Incidental Non-cardiac Findings in Coronary Computed Tomography Angiography: Is it Worth Reporting?

Variability of pulmonary nodule volumetry on coronary CT angiograms

This study aims to investigate the variability of pulmonary nodule (PN) volumetry on multiphase coronary CT angiograms (CCTA). Two radiologists reviewed 5973 CCTA scans in this cross-sectional study to detect incidental solid noncalcified PNs measuring between 5 and 8 mm. Each radiologist measured the nodules' diameters and volume, in systole and diastole, using 2 commercially available software packages to analyze PNs. Bland-Altman analysis was applied between different observers, software packages, and cardiac phases. Bland-Altman subanalysis for the systolic and diastolic datasets were also performed. A total of 195 PNs were detected within the inclusion criteria and measured in systole and diastole. Bland-Altman analysis was used to test the variability of volumetry between cardiac phases ([-47.0%; 52.3%]), software packages ([-50.2%; 68.2%]), and observers ([-14.5%; 27.8%]). The inter-observer variability of the systolic and diastolic subsets was [-13.6%; 31.4%] and [-13.9%; 19.7%], respectively. Using diastolic volume measurements, the variability of PN volumetry on CCTA scans is similar to the reported variability of volumetry on low-dose CT scans. Therefore, growth estimation of PNs on CCTA scans could be feasible.

Clinical and economic impact of extracardiac lesions on coronary CT angiography

Objective

When reporting coronary CT angiography (CCTA), extracardiac structures are routinely assessed, usually on a wide field-of-view (FOV) reconstruction. We performed a retrospective observational cross-sectional study to investigate the impact of incidental extracardiac abnormalities on resource utilisation and treatment, and cost-effectiveness.

Methods

All patients undergoing CCTA at a single institution between January 2012 and March 2020 were identified. The indication for CCTA was chest pain or dyspnoea in >90%. Patients with ≥1 significant extracardiac findings were selected. Clinical follow-up, investigations and treatment were documented, and costs were calculated.

Results

4340 patients underwent CCTA; 717 extracardiac abnormalities were identified in 687 individuals (15.8%; age 62±12 years; male 336, 49%). The abnormality was already known in 162 (23.6%). Lung nodules and cysts were the most common abnormalities (296, 43.1%). Clinical and/or imaging follow-up was pursued in 292 patients (42.5%). Treatment was required by 14 patients (0.3% of the entire population), including lung resection for adenocarcinoma in six (0.1%). All but two abnormalities (both adenocarcinomas) were identifiable on the limited cardiac FOV. The cost of reporting (£20) and follow-up (£33) of extracardiac abnormalities was £53 per patient. The cost per discounted quality-adjusted life year was £23 930, increasing to £46 674 for reporting the wide FOV rather than the cardiac FOV alone.

Conclusions

Extracardiac abnormalities are common on CCTA, but identification and follow-up are costly. The few requiring treatment are usually identifiable without review of the wide FOV. The way in which CCTAs are scrutinised for extracardiac abnormalities in a resource-limited healthcare system should be questioned.

The impact of cardiopulmonary hemodynamic factors in volumetry for pulmonary nodule management

BACKGROUND

The acceptance of coronary CT angiogram (CCTA) scans in the management of stable angina has led to an exponential increase in studies performed and reported incidental findings, including pulmonary nodules (PN). Using low-dose CT scans, volumetry tools are used in growth assessment and risk stratification of PN between 5 and 8 mm in diameter. Volumetry of PN could also benefit from the increased temporal resolution of CCTA scans, potentially expediting clinical decisions when an incidental PN is first detected on a CCTA scan, and allow for better resource management and planning in a Radiology department. This study aims to investigate how cardiopulmonary hemodynamic factors impact the volumetry of PN using CCTA scans. These factors include the cardiac phase, vascular distance from the main pulmonary artery (MPA) to the nodule, difference of the MPA diameter between systole and diastole, nodule location, and cardiomegaly presence.

MATERIALS AND METHODS

Two readers reviewed all CCTA scans performed from 2016 to 2019 in a tertiary hospital and detected PN measuring between 5 and 8 mm in diameter. Each observer measured each nodule using two different software packages and in systole and diastole. A multiple linear regression model was applied, and inter-observer and inter-software agreement were assessed using intraclass correlation.

RESULTS

A total of 195 nodules from 107 patients were included in this retrospective, cross-sectional and observational study. The regression model identified the vascular distance (p < 0.001), the difference of the MPA diameter between systole and diastole (p < 0.001), and the location within the lower or posterior thirds of the field of view (p < 0.001 each) as affecting the volume measurement. The cardiac phase was not significant in the model. There was a very high inter-observer agreement but no reasonable inter-software agreement between measurements.

CONCLUSIONS

PN volumetry using CCTA scans seems to be sensitive to cardiopulmonary hemodynamic changes independently of the cardiac phase. These might also be relevant to non-gated scans, such as during PN follow-up. The cardiopulmonary hemodynamic changes are a new limiting factor to PN volumetry. In addition, when a patient experiences an acute or deteriorating cardiopulmonary disease during PN follow-up, these hemodynamic changes could affect the PN growth estimation.

Socioeconomics of coronary artery calcium: Is it scored or ignored?

IMPORTANCE

Chicago is one of the most racially segregated cities in the US, with the largest mortality gap between neighborhoods. Computed tomographic coronary artery calcium scoring (CACS) is an excellent risk stratification tool, but costs about $200 out-of-pocket, making it inaccessible to some.

OBJECTIVE

To determine whether this ACC/AHA guideline-recommended screening tool is accessible to all populations and neighborhoods, we evaluated the price and availability of CACS in Chicago area hospitals.

DESIGN

We used the Illinois Department of Public Health list of area hospitals to inquire about CACS availability and price. We compared these results to US Census Bureau data for each hospital's service area's demographic, ethnic and socioeconomic population characteristics.

RESULTS

Out of the 40 hospitals in Chicagoland, 30 offered CACS. The 10 hospitals without CACS were smaller hospitals in zip codes with a higher population density (p ​< ​0.01), higher poverty rates (22% vs. 13%, p ​< ​0.01), lower percentage of white population (p ​< ​0.02), lower frequency of higher education (35% vs. 51%, p ​< ​0.05), and a trend toward more black residents (p ​< ​0.10). Life expectancy was greater in areas with CACS available (78 vs. 75 years, p ​< ​0.05). Even in areas with CACS, there was wide price variation, with higher prices in poorer areas (r ​= ​0.57, p ​< ​0.01). The highest vs. lowest quintile of income had higher education, larger white population (80% vs. 14%, p ​< ​0.0001), and longer life expectancy (81 vs. 72 years, p ​< ​0.0002), but tended to have a lower price of CACS ($86 vs. $487, p ​< ​0.08).

CONCLUSIONS AND RELEVANCE

CACS is a powerful, evidenced-based clinical tool, but the availability and price vary widely in Chicagoland, and directly correlate with the socioeconomic and health care disparities that are known to exist. Removing these barriers to coronary artery disease screening may be one method to improve the poor cardiovascular outcomes in these areas.

Relative clinical value of coronary computed tomography and stress echocardiography-guided management of stable chest pain patients: a propensity-matched analysis

AIMS

The European Society of Cardiology recommends coronary computed tomography (CCT) for the assessment of low-risk patients with suspected stable angina. We aimed to assess in a real-life setting the relative clinical value of stress echocardiography (SE)- and CCT-guided management in this population.

METHODS AND RESULTS

Patients with stable chest pain and no prior history of coronary artery disease (CAD) who underwent CCT or SE as the initial investigative strategy were propensity-matched (990 patients each group-age: 59 ± 13.2 years, males: 47.9%) to account for baseline differences in cardiovascular risk factors. Inconclusive tests were 6% vs. 3% (P < 0.005) in CCT vs. SE. Severe (≥70% stenosis) on CCT and inducible ischaemia on SE detected obstructive CAD by invasive coronary angiography in 63% vs. 57% patients (P = 0.33). Over the follow-up period (median 717, interquartile range 93-1069 days) more patients underwent invasive coronary angiography (21.5% vs. 7.3%, P < 0.005), revascularization (7.3% vs. 3.5%, P < 0.005), further functional testing 33.4% vs. 8.7% (P < 0.005), but more patients were prescribed statins 8.8% vs. 3.8% (P < 0.005) in the CCT vs. the SE arm, respectively. Combined all-cause mortality and acute myocardial infarction was low-CCT-2.3% and SE-3.3%-with no significant difference (P = 0.16).

CONCLUSION

Initial SE-guided management was similar for the detection of obstructive CAD, demonstrated better resource utilization, but was associated with reduced prescription of statins although with no difference in medium-term outcome compared to CCT in this very low-risk population. However, a randomized study with longer follow-up is needed to confirm the clinical value of our findings.