Impact of recurrent COVID-19 disease waves on acute myocardial infarction epidemics: results from a regional network.

Aims: To assess the impact of COVID-19 related public containment measures during recurrent COVID-19 waves on hospital admission rate for acute myocardial infarction (AMI).Methods and results: Clinical characteristics, reperfusion therapy modalities, COVID-19 status and in-hospital mortality of consecutive AMI patients who were admitted in a regional AMI network were recorded during one year starting in March 2020 and were compared with the year before. The COVID-19 study period encompassed two waves: the first in March-May 2020 and the second in October-December 2020. A total of 1349 AMI patients were hospitalised of which 725 during the pre-COVID period and 624 during the COVID period (incidence rate ratio of 1.16, p = 0,006). The impact was predominantly present in the first wave (32% reduction: n = 204 vs 152) and evanished during the second wave (3% increase (152 vs 156). A similar pattern was observed for ACS with cardiac arrest with a 92% reduction (n = 36 vs 3) during the first wave and no change during the second wave (18 vs 18). After correction for temperature and air quality, COVID-19 epidemic remained associated with a decrease of AMI hospitalisation (p = 0.046). Reperfusion strategy for AMI patients, were comparable between both study periods. The in-hospital mortality between the two periods was comparable (2.6% versus 1.9%), but COVID-19 positive ACS patients (n = 7) had a high mortality rate (14%).Conclusion: COVID-19 related public containment measures resulted during the first wave in a 32% reduction of AMI hospitalisation, but this impact was not visible anymore during the second wave.

Normalization of FFRCT after surgical unroofing of a myocardial bridge: a case report.

Background: Cardiac computed tomography angiography derived fractional flow reserve (FFRCT) is a diastolic measurement and has emerged as a valuable non-invasive alternative to FFR in patients with stable coronary artery disease. It has, unlike FFR during coronary angiography, not been validated for the physiological evaluation of an isolated myocardial bridge (MB) so far. Case summary: Our patient, previously known with a long myocardial bridge of the mid-segment of the left anterior descending artery, presented with a non-ST-segment elevation myocardial infarction that was treated by surgical unroofing of the MB. FFRCT after surgery confirms a major amelioration of coronary blood flow. Discussion: Myocardial bridge may rarely present as a non-ST-segment elevation myocardial infarction. FFRCT has thus far been accepted as a useful diagnostic tool in stable coronary artery disease. Our case report suggests that cardiac computed tomography angiography may be considered a useful technique for anatomical and physiological evaluation of MBs.

Clinical and prognostic incremental value of FFRCT in screening of patients with obstructive coronary artery disease.

BACKGROUND: Coronary computed tomography angiography (CCTA) -derived fractional flow reserve (FFRCT) is recommended to evaluate the functional consequences of obstructive coronary artery disease (OCAD). Real-world incremental impacts of FFRCT use still remains under debate. METHODS: 1601 patients with suspected OCAD on CCTA (>50 â€‹% stenosis), including 808 (50.5 â€‹%) patients evaluated by FFRCT, were included from a 2013-2021 registry. Propensity adjusted impacts of FFRCT use on rates of invasive coronary angiography (ICA), myocardial revascularization (MR) and post MR major adverse cardiac events (MACE) were reported, including a sensitivity analysis in severe OCAD (>70 â€‹% stenosis) (n â€‹= â€‹450). Accuracy of numerical and comprehensive FFRCT interpretations in selection of patients requiring a MR were also compared. RESULTS: 1160 (72,5 â€‹%) ICA, 559 (34.9 â€‹%) MR and 137 (24.5 â€‹%) post MR MACE occurred at 4.7 â€‹± â€‹1.9 years. FFRCT use was independently associated with decreased rate of ICA and MR (OR: 0.66; 95 â€‹% CI 0.53-0.83, p â€‹< â€‹0.001 and OR: 0.71; 95 â€‹% CI 0.58-0.88, p â€‹< â€‹0.01, respectively). Compared to the numerical interpretation, the FFRCT comprehensive assessment increased the ratio of MR per ICA (61.7 â€‹% vs 50.1 â€‹%, p â€‹< â€‹0.01) and was more accurate in selection of patients requiring MR. FFRCT reduced post MR MACE (OR: 0.64; 95 â€‹% CI 0.43-0.96, p â€‹< â€‹0.05). All these associations were no longer observed in severe OCAD. CONCLUSION: Implementing FFRCT in OCAD patients reduces ICA use, improves selection of patients requiring MR and reduces post MR MACE. However, these incremental values of FFRCT were no longer observed in severe OCAD.

Impact of vessel morphology on CT-derived fractional-flow-reserve in non-obstructive coronary artery disease in right coronary artery.

OBJECTIVES: Computed tomography (CT)-derived fractional flow reserve (FFRCT) decreases continuously from proximal to distal segments of the vessel due to the influence of various factors even in non-obstructive coronary artery disease (NOCAD). It is known that FFRCT is dependent on vessel-length, but the relationship with other vessel morphologies remains to be explained. PURPOSE: To investigate morphological aspects of the vessels that influence FFRCT in NOCAD in the right coronary artery (RCA). METHODS: A total of 443 patients who underwent both FFRCT and invasive coronary angiography, with < 50% RCA stenosis, were evaluated. Enrolled RCA vessels were classified into two groups according to distal FFRCT: FFRCT ≤ 0.80 (n = 60) and FFRCT > 0.80 (n = 383). Vessel morphology (vessel length, lumen diameter, lumen volume, and plaque volume) and left-ventricular mass were assessed. The ratio of lumen volume and vessel length was defined as V/L ratio. RESULTS: Whereas vessel-length was almost the same between FFRCT ≤ 0.80 and > 0.80, lumen volume and V/L ratio were significantly lower in FFRCT ≤ 0.80. Distal FFRCT correlated with plaque-related parameters (low-attenuation plaque, intermediate-attenuation plaque, and calcified plaque) and vessel-related parameters (proximal and distal vessel diameter, vessel length, lumen volume, and V/L ratio). Among all vessel-related parameters, V/L ratio showed the highest correlation with distal FFRCT (r = 0.61, p < 0.0001). Multivariable analysis showed that calcified plaque volume was the strongest predictor of distal FFRCT, followed by V/L ratio (ß-coefficient = 0.48, p = 0.03). V/L ratio was the strongest predictor of a distal FFRCT ≤ 0.80 (cut-off 8.1 mm3/mm, AUC 0.88, sensitivity 90.0%, specificity 76.7%, 95% CI 0.84-0.93, p < 0.0001). CONCLUSIONS: Our study suggests that V/L ratio can be a measure to predict subclinical coronary perfusion disturbance. CLINICAL RELEVANCE STATEMENT: A novel marker of the ratio of lumen volume to vessel length (V/L ratio) is the strongest predictor of a distal CT-derived fractional flow reserve (FFRCT) and may have the potential to improve the diagnostic accuracy of FFRCT. KEY POINTS: • Physiological FFRCT decline depends not only on vessel length but also on the lumen volume in non-obstructive coronary artery disease in the right coronary artery. • FFRCT correlates with plaque-related parameters (low-attenuation plaque, intermediate-attenuation plaque, and calcified plaque) and vessel-related parameters (proximal and distal vessel diameter, vessel length, lumen volume, and V/L ratio). • Of vessel-related parameters, V/L ratio is the strongest predictor of a distal FFRCT and an optimal cut-off value of 8.1 mm3/mm.

FFRct use for acute chest pain triage in the emergency department: a cost-effectiveness analysis.

AIMS: To model and assess the cost-effectiveness of CT-based fractional flow reserve (FFRct) for a population of low to intermediate risk patients for coronary artery disease (CAD) presenting to the emergency department (ED) with acute chest pain. METHODS AND RESULTS: Using a decision tree model with a 1 year time horizon and from a health care perspective, two diagnostic pathways using FFRct are compared to current clinical routine combining coronary computed tomography angiography (CCTA) with an exercise test. Model data are drawn from the literature and nationally reported data. Outcomes are assessed as the number of avoided invasive coronary angiographies (ICAs) showing no obstructive CAD and quality of life (QoL) in a theoretical cohort of 1000 patients. Sensitivity analyses are performed to test the robustness of the results. Determining FFRct when CCTA is inconclusive is a cost-effective and dominant strategy with a potential saving of 198€/patient, 154 avoided unnecessary ICA showing no obstructive CAD (uICA)/1000 patients and an average improvement in QoL of 0.008 QALY/patient. With an additional 574€/patient, 8 avoided uICA/1000 patients and an improvement in QoL of 0.001 QALY/patient, a strategy where FFRct is always performed is cost-effective only when considering high cost-effectiveness thresholds. CONCLUSIONS: For patients presenting to the ED with acute chest pain and a low to intermediate pre-test probability of CAD, a diagnostic strategy where FFRct is determined after an inconclusive CCTA is cost-effective. Clinical trials investigating both sensitivity and specificity of FFRct, as well as QoL associated with the use of this technology in this setting are warranted.

Depression and Malnutrition for Prediction of Mortality after Transcatheter Aortic Valve Replacement: A Registry Study of a Tertiary Referral Hospital.

Moderate to severe frailty is a predictor of a poor outcome after transcatheter aortic valve replacement (TAVR), but little is known about the prognostic importance of different geriatric frailty markers in an overall fit or pre-frail geriatric population undergoing TAVR. This retrospective study aimed to examine the incremental value of adding patient frailty markers to conventional surgical risk score to predict all-cause mortality in relatively fit elderly patients undergoing TAVR. Overall patient frailty was assessed using the comprehensive geriatric assessment frailty index (CGA-FI). Multivariable Cox regression models were used to evaluate relationships of different geriatric frailty markers with all-cause mortality and single and combined frailty models were compared to a baseline model that included EuroSCORE II factors. One hundred relatively fit geriatric patients (84 ± 4 years old, mean CGA-FI 0.14 ± 0.05) were included, and 28% died during a median follow-up of 24 months. After adjustment, risk of depression (geriatric depression scale 15 (GDS-15)) and malnutrition remained significantly associated with all-cause mortality (HR 4.381, 95% CI 1.787-10.743; p = 0.001 and HR 3.076, 95% CI 1.151-8.217; p = 0.025, respectively). A combined frailty marker model including both GDS-15 and malnutrition on top of EuroSCORE II improved the discriminative ability to predict all-cause mortality (change in c-index: + 0.044). Screening for those frailty markers on top of the traditionally used EuroSCORE II may improve risk stratification and prognosis in relatively fit geriatric patients undergoing TAVR.

The impact of iodine contrast agent on radiation dose of heart and blood: a comparison between coronary CT angiography and cardiac calcium scoring CT.

BACKGROUND: Iodine contrast agent (CA) is widely used in cardiac computed tomography (CT). The CA can increase the organ radiation doses due to the photoelectric effect. PURPOSE: To investigate the impact of CA on radiation dose in cardiac CT by comparing the radiation dose between contrast coronary CT angiography (CCTA) and non-contrast calcium scoring CT (CSCT). MATERIAL AND METHODS: Radiation doses were computationally calculated for 30 individual patients who received CSCT and CCTA in the same exam session. The geometry and acquisition parameters were modeled in the simulations based on individual patient CT images and acquisitions. Doses in the presence and absence of CA were obtained in the aorta, left ventricle (LV), right ventricle (RV), and myocardial tissue (MT). The dose values were normalized by size-specific dose estimate (SSDE). The dose enhancement factors (DEFSSDE) were calculated as the ratio of doses in CCTA over doses in CSCT. RESULTS: Compared to the CSCT scans, doses increase in the CCTA scans in the aorta (DEFSSDE = 2.14 ± 0.20), LV (DEFSSDE = 1.78 ± 0.26), and RV (DEFSSDE = 1.31 ± 0.22). A linear relation is observed between the local CA concentrations and the dose increase in the heart; DEFSSDE = 0.07*I(mg/mL) + 0.80 (R2 = 0.8; p < 0.01). The DEFSSDE in the MT (DEFSSDE = 0.96 ± 0.08) showed no noticeable impact of CA on the dose in this tissue. In addition, patient variability in the dose distributions was observed. CONCLUSION: A linear causal relation exists between local CA concentration and increase in radiation dose in cardiac CT. For the same CT exposure, dose to the heart is on average 55% higher in contrast cardiac CT.

A chart review on surgical myocardial debridging in symptomatic patients: a safe procedure with good long-term clinical outcome and coronary computed tomographic angiography results.

OBJECTIVES: Myocardial bridging is mostly diagnosed as an incidental imaging finding but can result in severe vessel compression and significant clinical adverse complications. Since there is still an ongoing debate when to propose surgical unroofing, we studied a group of patients where this was performed as an isolated procedure. METHODS: In 16 patients (38.9 ± 15.7 years, 75% men) who had surgical unroofing for symptomatic isolated myocardial bridges of the left anterior descending artery, we retrospectively analysed symptomatology, medication, imaging modalities used, operative techniques, complications and long-term outcome. Computed tomographic fractional flow reserve was calculated to understand its potential value for decision-making. RESULTS: Most procedures were performed on-pump (75%, mean cardiopulmonary bypass 56.5 ± 27.9 min, mean aortic cross-clamping 36.4 ± 19.7 min). Three patients needed a left internal mammary artery bypass since the artery dived inside the ventricle. There were no major complications or deaths. The mean follow-up was 5.5 years. Although there was a dramatic improvement in symptoms, still 31% experienced atypical chest pain at various moments during follow-up. Postoperative radiological control was performed in 88%, showing no residual compression or recurrent myocardial bridge and patent bypass if performed. All postoperative computed tomographic flow calculations (7) showed a normalization of coronary flow. CONCLUSIONS: Surgical unroofing for symptomatic isolated myocardial bridging is a safe procedure. Patient selection remains difficult but introducing standard coronary computed tomographic angiography with flow calculations could be helpful in preoperative decision-making and during follow-up.

Impact of ramus coronary artery on computed tomography derived fractional flow reserve (FFRCT ) in no apparent coronary artery disease.

BACKGROUND: The ramus artery contributes to the development of turbulence, which may influence computed tomography (CT) derived fractional flow reserve (FFRCT ) even without coronary artery disease (CAD). The relationship between ramus-induced turbulence and FFRCT is unclear. METHOD AND RESULTS: A total of 120 patients with <20% coronary stenosis assessed by both FFRCT and invasive coronary angiography were evaluated. The patients were divided into three groups: absent-ramus (n = 72), small-ramus that could not be analyzed by FFRCT (n = 18), and large-ramus that could be analyzed by FFRCT (n = 30). FFRCT measurements were performed at the proximal and distal segments of the left anterior descending (LAD), left circumflex (LCX), and ramus artery. With absent-ramus and small-absent ramus groups, FFRCT was measured at the distal end of the left main trunk at the same level for the proximal segments of the LAD and LCX. In absent-ramus group, proximal FFRCT showed no significant differences between three vessels (LAD = .96 ± .02; MID = .97 ± .02; LCX = .97 ± .02). However, in small and large-ramus groups, proximal FFRCT was significantly higher in the ramus artery than LAD and LCX (small-ramus, LAD = .95 ± .03, Ramus = .97 ± .02, LCX = .95 ± .03; large-ramus: LAD = .95 ± .03, Ramus = .98 ± .01; LCX = .96 ± .03; p < .05). A large ramus was associated with a higher prevalence of a distal FFRCT ≤.80 (odds ratio 7.0, 95% CI 1.2-40.1, p = .03). A proximal ramus diameter predicted distal FFRCT ≤.80 (cut-off 2.1 mm, AUC .76, sensitivity 100%, specificity 52%, 95% CI .61-.90). CONCLUSIONS: The presence of a large-ramus artery may cause an FFRCT decline in no apparent CAD.

Evaluation of coronary artery disease in patients undergoing atrial fibrillation ablation: a non-invasive FFR computed tomography study.

To evaluate coronary artery disease (CAD) with computed tomography coronary angiography (CTCA)-derived fractional flow reserve (FFR) in patients with atrial fibrillation (AF) requiring ablation. The study population consisted of 151 patients who underwent CTCA before AF ablation (AF group), and a control group of 151 patients from the outpatient clinic who underwent CTCA without any history of AF (non-AF group), matched for age, sex, BMI, and angina symptomatology. All study patients underwent CTCA with subdivision of coronary lesion type into severe (≥ 70% luminal narrowing), moderate (50% ≤ luminal narrowing < 70%), and mild stenosis (< 50% luminal narrowing). In patients with ≥ 1 moderate or severe stenosis, non-invasive FFR was calculated from CTCA (FFRCT). Baseline characteristics and CAD risk factors were similar between the 2 groups. During CTCA, 38% of the patients in the AF group were in ongoing atrial arrhythmia (either AF or regular atrial tachycardia). The number of patients with severe (10 (6.6%) vs 10 (6.6%), P = 1.00), moderate (14 (9.5%) vs 10 (6.7%), P = 0.4), and mild stenosis (43 (28.5%) vs 56 (37.1%), P = 0.11) was not significantly different between the 2 groups. Performance of FFRCT was feasible in 32/44 patients (73%), and failed in 27% of the patients (7 and 5 patients in the AF and non-AF group, respectively, P = 0.74). No difference was observed in the prevalence of hemodynamically significant stenosis (FFRCT ≤ 0.80) (15 (9.9%) vs 12 (7.9%), P = 0.85). Our study showed technical feasibility of CTCA in all patients of both groups, including the patients with AF as presenting rhythm. The FFRCT add-on analysis failed equally frequent in patients of the AF versus non-AF group. An equal rate of CAD was observed in the AF group and non-AF group, favoring the concept of shared associated risk factors for CAD and AF.

Diagnostic performance of exercise stress tests for detection of epicardial and microvascular coronary artery disease: the UZ Clear study.

BACKGROUND: Cardiac stress tests remain the cornerstone for evaluating patients suspected of having obstructive coronary artery disease (CAD). Coronary microvascular dysfunction (CMD) can lead to abnormal non-invasive tests. AIMS: We sought to assess the diagnostic performance of exercise stress tests with indexes of epicardial and microvascular resistance as reference. METHODS: This was a prospective, single-arm, multicentre study of patients with an intermediate pretest probability of CAD and positive exercise stress tests who were referred for invasive angiography. Patients underwent an invasive diagnostic procedure (IDP) with measurement of fractional flow reserve (FFR) and index of microvascular resistance (IMR) in at least one coronary vessel. Obstructive CAD was defined as diameter stenosis (DS) >50% by quantitative coronary angiography (QCA). The objective was to determine the false discovery rate (FDR) of cardiac exercise stress tests with both FFR and IMR as references. RESULTS: One hundred and seven patients (137 vessels) were studied. The mean age was 62.1±8.7, and 27.1% were female. The mean diameter stenosis was 37.2±27.5%, FFR was 0.84±0.10, coronary flow reserve was 2.74±2.07, and IMR 20.3±11.9. Obstructive CAD was present in 39.3%, whereas CMD was detected in 20.6%. The FDR was 60.7% and 62.6% with QCA and FFR as references (p-value=0.803). The combination of FFR and IMR as clinical reference reduced the FDR by 25% compared to QCA (45.8% vs 60.7%; p-value=0.006). CONCLUSIONS: In patients with evidence of ischaemia, an invasive functional assessment accounting for the epicardial and microvascular compartments led to an improvement in the diagnostic performance of exercise tests, driven by a significant FDR reduction.

Impact of coronary bifurcation angle on computed tomography derived fractional flow reserve in coronary vessels with no apparent coronary artery disease.

OBJECTIVES: Computed tomography (CT) derived fractional flow reserve (FFRCT) decreases from the proximal to the distal part due to a variety of factors. The energy loss due to the bifurcation angle may potentially contribute to a progressive decline in FFRCT. However, the association of the bifurcation angle with FFRCT is still not entirely understood. This study aimed to investigate the impact of various bifurcation angles on FFRCT decline below the clinically crucial relevance of 0.80 in vessels with no apparent coronary artery disease (CAD). METHODS: A total of 83 patients who underwent both CT angiography including FFRCT and invasive coronary angiography, exhibiting no apparent CAD were evaluated. ΔFFRCT was defined as the change in FFRCT from the proximal to the distal in the left anterior descending artery (LAD) and left circumflex artery (LCX). The bifurcation angle was calculated from three-dimensional volume rendered images. Vessel morphology and plaque characteristics were also assessed. RESULTS: ΔFFRCT significantly correlated with the bifurcation angle (LAD angle, r = 0.35, p = 0.001; LCX angle, r = 0.26, p = 0.02) and vessel length (LAD angle, r = 0.30, p = 0.005; LCX angle, r = 0.49, p < 0.0001). In LAD, vessel length was the strongest predictor for distal FFRCT of ≤ 0.80 (ß-coefficient = 0.55, p = 0.0003), immediately followed by the bifurcation angle (ß-coefficient = 0.24, p = 0.02). The bifurcation angle was a good predictor for a distal FFRCT ≤ 0.80 (LAD angle, cut-off 31.0°, AUC 0.70, sensitivity 74%, specificity 68%; LCX angle, cut-off 52.6°, AUC 0.86, sensitivity 88%, specificity 85%). CONCLUSIONS: In vessels with no apparent CAD, vessel length was the most influential factor on FFRCT, directly followed by the bifurcation angle. KEY POINTS: • Both LAD and LCX bifurcation angles are factors influencing FFR CT. • Bifurcation angle is one of the predictors of a distal FFRCT of ≤ 0.80 and an optimal cut-off value of 31.0° for the LAD and 52.6° for the LCX. • Bifurcation angle should be taken into consideration when interpreting numerical values of FFRCT.

Effects of left ventricular mass on computed tomography derived fractional flow reserve in significant obstructive coronary artery disease.

BACKGROUND: In significant obstructive coronary artery disease (SOCAD), a mismatch in assessment of severity of coronary artery stenosis may occur between invasive coronary angiography (ICA) and computed tomography (CT) derived fractional flow reserve (FFRCT). The present study aimed to identify the factors giving an FFRCT > 0.80 and leading to an underestimation of coronary artery severity in SOCAD vessels. METHODS: A total of 141 consecutive patients who underwent both CT angiography including FFRCT and ICA, the latter showing >75% coronary artery stenosis were evaluated. Vessels were divided into two groups according to FFRCT at the distal aspect of the vessel: FFRCT > 0.80 (n = 12) and FFRCT ≤ 0.80 (n = 153). Vessel morphology, plaque characteristics, left-ventricular (LV) wall thickness at each site of the myocardium, and LV mass were also assessed. RESULTS: LV myocardium-related parameters including LV wall thickness (base, middle, apex, average, and maximal), LV mass, and LV mass index were higher in FFRCT > 0.80, whereas vessel-related parameters including, vessel morphology and plaque characteristics were not significantly different between >0.80 and < 0.80. Vessel morphology and plaque characteristics had no effect on FFRCT, whereas maximum LV wall thickness, LV mass, and LV mass index influenced FFRCT. LV mass index was the strongest predictor of distal FFRCT > 0.80 with an area under the curve of 0.81, and an optimal cut-off value of 66.5 g/m2 (sensitivity 77.8%, specificity 89.6%). CONCLUSIONS: The presence of a high LV mass is a major cause for underestimation of coronary artery severity on FFRCT in SOCAD vessels. LV myocardium-related parameters should be considered when interpreting numerical values of FFRCT.

Long term effects of surgical and transcatheter aortic valve replacement on FFRCT in patients with severe aortic valve stenosis.

The long-term variations of fractional flow reserve derived from coronary computed tomography (FFRCT) after surgical (SAVR) or transcatheter (TAVR) aortic valve replacement in patients with severe aortic valve stenosis (AS) have not been investigated. A total of 25 patients with isolated, severe AS underwent coronary computed tomography with 3-vessel FFRCT analysis (Heartflow Inc.-Redwood City, California, USA) and measurement of total coronary volume (V), left ventricular mass (M) and their ratio (V/M) before and 6 months after SAVR or TAVR. A significant increase in V/M due to a decrease in left ventricular mass 6 months after intervention was observed, whereas total coronary volume did not change (coronary volume pre: 2924.5 ± 867.9 mm3, coronary volume post: 2844.2 ± 792.8 mm3, P = 0.158; LV mass pre: 151.7 ± 40.7 g, LV mass post: 127.3 ± 34.7 g, P < 0.001; V/M pre: 19.5 ± 4.1 mm3/g, V/M post: 22.7 ± 4.28 mm3/g, P = 0.002). FFRCT (expressed as area under the virtual pullback curve) remained constant. This proof-of-concept study showed that FFRCT was not subject to the confounding effect of left ventricular mass regression after SAVR or TAVR. Despite significant left ventricular remodeling at 6 months after AS treatment, FFRCT values remained constant. Further studies are needed comparing the performance of the different invasive and non-invasive coronary physiological indices in this patient cohort.

Impact of vascular morphology and plaque characteristics on computed tomography derived fractional flow reserve in early stage coronary artery disease.

BACKGROUND: Computed-tomography (CT) derived fractional-flow-reserve (FFRCT) gradually may decrease from proximal to distal vessels even without apparent coronary artery disease (CAD). It may be unclear whether the decrease in FFRCT at the distal coronal artery is physiological or due to stenosis. We decided to study predictive factors of an FFRCT decline below the pathological value of 0.80 in no-apparent CAD. METHODS: A total of 150 consecutive patients who had both CT angiography coupled to FFRCT analysis and invasive angiogram showing < 20% coronary stenosis were included. Vessels were divided into two groups according to FFRCT at the distal vessel: FFRCT > 0.80 (n = 317) and FFRCT ≤ 0.80 (n = 114). ΔFFRCT was defined as the change in FFRCT from proximal to distal vessel. Vessel morphology (vessel length and lumen volume) and plaque characteristics [low-attenuation plaque volume, intermediate-attenuation (IAP) plaque volume, and calcified plaque volume] were evaluated. RESULTS: FFRCT decreased from proximal to distal for the three major vessels in both FFRCT > 0.80 and FFRCT ≤ 0.80. Compared to FFRCT > 0.80, IAP volume was significantly higher in all three major vessels in FFRCT ≤ 0.80. ΔFFRCT was correlated with vessel length and lumen volume in FFRCT > 0.80, whereas ΔFFRCT was correlated with IAP volume in FFRCT ≤ 0.80. IAP volume above 44.8 mm3 was the strongest predictor of distal FFRCT of ≤ 0.80. CONCLUSIONS: The presence of IAP is a major predictor of gradual decrease of FFRCT below 0.80 in no-apparent CAD vessels. Vessel morphology and plaque characteristics should be considered when interpreting FFRCT.

Guiding Myocardial Revascularization by Algorithmic Interpretation of FFR Pullback Curves: A Proof of Concept Study.

Background: Coronary artery disease distribution along the vessel is a main determinant of FFR improvement after PCI. Identifying focal from diffuse disease from visual inspections of coronary angiogram (CA) and FFR pullback (FFR-PB) are operator-dependent. Computer science may standardize interpretations of such curves. Methods: A virtual stenting algorithm (VSA) was developed to perform an automated FFR-PB curve analysis. A survey analysis of the evaluations of 39 vessels with intermediate disease on CA and a distal FFR <0.8, rated by 5 interventional cardiologists, was performed. Vessel disease distribution and PCI strategy were successively rated based on CA and distal FFR (CA); CA and FFR-PB curve (CA/FFR-PB); and CA and VSA (CA/VSA). Inter-rater reliability was assessed using Fleiss kappa and an agreement analysis of CA/VSA rating with both algorithmic and human evaluation (operator) was performed. We hypothesize that VSA would increase rater agreement in interpretation of epicardial disease distribution and subsequent evaluation of PCI eligibility. Results: Inter-rater reliability in vessel disease assessment by CA, CA/FFR-PB, and CA/VSA were respectively, 0.32 (95% CI: 0.17-0.47), 0.38 (95% CI: 0.23-0.53), and 0.4 (95% CI: 0.25-0.55). The raters' overall agreement in vessel disease distribution and PCI eligibility was higher with the VSA than with the operator (respectively, 67 vs. 42%, and 80 vs. 70%, both p < 0.05). Compared to CA/FFR-PB, CA/VSA induced more reclassification toward a focal disease (92 vs. 56.2%, p < 0.01) with a trend toward more reclassification as eligible for PCI (70.6 vs. 33%, p = 0.06). Change in PCI strategy did not differ between CA/FFR-PB and CA/VSA (23.6 vs. 28.5%, p = 0.38). Conclusions: VSA is a new program to facilitate and standardize the FFR pullback curves analysis. When expert reviewers integrate VSA data, their assessments are less variable which might help to standardize PCI eligibility and strategy evaluations. Clinical Trial Registration: https://www.clinicaltrials.gov/ct2/show/NCT03824600.

Adherence to quality indicators for ST-elevation myocardial infarction and its relation to mortality: a hospital network analysis from the Belgian STEMI database.

AIMS: To assess the adherence to established quality indicators (QIs) for ST-elevation myocardial infarction (STEMI) at the hospital-network level and its relation to outcome. METHODS AND RESULTS: The data of 7774 STEMI patients admitted to 32 STEMI networks during the period 2014-18 were extracted from the Belgian STEMI database. Five QIs [primary percutaneous coronary intervention use, diagnosis-to-balloon time (DiaTB) <90 min, door-to-balloon time (DoTB) <60 min, P2Y12 inhibitor and statin prescription at discharge, and a composite QI score ranging from 0 to 10] were correlated with in-hospital mortality adjusted for differences in baseline risk profile (TIMI risk score). The median composite QI score was 6.5 [interquartile range (IQR) 6-8]. The most important gaps in quality adherence were related to time delays: the recommended DiaTB and DoTB times across the different networks were achieved in 68% (IQR 53-71) and 67% (IQR 50-78), respectively. Quality adherence was better in networks taking care of more high-risk STEMI patients. The median in-hospital mortality among the STEMI networks was 6.4% (IQR 4.1-7.9%). There was a significant independent inverse correlation between the composite QI score and in-hospital mortality (partial correlation coefficient: -0.45, P = 0.013). Stepwise regression analysis revealed that among the individual QIs, prolonged DiaTB was the most important independent outcome predictor. CONCLUSION: Among established STEMI networks, the time delay between diagnosis and treatment was the most variable and the most relevant prognostic QI, underscoring the importance of assessing quality of care throughout the whole network.

Impact of COVID-19-related public containment measures on the ST elevation myocardial infarction epidemic in Belgium: a nationwide, serial, cross-sectional study.

AIMS: The current study assessed the impact of COVID-19-related public containment measures (i.e. lockdown) on the ST elevation myocardial infarction (STEMI) epidemic in Belgium. METHODS AND RESULTS: Clinical characteristics, reperfusion therapy modalities, COVID-19 status and in-hospital mortality of consecutive STEMI patients who were admitted to Belgian hospitals for percutaneous coronary intervention (PCI) were recorded during a three-week period starting at the beginning of the lockdown period on 13 March 2020. Similar data were collected for the same time period for 2017-2019. An evaluation of air quality revealed a 32% decrease in ambient NO2 concentrations during lockdown (19.5 µg/m³ versus 13.2 µg/m³, p < .001). During the three-week period, there were 188 STEMI patients admitted for PCI during the lockdown versus an average 254 STEMI patients before the lockdown period (incidence rate ratio = 0.74, p = .001). Reperfusion strategy was predominantly primary PCI in both time periods (96% versus 95%). However, there was a significant delay in treatment during the lockdown period, with more late presentations (>12 h after onset of pain) (14% versus 7.6%, p = .04) and with longer door-to-balloon times (median of 45 versus 39 min, p = .02). Although the in-hospital mortality between the two periods was comparable (5.9% versus 6.7%), 5 of the 7 (71%) COVID-19-positive STEMI patients died. CONCLUSION: The present study revealed a 26% reduction in STEMI admissions and a delay in treatment of STEMI patients. Less exposure to external STEMI triggers (such as ambient air pollution) and/or reluctance to seek medical care are possible explanations of this observation.

Evaluation of epicardial coronary resistance using computed tomography angiography: A Proof Concept.

AIMS: Fractional flow reserve (FFR) pullback allows to assess the distribution of pressure loss along the coronary vessels. FFR derived from CT (FFRCT) provides a virtual pullback curve that may also aid in the assessment of the distribution of epicardial coronary resistance in the non-invasive setting. The present study aims to determine the accuracy of the virtual FFRCT pullback curve using a motorized invasive FFR pullback as reference in patients with stable coronary artery disease. METHODS AND RESULTS: FFR values were extracted from coronary vessels at approximately 1 mm to generate pullback curves. Invasive motorized FFR pullbacks were acquired using a dedicated device at a speed of 1 mm/s. A total of 3172 matched FFRCT and FFR values were obtained in 24 vessels. The correlation coefficient between FFRCT and FFR was 0.76 (95%CI 0.75 to 0.78; p < 0.001). The area under the pullback curve was similar between FFRCT and invasive FFR (79.0 ±â€¯16.1 vs. 85.3 ±â€¯16.4, p = 0.097). The mean difference in lesion gradient between FFRCT and FFR was -0.07 (LOA -0.26 to 0.13) whereas in non-obstructive segments was -0.01 (LOA -0.06 to 0.05). CONCLUSION: The evaluation of epicardial coronary resistance using coronary CT angiography with FFRCT was feasible. FFRCT virtual pullback appears to be accurate for the evaluation of pressure gradients. FFRCT has the potential to identify the pathophysiological pattern of coronary artery disease in the non-invasive setting.

Measurement of Hyperemic Pullback Pressure Gradients to Characterize Patterns of Coronary Atherosclerosis.

BACKGROUND: Diffuse atherosclerosis is commonly observed in angiographically normal segments in patients with stable coronary artery disease (CAD). The distribution of epicardial resistance along the vessel can be evaluated using coronary physiology. OBJECTIVES: The purpose of this study was to characterize the pathophysiological patterns of CAD using invasive pressure pullbacks during continuous hyperemia. METHODS: In this prospective, multicenter study of patients undergoing clinically-indicated coronary angiography due to stable angina, a pressure-wire pullback device was set at a speed of 1 mm/s. Based on coronary angiography and on the fractional flow reserve (FFR) pullback curve, the patterns of CAD were adjudicated as focal, diffuse, or a combination of both. The distribution of epicardial resistance was characterized using the hyperemic pullback pressure gradients (PPGs). The PPG index, a continuous metric based on the magnitude of pressure drop over 20 mm and on the extent of functional disease was computed to determine the pattern of CAD. Low PPG index indicates diffuse CAD. RESULTS: A total of 158 vessels (n = 117) were included. Overall, 984,813 FFR values were used to generate 100 FFR pullback curves. Using coronary physiology, 36% of the vessel disease patterns were reclassified compared to angiography. The median of maximal PPG over 20 mm was 0.083 (interquartile range: 0.063 to 0.118) FFR units, and the mean extent of functional disease was 39.3 ± 21.3 mm. The mean PPG index was 0.58 ± 0.18 and differentiated pathophysiological focal and diffuse disease (p < 0.001). CONCLUSIONS: Pathophysiological patterns of CAD can be characterized by motorized hyperemic PPGs. The evaluation of the FFR pullback curve reclassified one-third of the vessels' disease patterns compared with conventional angiography. The PPG index is a novel metric that quantifies the distribution of epicardial resistance and discriminates focal from diffuse CAD. (Physiological Patterns of Coronary Artery Disease; NCT03824600).