Imaging Utilization and Outcomes in Vulnerable Populations during COVID-19 in New York City.

BACKGROUND: Coronavirus disease 2019 (COVID-19) affects vulnerable populations (VP) adversely. PURPOSE: To evaluate overall imaging utilization in vulnerable subgroups (elderly, racial/ethnic minorities, socioeconomic status [SES] disadvantage) and determine if a particular subgroup has worse outcomes from COVID-19. MATERIALS/METHODS: Of 4110 patients who underwent COVID-19 testing from March 3-April 4, 2020 at NewYork-Presbyterian Hospital (NYP) health system, we included 1121 COVID-19 positive adults (mean age 59±18 years, 59% male) from two academic hospitals and evaluated imaging utilization rates and outcomes, including mortality. RESULTS: Of 897 (80%) VP, there were 465 (41%) elderly, 380 (34%) racial/ethnic minorities, and 479 (43%) SES disadvantage patients. Imaging was performed in 88% of patients and mostly portable/bedside studies, with 87% of patients receiving chest radiographs. There were 83% hospital admissions, 25% ICU admissions, 23% intubations, and 13% deaths. Elderly patients had greater imaging utilization, hospitalizations, ICU/intubation requirement, longer hospital stays, and >4-fold increase in mortality compared to non-elderlies (adjusted hazard ratio[aHR] 4.79, p<0.001). Self-reported minorities had fewer ICU admissions (p=0.03) and reduced hazard for mortality (aHR 0.53, p=0.004; complete case analysis: aHR 0.39, p<0.001 excluding "not reported"; sensitivity analysis: aHR 0.61, p=0.005 "not reported" classified as minorities) with similar imaging utilization, compared to non-minorities. SES disadvantage patients had similar imaging utilization and outcomes as compared to their counterparts. CONCLUSIONS: In a predominantly hospitalized New York City cohort, elderly patients are at highest mortality risk. Racial/ethnic minorities and SES disadvantage patients fare better or similarly to their counterparts, highlighting the critical role of access to inpatient medical care during the COVID-19 pandemic.

Long-term health outcomes and cost-effectiveness of coronary CT angiography in patients with suspicion for acute coronary syndrome.

BACKGROUND: Randomized trials have shown favorable clinical outcomes for coronary CT angiography (CTA) in patients with suspected acute coronary syndrome (ACS). Our goal was to estimate the cost-effectiveness of coronary CTA as compared to alternative management strategies for ACP patients over lifetime. METHODS: Markov microsimulation model was developed to compare cost-effectiveness of competitive strategies for ACP patients: 1) coronary CTA, 2) standard of care (SOC), 3) AHA/ACC Guidelines, and 4) expedited emergency department (ED) discharge protocol with outpatient testing. ROMICAT-II trial was used to populate the model with low to intermediate risk of ACS patient data, whereas diagnostic test-, treatment effect-, morbidity/mortality-, quality of life- and cost data were obtained from the literature. We predicted test utilization, costs, 1-, 3-, 10-year and over lifetime cardiovascular morbidity/mortality for each strategy. We determined quality adjusted life years (QALY) and incremental cost-effectiveness ratio. Observed outcomes in ROMICAT-II were used to validate the short-term model. RESULTS: Estimated short-term outcomes accurately reflected observed outcomes in ROMICAT-II as coronary CTA was associated with higher costs ($4,490 vs. $2,513-$4,144) and revascularization rates (5.2% vs. 2.6%-3.7%) compared to alternative strategies. Over lifetime, coronary CTA dominated SOC and ACC/AHA Guidelines and was cost-effective compared to expedited ED protocol ($49,428/QALY). This was driven by lower cardiovascular mortality (coronary CTA vs. expedited discharge: 3-year: 1.04% vs. 1.10-1.17; 10-year: 5.06% vs. 5.21-5.36%; respectively). CONCLUSION: Coronary CTA in patients with suspected ACS renders affordable long-term health benefits as compared to alternative strategies.

Age- and sex-based resource utilisation and costs in patients with acute chest pain undergoing cardiac CT angiography: pooled evidence from ROMICAT II and ACRIN-PA trials.

OBJECTIVES: To determine resource utilisation according to age and gender-specific subgroups in two large randomized diagnostic trials. METHODS: We pooled patient-specific data from ACRIN-PA 4005 and ROMICAT II that enrolled subjects with acute chest pain at 14 US sites. Subjects were randomized between a standard work-up and a pathway utilizing cardiac computed tomography angiography (CCTA) and followed for the occurrence of acute coronary syndrome (ACS) and resource utilisation during index hospitalisation and 1-month follow-up. Study endpoints included diagnostic accuracy of CCTA for the detection of ACS as well as resource utilisation. RESULTS: Among 1240 patients who underwent CCTA, negative predictive value of CCTA to rule out ACS remained very high (≥99.4%). The proportion of patients undergoing additional diagnostic testing and cost increased with age for both sexes (p < 0.001), and was higher in men as compared to women older than 60 years (43.1% vs. 23.4% and $4559 ± 3382 vs. $3179 ± 2562, p < 0.01; respectively). Cost to rule out ACS was higher in men (p < 0.001) and significantly higher for patients older than 60 years ($2860-5935 in men, p < 0.001). CONCLUSIONS: CCTA strategy in patients with acute chest pain results in varying resource utilisation according to age and gender-specific subgroups, mandating improved selection for advanced imaging. KEY POINTS: • In this analysis, CAD and ACS increased with age and male gender. • CCTA in patients with acute chest pain results in varying resource utilisation. • Significant increase of diagnostic testing and cost with age for both sexes. • Cost to rule out ACS is higher in men and patients >60 years. • Improved selection of subjects for cardiac CTA result in more resource-driven implementation.

Systematic Evaluation of Endothelin 1 Measurement Relative to Traditional and Modern Biomarkers for Clinical Assessment and Prognosis in Patients With Chronic Systolic Heart Failure: Serial Measurement and Multimarker Testing.

OBJECTIVES: To define the role of single or serial measurement of endothelin 1 (ET-1) for prognostication beyond traditional and modern markers of risk in heart failure (HF). METHODS: In total, 115 patients with chronic systolic HF were followed for 10 months. Clinical assessment and ET-1, N-terminal pro-B-type natriuretic peptide (NT-proBNP), highly sensitive troponin I (hsTnI), soluble ST2 (sST2), and galectin 3 were measured at each visit. RESULTS: Elevated ET-1 was associated with worse HF, lower right ventricular function, higher pulmonary pressure, and higher left atrial volume index despite similar left ventricular function. ET-1 correlated with angiotensin-converting enzyme inhibitor use. A model containing traditional risk factors, ET-1, NT-proBNP, hsTnI, and sST2 best predicted cardiovascular events, and ET-1 improved reclassification. In an adjusted time-integrated model, percent time spent with ET-1 of 5.90 pg/mL or less was predictive of fewer cardiovascular events (odds ratio, 0.75; 95% confidence interval, 0.62-0.91). ET-1 reduction over time was associated with a lower rate of cardiovascular events compared with increasing or stable ET-1 (24.4% vs 50.0%). CONCLUSIONS: ET-1 may be a unique predictor of HF prognosis, complementing other biomarkers in a multimarker profile. Serial measurement of ET-1 may provide additional prognostic information.

Cost-effectiveness of follow-up of pulmonary nodules incidentally detected on cardiac computed tomographic angiography in patients with suspected coronary artery disease.

BACKGROUND: Pulmonary nodules (PNs) are often detected incidentally during coronary computed tomographic (CT) angiography, which is increasingly being used to evaluate patients with chest pain symptoms. However, the efficiency of following up on incidentally detected PN is unknown. METHODS AND RESULTS: We determined demographic and clinical characteristics of stable symptomatic patients referred for coronary CT angiography in whom incidentally detected PNs warranted follow-up. A validated lung cancer simulation model was populated with data from these patients, and clinical and economic consequences of follow-up per Fleischner guidelines versus no follow-up were simulated. Of the 3665 patients referred for coronary CT angiography, 591 (16%) had PNs requiring follow-up. The mean age of patients with PNs was 59±10 years; 66% were male; 67% had ever smoked; and 21% had obstructive coronary artery disease. The projected overall lung cancer incidence was 5.8% in these patients, but the majority died of coronary artery disease (38%) and other causes (57%). Follow-up of PNs was associated with a 4.6% relative reduction in cumulative lung cancer mortality (absolute mortality: follow-up, 4.33% versus non-follow-up, 4.54%), more downstream testing (follow-up, 2.34 CTs per patient versus non-follow-up, 1.01 CTs per patient), and an average increase in quality-adjusted life of 7 days. Costs per quality-adjusted life-year gained were $154 700 to follow up the entire cohort and $129 800 per quality-adjusted life-year when only smokers were included. CONCLUSIONS: Follow-up of PNs incidentally detected in patients undergoing coronary CT angiography for chest pain evaluation is associated with a small reduction in lung cancer mortality. However, significant downstream testing contributes to limited efficiency, as demonstrated by a high cost per quality-adjusted life-year, especially in nonsmokers.

Cost and resource utilization associated with use of computed tomography to evaluate chest pain in the emergency department: the Rule Out Myocardial Infarction using Computer Assisted Tomography (ROMICAT) study.

BACKGROUND: Coronary computed tomographic angiography (cCTA) allows rapid, noninvasive exclusion of obstructive coronary artery disease (CAD). However, concern exists whether implementation of cCTA in the assessment of patients presenting to the emergency department with acute chest pain will lead to increased downstream testing and costs compared with alternative strategies. Our aim was to compare observed actual costs of usual care (UC) with projected costs of a strategy including early cCTA in the evaluation of patients with acute chest pain in the Rule Out Myocardial Infarction Using Computer Assisted Tomography I (ROMICAT I) study. METHODS AND RESULTS: We compared cost and hospital length of stay of UC observed among 368 patients enrolled in the ROMICAT I study with projected costs of management based on cCTA. Costs of UC were determined by an electronic cost accounting system. Notably, UC was not influenced by cCTA results because patients and caregivers were blinded to the cCTA results. Costs after early implementation of cCTA were estimated assuming changes in management based on cCTA findings of the presence and severity of CAD. Sensitivity analysis was used to test the influence of key variables on both outcomes and costs. We determined that in comparison with UC, cCTA-guided triage, whereby patients with no CAD are discharged, could reduce total hospital costs by 23% (P<0.001). However, when the prevalence of obstructive CAD increases, index hospitalization cost increases such that when the prevalence of ≥ 50% stenosis is >28% to 33%, the use of cCTA becomes more costly than UC. CONCLUSIONS: cCTA may be a cost-saving tool in acute chest pain populations that have a prevalence of potentially obstructive CAD <30%. However, increased cost would be anticipated in populations with higher prevalence of disease.

Assessment of mitral valve adaptation with gated cardiac computed tomography: validation with three-dimensional echocardiography and mechanistic insight to functional mitral regurgitation.

BACKGROUND: Mitral valve (MV) enlargement is a compensatory mechanism capable of preventing functional mitral regurgitation (FMR) in dilated ventricles. Total leaflet area and its relation with closure area measured by 3-dimensional (3D) echocardiography have been related to FMR. Whether these parameters can be assessed with other imaging modalities is not known. Our objectives are to compare cardiac computed tomography (CT)-based measurements of MV leaflets with 3D echocardiography and determine the relationship of these metrics to the presence of FMR. METHODS AND RESULTS: We used 2 cohorts of patients who had cardiac CT to measure MV total leaflet, closure, and annulus areas. In cohort 1 (26 patients), we validated these CT metrics to 3D echocardiography. In cohort 2 (66 patients), we assessed the relation of MV size with the presence of FMR in 3 populations: heart failure with FMR, heart failure without FMR, and normal controls. Cardiac CT and 3D echocardiography produced similar results for total leaflet (R(2)=0.97), closure (R(2)=0.89), and annulus areas (R(2)=0.84). MV size was the largest in heart failure without FMR compared with controls and patients with FMR (9.1 ± 1.7 versus 7.5 ± 1.0 versus 8.1 ± 0.9 cm(2)/m(2); P<0.01). Patients with FMR had reduced ratios of total leaflet to closure areas and total leaflet to annulus areas when compared with patients without FMR (P<0.01). CONCLUSIONS: MV size measured by CT is comparable with 3D echocardiography. MV enlargement in cardiomyopathy suggests leaflet adaptation. Patients with FMR have inadequate adaptation as reflected by decreased ratios of leaflet area and areas determined by ventricle size (annulus and closure areas). These measurements provide additional insight into the mechanism of FMR.

Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: comparison with cardiac magnetic resonance.

BACKGROUND: Tube current modulation in retrospective ECG gated cardiac computed tomography (CT) results in increased image noise and may reduce the accuracy of left ventricular (LV) ejection fraction (EF) and mass assessment. OBJECTIVE: To examine the effects of a novel CT phase-based noise reduction (NR) algorithm on LV EF and mass quantification as compared to cardiac magnetic resonance (CMR). METHODS: In 40 subjects, we compared the LV EF and mass between CT and CMR. In a subset of 24 subjects with tube current modulated CT, the effect of phase-based noise reduction strategies on contrast-to-noise ratio (CNR) and the assessment of LV EF and mass was compared to CMR. RESULTS: There was excellent correlation between CT and CMR for EF (r=0.94) and mass (r=0.97). As compared to CMR, the limits of agreement improved with increasing strength of NR strategy. There was a systematic underestimation of LV mass by CT compared to CMR with no NR (-10.3±10.1g) and low NR (-10.3±12.5g), but was attenuated with high NR (-0.5±8.3g). Studies without NR had lower CNR compared to low and high NR at both the ES phase and ED phase (all p<0.01). CONCLUSIONS: A high NR strategy on tube current modulated functional cardiac CT improves correlation of EF compared to CMR and reduces variability of EF and mass evaluation by increasing the CNR. In an effort to reduce radiation dose with tube current modulation, this strategy provides better image quality when LV function and mass quantification is needed.

Coronary CT angiography versus standard evaluation in acute chest pain.

BACKGROUND: It is unclear whether an evaluation incorporating coronary computed tomographic angiography (CCTA) is more effective than standard evaluation in the emergency department in patients with symptoms suggestive of acute coronary syndromes. METHODS: In this multicenter trial, we randomly assigned patients 40 to 74 years of age with symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic changes or an initial positive troponin test to early CCTA or to standard evaluation in the emergency department on weekdays during daylight hours between April 2010 and January 2012. The primary end point was length of stay in the hospital. Secondary end points included rates of discharge from the emergency department, major adverse cardiovascular events at 28 days, and cumulative costs. Safety end points were undetected acute coronary syndromes. RESULTS: The rate of acute coronary syndromes among 1000 patients with a mean (±SD) age of 54±8 years (47% women) was 8%. After early CCTA, as compared with standard evaluation, the mean length of stay in the hospital was reduced by 7.6 hours (P<0.001) and more patients were discharged directly from the emergency department (47% vs. 12%, P<0.001). There were no undetected acute coronary syndromes and no significant differences in major adverse cardiovascular events at 28 days. After CCTA, there was more downstream testing and higher radiation exposure. The cumulative mean cost of care was similar in the CCTA group and the standard-evaluation group ($4,289 and $4,060, respectively; P=0.65). CONCLUSIONS: In patients in the emergency department with symptoms suggestive of acute coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency of clinical decision making, as compared with a standard evaluation in the emergency department, but it resulted in an increase in downstream testing and radiation exposure with no decrease in the overall costs of care. (Funded by the National Heart, Lung, and Blood Institute; ROMICAT-II ClinicalTrials.gov number, NCT01084239.).

Incremental diagnostic value of regional left ventricular function over coronary assessment by cardiac computed tomography for the detection of acute coronary syndrome in patients with acute chest pain: from the ROMICAT trial.

BACKGROUND: The incremental value of regional left ventricular function (LVF) over coronary assessment to detect acute coronary syndrome (ACS) is uncertain. METHODS AND RESULTS: We analyzed 356 patients (mean age, 53+/-12 years; 62% men) with acute chest pain and inconclusive initial emergency department evaluation. Patients underwent 64-slice contrast-enhanced cardiac computed tomography before hospital admission. Caregivers and patients remained blinded to the results. Regional LVF and presence of coronary atherosclerotic plaque and significant stenosis (>50%) were separately assessed by 2 independent readers. Incremental value of regional LVF to predict ACS was determined in the entire cohort and in subgroups of patients with nonobstructive coronary artery disease, inconclusive assessment for stenosis (defined as inability to exclude significant stenosis due to calcium or motion), and significant stenosis. During their index hospitalization, 31 patients were ultimately diagnosed with ACS (8 myocardial infarction, 22 unstable angina), of which 74% (23 patients) had regional LV dysfunction. Adding regional LVF resulted in a 10% increase in sensitivity to detect ACS by cardiac computed tomography (87%; 95% confidence interval, 70% to 96%) and significantly improved the overall accuracy (c-statistic: 0.88 versus 0.94 and 0.79 versus 0.88, for extent of plaque and presence of stenosis, respectively; both P<0.03). The diagnostic accuracy of regional LVF for detection of ACS has 89% sensitivity and 86% specificity in patients with significant stenosis (n=33) and 60% sensitivity and 86% specificity in patients with inconclusive coronary computed tomographic angiography (n=33). CONCLUSIONS: Regional LVF assessment at rest improves diagnostic accuracy for ACS in patients with acute chest pain, especially in those with coronary artery disease and thus may be helpful to guide further management in patients at intermediate risk for ACS.

Quantitative assessment of left atrial volume by electrocardiographic-gated contrast-enhanced multidetector computed tomography.

BACKGROUND: Left atrial (LA) volume is a predictor of cardiovascular events. Information on LA volume is available on contrast-enhanced electrocardiogram (EGC)-gated multidetector computed tomography (MDCT) scans. OBJECTIVE: To assess interobserver and intraobserver reproducibility of 3-dimensional threshold-based volume (3DTV) and 2-dimensional (2D) measurements for the assessment of LA volumes with contrast-enhanced cardiac 64-slice MDCT. METHODS: Contrast-enhanced 64-slice MDCT (0.6-mm slice thickness, 120 kVp, 850 mAseff) was performed in 96 consecutive subjects (mean age 52 years; 48% women) as a subset of the Rule Out Myocardial Infarction using Computer Assisted Tomography trial. Two observers independently measured maximal (LAV(max)) and minimal (LAV(min)) LA volumes with (1) a modified Simpson's method (3DTV) based on delineation of LA areas in axial slices and (2) estimated LA volumes typically used in 2D echocardiography (area length and prolate ellipse). Interobserver and intraobserver reproducibility for each method as well as correlations between the methods were calculated. RESULTS: Interobserver (n = 96) and intraobserver (n = 20) variability was significantly lower for 3DTV (8%) than for area length (13%; P < 0.001) or prolate ellipse (16%; P < 0.001). 2D-based measurements rendered significantly lower LA volumes than did 3DTV (area length: -17% and -22%; prolate ellipse: -43% and -46% for LAV(max) and LAV(min), respectively; P < 0.001 for all). By 3DTV, mean LA volume was 90.4 +/- 24.5 mL for LAV(max) and 52.5 +/- 17.6 mL for LAV(min). CONCLUSION: ECG-gated contrast-enhanced cardiac MDCT offers volumetric assessment of LA volume with excellent reproducibility without additional contrast administration or radiation exposure. 3D measures of LA volume are more reproducible and render larger volumes than 2D-derived estimates, typically used in echocardiography.