Diagnostic Performance of Diastolic Hyperemia-Free Ratio Compared With Invasive Fractional Flow Reserve for Evaluation of Coronary Artery Disease.

Hyperemic and nonhyperemic pressure ratios are frequently used to assess the hemodynamic significance of coronary artery disease and to guide the need for myocardial revascularization. However, there are limited data on the diagnostic performance of the diastolic hyperemia-free ratio (DFR). We evaluated the diagnostic performance of the DFR compared with invasive fractional flow reserve (FFR). We performed a prospective, single-center study of 308 patients (343 lesions) who underwent DFR and FFR for evaluation of visually estimated 40% to 90% stenoses. Diagnostic performance of the DFR compared with FFR was evaluated using linear regression, Bland-Altman analysis, and receiver operating characteristic curves. The overall diagnostic accuracy of the DFR was 83%; the accuracy rates were 86%, 40%, and 95% when the DFR was <0.86, 0.88 to 0.90, and >0.93, respectively. The sensitivity, specificity, positive predicative value, and negative predictive value were 60%, 91%, 71%, and 87%, respectively. The Pearson correlation coefficient was 0.75 (p <0.05). The Bland-Altman analysis showed a mean difference of 0.09, and the area under the receiver operating characteristic curve was 0.88 (95% confidence interval 0.84 to 0.92, p <0.05). In conclusion, the DFR has a good diagnostic performance compared with FFR but 17% of the measurements were discordant. The diagnostic accuracy of the DFR was only 40% when the DFR was 0.88 to 0.90, suggesting that FFR may be useful in these arteries.

Computed Tomography-Derived Physiology Assessment: State-of-the-Art Review.

Coronary computed tomography angiography (CCTA) and CCTA-derived fractional flow reserve (FFRCT) are the best non-invasive techniques to assess coronary artery disease (CAD) and myocardial ischemia. Advances in these technologies allow a paradigm shift to the use of CCTA and FFRCT for advanced plaque characterization and planning myocardial revascularization.

Valve-in-Mitral Annular Calcification Transcatheter Mitral Valve Replacement After Thrombosis of Extracardiac Valved Conduit.

We report a patient with severe mitral annular calcification, mitral stenosis/regurgitation, hypertrophic obstructive cardiomyopathy, and subaortic membrane treated with valved left atrium-left ventricle conduit, septal myectomy, and membrane resection. Subsequent thrombosis of the conduit prompted successful valve-in- mitral annular calcification transcatheter mitral valve replacement and laceration of the anterior mitral leaflet to prevent outflow obstruction. (Level of Difficulty: Advanced.).

Renal artery stenosis.

Renal artery stenosis is the most common secondary cause of hypertension and predominantly caused by atherosclerosis. In suspected patients, a non-invasive diagnosis with ultrasound is preferred. Asymptomatic, incidentally found RAS does not require revascularization. In symptomatic patients requiring revascularization, renal artery stenting is the preferred therapy. Selecting appropriate patients for revascularization requires careful consideration of lesion severity and is optimized with a multidisciplinary team. All patients with atherosclerotic RAS should be treated with guideline-directed medical therapy, including hypertension control, diabetes control, statins, antiplatelet therapy, smoking cessation and encouraging activity.

Importance of measurement site on assessment of lesion-specific ischemia and diagnostic performance by coronary computed tomography Angiography-Derived Fractional Flow Reserve.

BACKGROUND: Values of fractional flow reserve (FFRCT) by coronary computed tomography angiography (CTA) decline from the ostium to the terminal vessel, irrespective of stenosis severity. The purpose of this study is to determine if the site of measurement of FFRCT impacts assessment of ischemia and its diagnostic performance relative to invasive FFR (FFRINV). METHODS: 1484 patients underwent FFRCT; 1910 vessels were stratified by stenosis severity (normal; <25%, 25-50%, 50-70%, and >70% stenosis). The rates of positive FFRCT (≤0.8) were determined by measuring FFRCT from the terminal vessel and from distal-to-the-lesion. Reclassification rates from positive to negative FFRCT were calculated. Diagnostic performance of FFRCT relative to FFRINV was evaluated in 182 vessels using linear regression, Bland Altman analysis, and receiver operating characteristic (ROC) curves. RESULTS: Positive FFRCT was identified in 24.9% of vessels using terminal vessel FFRCT and 10.1% using FFRCT distal-to-the-lesion (p â€‹< â€‹0.001). FFRCT obtained distal-to-the-lesion resulted in reclassification of 59.6% of positive terminal FFRCT to negative FFRCT. Relative to FFRINV, there were improvements in specificity (50% to 86%, p â€‹< â€‹0.001), diagnostic accuracy (65% to 88%, p â€‹< â€‹0.001), positive predictive value (50% to 78%, p â€‹< â€‹0.001), and area-under-the-curve (AUC, 0.83 to 0.91, p â€‹< â€‹0.001) when FFRCT was measured distal-to-the-lesion. CONCLUSION: FFRCT values from the terminal vessel should not be used to assess lesion-specific ischemia due to high rates of false positive results. FFRCT measured distal-to-the-lesion improves the diagnostic performance of FFRCT relative to FFRINV, ensures that FFRCT values are due to lesion-specific ischemia, and could reduce the rate of unnecessary invasive procedures.

Strategic Deployment of Cardiology Fellows in Training Using the Accreditation Council for Graduate Medical Education Coronavirus Disease 2019 Framework.

Coronavirus disease 2019 is a global pandemic affecting >3 million people in >170 countries, resulting in >200 000 deaths; 35% to 40% of patients and deaths are in the United States. The coronavirus disease 2019 crisis is placing an enormous burden on health care in the United States, including residency and fellowship training programs. The balance between mitigation, training and education, and patient care is the ultimate determinant of the role of cardiology fellows in training during the coronavirus disease 2019 crisis. On March 24, 2020, the Accreditation Council for Graduate Medical Education issued a formal response to the pandemic crisis and described a framework for operation of graduate medical education programs. Guidance for deployment of cardiology fellows in training during the coronavirus disease 2019 crisis is based on the principles of a medical mission, and adherence to preparation, protection, and support of our fellows in training. The purpose of this review is to describe our departmental strategic deployment of cardiology fellows in training using the Accreditation Council for Graduate Medical Education framework for pandemic preparedness.

Invasive fractional flow reserve: Which technology is best?

Invasive pressure measurements using hyperemic fractional flow reserve (FFR) and nonhyperemic pressure measurements (NHPR) are superior to angiography alone for assessment of 50-90% stenoses. FFR devices using piezoelectric and optical sensors achieve 94% concordance in FFR values; microcatheter designs have more lesion-crossing failures and less pressure drift compared with guidewire designs. Despite the similarity in statistical performance among FFR devices, interventional cardiologists may prefer to use NHPR to avoid the need for adenosine-related side effects, variations in vasodilator response, and limited application in patients with certain clinical and anatomic features.

Clinical Use of CT-Derived Fractional Flow Reserve in the Emergency Department.

OBJECTIVES: This study sought to examine the feasibility, safety, clinical outcomes, and costs associated with computed tomography-derived fractional flow reserve (FFRCT) in acute chest pain (ACP) patients in a coronary computed tomography angiography (CTA)-based triage program. BACKGROUND: FFRCT is useful in determining lesion-specific ischemia in patients with stable ischemic heart disease, but its utility in ACP has not been studied. METHODS: ACP patients with no known coronary artery disease undergoing coronary CTA and coronary CTA with FFRCT were studied. FFRCT ≤0.80 was considered positive for hemodynamically significant stenosis. RESULTS: Among 555 patients, 297 underwent coronary CTA and FFRCT (196 negative, 101 positive), whereas 258 had coronary CTA only. The rejection rate for FFRCT was 1.6%. At 90 days, there was no difference in major adverse cardiac events (including death, nonfatal myocardial infarction, and unexpected revascularization after the index visit) between the coronary CTA and FFRCT groups (4.3% vs. 2.7%; p = 0.310). Diagnostic failure, defined as discordance between the coronary CTA or FFRCT results with invasive findings, did not differ between the groups (1.9% vs. 1.68%; p = NS). No deaths or myocardial infarction occurred with negative FFRCT when revascularization was deferred. Negative FFRCT was associated with higher nonobstructive disease on invasive coronary angiography (56.5%) than positive FFRCT (8.0%) and coronary CTA (22.9%) (p < 0.001). There was no difference in overall costs between the coronary CTA and FFRCT groups ($8,582 vs. $8,048; p = 0.550). CONCLUSIONS: In ACP, FFRCT is feasible, with no difference in major adverse cardiac events and costs compared with coronary CTA alone. Deferral of revascularization is safe with negative FFRCT, which is associated with higher nonobstructive disease on invasive angiography.

Transfemoral Transcatheter Aortic Valve Replacement Using Fascia Iliaca Block as an Alternative Approach to Conscious Sedation as Compared to General Anesthesia.

BACKGROUND/PURPOSE: General Anesthesia (GA) and conscious sedation (CS) are anesthetics for transfemoral transcatheter aortic valve replacement (TF-TAVR). We compared TF-TAVR outcomes using a novel anesthetic approach with fascia iliaca block (FIB) plus minimal CS (MCS) versus GA. METHODS: This retrospective propensity-matched study included consecutive TF-TAVR patients from January 2013 to December 2017 and dichotomized into FIB-MCS vs. GA. Data were collected from electronic records, Society of Thoracic Surgery (STS) database, and the Transcatheter Valve Therapies (TVT) Registry. Primary endpoints were operating room (OR) time, intensive care unit (ICU) and hospital length of stay (LOS). Secondary endpoints were 30-day, 1-year mortality, quality of life, 30-day re-hospitalization rate, failure of FIB-MCS, and hospital safety outcomes. RESULTS: A total of 304 TF-TAVR patients; FIB-MCS (n = 219) vs. GA (n = 85). Propensity matched 162 patients; FIB-MCS (n = 108) vs. GA (n = 54). FIB-MCS had shorter OR time (197.6 ±â€¯56.3 vs. 248.2 ±â€¯46.3 min, p < 0.001), ICU (67.8 ±â€¯71.7 vs. 84.9 ±â€¯72.1 h, p = 0.004) and hospital LOS (3.2 ±â€¯3.7 vs. 5.9 ±â€¯3.5 d, p < 0.001). FIB-MCS had lower rate of blood transfusion. FIB-MCA vs. GA 30-day and 1-year mortality were similar in the entire (2.3 vs. 2.4%, p = 1.0; and 8.2 vs. 5.9%, p = 0.49) and matched cohorts (0 vs. 3.7%, p = 0.11 and 7.4 vs. 5.6%, p = 0.75). FIB-MCS were less likely to be re-hospitalized [Odd Ratio: 0.32, CI:0.13-0.76] and 2% to 3% higher KCCQ-12 score. CONCLUSION: TF-TAVR using FIB-MCS is feasible and safe with shorter OR time, ICU and hospital LOS, lower risk of 30-day re-hospitalization, similar 30-day and 1-year mortality with better quality of life at 1-year follow-up.

Optimizing the Technique for Invasive Fractional Flow Reserve to Assess Lesion-Specific Ischemia.

BACKGROUND: Invasive fractional flow reserve (FFRINV) is the standard technique for assessing myocardial ischemia. Pressure distortions and measurement location may influence FFRINV interpretation. We report a technique for performing invasive fractional flow reserve (FFRINV) by minimizing pressure distortions and identifying the proper location to measure FFRINV. METHODS: FFRINV recordings were obtained prospectively during manual hyperemic pullback in 100 normal and diseased coronary arteries with single stenosis, using 4 measurements from the terminal vessel, distal-to-the-lesion, proximal vessel, and guiding catheter. FFRINV profiles were developed by plotting FFRINV values (y-axis) and site of measurement (x-axis), stratified by stenosis severity. FFRINV≤0.8 was considered positive for lesion-specific ischemia. RESULTS: Erroneous FFRINV values were observed in 10% of vessels because of aortic pressure distortion and in 21% because of distal pressure drift; these were corrected by disengagement of the guiding catheter and re-equalization of distal pressure/aortic pressure, respectively. There were significant declines in FFRINV from the proximal to the terminal vessel in normal and stenotic coronary arteries (P<0.001). The rate of positive FFRINV was 41% when measured from the terminal vessel and 20% when measured distal-to-the-lesion (P<0.001); 41.5% of positive terminal measurements were reclassified to negative when measured distal-to-the-lesion. Measuring FFRINV 20 to 30 mm distal-to-the-lesion (rather than from the terminal vessel) can reduce errors in measurement and optimize the assessment of lesion-specific ischemia. CONCLUSIONS: Meticulous technique (disengagement of the guiding catheter, FFRINV pullback) is required to avoid erroneous FFRINV, which occur in 31% of vessels. Even with optimal technique, FFRINV values are influenced by stenosis severity and the site of pressure measurement. FFRINV values from the terminal vessel may overestimate lesion-specific ischemia, leading to unnecessary revascularization.

Coronary CT Angiography-derived Fractional Flow Reserve Testing in Patients with Stable Coronary Artery Disease: Recommendations on Interpretation and Reporting.

Noninvasive fractional flow reserve derived from coronary CT angiography (FFRCT) is increasingly used in patients with coronary artery disease as a gatekeeper to the catheterization laboratory. While there is emerging evidence of the clinical benefit of FFRCT in patients with moderate coronary disease as determined with coronary CT angiography, there has been less focus on interpretation, reporting, and integration of FFRCT results into routine clinical practice. Because FFRCT analysis provides a plethora of information regarding pressure and flow across the entire coronary tree, standardized criteria on interpretation and reporting of the FFRCT analysis result are of crucial importance both in context of the clinical adoption and in future research. This report represents expert opinion and recommendation on a standardized FFRCT interpretation and reporting approach. Published under a CC BY 4.0 license.

Planning percutaneous coronary interventions using computed tomography angiography and fractional flow reserve-derived from computed tomography: A state-of-the-art review.

Fractional flow reserve derived by coronary computed tomography angiography (CTA; FFRCT) is an accurate noninvasive method for identifying coronary artery disease (CAD) and detecting hemodynamically significant stenosis. Although initially proposed as noninvasive tools to "rule out" significant CAD in low-risk patients, CTA and FFRCT are now utilized in higher-risk patients. Furthermore, new applications of CTA and FFRCT include a planning tool for percutaneous coronary intervention (PCI), which allows the cardiologist to assess lesion-specific ischemia, plan stent locations and sizes, and use virtual remodeling of the lumen (virtual stenting) to assess the functional impact of PCI. The purpose of this review is to discuss the principles of CTA and FFRCT acquisition, and their application for PCI planning, even before invasive angiography is performed.

Assessment of lesion-specific ischemia using fractional flow reserve (FFR) profiles derived from coronary computed tomography angiography (FFRCT) and invasive pressure measurements (FFRINV): Importance of the site of measurement and implications for patient referral for invasive coronary angiography and percutaneous coronary intervention.

BACKGROUND: Fractional flow reserve (FFR)-derived from computed tomography angiography (CTA; FFRCT) and invasive FFR (FFRINV) are used to assess the need for invasive coronary angiography (ICA) and percutaneous coronary intervention (PCI). The optimal location for measuring FFR and the impact of measurement location have not been well defined. METHODS: 930 patients (age 60.7 + 10 years, 59% male) were included in this study. Normal and diseased coronary arteries were classified into stenosis grades 0-4 in the left anterior descending artery (LAD, n = 518), left circumflex (LCX, n = 112) and right coronary artery (RCA, n = 585). FFRCT (n = 1215 arteries) and FFRINV (n = 26 LAD) profiles were developed by plotting FFR values (y-axis) versus site of measurement (x-axis: ostium, proximal, mid, distal segments). The best location to measure FFR was defined relative to the distal end of the stenosis. FFR ≤0.8 was considered positive for ischemia. RESULTS: In normal and stenotic coronary arteries there are significant declines in FFRCT and FFRINV from the ostium to the distal vessel (p < 0.001), due to lesion-specific ischemia and to effects unrelated to the lesion. A reliable location (distal to the stenosis) is 10.5 mm [IQR 7.3-14.8 mm] for FFRCT and within 20-30 mm for FFRINV. Rates of positive FFR (from the distal vessel) reclassified to negative FFR (distal to the stenosis) are 61% (FFRCT) and 33% (FFRINV). CONCLUSION: FFRCT and FFRINV values are influenced by stenosis severity and the site of measurement. FFR measurements from the distal vessel may over-estimate lesion-specific ischemia and result in unnecessary referrals for ICA and PCI.

Carotid stenting with double layered stents: Double trouble or double benefit?

The use of double layer (covered) stents during carotid artery stenting (CAS) appears to be safe; attenuation of plaque prolapse and distal embolization is reasonable but unproven. Double layer stents are commercially available in Europe but not in the United States; similar benefits might be obtained by implanting two self-expanding stents, to decrease the effective free cell area. Embolic protection devices (EPDs) are recommended in all CAS patients; the use of double layer stents does not eliminate the need for EPDs.

Is optical coherence tomography a coherent strategy for carotid artery stenting?

Optical coherence tomography (OCT) is rarely necessary to guide clinical decisions about the appropriateness of carotid revascularization. For carotid artery stenting (CAS), computed tomography angiography is the best imaging tool to assess arch, carotid, and lesion-specific anatomy, including vessel dimensions and calcification. OCT is a coherent strategy after CAS to assess ambiguous angiographic findings and to guide appropriate therapy for dissection, thrombosis, and plaque prolapse.

CO2 angiography: Colorless, odorless, but definitely not useless!

Contemporary approaches to minimize the risk of acute kidney injury from radiographic contrast (AKI-RC) rely on preferential use of low- or non-ionic contrast; pre-hydration; and limiting contrast volume. This study utilized a meta-analysis of 677 patients to compare the risk of AKI-RC after CO2 peripheral angiography versus iodinated contrast (4.3% vs. 11.1%, odds ratio [OR] 0.465, P = 0.048). There was no difference in AKI-RC in patients with CKD. This study has many limitations. CO2 angiography is an important technique; proper understanding of its strengths and limitations is essential.