Transient Ischemia


MS-DRG	CMS DRG (Prior to 10/1/2007)
069	Transient Ischemia	524	Transient Eschemia

Transient Ischemia Attack (TIA)

Transient Ischemic Attack (TIA) results from a disruption of blood flow in either the internal carotid or vertebral basilar arteries. Category 435 includes neurologic deficits of sudden onset and brief duration. The deficit may last from 5 minutes to 24 hours and is referred to as reversible. Most TIAs are due to cerebral emboli from ulcerated atherosclerotic plaques in the carotid or vertebral arteries in the neck or, less often, from mural thrombi in a diseased heart. The symptoms of TIAs are identical to those of stroke but are transient and depend on which system is affected (carotid artery or vertebrobasilar system). When TIAs last for hours, patients may have infarcts, seen on subsequent brain CT or MRI scans, even without persistent neurologic abnormalities.

Principal Diagnosis Codes To DRG 069

435.x: Ischemia, transient, cerebral
437.1: Disease, other, general, ischemic, cerebrovascular

Coding Guidelines

The difference between CVA and TIA is the duration of symptoms and whether the symptoms resolve.
When the physician documents a "stroke" and the symptoms seem to have resolved within 24 hours, query the physician as to whether the TIA is the more appropriate diagnosis.
When TIA and CVA are used interchangeably throughout the medical record, query the physician to verify the correct principal diagnosis established after study.

Documentation and Effects on Coding

CASE EXAMPLES

Example #1

Patient was admitted with slurred speech x4 minutes now resolved. Probable TIA but will rule out CVA. CT of the head was performed and the result is negative. Will discharge the patient

Rationale:

The physician documented "probable" TIA and ordered a CT of the head to rule out CVA. Negative CT scan results were documented. Coding guidelines allows assigning "probable" condition TIA is appropriate for principal diagnosis

Example #2

Patient with complaints of left sided weakness and difficulty speaking. Patient is later ruled in for a cerebral infarction. Which of the following is considered sufficient documentation for cerebral infarction?

Progress notes by the physician clearly indicate that a cerebral infarction has occurred
CAT scan report indicating an infarction has occurred
Carotid Doppler results indicating 85% occlusions in LCA and 80% occlusion in RCA. The physician documentation stating occlusion is symptomatic
The physician progress notes indicating symptoms of aphasia, hemiplegia, dysphagia, etc, etc have been persisting for more than 24 hours

Rationale:

The answer is #1 - progress notes by the physician clearly indicate that a cerebral infarction has occurred. All other answers are inappropriate due to the physician's failure to document "infarction"

Example #3

Progress notes stated as follows:

5/4 Patient admitted with headache, and weakness on left side. Admitting diagnosis: CVA/TIA
5/5 CT scan results noted. Patient stable
5/6 Discharge to rehab
Discharge diagnosis: CVA

Rationale:

Poor documentation
The coder should query the physician for a more specific diagnosis
ICD-9-CM code 436 for acute but ill-defined cerebrovascular disease should only be assigned if it is impossible to be more specific (Coding Clinic 2nd Quarter 1989 p.8)

References

Coding Clinic

1995 2nd Quarter p 14
1990 3rd Quarter p 16
1989 2nd Quarter p 8
1985 March/April p 6-7