Study objective Three large, multicenter, randomized, clinical trials have shown that coronary computed tomography (CT) angiography allows efficient evaluation and safe discharge of patients with ...low- to intermediate-risk chest pain who present to the emergency department (ED). We report 1-year event rates and resource use from the American College of Radiology Imaging Network-Pennsylvania 4005 multicenter trial. Methods Patients with low- to intermediate-risk chest pain and presenting to the ED were randomized in a 2:1 ratio to a coronary CT angiography care pathway or traditional care. Subjects were contacted by telephone at least 1 year after ED presentation. Medical record review was performed for all cardiac hospitalizations, procedures and diagnostic tests, and adverse cardiac events. Our main outcome was the composite of cardiac death and myocardial infarction within 1 year. The secondary outcome was resource use. Results One thousand three hundred sixty-eight patients enrolled and 1,285 (94%) had direct participant or proxy contact at 1 year. All others had record review or death index search. From index presentation through 1 year, there was no difference between patients in the coronary CT angiography arm versus traditional care with respect to major adverse cardiac event (1.4% versus 1.1%; difference 0.3%; 95% CI –5.5% to 6.0%). From hospital discharge through 1 year, there was also no difference in ED revisits (36% versus 38%; difference –2.1%; 95% CI –7.9% to 3.7%), hospital admissions (16% versus 17%; difference –0.9%; 95% CI –6.7% to 4.9%), or subsequent cardiac testing (13% versus 13%; difference –0.4%; 95% CI –6.2% to 5.5%). One of 640 subjects with a negative coronary CT angiography result had a major adverse cardiac event within 1 year of presentation (0.16%; 95% CI 0.004% to 0.87%). Conclusion A coronary CT angiography–based strategy for evaluation of patients with low- to intermediate-risk chest pain who present to the ED does not result in increased resource use during 1 year. A negative coronary CT angiography result is associated with a less than 1% major adverse cardiac event rate during the first year after testing.
Summary Background Annual low-dose CT screening for lung cancer has been recommended for high-risk individuals, but the necessity of yearly low-dose CT in all eligible individuals is uncertain. This ...study examined rates of lung cancer in National Lung Screening Trial (NLST) participants who had a negative prevalence (initial) low-dose CT screen to explore whether less frequent screening could be justified in some lower-risk subpopulations. Methods We did a retrospective cohort analysis of data from the NLST, a randomised, multicentre screening trial comparing three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals (aged 55–74 years with at least a 30 pack-year history of cigarette smoking, and, if a former smoker, had quit within the past 15 years), recruited from US medical centres between Aug 5, 2002, and April 26, 2004. Participants were followed up for up to 5 years after their last annual screen. For the purposes of this analysis, our cohort consisted of all NLST participants who had received a low-dose CT prevalence (T0) screen. We determined the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. We also estimated the effect on mortality if the first annual (T1) screen in participants with a negative T0 screen had not been done. The NLST is registered with ClinicalTrials.gov , number NCT00047385. Findings Our cohort consisted of 26 231 participants assigned to the low-dose CT screening group who had undergone their T0 screen. The 19 066 participants with a negative T0 screen had a lower incidence of lung cancer than did all 26 231 T0-screened participants (371·88 95% CI 337·97–408·26 per 100 000 person-years vs 661·23 622·07–702·21) and had lower lung cancer-related mortality (185·82 95% CI 162·17–211·93 per 100 000 person-years vs 277·20 252·28–303·90). The yield of lung cancer at the T1 screen among participants with a negative T0 screen was 0·34% (62 screen-detected cancers out of 18 121 screened participants), compared with a yield at the T0 screen among all T0-screened participants of 1·0% (267 of 26 231). We estimated that if the T1 screen had not been done in the T0 negative group, at most, an additional 28 participants in the T0 negative group would have died from lung cancer (a rise in mortality from 185·82 95% CI 162·17–211·93 per 100 000 person-years to 212·14 186·80–239·96) over the course of the trial. Interpretation Participants with a negative low-dose CT prevalence screen had a lower incidence of lung cancer and lung cancer-specific mortality than did all participants who underwent a prevalence screen. Because overly frequent screening has associated harms, increasing the interval between screens in participants with a negative low-dose CT prevalence screen might be warranted. Funding None.