Throwing a cat amongst the pigeons – cancer risk – will it change our referral pattern for cardiac diagnostic testing?

The recently published retrospective Canadian study of 5 year cancer risk following heart attack in 1996-2006 seems to demonstrate a consistent 3% increased risk in cancer per 10 milliSv radiation dose when adjusted for sex, age, comorbities (but strangely, not for smoking status, nor for actual measured radiation dosage but for presumed, estimated dosage based on investigations and procedures which were billed). Nevertheless, the increased risk seems consistently increased as radiation dose increases and thus the results may be plausible. Given the average age of these patients being ~61 years, some 14% were diagnosed with new cancers in the 2-5 years following their AMI, thus a relative increased risk of 3% per 10mSv is something to stress us! See here for the paper. This will inevitably put pressure on us NOT to refer patients for stress MIBI scans, nor diagnostic coronary artery CT scans. In an ideal world, we would have timely access to a sensitive and specific radiation free investigation. Unfortunately, stress ECG testing has a relatively low sensitivity and in younger women a higher false positive rate. That leaves us with stress echocardiography, but availability and operator dependence means this also has issues at present. Furthermore, the added morbidity associated with cancer risk may also impact who we should actually be referring for angiography and/or angioplasty. Time will tell, but in the interim, perhaps the least we can do is provide adequate informed cons...
Source: Oz E Medicine - emergency medicine in Australia - Category: Emergency Medicine Authors: Tags: Cardiology cancer risk diagnostic testing Source Type: blogs