CHD patients have 8 times the risk of hemorrhagic stroke at young age
Children and young adults who were born with congenital heart disease (CHD) have an eight-fold risk of intracerebral hemorrhage (ICH) when compared to the general population, according to a Swedish study published online April 6 in Stroke.
Despite this steep relative risk increase, however, the absolute risk of ICH remained low—1.18 cases per 10,000 person-years, wrote Kok Wai Giang, PhD, and colleagues. Almost 22,000 individuals with CHD were followed up to the age of 42, with outcomes for each patient matched against 10 randomly selected controls from the general population.
Patients with severe nonconotruncal defects or coarctation of the aorta had the highest risk of developing hemorrhagic stroke during the study period at 3.22 and 2.79 cases per 10,000 person-years, respectively. Subarachnoid hemorrhage (SAH) occurred in CHD patients at a rate 7.64 times that of the general population, although those absolute rates were low as well (0.96 per 1,000 years).
“Risk factors for hemorrhagic stroke, such as hypertension and intracranial aneurysm, have previously been shown to be more prevalent among patients with CHD, which may at least partially explain our results,” Giang and coauthors wrote. “Among different birth cohorts, the absolute risk of hemorrhagic stroke decreased over time, but the risk was still relatively high compared with controls. Improvements in perinatal and pediatric care, for both patients with CHD as well as controls, may explain the decline in the rate of ICH/SAH observed in both groups.”
The researchers noted the mortality rates following ICH and SAH were high among individuals with CHD, although not significantly different than those who suffered strokes in the general population. Again, they attributed this finding to advancements in care for both CHD and stroke.
“Improvements in treatment after stroke, and the introduction of specialized stroke units for adults, have most likely contributed to better survival after stroke,” they wrote. “In addition, recent advances in surgical procedures, treatments, and pediatric care for patients with CHD over time may have affected overall survival.”
The study was limited by its lack of registry data on medication, blood pressure levels and other clinical variables that may have contributed to individual stroke risk. Although the researchers used nationwide registries to capture all CHD patients in Sweden, the number of hemorrhagic strokes was low.
“Further studies are required to investigate mechanisms and prevention strategies for hemorrhagic stroke among CHD patients,” Giang et al. wrote.