Updated CARPREG II risk score IDs pregnant women at risk for cardiac complications

Pregnancy increases the risk of morbidity in women who exhibit cardiovascular disease (CVD). Complications in expecting mothers may be predicted by a risk index that integrates lesion-specific, delivery-of-care and generic variables, according to a new study published in the Journal of the American College of Cardiology’s May 2018 issue.

The researchers, led by Candice K. Silversides, of Mount Sinai Hospital in Toronto, Canada, sought to determine sequential trends of cardiac complications during pregnancy.

They also looked to develop a more complex risk stratification index that not only utilizes general or lesion-specific predictors, but also incorporates specific cardiac diagnosis, general cardiac variables and factors related to process of care.

Currently, the CARPREG (Cardiac Disease in Pregnancy Study) risk index is widely used by clinicians for the assessment of pregnancy risk. The researchers analyzed data from more than 1,900 pregnant women exhibiting heart disease—including congenital heart disease, acquired heart disease and arrhythmias.

Cardiac complications occurred in 16 percent of the pregnancies, stemming primarily from arrhythmias (9 percent) and heart failure (6 percent).

The researchers noted overall rates of cardiac complications during pregnancy did not change over the years. Additionally, the frequency of pulmonary edema decreased from 8 percent between 1994 to 2001 to 4 percent between 2001 to 2014.

They identified 10 predictors of maternal complications after review of the data, which were incorporated into CARPREG II, their updated risk index.

The five general predictors were prior cardiac events or arrhythmias, poor functional class or cyanosis, high-risk valve disease/left ventricular outflow tract obstruction, systemic ventricular dysfunction, and no prior cardiac interventions.

The four lesion-specific predictors were listed as mechanical valves, high-risk aortopathies, pulmonary hypertension and coronary artery disease. Late pregnancy assessment was the one delivery-of-care predictor.

In an accompanying editorial, Uri Elkayam, MD, of the Keck School of Medicine at the University of Southern California, wrote the original CARPREG scoring system was adequate for risk assessment of patients with congenial, calculary and myocardial disease and those with a history of arrhythmias. He argued, however, the CARPREG scoring system only addressed important risk factors including prosthetic heart valves, aortopathies and pulmonary arterial hypertension if they were associated with symptoms of other cardiac events before pregnancy.

Elkayam said CARPREG II has its limitations in distinguishing mild and easily manageable events that do not have serious effects on maternal or fetal outcomes from those that may be severe, life threatening, or require hospitalizations.

“This is especially important because the patient population included in this study was at a relatively low risk and was managed in tertiary-care institutions with state-of-the-art care by multidisciplinary teams with considerable expertise and long-term experience, which may not be available for many clinicians around the world,” he wrote.