The natural and unnatural history of the Mustard procedure: long-term outcome up to 40 years

Area of Science:

• Cardiology
• Pediatric Cardiology
• Cardiac Surgery

Background:

• The Mustard repair is a palliative surgical procedure for transposition of the great arteries (TGA).
• Long-term outcomes and clinical status after Mustard repair are a significant concern.
• This study evaluates long-term survival and clinical sequelae in TGA patients post-Mustard repair.

Purpose of the Study:

• To describe long-term survival, clinical outcome, and ventricular systolic function in patients after Mustard repair for TGA.
• To identify predictors of adverse events and long-term morbidity.

Main Methods:

• A longitudinal, single-center study of 91 patients who underwent Mustard repair before 1980.
• Median follow-up of 35 years with in-hospital evaluations every 10 years.
• Comprehensive assessment including ECG, echocardiography, exercise testing, NT-proBNP, Holter, and cardiac MRI in survivors.

Main Results:

• Cumulative survival was 68% at 39 years; event-free survival was 19%.
• Reinterventions were primarily for baffle issues; 39% required pacemaker/ICD. Arrhythmias occurred in 28% (supraventricular) and 6% (ventricular).
• Right ventricular systolic function was impaired in nearly all survivors; 14% developed heart failure. 92% had elevated NT-proBNP. Early postoperative arrhythmias predicted late arrhythmias and heart failure.

Conclusions:

• Long-term survival after Mustard repair is diminished, with significant morbidity.
• Early postoperative arrhythmias are a key predictor of late arrhythmias and heart failure development.
• Impaired ventricular function and elevated NT-proBNP are common long-term sequelae.