Editor:
We have read with great interest the article recently published in your journal by Drosch et al about the absence of coronary calcification in patients with significant coronary artery disease (CAD) . Previous studies have also evaluated whether the absence of coronary calcium could rule out significative coronary stenosis or the need of revascularization, with the same conclusions as the authors .
As we know, a high calcium score (CS) increases the probability of presenting adverse cardiovascular events, whereas the calcium absence has been associated with low risk of significant coronary disease. Nevertheless, a zero CS does not guarantee the absence of significative lesions, especially in symptomatic patients.
In a similar way as Drosch et al, we have also analyzed the prevalence of significant CAD (luminal stenosis ≥50%) in symptomatic patients with zero CS (according to the Agatston index). We studied 184 consecutive symptomatic patients (45% men, average age 59 ± 14 years) with inconclusive or unfeasible stress test results, who were referred for CS and noninvasive coronariography. We compared findings between those with zero CS and the rest. We used 64 multidetector spiral computed tomography. For the previous classification of risk of patients, we applied the Systematic Coronary Risk Evaluation (SCORE chart) of the European Society of Cardiology, defining a low or intermediate risk when it was <5%.
As a result, 107 patients presented a zero CS; among these were 92 who showed low or intermediate risk. The rest, 15 patients, presented high risk (scale SCORE ≥5%). Significant CAD was found in 7 patients (6.5%) within the group of zero CS (all of them with low or intermediate risk) and in 15 patients (19.5%) in the CS group >0 (OR = 0.289; CI = 0.112–0.749; P = .008).
In conclusion, in our sample, the presence of significant CAD in patients with zero CS and low or intermediate risk has been significantly smaller than in the group of patients with CS >0. Nevertheless, 6.5% of the patients with zero CS had significant CAD; therefore, zero CS should not make us assume the absence of significant lesions in symptomatic patients even with low or intermediate risk.
References
1. Drosch T., Reimann A., Thomas C., et. al.: Prevalence and clinical characteristics of symptomatic patients with obstructive coronary artery disease in the absence of coronary calcification. Acad Radiol 2010; 17: pp. 1254-1258.
2. Gottlieb I., Miller J.M., Arbab-Zadeh A., et. al.: The absence of coronary calcification does not exclude obstructive coronary artery disease or the need for revascularization in patients referred for conventional coronary angiography. J Am Coll Cardiol 2010; 55: pp. 627-634.