Doctors often overlook incidental coronary artery calcification on non-cardiac CT scans, resulting in missed opportunities for statin therapy, an Australian study suggests.
Researchers say their study published in Heart, Lung and Circulation [link here] underscores the need for practice-changing measures to standardise reporting so that patients with subclinical coronary disease can be identified and managed with preventive therapies.
They analysed non-ECG-gated CT chest scans (both contrast and non-contrast) from 123 inpatients at a single centre who had been referred from January to December 2022 and had incidental coronary artery calcifications (CAC) identified.
Patients who had a history of known coronary artery disease, a history of coronary stent or bypass or an implanted cardiac device were excluded.
The team from the Alfred Health and Peninsula Health in Melbourne said CAC prevalence in their study was 6.2%, which was likely a large underestimate.
Patients (mean age 76, 55% male) were mostly asymptomatic (34%); symptoms most commonly reported were dyspnoea (31%) and chest pain (20%).
The majority of CT chest performed were contrasted scans (91.1%) and the most common indication for the scan was suspected pulmonary embolism.
Only 27.8% of CTs reported the severity of CAC with visual quantification, with 7.3% each reported for moderate and severe calcification, the researchers noted.
Just over one in five studies reported the epicardial arteries involved; left anterior descending artery was involved in 18.7% of patients, right coronary artery in 9.8% of patients, left circumflex in 11.4% of patients and left main in 0.8% of patients.
Only 2.4% of CAC were reported in the conclusion of the CT report.
Further, there were no cardiology referrals indicated for incidental CAC. The cardiology team was only consulted for ECG changes, chest pain, troponin elevation, new heart failure, left ventricle thrombus and left ventricle aneurysm.
Ten people died (8.1%) with only one cardiovascular-related death.
Nearly half of the patients were not taking any cardiovascular medications, with 34% and 24% of patients on statins and aspirin, respectively, at baseline.
Of the 61 patients who had troponins tested, 62% had elevation, with the majority diagnosed as type 2 myocardial infarction in the setting of other acute illnesses.
These patients had higher hospital mortality (15.8% v 4.3%) and more downstream cardiology investigations (23.7% v 13%) compared to those with normal levels.
Only one patient started on new statin therapy on discharge.
The authors acknowledged there was debate on the utility of statins for primary prevention in older people due to the lack of randomised control trial evidence.
“There are varying recommendations from guidelines for older adults which have led to confusion among clinicians and patients. However, the data from existing trials suggest potential efficacy and safety in this population,” they wrote.
Despite this, the authors said their study “highlights a tremendous opportunity for clinicians to improve patients’ cardiovascular risk profile from opportunistic screening for a very commonly performed test in inpatient settings.”
“Addressing this will require a multidisciplinary approach from radiology in prominently highlighting the presence of CAC and requesting teams to acknowledge the finding and act on it.
“Cardiology teams who are consulting also have an important role in looking at the non-cardiac CT images to avoid a Swiss cheese-type situation where CAC can fall through the cracks,” they said