Ultra-high-resolution CT vs. invasive angiography for detecting hemodynamically significant coronary artery disease: Rationale and methods of the CORE-PRECISION multicenter study.

BACKGROUND: Direct coronary arterial evaluation via computed tomography (CT) angiography is the most accurate noninvasive test for the diagnosis of coronary artery disease (CAD). However, diagnostic accuracy is limited in the setting of severe coronary calcification or stents. Ultra-high-resolution CT (UHR-CT) may overcome this limitation, but no rigorous study has tested this hypothesis. METHODS: The CORE-PRECISION is an international, multicenter, prospective diagnostic accuracy study testing the non-inferiority of UHR-CT compared to invasive coronary angiography (ICA) for identifying patients with hemodynamically significant CAD. The study will enroll 150 patients with history of CAD, defined as prior documentation of lumen obstruction, stenting, or a calcium score ≥400, who will undergo UHR-CT before clinically prompted ICA. Assessment of hemodynamically significant CAD by UHR-CT and ICA will follow clinical standards. The reference standard will be the quantitative flow ratio (QFR) with <0.8 defined as abnormal. All data will be analyzed in independent core laboratories. RESULTS: The primary outcome will be the comparative diagnostic accuracy of UHR-CT vs. ICA for detecting hemodynamically significant CAD on a patient level. Secondary analyses will focus on vessel level diagnostic accuracy, quantitative stenosis analysis, automated contour detection, in-depth plaque analysis, and others. CONCLUSION: CORE-PRECISION aims to investigate if UHR-CT is non-inferior to ICA for detecting hemodynamically significant CAD in high-risk patients, including those with severe coronary calcification or stents. We anticipate this study to provide valuable insights into the utility of UHR-CT in this challenging population and for its potential to establish a new standard for CAD assessment.

Ultra-High-Resolution Coronary CT Angiography for Assessment of Patients with Severe Coronary Artery Calcification: Initial Experience.

PURPOSE: Conventional CT technology yields only modest accuracy of coronary artery stenosis assessment in severely calcified lesions. Reported herein are this study's initial observations on the potential of ultra-high-resolution CT (UHR-CT) for evaluating severely calcified coronary arterial lesions. MATERIALS AND METHODS: Fifteen patients 45 years of age or older, with history of coronary artery disease, referred for invasive coronary angiography, were prospectively enrolled. Patients underwent UHR-CT within 30 days prior to cardiac catheterization. Image noise levels and diagnostic confidence (level 1-5) using UHR-CT were compared with reconstructed images simulating conventional CT technology. Stenosis assessment for the major coronary arteries and the left main coronary artery with UHR-CT and invasive angiography were compared. Results from clinically driven coronary CT using conventional technology were considered for comparison when available. RESULTS: Mean patient age was 67 years (range, 53-79 years). Thirteen patients were men, nine had obesity. Radiation dose was 9.3 mSv owing to expanded x-ray exposure to accommodate research software application (70%-99% of R-R cycle). Overall image noise was considerably greater for UHR-CT (50.9 ± 7.8 [standard deviation]) versus conventional CT image reconstruction (19.5 ± 8.3, P < .01), yet diagnostic confidence scores for UHR-CT were high (4.3 ± 0.9). Average calcium score in patients without stents (n = 6) was 1205, and of 86 vessels evaluated, 22 had 70% or greater stenosis depicted with invasive angiography (26%). Stenosis comparison with invasive angiography yielded 86% (19 of 22) sensitivity and 88% (56 of 64) specificity (95% CI: 65%, 97%; and 77%, 95%, respectively). CONCLUSION: Initial observations suggest UHR-CT may be effective in overcoming the limitation of conventional CT for accurately evaluating coronary artery stenoses in severely calcified vessels.Keywords: CT-Angiography, Coronary Arteries, ArteriosclerosisClinical trial registration no. NCT04272060See also commentary by Shanbhag and Chen in this issue.© RSNA, 2021.

Myocardial Injury in Severe COVID-19 Compared With Non-COVID-19 Acute Respiratory Distress Syndrome.

BACKGROUND: Knowledge gaps remain in the epidemiology and clinical implications of myocardial injury in coronavirus disease 2019 (COVID-19). We aimed to determine the prevalence and outcomes of myocardial injury in severe COVID-19 compared with acute respiratory distress syndrome (ARDS) unrelated to COVID-19. METHODS: We included intubated patients with COVID-19 from 5 hospitals between March 15 and June 11, 2020, with troponin levels assessed. We compared them with patients from a cohort study of myocardial injury in ARDS and performed survival analysis with primary outcome of in-hospital death associated with myocardial injury. In addition, we performed linear regression to identify clinical factors associated with myocardial injury in COVID-19. RESULTS: Of 243 intubated patients with COVID-19, 51% had troponin levels above the upper limit of normal. Chronic kidney disease, lactate, ferritin, and fibrinogen were associated with myocardial injury. Mortality was 22.7% among patients with COVID-19 with troponin under the upper limit of normal and 61.5% for those with troponin levels >10 times the upper limit of normal (P<0.001). The association of myocardial injury with mortality was not statistically significant after adjusting for age, sex, and multisystem organ dysfunction. Compared with patients with ARDS without COVID-19, patients with COVID-19 were older and had higher creatinine levels and less favorable vital signs. After adjustment, COVID-19-related ARDS was associated with lower odds of myocardial injury compared with non-COVID-19-related ARDS (odds ratio, 0.55 [95% CI, 0.36-0.84]; P=0.005). CONCLUSIONS: Myocardial injury in severe COVID-19 is a function of baseline comorbidities, advanced age, and multisystem organ dysfunction, similar to traditional ARDS. The adverse prognosis of myocardial injury in COVID-19 relates largely to multisystem organ involvement and critical illness.

Evaluation and Management of Patients With Stable Angina: Beyond the Ischemia Paradigm: JACC State-of-the-Art Review.

Coronary heart disease is a chronic, systemic disease with a wide range of associated symptoms, clinical outcomes, and health care expenditure. Adverse events from coronary heart disease can be mitigated or avoided with lifestyle and risk factor modifications, and medical therapy. These measures are effective in slowing the progression of atherosclerotic disease and in reducing the risk of thrombosis in the setting of plaque disruptions. With increasing effectiveness of prevention and medical therapy, the role of coronary artery revascularization has decreased and is largely confined to subgroups of patients with unacceptable angina, severe left ventricular systolic dysfunction, or high-risk coronary anatomy. There is a compelling need to allocate resources appropriately to improve prevention. Herein, we review the scientific evidence in support of medical therapy and revascularization for the management of patients with stable coronary heart disease and discuss implications for the evaluation of patients with stable angina and public policy.

The correlation between intensive care unit attending physician continuity of care with financial and clinical outcomes.

PURPOSE: "Attending rotations" on intensive care unit (ICU) services have been in place in most teaching hospitals for decades. However, the ideal frequency of patient care handoffs is unknown. Frequent attending physician handoffs could result in delays in care and other complications, while too few handoffs can lead to provider burnout and exhaustion. Therefore, we sought to determine the correlation between frequency of attending shifts with ICU charges, 30-day readmission rates, and mortality rates. METHODS: We performed a retrospective cohort study at a large, urban, academic community hospital in Baltimore, MD. We included patients admitted into the cardiac or medical ICUs between September 1, 2012, and December 10, 2015. We tracked the number of attending shifts for each patient and correlated shifts with financial outcomes as a primary measure. RESULTS: For any given ICU length of stay, we found no distinct association between handoff frequency and charges, 30-day readmission rates, or mortality rates. CONCLUSIONS: Despite frequent handoffs in care, there was no objective evidence of care compromise or differences in cost. Further validation of these observations in a larger cohort is justified.

Eliminating Creatine Kinase-Myocardial Band Testing in Suspected Acute Coronary Syndrome: A Value-Based Quality Improvement.

Cardiac biomarker testing is estimated to occur in nearly 30 million emergency department visits nationwide each year in the United States. The American College of Cardiology/European Society of Cardiology indicate that cardiac troponin is the biomarker of choice owing to its nearly absolute myocardial tissue specificity and high clinical sensitivity for myocardial injury. Multiple academic medical centers have implemented interventions to eliminate the routine ordering of creatine kinase-myocardial band tests, with published patient safety outcomes data; however, creatine kinase-myocardial band testing is still ordered in many hospitals and emergency departments. Eliminating a simple laboratory test that provides no incremental value to patient care can lead to millions of health care dollars saved without adversely affecting patient care quality, and in this case potentially improving patient care.

Usefulness of a Noninvasive Device to Identify Elevated Left Ventricular Filling Pressure Using Finger Photoplethysmography During a Valsalva Maneuver.

The high rate of re-hospitalization for heart failure might be reduced by improving noninvasive techniques for identifying elevated left ventricular (LV) filling pressure. We previously showed that changes in a finger photoplethysmography (PPG) waveform during the Valsalva maneuver (VM) reflect invasively measured LV end-diastolic pressure (LVEDP). We have since developed a hand-held device that analyzes PPG while guiding the expiratory effort of a VM. Here we assessed the sensitivity and specificity of this device for identifying elevated LVEDP in patients. We tested 82 participants (28 women), aged 40 to 85 years, before a clinically indicated left heart catheterization. Each performed a VM between 18 and 25 mm Hg for 10 seconds into a pressure transducer. PPG was recorded continuously before and during the VM. LVEDP was measured during the catheterization. An equation for calculating LVEDP was derived using (1) ratio of signal amplitudes: minimum during VM to average at baseline, (2) ratio of peak-to-peak time intervals: minimum during VM to average at baseline, and (3) mean blood pressure. Calculated and measured LVEDP were compared. The range of measured LVEDP was 4 to 35 mm Hg. Calculated LVEDP correlated with measured LVEDP (p <0.0001, r = 0.56). A calculated LVEDP >20 mm Hg had a 70% sensitivity and 86% specificity for identifying measured LVEDP >20 mm Hg (area under receiver-operating characteristic curve 0.83). In conclusion, a hand-held device for assessing LV filling pressure had high specificity and good sensitivity for identifying LVEDP >20 mm Hg, a clinically meaningful threshold in heart failure.

Development of a method for automated and stable myocardial perfusion measurement using coronary X-ray angiography images.

The purpose of this study was to develop a method for automatic and stable determination of the optimal time range for fitting with a Patlak plot model in order to measure myocardial perfusion using coronary X-ray angiography images. A conventional two-compartment model is used to measure perfusion, and the slope of the Patlak plot is calculated to obtain a perfusion image. The model holds for only a few seconds while the contrast agent flows from artery to myocardium. Therefore, a specific time range should be determined for fitting with the model. To determine this time range, automation is needed for routine examinations. The optimal time range was determined to minimize the standard error between data points and their least-squares regression straight line in the Patlak plot. A total of 28 datasets were tested in seven porcine models. The new method successfully detected the time range when contrast agent flowed from artery to myocardium. The mean cross correlation in the linear regression analysis (R(2)) was 0.996 ± 0.004. The mean length of the optimal time range was 3.61 ± 1.29 frames (2.18 ± 1.40 s). This newly developed method can automatically determine the optimal time range for fitting with the model.

Reducing excess cardiac biomarker testing at an academic medical center.

BACKGROUND: Elimination of wasteful diagnostic testing will improve value for the United States health care system. OBJECTIVE: Design and implement a multimodal intervention to improve evidence-based ordering of cardiac biomarkers for the diagnosis of acute coronary syndrome (ACS). DESIGN: Interrupted times series. SUBJECTS: A total of 60,494 adult inpatient admissions from January 2009 through July 2011 (pre-intervention) and 24,341 admissions from November 2011 through October 2012 (post-intervention) at an academic medical center in Baltimore, Maryland. INTERVENTION: Multimodal intervention introduced August through October 2011 that included dissemination of an institutional guideline and changes to the computerized provider order entry system. MAIN MEASURES: The primary outcome was percentage of patients with guideline-concordant ordering of cardiac biomarkers, defined as three or fewer troponin tests and zero CK-MB tests in patients without a diagnosis of ACS. Secondary outcomes included counts of tests ordered per patient, incidence of diagnosis of ACS, and estimated change in charges for cardiac biomarker tests in the post-intervention period. KEY RESULTS: Twelve months following the intervention, we estimated that guideline-concordant ordering of cardiac biomarkers increased from 57.1 % to 95.5 %, an absolute increase of 38.4 % (95 % CI, 36.4 % to 40.4 %). We estimated that the intervention led to a 66 % reduction in the number of tests ordered, and a $1.25 million decrease in charges over the first year. At 12 months, there was an estimated absolute increase in incidence of primary diagnosis of ACS of 0.3 % (95 % CI, 0.0 % to 0.5 %) compared with the expected baseline rate. CONCLUSIONS: We implemented a multimodal intervention that significantly increased guideline-concordant ordering of cardiac biomarker testing, leading to substantial reductions in tests ordered without impacting diagnostic yield. A trial of this approach at other institutions and for other diagnostic tests is warranted and if successful, would represent a framework for eliminating wasteful diagnostic testing.

Development of a theory for generating regional cardiac perfusion images during coronary angiography in the coronary angiography lab.

The purpose of this study was to develop a novel theory and method for generating regional myocardial perfusion images using fluoroscopy in the coronary angiography lab. We modified the Kety model to introduce the Patlak plot method for two-dimensional fluoroperfusion (FP) imaging. For evaluation, seven porcine models of myocardial ischemia with stenosis in the left coronary artery were prepared. Rest and stress FP imaging were performed using cardiovascular X-ray imaging equipment during the injection of iopamidol via the left main coronary artery. Images were acquired and retrospectively ECG gated at 80 % of the R-R interval. FP myocardial blood flow (MBF) was obtained using the Patlak plot method applied to time-intensity curve data of the proximal artery and myocardium. The results were compared to microsphere MBF measurements. Time-intensity curves were also used to generate color-coded FP maps. There was a moderate linear correlation between the calculated FP MBF and the microsphere MBF (y = 0.9758x + 0.5368, R² = 0.61). The color-coded FP maps were moderately correlated with the regional distribution of flow. This novel method of first-pass contrast-enhanced two-dimensional fluoroscopic imaging can quantify MBF and provide color coded FP maps representing regional myocardial perfusion.

Treatment of acute coronary syndrome: part 2: ST-segment elevation myocardial infarction.

OBJECTIVE: Familiarize clinicians with recent information regarding the diagnosis and treatment of ST-segment elevation myocardial infarction. DATA SOURCES: PubMed search and review of relevant medical literature. SUMMARY: Definition, pathophysiology, clinical presentation, diagnosis, and treatment of ST-segment elevation myocardial infarction are reviewed. CONCLUSIONS: Patients with ST-segment elevation myocardial infarction benefit from prompt reperfusion therapy. Adjunctive antianginal, antiplatelet, antithrombotic, beta blocker, angiotensin-converting enzyme inhibitor, and statin agents minimize ongoing cardiac ischemia, prevent thrombus propagation, and reduce the risk of recurrent cardiovascular events.

Finger photoplethysmography during the Valsalva maneuver reflects left ventricular filling pressure.

It is often challenging to assess cardiac filling pressure clinically. An improved system for detecting or ruling out elevated cardiac filling pressure may help reduce hospitalizations for heart failure. The blood pressure response to the Valsalva maneuver reflects left heart filling pressure, but its underuse clinically may be due in part to lack of continuous blood pressure recording along with lack of standardization of expiratory effort. In this study, we tested whether Valsalva-induced changes in the pulse amplitude of finger photoplethysmography (PPG), a technology already widely available in medical settings, correlate with invasively measured left ventricular end-diastolic pressure (LVEDP). We tested 33 subjects before clinically scheduled cardiac catheterizations. A finger photoplethysmography waveform was recorded during a Valsalva effort of 20 mmHg expiratory pressure sustained for 10 s, an effort most patients can achieve. Pulse amplitude ratio (PAR) was calculated as the PPG waveform amplitude just before release of expiratory effort divided by the waveform amplitude at baseline. PAR was well correlated with LVEDP (r = 0.68; P < 0.0001). For identifying LVEDP > 15 mmHG, PAR > 0.4 was 85% sensitive [95% confidence interval (95CI): 54-97%] and 80% specific (95CI: 56-93%). In conclusion, finger PPG, a technology already ubiquitous in medical centers, may be useful for assessing clinically meaningful categories of left heart filling pressure, using simple analysis of the waveform after a Valsalva maneuver effort that most patients can achieve.