Coronary Calcium in COVID-19 Patients Linked to Worse Outcomes

Elevated coronary artery calcium (CAC) is a marker for worse prognosis among patients hospitalized for COVID-19, according to a French analysis.

“The severity of immune response, endothelial dysfunction, and myocardial stress due to COVID-19 could be exacerbated in patients with subclinical coronary atherosclerosis,” write Jean Guillaume Dillinger, MD, PhD (Lariboisiere Hospital, Paris, France), and colleagues.

Although small, the study supports the practice of analyzing CAC in every COVID-19 patient, since it is a “freebie” that can help plan appropriate management, said Harvey Hecht, MD (Mount Sinai Medical Center, New York, NY), who was not involved in the study. “You're getting a CT scan of the lungs on every COVID patient and that information is just there. You simply can't miss it. So it takes virtually no additional time to do the measurements,” he told TCTMD, acknowledging that this information is not always reported on a routine basis despite guideline recommendations.

In those patients with COVID-19 and elevated CAC, Hecht advised physicians to “follow that patient more carefully and perhaps be more aggressive at the first signs of worsening of their COVID status and their pneumonia. You should be more aggressive in treating that with all available tools.”

CAC and 30-Day Outcomes

For the study, published online July 17, 2020, ahead of print in JACC: Cardiovascular Imaging, Dillinger and colleagues included 209 consecutive patients between 40 and 80 years old (median 62 years) with no history of cardiovascular disease who were hospitalized for COVID-19 at their institution between March 15 and May 3, 2020. All patients received a noncontrast chest CT upon admission and CAC was detected in 50.7% (defined as “any area ≥ 1 mm² with a density > 130 Hounsfield units on the known coronary tract”).

Significantly more patients with CAC reported a primary endpoint event—the first occurrence of mechanical noninvasive or invasive ventilation, extracorporeal membrane oxygenation, or death within 30 days following hospital admission—than did those with negative CAC (50.0% vs 17.5%; HR 3.5; 95% CI 2.2-5.8).

This finding was similar among patients younger than 62 years, of whom 32% had detectable CAC (55% vs 20%; HR 5.4; 95% CI 2.4-12.2), as well as those 62 years and older, of whom 69% had CAC (48% vs 13%; HR 3.2; 95% CI 1.6-6.3). Additionally, the results were maintained when calcium was defined by Agatston score.

On multivariate analysis adjusted for age, sex, hypertension, smoking, and diabetes, the presence of CAC was an independent predictor of the primary outcome (HR 4.4; 95% CI 2.4-8.0).

Over follow-up, one STEMI was reported but no strokes. Also, there was no difference in how many patients reported a significant increase in peak high-sensitivity cardiac troponin I by CAC presence or absence (9.1% vs 3.4%; P = 0.16).

A Powerful, Underutilized Tool

The study “adds to the body of evidence that coronary calcium is a powerful, underutilized prognostic tool not just for coronary artery disease,” said Hecht. “It also turns out to be a powerful marker for . . . different forms of cancer [and] lung disease. So there seems to be a general association of coronary calcium with bad outcomes, not just coronary outcomes.”

When examining risk, coronary calcium gives information “over and above” other factors like age, diabetes, hypertension, smoking, and hyperlipidemia, he added. “It made its own unique contribution irrespective of age and the other risk factors. So it helps identify people who are at higher risk for mortality from COVID, although the mechanism why it should be doing that is not 100% clear.”

If he had to guess, Hecht said “it may have to do with endothelial function throughout the body, not just in the coronary arteries. We know that people who have more plaque, have more inflammation, have reduced endothelial function, as well. But the exact mechanism is definitely not known.”

Looking forward, he would like to see similar studies examining more patients for CAC and its relationship with COVID-19 over a longer period of time. “There is increasing concern that COVID infection has longer term effects upon the heart,” Hecht said. “I suspect that coronary calcium would probably be higher in [long-term survivors of COVID-19] as well.”