In the present day, coronary angiography and percutaneous coronary intervention are considered to be safe procedures with low complication rates in general. Nevertheless due to their widespread use and their application in a continually aging population known to carry a higher risk for complications, periprocedural stroke affects thousands of patients undergoing coronary angiography and percutaneous coronary intervention worldwide every year. Stroke is reported to occur in 0.05-0.1% of diagnostic cardiac catheterizations and in 0.18-0.44% of patients treated with percutaneous coronary intervention in clinical routine today. Despite all improvements in pharmacological and technical issues, the rate of stroke after cardiac catheterization has remained almost constant over the last 20 years of invasive cardiology of invasive and interventional cardiology, which is most probably due to the immutability of the majority of risk factors before cardiac procedures. An advanced age, arterial hypertension, diabetes mellitus, coronary angiography performed under emergency conditions, history of stroke, renal failure, the use of an intra-aortic balloon pump, congestive heart failure and interventions at bypass grafts have been identified as risk factors for periprocedural stroke in large registries. Due to exceedingly high rates of mortality and disability stroke after coronary angiography still has an enormous impact on the patient’s prognosis and on quality of life. If patients survive this devastating complication, most of them suffer from persistent neurological deficits such as motor or speech disorders. Silent embolic cerebral infarction (SECI) has clinical significance because it can progress to a decline in cognitive function and increase the risk of dementia in the long term.
The mechanism of ischemic stroke is similar between diagnostic and interventional procedures. However, interventional catheters are on average larger than diagnostic catheters and the procedures are often longer and thus there may be a theoretical increase in risk.
Ultimately, one or more catheters end up in one of the cardiac chambers or in the coronaries arteries. Catheterization across a degenerated aortic valve may lead to thromboembolism and the risk of stroke may be particularly high in patients with significant valvular aortic stenosis (AS)
https://www.ncbi.nlm.nih.gov/pubmed/23190068
http://www.uptodate.com/contents/stroke … terization
PS: We are old timers. That is true. But we have been treating coronary artery diseases over the decades. There are so many still visiting us without undergoing any interventional procedures. The maximum that we do medical thrombolysis, that too if only they come to hospital within twelve hours after the chest pain. There are so many physicians still practising this sort of medicines even now. But the picture is slowly changing. More and more corporate hospitals are coming up with huge investment. They cannot survive if they practice in the old manner. So all new or old CAD patients are subjected to interventions. And more often than not, there is no time to waste in usual history taking or clinical examination of the patients and no discretion in selecting the cases for procedures. We understand that even PCI just like medical thrombolysis is not going to benefit much if delayed more than 12 hours. More often this rule is waived. The complications mentioned above may not many in number. But according to the article above during last 20 years the incidence of these complications has not come down with increasing advances in medicine. But complications like stroke may be taken not of immediately. But lesser complications of brain causing cognitive impairment and depression may be taken seriously by the treating doctors, more so in a busy centres. The brain injuries are the result of dislodgment of atheromatous plaques from coronary arteries or valve during the catheter movement during the procedures, either diagnostic or therapeutic. Sometimes even these atheromatous debris may get lodged in retina or kidney resulting havoc.

UA Mohammed