Arrhythmi and Mortality After the Mustard Procedure: 30-Year Single-Center Experience

Objectives. Our purpose was to assess the risk factors for late mortality, loss of sinus rhythm and atrial flutter after the Mustard operation. Background. The Mustard operation provides correction of cyanosis with low surgical risk in transposition of the great vessels. However, right ventricular failure, loss of sinus rhythm, atrial flutter and death are frequent long-term complications. Methods. Records of 534 children who underwent the Mustard operation at single center since 1962 were reviewed for demographic, anatomic, electrocardiographic and physiologic predictors and outcomes. Results. There were 52 early deaths (9.7%). Survival analysis was undertaken for 478 early survivors with mean follow-up interval of 11.6 ± 7.2 years. There were 77 late deaths (16.1%), with sudden death (n = 31) the most frequent cause. Survival estimates were 89% at 5 years and 76% at 20 years of age. Risk factors were an earlier date of operation, operative period arrhythmi and an associated ventricular septal defect. Risk (hazard) of late death declined in the first decade, with further peaks in the second decade. Sinus rhythm was present in 77% at 5 years and 40% at 20 years. Loss of sinus rhythm was associated with previous septectomy, postoperative bradycardi and late atrial flutter. Freedom from atrial flutter was 92% at 5 years and 73% at 20 years of age. Risk factors for atrial flutter were the occurrence of perioperative bradyarrhythmia, reoperation and loss of sinus rhythm during follow-up. Risk of atrial flutter demonstrates late increase. Conclusions. Ongoing loss of sinus rhythm and late peaks in the risk of atrial flutter and death necessitate continued follow-up.