Blood Clot 5 weeks after heart cath

My husband is 65 years old with a history of high cholesterol (controlled by medication) and recently has developed high blood pressure.  His cardiologist decided my husband needed a heart cath because he said his EI had gone from 50 to 32 over 2 years.  The cath was performed and nothing was found (other than a healthy heart for a 65 year old man).  Five weeks later my husband had a TIA (mini-stroke) and was hospitalized 2 days for testing.  His Echo at the hospital showed his EI was between 50-55.  Is it possible that a heart cath could have something to do with a blood clot that would have dislodged weeks after the procedure?  

[ed34]

Yes it is possible and it is usually stated at the time of signing the consent form that there is a risk of stroke or heart attack. I believe that also clotting material can build up around the heart valves and dislodge at any moment.