Results from previous studies suggest that survivors of preterm birth are at increased risk of hypertension, stroke, and cardiovascular mortality but not ischemic heart disease. Preterm birth was also associated with further alterations in cardiac structure and function in early life, but its association with new-onset HF in adulthood appears to be unknown. Therefore, Dr Casey Crump, MD, PhD and her team conducted a study to determine whether preterm birth is associated with increased risk of HF from childhood into mid-adulthood in a large population-based cohort.

It was a national cohort study conducted in Sweden with data from 1973 through 2015. The researchers included a total of 4 193 069 individuals, all singleton live births in Sweden during 1973 through 2014. The major outcome assessed was Heart failure, as identified from inpatient and outpatient diagnoses through 2015. The researchers also stratified their data by several measures of gestational age:

♦ Extremely preterm births (22-27 weeks),

♦ Moderately preterm births (28-33 weeks),

♦ Late preterm births (34-36 weeks) and early-term births (37-38 weeks).

Key findings of the study were:

• Among 85 million person-years of follow-up, the researchers identified 4158 persons with Heart failure.
• In this cohort, they found that preterm birth (gestational age <37 weeks) was associated with increased risk of HF at ages

♦younger than 1 year (adjusted HR [aHR], 4.49),

♦1 to 17 years (aHR, 3.42), and

♦18 to 43 years (aHR, 1.42) compared with full-term birth (gestational age, 39-41 weeks).

• They noted that the risk remained elevated after stratifying by each measure of gestational age among the adult cohort, as did the incidence of heart failure (per 100,000 person-years). However, they observed that both measures dropped with the longer gestational periods:

♦ Extremely preterm births: HR, 4.72; 31.7 cases,

♦ Moderately preterm births: HR, 1.93; 13.8 cases,

♦ Late preterm births: HR, 1.24; 8.7 cases,

♦ Early term births: HR, 1.09; 7.3 cases,

♦ Full-term births: 6.6 cases.

• They further noted that these associations persisted when excluding persons with structural congenital cardiac anomalies.
• They explained that these associations are linked to family history of preterm births and heart failure among those aged 18 to 43 years (but not <18 years).
• They noted that both male and female share a similar number of HF cases stemming from preterm birth.

The authors concluded, "In this large national cohort, preterm birth was associated with increased risk of new-onset HF into adulthood. Survivors of preterm birth may need long-term clinical follow-up into adulthood for risk reduction and monitoring for HF."

For further information:

https://jamanetwork.com/journals/jamapediatrics/article-abstract/2778224