests will be done according to their standard approved protocols. Overall,
patients will get on average 1 examination more than would be done outside of
this protocol.

The burden in the context of the study will comprise the following:
- At least 4 outpatient clinic visits in one of the participating tertiary
hospitals. 1 intake, 3 after treatment decision/post-surgery (6 months, 12
months, 24 months).
- 1 or 2 coronary CT angiographies, ECG triggered, 0.5-1mm slices. 1 during
work up, in case of surgery:1 at 6 months post-operative, however this will be
at the treating doctors discretion
- 1 coronary angiography (CAG) during work up, in case of an interarterial
course intravascular ultrasound (IVUS) and fractional flow reserve (FFR)
measurements will also be done. In the LUMC an IFR will also be included. Only
during work-up and at treating doctors discretion
- 1 transthoracic echocardiogram during work up.
- 1 or 2 examinations for ischemia detection, 1 during work up, in case of
surgery: 1 at 6 months post-operative, however this will be at the treating
doctors discretion
- 3 SF-36 fill outs: 1 during work-up, 1 at 6 months after inclusion/surgery, 1
at 12 months after inclusion/surgery
- Other appointments or examinations will only be planned on indication

All procedures are routinely done in daily practice. Risks associated with
participation are in general no greater than in other patients undergoing the
same examinations. Only for the CAG with FFR and IVUS there might be a slightly
increased risk of adverse events because of the abnormal coronary anatomy in
ACAOS. However, in a recent study done by Driesen et al. no complications were
made peri-procedural in 30 consecutive patients who underwent CAG with FFR and
IVUS.