Moderate-severe coronary calcification predicts long-term cardiovascular death in CT lung cancer screening: The ITALUNG trial.

PURPOSE: Coronary artery calcifications (CAC) are very strong indicators for increased cardio-vascular (CV) risk and can be evaluated also in low-dose computed tomography (LDCT) for lung cancer screening. We assessed whether a simple and fast CAC visual score is associated with CV mortality. METHODS: CAC were retrospectively assessed by two observers using a 4-score (absent, mild, moderate and severe) scale in baseline LDCT obtained in 1364 participants to the ITALUNG trial who had 55-69 years of age and a smoking history ≥20 pack-years. Correlations with CV risk factors at baseline and with CV mortality after 11 years of follow-up were investigated. RESULTS: CAC were absent in 470 (34.5%), mild in 433 (31.7%), moderate in 357 (26.2%) and severe in 104 (7.6%) subjects. CAC severity correlated (≤0.001) with age, male sex, pack-years, history of arterial hypertension or diabetes, obesity and treated hypercholesterolemia. Twenty-one CV deaths occurred. Moderate or severe CAC were significantly associated with higher CV mortality after adjustment for all other known risk factors (ARR = 2.72; 95 %CI:1.04-7.11). Notably, also in subjects with none or one only additional CV risk factor, the presence of moderate-severe CAC allowed to identify a subgroup of subjects with higher CV death risk (RR = 3.66; CI95%:1.06-12.6). CONCLUSIONS: Moderate or severe CAC visually assessed in LDCT examinations for lung cancer screening are independently associated with CV mortality.

Decreased cardiovascular mortality in the ITALUNG lung cancer screening trial: Analysis of underlying factors.

OBJECTIVES: In the ITALUNG lung cancer screening trial after 9.3 years of follow-up we observed an unexpected significant decrease of cardiovascular (CV) mortality in subjects invited for low-dose CT (LDCT) screening as compared to controls undergoing usual care. Herein we extended the mortality follow-up and analyzed the potential factors underlying such a decrease. MATERIALS AND METHODS: The following factors were assessed in screenes and controls: burden of CV disease at baseline, changes in smoking habits, use of CV drugs and frequency of planned vascular procedures after randomisation. Moreover, in the screenes we evaluated inclusion of presence of coronary artery calcification (CAC) in the LDCT report form that was transmitted to the participant and his/her General Practitioner. RESULTS: The 2-years extension of follow-up confirmed a significant decrease of CV mortality in the subjects of the active group compared to control subjects (15.6 vs 34.0 per 10,000; p = 0.001) that was not observed in the drops-out of the active group. None of the explaining factors we considered significantly differed between active and control group. However, the subjects of the active group with reported CAC experienced a not significantly lower CV mortality and showed a significantly higher use of CV drugs and frequency of planned vascular procedures than the control group. CONCLUSIONS: LDCT screening for lung cancer offers the opportunity for detection of CAC that is an important CV risk factor. Although the underlying mechanisms are not clear, our results suggest that the inclusion of information about CAC presence in the LDCT report may represent a candidate factor to explain the decreased CV mortality observed in screened subjects of the ITALUNG trial, possibly resulting in intervention for patient care to prevent CV deaths. Further studies investigating whether prospective reporting and rating of CAC have independent impact on such interventions and CV mortality are worthy.