Validity of Simple Algorithms to Identify Recurrence of Intracerebral Hemorrhage in Two Danish Nationwide Registries

Association of Statin Use With Risk of Stroke Recurrence After Intracerebral Hemorrhage

BACKGROUND AND OBJECTIVES

Survivors of spontaneous intracerebral hemorrhage (ICH) may have indications for statin therapy. The effect of statins on the risk of subsequent hemorrhagic and ischemic stroke (IS) in this setting is uncertain. We sought to determine the risk of any stroke (ischemic stroke, IS or recurrent ICH), IS, and recurrent ICH associated with statin use among ICH survivors.

METHODS

Using the Danish Stroke Registry, we identified all patients admitted to a hospital in Denmark (population 5.8 million) with a first-ever ICH between January 2003 and December 2021 who were aged 50 years or older and survived >30 days. Patients were followed up until August 2022. Within this cohort, we conducted 3 nested case-control analyses for any stroke, IS, and recurrent ICH. We matched controls for age, sex, time since first-ever ICH, and history of prior IS. The primary exposure was statin use before or on the date of subsequent stroke or the equivalent date in matched controls. Using conditional logistic regression, we calculated adjusted odds ratios (aORs) and corresponding 95% confidence intervals (CIs) for any stroke, IS, and recurrent ICH associated with statin exposure.

RESULTS

We identified 1,959 patients with any stroke (women 45.3%; mean [SD] age, 72.6 [9.7] years) who were matched to 7,400 controls; 1,073 patients with IS (women 42.0%; mean [SD] age, 72.4 [10.0] years) who were matched to 4,035 controls and 984 patients with recurrent ICH (women 48.7%; mean [SD] age, 72.7 [9.2] years) who were matched to 3,755 controls. Statin exposure was associated with a lower risk of both any stroke (cases 38.6%, controls 41.1%; aOR 0.88; 95% CI 0.78-0.99) and IS (cases 39.8%, controls 41.8%, aOR 0.79; 95% CI 0.67-0.92), but was not associated with recurrent ICH risk (cases 39.1%, controls 40.8%, aOR 1.05; 95% CI 0.88-1.24).

DISCUSSION

Exposure to statins was not associated with an increased risk of recurrent ICH but was associated with a lower risk of any stroke, largely due to a lower risk of IS. Confirmation of these findings in randomized trials is needed.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that statin use in patients with ICH is associated with a lower risk of any stroke and IS and not with increased risk of recurrent ICH.

Association of Prior Intracerebral Hemorrhage With Major Adverse Cardiovascular Events

IMPORTANCE

Patients with stroke due to nontraumatic (spontaneous) intracerebral hemorrhage (ICH) often harbor vascular risk factors and comorbidities, but it is unclear which major adverse cardiovascular events (MACEs) occur more frequently among patients with a prior ICH than the general population.

OBJECTIVE

To evaluate the risk of a MACE for patients with a prior ICH compared with the general population.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study identified 8991 patients with a first ICH in the Danish Stroke Registry from January 1, 2005, to June 30, 2018, who were aged 45 years or older and survived more than 30 days after an ICH. Patients in this ICH cohort were matched 1:40 on age, sex, and ICH-onset date with a comparison cohort of 359 185 individuals from the general population without a prior ICH. Both cohorts were followed up for 6 months or more until December 31, 2018, for outcomes using registry data. Data were analyzed from October 1, 2021, to July 19, 2022.

EXPOSURES

Intracerebral hemorrhage identified by a nationwide clinical database.

MAIN OUTCOMES AND MEASURES

The main outcomes were ICH, ischemic stroke, myocardial infarction, and a composite of MACEs. For each outcome, a case-control study nested within the cohorts was also performed, adjusting for time-varying exposures and potential confounders. Crude absolute event rates per 100 person-years, adjusted hazard ratios (aHRs) and 95% CIs and, in the nested case-control analyses, crude and adjusted odds ratios and 95% CIs were calculated.

RESULTS

The ICH cohort (n = 8991; 4814 men [53.5%]; mean [SD] age, 70.7 [11.5] years) had higher event rates than the comparison cohort (n = 359 185; 192 256 men [53.5%]; mean [SD] age, 70.7 [11.5] years) for MACEs (4.16 [95% CI, 3.96-4.37] per 100 person-years vs 1.35 [95% CI, 1.33-1.36] per 100 person-years; aHR, 3.13 [95% CI, 2.97-3.30]), ischemic stroke (1.52 [95% CI, 1.40-1.65] per 100 person-years vs 0.56 [95% CI, 0.55-0.57] per 100 person-years; aHR, 2.64 [95% CI, 2.43-2.88]), and ICH (1.44 [95% CI, 1.32-1.56] per 100 person-years vs 0.06 [95% CI, 0.06-0.07] per 100 person-years; aHR, 23.49 [95% CI, 21.12-26.13]) but not myocardial infarction (0.52 [95% CI, 0.45-0.60] per 100 person-years vs 0.48 [95% CI, 0.47-0.49] per 100 person-years; aHR, 1.12 [95% CI, 0.97-1.29]). Nested case-control analyses returned risk estimates of similar magnitude as the cohort analyses.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that Danish patients with a prior ICH had statistically significantly higher rates of MACEs than the general population, indicating a need for attention to optimal secondary prevention with blood pressure lowering and antithrombotic and statin therapies after an ICH in clinical research and practice.