The Heidelberg bleeding classification categorises intracranial haemorrhages (haemorrhagic transformation) occurring after ischaemic stroke and reperfusion therapy.

Anatomic description

• class 1: haemorrhagic transformation of infarcted brain tissue

  • 1a: HI1: scattered small petechiae, no mass effect

  • 1b: HI2: confluent petechiae, no mass effect

  • 1c: PH1: haematoma within infarcted tissue, occupying <30%, no substantive mass effect

• class 2: intracerebral haemorrhage within and beyond infarcted brain tissue

  • PH2: haematoma occupying ≥30% of the infarcted tissue, with obvious mass effect (PH2)

• class 3: intracerebral haemorrhage outside the infarcted brain tissue or intracranial-extracerebral haemorrhage

  • 3a: parenchymal haematoma remote from infarcted brain tissue

  • 3b: intraventricular haemorrhage

  • 3c: subarachnoid haemorrhage

  • 3d: subdural haemorrhage

HI indicates haemorrhagic infarction; PH indicates parenchymatous haematoma. This terminology is borrowed from the ECASS (European Cooperative Acute Stroke Study) classification of haemorrhagic transformation on an ischaemic infarct ^2-4.

Identification of symptomatic intracranial haemorrhage

The Heidelberg group recommends brain imaging within 48 hours of reperfusion therapy and thereafter during the hospitalisation based on new neurologic symptoms.

After the identification and anatomic description of an intracranial haemorrhage, it is further classified as symptomatic or asymptomatic:

• symptomatic intracranial haemorrhage (SICH) is new intracranial haemorrhage associated with any of the following:

  • ≥4 point increase in the NIH Stroke Scale (compared to the immediate pre-deterioration status)

  • ≥2 point increase in one NIH Stroke Scale subcategory

  • leading to major medical/surgical intervention such as intubation, hemicraniectomy, or external ventricular drain placement

  • absence of an alternative explanation for deterioration

• asymptomatic intracranial haemorrhage (aSICH) is new intracranial haemorrhage without substantive change in the patient's neurologic status and has no implications for prognosis or change in management

Symptomatic haemorrhages are considered definite if any intracranial haemorrhage is the dominant brain pathology on imaging causal for deterioration. However, in some cases, the causality is not certain because the ischaemic infarct may have contributed to the deterioration, so the following classifications are applied for trial and registry reporting purposes:

• symptomatic

  • probable relatedness: class 2 (PH2) haemorrhage

• asymptomatic

  • possible relatedness: class 1b (HI2), 1c (PH1), and 3 haemorrhages

  • unlikely relatedness: class 1a (HI1) haemorrhage

The relatedness to intervention is further specified following thrombolytic administration or endovascular therapy by the certainty of relatedness:

• definite: observed procedural complication (eg, perforation of artery during angiography)

• probable: treatment within last 24 hours and class 1c or 2 haemorrhage (PH) (symptomatic or asymptomatic)

• possible: treatment within last 24 hours and class 1a or 1b haemorrhage (HI) (symptomatic or asymptomatic)

• unrelated: no intervention in the 24 hours prior to haemorrhage detection