The long-term functional outcome in Mustard patients study: Another decade of follow-up

For over 20 years, we have followed a cohort of patients who underwent the Mustard procedure for d-transposition of the great arteries. The current study follows the same cohort from our last study in 2007 to reassess their functional capacity and quality of life.

Of the original 45 patients, six patients have required cardiac transplant and 10 patients have died, including two of the transplanted patients. Twenty-five of the remaining patients agreed to participate in this current study.

Patients underwent comparable testing to the previous studies when possible including exercise stress testing, echocardiography, MRI or CT evaluation of cardiac anatomy and function, Holter monitor, and quality of life questionnaire.

Thirty-one percent of patients have experienced cardiac death either in the form of mortality or cardiac transplantation. The major cause of death was systemic right ventricular failure. Sixty-five percent have continuing abnormalities of rhythm. Exercise time and workload showed a statistically significant decrease from the original study (Time 1) to both 10-year (Time 2) and 20-year (Time 3) follow-up points. Right ventricular ejection fraction decreased significantly from the Time 1 to Time 2, and again to this current follow-up. Quality of life measures of energy level decreased significantly from the original study to both the Time 2 and Time 3.

Cardiac mortality for Mustard patients remains high, and over time, systemic right ventricular ejection fraction, rhythm, exercise tolerance, and quality of life assessments show deterioration. There does not appear to be a single clear predictor of poor outcome.