While high cholesterol, high blood pressure, diabetes and smoking are well known heart disease risks, not everyone who has a heart attack has them. A new study finds that these patients had one thing in common: they all tended to have high levels of coronary calcium.
Previous research showed that 14 per cent to 27 per cent of heart attack patients have none of the standard risk factors -- high cholesterol, high blood pressure, diabetes and smoking.
The new study by researchers at Intermountain Health in the US show that scans that detect this kind of plaque buildup should be considered as part of their standard care, even in the absence of the four standard modifiable risk factors, so that these patients can be diagnosed and treated before their first heart attack event occurs.
"Measuring coronary calcium could have a major impact on how we identify who is at risk for heart disease," said lead author Jeffrey L. Anderson, research physician at Intermountain Health.
"We need to go beyond just the four major modifiable risk factors because there are risk factors we don't yet recognise or understand about what's causing increased risk of heart attack in these patients," he added.
The findings were presented at the American Heart Association's Scientific Sessions 2023 in Philadelphia, US.In the study, researchers identified 429 heart attack patients who also had coronary artery calcium scans. Of those, 369 had standard modifiable risk factors (SMuRF), like a diagnosis or treatment of hypertension, hyperlipidemia, diabetes, and or smoking; and 60 did not (SMuRF-less).
Researchers examined these patients' calcium artery scan scores, and then also major adverse cardiovascular events, like another heart attack, stroke, or death, at 60-days and long term.Researchers found that SMuRF-less patients had high rates of, and higher percentile of, coronary calcium scores.
They also found that 77 per cent of these patients met their criteria for preventative therapy, like statins and/or aspirin. Patients with SMuRF, as expected, also had high CAC scores and percentiles. Outcomes were more favourable overall for SMuRF-less patients and for those patients with lower coronary artery calcium scores. While coronary artery calcium scans are becoming more common and affordable, they're still not part of guideline-directed standard of care.
"We're missing about a quarter of people who are at risk for heart attack events because we're still relying on just the standard risk factors," said Dr Anderson. "We haven't been doing scans in low-risk patients that don't have these common risk factors, but that may need to change given our findings, so that we can identify these seemingly low-risk patients who care not, and provide preventive therapy."