Older Age May Predict MCS, Heart Transplantation, or Mortality in ccTGA

Patients with congenitally corrected transposition of the great arteries (ccTGA) are more likely to have deterioration to end-stage heart failure or death, especially between the ages of 51 and 69 years, if they have history of arrhythmic and congestive heart failure events. These findings were published in the European Heart Journal.

The multicenter, retrospective, cohort study enrolled patients aged 18 years or older with ccTGA, who were seen at least twice at an adult congenital heart disease (ACHD) outpatient clinic during a period of a year or longer.

An initial visit was defined as the first outpatient ACHD encounter since January 1, 2002, and the primary outcome was the first occurrence of mechanical circulatory support (MCS), heart transplantation, or death.

The analysis included 558 patients (48% women) from 29 centers. The participants had a median age of 32.8 (IQR, 23.5-47.1) years at their initial visit and 42.1 (IQR, 32.5-55.6) years at their last follow-up.

The mean follow-up was 8.7±4.9 years (1.0-19.1 years) and was comparable between those who did and those who did not have a primary outcome event. A total of 75 individuals had a primary outcome event (13.4%; 95% CI, 11%-17%; 15.4 events per 1000 person-years), including 11 MCS implantations, 12 transplantations without MCS, and 52 deaths without previous MCS or transplantation.

The proportion of patients who had a primary outcome event increased with age, from 4.2 (95% CI, 1.6%-6.7%) for those aged younger than 30 years to 34.6 (95% CI, 16.3-52.9) for those aged 60 to 70 years.

Participants who had a primary outcome event were older at their initial visit, were more likely to have diabetes, and had greater weight and body mass index (BMI). The primary outcome also was more common in those who were taking beta-blockers and those who had a higher prevalence of atrial arrhythmia before their initial visit.

After exclusion of patients with tricuspid valve replacement before their initial visit (n=62), event rates were lowest in patients with right ventricular (RV) dysfunction and tricuspid regurgitation (TR) in the normal-mild range (13/181, 7%) and highest in those with RV dysfunction and TR in the moderate-severe range (31/110, 28%, P <.001, not accounting for follow-up duration).

Participants who had a primary outcome were more likely to have initiated a loop diuretic (32% vs 13%, P <.001) or an aldosterone antagonist (28% vs 11%, P <.001) during the follow-up period.

Multivariable modeling with initial visit findings showed that the only independent predictors of the composite primary outcome were older age at initial visit (hazard ratio [HR], 1.44 per decade; 95% CI, 1.21-1.70; P <.001), previous heart failure admission (HR, 4.44; 95% CI, 2.61-7.56; P <.001), and severe RV dysfunction designation by echocardiography (HR, 3.50; 95% CI, 1.98-6.21; P <.001). Atrial arrhythmia, ventricular arrhythmia, QRS duration, beta-blocker use, diuretic use, and estimated glomerular filtration rate were not independently predictive.

Among several limitations, survivorship and referral bias affected the sample, and the population is skewed toward younger participants. Also, practice patterns vary between centers, and variation likely occurred regarding frequency of testing and use of medications. Furthermore, the multivariable modeling for risk calculation is limited in part because of missing data such as QRS duration, exercise, or cardiovascular magnetic resonance findings.

“Despite the relatively large multicenter cohort, it remains difficult to reliably predict which patients are most likely to rapidly progress towards end-stage heart failure,” wrote the study authors. “Additional analyses of this dataset will further elucidate predictors for worse outcomes in ccTGA patients.”