Low infant weight increases risk of cardiac cath complications

Cardiac catheterization becomes more risky with lower infant birth weights, according to a study published in the Nov. 1 issue of Catheterization and Cardiovascular Interventions. The risk is significantly higher in infants weighing less than 2 kilograms (kg).

Previous studies found that infants less than 1 year old are at higher risk, but “it is unclear whether low weight infants experience a risk above and beyond that adjusted for infants one year of age and lower and, if so, which low weight groups may be at particularly increased risk,” wrote the authors, led by Carl H. Backes, MD, of Nationwide Children’s Hospital in Columbus, Ohio.

Backes and colleagues gathered data on infants less than 1 year of age between 2007 and 2010 from the Congenital Cardiac Catheterization Outcomes Project, a registry that includes eight cardiac catheterization programs. They collected information on variables identified as part of the Catheterization for Congenital Heart Disease Adjustment for Risk Method (CHARM), including procedure type risk group and hemodynamic vulnerability score.

There were 3,679 infants in the study cohort, and 57 (1.5 percent) weighed less than 2 kg. Compared with infants in the other weight groups (2 to 3 kg, 3-5 kg and greater than 5 kg), the lowest-weight infants were at highest risk for adverse events related to cardiac catheterization (odds ratio 2), even after adjusting for hemodynamic vulnerability and procedure type risk group.

Death was more common in infants weighing less than 2 kg (12 percent) compared with a rate of less than 1 percent in the other weight groups. After multivariate analysis, weights on less than 2 kg, 2 to 3 kg and 3 to 5 kg were independently associated with higher adverse event severity level.

Despite the risks, the authors argued that the findings do not preclude cardiac catheterizations for infants who need them.

“The inherent risks of catheter procedures in these patients have to be weighed against those associated with alternative surgical and medical management options, which may themselves carry higher risks of adverse patient outcome,” they wrote.