Trial Short Case 1April 2022

Answers

Question 1

Primary pathology is Cor triatriatum.

Cor triatriatum is a very rare congenital cardiac anomaly with a reported incidence of 0.1% of all congenital heart defects. If diagnosed in adulthood – isolated atrial fibrillation has been attributed to be the presenting symptom.

Two types of cor triatriatum:

  1. Dexter involves right atrial division

  2. Sinister involves left atrial division.

Dexter: Right atrium is divided into two chambers by exaggerated foetal Eustachian and Thebesian valves, as a remnant from poor regression of the right valve of the right horn of the embryologic sinus venosus, which come together to form an incomplete septum across the lower part of the atrium.

Sinister: Left atrium is divided into two chambers by a fibromuscular septum, with the pulmonary veins entering a posterior-superior chamber separated from the anterior-inferior distal chamber containing the mitral valve. The embryologic origin of this defect remains unclear

Question 2

Investigations in this case:

This patient’s echocardiogram demonstrates a two chamber left atrium with a thick membrane and a small fenestration that has an increased gradient with exertion

TOE – demonstrated the pulmonary veins to be draining into the superior compartment of the LA

Right heart catheterization has demonstrated elevated PA pressures and LA pressures.

Left heart catheterization has demonstrated a normal LVEDP + significant right PDA coronary artery disease

Interpretation of investigations:

Requires CABG x 1 to the right PDA

A raised Pulmonary capillary wedge pressure (PCWP), elevated pulmonary pressures, normal LVEDP à concern over severe mitral stenosis HOWEVER with the membrane evident on echocardiogram with the raised gradient over that membrane on exertion à Cor Triatriatum Sinister.

As the PCWP is elevated, the elevated PA pressures are not explained by isolated pulmonary hypertension. Therefore his increasing SOB is due to the elevated pressures secondary to the Cor Triatriatum Sinister.

As a result of this membrane with gradient on exertion à dilation of LA, raised PA pressures and subsequent AF

Question 3

Surgical ablation: can be performed without additional operative risk of mortality or major morbidity, and is recommended at the time of concomitant isolated aortic valve replacement, isolated coronary artery bypass graft surgery, and aortic valve replacement plus coronary artery bypass graft operations to restore sinus rhythm. (Class I, Level B nonrandomized)

HOWEVER:

Surgical ablation for symptomatic AF in the setting of left atrial enlargement (‡4.5 cm/>40 ml/m2) or more than moderate mitral regurgitation by pulmonary vein isolation alone is not recommended. (Class III no benefit, Level C expert opinion)

Left Atrial Appendage Closure: At the time of concomitant cardiac operations in patients with AF, it is reasonable to surgically manage the left atrial appendage for longitudinal thromboembolic morbidity prevention. (Class IIA, Level C expert opinion). The LAAOS III Trial demonstrated a decreased post operative stroke risk for those patient with atrial fibrillation who had their left atrial appendage occluded at time of surgery

Therefore – not appropriate for surgical ablation for AF in this case as LA severely dilated. Reasonable to address the left atrial appendage at time of surgery

Question 4

For patients with AF and an elevated CHA2DS2-VASc score (≥2 in men, ≥3 in women), oral anticoagulants are recommended. (Strength of recommendation I, strong, benefit strongly exceeds risk; level of evidence A, high-quality evidence from ≥1 randomized clinical trial [RCT]).

This patients CHADS2-VASc score is currently 2 (Hypertension and T2DM). Will increase to 3 as age increases.

Although his appendage has been occluded - there is no clear evidence yet over the safety of cessation of anticoagulation with a closed left atrial appendage. The LAAOS III Trial did not compare stroke risk between those on or ceased anticoagulation post operatively. Need to ascertain the reasons for cessation i.e. symptoms of haemorrhage. If able to tolerate anticoagulation it would be safest to do so.