Intracranial Hemorrhage From Thrombolytic Therapy Calculator

Risk factors

This risk predictor tool is addressed to patients who undergo or are about to be initiated on thrombolytic therapy due to a cardiovascular condition (myocardial infarction).

In these patients, because of the medication there is a high risk of intracerebral hemorrhage complications, risk further increased in case there are other bleeding risk factors present too.

The eight items accounted for in the above calculator are:

Please note that excessive anticoagulation in the setting of MI with agents such as heparin or hirudin increases cerebral bleeding risk.

When tissue plasminogen activator is used as thrombolytic agent, the intracranial haemorrhage rate is higher (3 in 1000 treated) than when streptokinase is used.

Result interpretation

Each of the 8 items in the above risk predictor refer to an independent bleeding risk factor. When the factor is present, the item is awarded 1 point, thus the final score varies from 0 (with no risk factors) to 8 (all bleeding risk factors present).

This is the association between final results and intracranial hemorrhage risk percentages:

This bleeding risk stratification tool has yet to be externally validated and compared with similar scores.

About the study

In 2000, Brass et al. quantified and identified predictors of intracranial haemorrhage that were associated with thrombolytic therapy, during a retrospective cohort study on patients diagnosed with acute myocardial infarction.

The rate of intracranial hemorrhage was 1.43% (455 cases of 31,732 studied). In a logistic model the eight risk factors were awarded a weight.

The above risk predictor was found to be accurate in identifying patients at low and high risk for intracranial haemorrhage, from those diagnosed with AMI and undergoing thrombolytic therapy.

Hemorrhage and thrombolytic therapy

There are significant haemorrhage and stroke risks associated with thrombolytic therapy, especially in elderly populations (in some studies intracranial haemorrhage risk is quoted as 50%).

Low risk patients can be initiated tPA (tissue plasminogen activator) or other thrombolytic agents in acute myocardial infarction.

The medication lyses infarct artery thrombi with the aim to achieve reperfusion. This in turn reduces infarct size while preserving left ventricular function.

High risk patients may benefit from lower bleeding risk therapies such as primary percutaneous transluminal coronary angioplasty for acute reperfusion.

There are other conditions in which thrombolytic therapy is recommended:

■ Pulmonary embolism (PE);

■ Acute ischemic stroke (AIS);

■ Deep vein thrombosis (DVT);

■ Ischemic limb injury.

Beside presence of haemorrhage risk factors, there are other contraindications for thrombolytic therapy:

■ Major surgery, trauma, or bleeding within 3 weeks;

■ Suspected aortic dissection;

■ Internal bleeding within 6 weeks;

■ History of dementia, or central nervous system damage within 12 months;

■ Known intracranial neoplasm.

Original source

Brass LM, Lichtman JH, Wang Y, Gurwitz JH, Radford MJ, Krumholz HM. Intracranial hemorrhage associated with thrombolytic therapy for elderly patients with acute myocardial infarction: results from the Cooperative Cardiovascular Project. Stroke. 2000; 31(8):1802-11.

Other references

1. Goldstein JN, Marrero M, MD; Masrur S et al. Management of Thrombolysis-Associated Symptomatic Intracerebral Hemorrhage. JAMA Neurology. 2010; 67(8).

2. Gebel JM, Sila CA, Sloan MA et al. Thrombolysis-Related Intracranial Hemorrhage. A Radiographic Analysis of 244 Cases From the GUSTO-1 Trial With Clinical Correlation. Stroke. 1998; 29: 563-569.

3. Alpert JS. Intracranial Hemorrhage After Thrombolytic Therapy: A Therapeutic Conflict. JACC. 1992; 19(2):295- 6.