Rates of major ischemic and hemorrhagic vascular events are higher among patients with a prior intracerebral hemorrhage (ICH) in comparison with the general population, a new study shows. The finding emphasizes the need for better secondary preventive measures to reduce these risks.
“This is one of the largest studies to look at the rate of major cardiovascular and cerebrovascular events after an ICH and comparing this with a control group. This study gives us more robust information on the type of events that occur after an ICH and on the consequences of those events,” lead author David Gaist, PhD, professor of clinical neurology at Odense University Hospital, Denmark, told theheart.org | Medscape Cardiology.
“We found that, in patients who have had an ICH, the risk of both ischemic events and ICH was higher than in the matched control cohort, particularly in the first year. This suggests that the first year after an ICH is a crucial period and gives us a window of opportunity for focusing on secondary prevention approaches,” he added.
The study was published online in JAMA Network Open on October 3.
Gaist explained that few studies have compared cardiovascular and cerebrovascular events in post-ICH patients with those in the background population. These studies have focused mainly on ischemic events, and because of relatively small sample sizes, it has been hard to pin down the risks of different outcomes.
“We used a larger sample to look at the occurrence of both ischemic and hemorrhagic events, and we also looked at the consequence of these events in terms of severity and case fatality rates,” he noted.
The researchers used data from the Danish Stroke Registry to identify 8991 patients with a first spontaneous ICH who were aged 45 years or older and who survived more than 30 days after the ICH. They were matched with respect to age and sex in a 1:40 ratio with a comparison cohort of 359,185 individuals from the general population without a prior ICH via use of the Civil Registration System.
Primary outcomes were ischemic stroke, ICH, myocardial infarction (MI) and major adverse cardiovascular events (MACE), including stroke, MI, systemic embolism, and vascular death. Information on these outcomes was derived from the Danish National Patient Registry.
Results showed that after a mean follow-up of 4.2 years, among the ICH cohort, rates of ischemic stroke, ICH, and MACE were higher than among the comparison cohort.
Event rates per 100 person-years were 1.52 (ICH cohort) vs 0.56 (control) for ischemic stroke; 1.44 vs 0.06 for ICH; and 4.16 vs 1.35 for MACE.
There was no difference in rates of MI between the two cohorts ― 0.52 (ICH cohort) vs 0.48 (control) per 100 person-years.
Nested case-control analyses returned risk estimates of similar magnitude as the cohort analyses.
Annual incidence rates showed that rates of ICH, ischemic stroke, and MACE in the ICH cohort were markedly higher in the first year of follow-up. First-year event rates per 100 person-years were 2.16 for ischemic stroke, 2.58 for ICH, and 6.52 for MACE. Rates of MI were also higher in the ICH cohort in the first year (0.81 per 100 person-years) than in subsequent years.
In both the ICH cohort and the comparison cohort, ICH during follow-up was associated with more severe strokes and higher case fatality rates than ischemic stroke.
The 30-day case fatality rate in the ICH cohort was 7.2% for ischemic stroke and 28.6% for ICH. In the control cohort, the 30-day case fatality rates were 8.0% for ischemic stroke and 32.0% for ICH.
The authors point out that these data identify the first year after an ICH as a particularly high-risk period for both ischemic and hemorrhagic events.
This high risk could be due to disability after an ICH, complications of the ICH, withdrawal of secondary prevention agents (such as antithrombotic and cholesterol-lowering agents) after an ICH, or low uptake of secondary prevention agents and blood pressure–lowering agents, they suggest.
“The first year after an ICH constitutes a window of opportunity for early interventions to reduce the risk of all MACEs with standard and novel approaches to secondary prevention in the short and long term after an ICH,” they conclude.
The study received funding from the Novo Nordisk Foundation. Gaist received grants from the Novo Nordisk Foundation during the conduct of the study and honoraria from Bristol-Myers Squibb outside the submitted work.
JAMA Network Open. Published online October 3. Full text