Iatrogenic catheter-induced ostial coronary artery dissections: Prevalence, management, and mortality from a cohort of 55,968 patients over 10 years.

OBJECTIVE: We sought to describe the prevalence, management strategies and evaluate the prognosis of patients with iatrogenic catheter-induced ostial coronary artery dissection (ICOCAD). BACKGROUND: ICOCAD is a rare but potentially devastating complication of cardiac catheterisation. The clinical manifestations of ICOCAD vary from asymptomatic angiographic findings to abrupt vessel closure leading to myocardial infarction and death. METHODS: 55,968 patients who underwent coronary angiography over a 10-year period were screened for ICOCAD as defined by the National Heart, Lung, and Blood Institute. The management and all-cause mortality were retrieved from local and national databases. RESULTS: The overall prevalence of ICOCAD was 0.09% (51/55,968 patients). Guide catheters accounted for 75% (n = 37) of cases. Half of the ICOCAD cases involved the right coronary artery while the remaining were related to left main stem (23/51; 45%) and left internal mammary artery (2/51; 4%). Two-thirds of ICOCAD were high grade (type D, E, and F). The majority of cases were type F dissections (n = 18; 66%), of which two third occurred in females in their 60s. The majority of ICOCAD patients (42/51; 82%) were treated with percutaneous coronary intervention while the remaining underwent coronary artery bypass grafting (3/51; 6%) or managed conservatively (6/51; 12%). Three deaths occurred during the index admission while 48/51 patients (94.1%) were safely discharged without further mortality over a median follow-up of 3.6 years. CONCLUSIONS: ICOCAD is a rare but life-threatening complication of coronary angiography. Timely recognition and prompt bailout PCI is a safe option for majority of patients with good clinical outcomes.

International External Validation Study of the 2014 European Society of Cardiology Guidelines on Sudden Cardiac Death Prevention in Hypertrophic Cardiomyopathy (EVIDENCE-HCM).

BACKGROUND: Identification of people with hypertrophic cardiomyopathy (HCM) who are at risk of sudden cardiac death (SCD) and require a prophylactic implantable cardioverter defibrillator is challenging. In 2014, the European Society of Cardiology proposed a new risk stratification method based on a risk prediction model (HCM Risk-SCD) that estimates the 5-year risk of SCD. The aim was to externally validate the 2014 European Society of Cardiology recommendations in a geographically diverse cohort of patients recruited from the United States, Europe, the Middle East, and Asia. METHODS: This was an observational, retrospective, longitudinal cohort study. RESULTS: The cohort consisted of 3703 patients. Seventy three (2%) patients reached the SCD end point within 5 years of follow-up (5-year incidence, 2.4% [95% confidence interval {CI}, 1.9-3.0]). The validation study revealed a calibration slope of 1.02 (95% CI, 0.93-1.12), C-index of 0.70 (95% CI, 0.68-0.72), and D-statistic of 1.17 (95% CI, 1.05-1.29). In a complete case analysis (n= 2147; 44 SCD end points at 5 years), patients with a predicted 5-year risk of <4% (n=1524; 71%) had an observed 5-year SCD incidence of 1.4% (95% CI, 0.8-2.2); patients with a predicted risk of ≥6% (n=297; 14%) had an observed SCD incidence of 8.9% (95% CI, 5.96-13.1) at 5 years. For every 13 (297/23) implantable cardioverter defibrillator implantations in patients with an estimated 5-year SCD risk ≥6%, 1 patient can potentially be saved from SCD. CONCLUSIONS: This study confirms that the HCM Risk-SCD model provides accurate prognostic information that can be used to target implantable cardioverter defibrillator therapy in patients at the highest risk of SCD.

Routine use of fluoroscopic guidance and up-front femoral angiography results in reduced femoral complications in patients undergoing coronary angiographic procedures: an observational study using an Interrupted Time-Series analysis.

Transradial access is increasingly used for coronary angiography and percutaneous coronary intervention, however, femoral access remains necessary for numerous procedures, including complex high-risk interventions, structural procedures, and procedures involving mechanical circulatory support. Optimising the safety of this approach is crucial to minimize costly and potentially life-threatening complications. We initiated a quality improvement project recommending routine fluoroscopic guidance (femoral head), and upfront femoral angiography should be performed to assess for location and immediate complications. We assessed the effect of these measures on the rate of vascular complications. Data were collected prospectively on 4534 consecutive patients undergoing femoral coronary angiographic procedures from 2015 to 2017. The primary end-point was any access complication. Outcomes were compared pre and post introduction including the use of an Interrupted Time-Series (ITS) analysis. 1890 patients underwent angiography prior to the introduction of routine fluoroscopy and upfront femoral angiography and 2644 post. All operators adopted these approaches. Baseline characteristics, including large sheath use, anticoagulant use and PCI rates were similar between the 2 groups. Fluoroscopy-enabled punctures were made in the 'safe zone' in over 91% of cases and upfront femoral angiography resulted in management changes i.e. procedural abandonment prior to heparin administration in 21 patients (1.1%). ITS analysis demonstrated evidence of a reduction in femoral complication rates after the introduction of the intervention, which was over and above the existing trend before the introduction (40% decrease RR 0.58; 95% CI: 0.25-0.87; P < 0.01). Overall these quality improvement measures were associated with a significantly lower incidence of access site complications (0.9% vs. 2.0%, P < 0.001). Routine fluoroscopy guided vascular access and upfront femoral angiography prior to anticoagulation leads to lower vascular complication rates. Thus, study shows that femoral intervention can be performed safely with very low access-related complication rates when fluoroscopic guidance and upfront angiography is used to obtain femoral arterial access.

Doppler echocardiography underestimates the prevalence and magnitude of mid-cavity obstruction in patients with symptomatic hypertrophic cardiomyopathy.

OBJECTIVES: To evaluate utility of Doppler echocardiography in the assessment of left ventricular (LV) mid-cavity obstructive (LVMCO) hypertrophic cardiomyopathy (HCM). BACKGROUND: LVMCO is a relatively under-diagnosed complication of HCM and may occur alone or in combination with LV outflow tract obstruction (LVOTO). Identifying and quantifying LVMCO and differentiating it from LVOTO has important implications for patient management. We aimed to assess diagnostic performance of Doppler echocardiography in the assessment of suspected LV obstruction. METHODS: Forty symptomatic HCM patients with suspected obstruction underwent cardiac catheterization, and comparison of location and magnitude of Doppler derived gradients with synchronous invasive measurements (reference standard), at rest and isoprenaline stress (IS). RESULTS: Doppler's diagnostic accuracy for any obstruction (≥30 mmHg) in this cohort was 75% with false positive and false negative rates of 2.5 and 22.5%, respectively. During subanalysis, Doppler's diagnostic accuracy for isolated LVOTO in this selected cohort is 83% with false positive and false negative rates of 4 and 12.5%, respectively. For LVMCO, the accuracy is only 50%, with false positive and false negative rates of 10 and 40%, respectively. Doppler gradients for isolated LVOTO were similar to invasive: 85 ± 51 and 87 ± 35 mmHg, respectively (P = 0.77). Doppler gradients in LVMCO were consistently lower than invasive: 45 ± 38 and 81 ± 31 mmHg, respectively (P = 0.0002). Mid-systolic flow cessation and/or contamination of spectral signals were identified as causes of Doppler-derived inaccuracies. CONCLUSIONS: Doppler echocardiography under-diagnoses and underestimates severity of LVMCO in symptomatic HCM patients. Recognition of abrupt mid-systolic flow cessation and invasive measurements may improve detection of LVMCO in HCM.

A novel clinical risk prediction model for sudden cardiac death in hypertrophic cardiomyopathy (HCM risk-SCD).

AIMS: Hypertrophic cardiomyopathy (HCM) is a leading cause of sudden cardiac death (SCD) in young adults. Current risk algorithms provide only a crude estimate of risk and fail to account for the different effect size of individual risk factors. The aim of this study was to develop and validate a new SCD risk prediction model that provides individualized risk estimates. METHODS AND RESULTS: The prognostic model was derived from a retrospective, multi-centre longitudinal cohort study. The model was developed from the entire data set using the Cox proportional hazards model and internally validated using bootstrapping. The cohort consisted of 3675 consecutive patients from six centres. During a follow-up period of 24 313 patient-years (median 5.7 years), 198 patients (5%) died suddenly or had an appropriate implantable cardioverter defibrillator (ICD) shock. Of eight pre-specified predictors, age, maximal left ventricular wall thickness, left atrial diameter, left ventricular outflow tract gradient, family history of SCD, non-sustained ventricular tachycardia, and unexplained syncope were associated with SCD/appropriate ICD shock at the 15% significance level. These predictors were included in the final model to estimate individual probabilities of SCD at 5 years. The calibration slope was 0.91 (95% CI: 0.74, 1.08), C-index was 0.70 (95% CI: 0.68, 0.72), and D-statistic was 1.07 (95% CI: 0.81, 1.32). For every 16 ICDs implanted in patients with ≥4% 5-year SCD risk, potentially 1 patient will be saved from SCD at 5 years. A second model with the data set split into independent development and validation cohorts had very similar estimates of coefficients and performance when externally validated. CONCLUSION: This is the first validated SCD risk prediction model for patients with HCM and provides accurate individualized estimates for the probability of SCD using readily collected clinical parameters.

Relation between serum N-terminal pro-brain natriuretic peptide and prognosis in patients with hypertrophic cardiomyopathy.

AIMS: To determine the relation between serum concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and prognosis in patients with hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: In total, 847 patients (53 ± 15 years; 67% male) with HCM (28% with left ventricular outflow tract obstruction ≥ 30 mmHg at rest) were followed for 3.5 years (IQR 2.5-4.5 years). The median NT-proBNP concentration was 78 pmol/L (range < 5-1817 pmol/L and IQR 31-183 pmol/L). Sixty-eight patients (8%) reached the primary endpoint of all-cause mortality or cardiac transplantation. NT-proBNP concentration predicted long-term survival from the primary endpoint [area under the receiver operating characteristic curve of 0.78 (95% confidence interval 0.73-0.84)]. A serum concentration of ≥ 135 pmol/L was associated with an annual event rate of 6.1% (95% CI 4.4-7.7). Three independent predictors of primary outcome were identified in a multivariable Cox model: New York Heart Association class III/IV (HR 2.10, 95% CI 1.21-3.65, P = 0.008), ejection fraction (HR 0.98, 95% CI 0.96-1.00, P = 0.035), log NT-proBNP (HR 2.04, 95% CI 1.56-2.66, P < 0.001). Log NT-proBNP was a significant predictor of heart failure (HF) and transplant-related deaths (n = 23; HR 3.03, 95% CI 1.99-4.60, P < 0.001) but not sudden death or appropriate implantable cardioverter defibrillator shock (n = 11; HR 1.54, 95% CI 0.91-2.60, P = 0.111). In patients with ejection fraction ≥ 50% (n = 673), log NT-proBNP remained an independent predictor of the primary outcome (HR 2.11, 95% CI 1.54-2.90, P < 0.001). CONCLUSION: In patients with HCM, elevated NT-proBNP concentration is a strong predictor of overall prognosis, particularly HF-related death and transplantation.

Prevalence of Pathogenic Variants in Cardiomyopathy-Associated Genes in Acute Myocarditis: A Systematic Review and Meta-Analysis.

BACKGROUND: Acute myocarditis is an inflammatory condition that may precede the development of dilated or arrhythmogenic cardiomyopathy. OBJECTIVES: The aim of this study was to investigate the reported prevalence of pathogenic or likely pathogenic (P/LP) variants in cardiomyopathy-associated genes in patients with acute myocarditis. METHODS: For this systematic review and meta-analysis, the PubMed and Embase databases were searched on March 4, 2023. Observational studies evaluating the prevalence of P/LP variants in cardiomyopathy-associated genes in patients with acute myocarditis were included. Studies were stratified into adult and pediatric age groups and for the following scenarios: 1) complicated myocarditis (ie, presenting with acute heart failure, reduced left ventricular ejection fraction, or life-threatening ventricular arrhythmias); and 2) uncomplicated myocarditis. The study was registered with the International Prospective Register of Systematic Reviews (CRD42023408668) and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Of 732 studies identified, 8 met the inclusion criteria, providing data for 586 patients with acute myocarditis. A total of 89 P/LP variants in cardiomyopathy-associated genes were reported in 85 patients. For uncomplicated myocarditis, the pooled prevalence was 4.2% (95% CI: 1.8%-7.4%; I2 = 1.4%), whereas for complicated myocarditis, the pooled prevalence was 21.9% (95% CI: 14.3%-30.5%; I2 = 38.8%) and 44.5% (95% CI: 22.7%-67.4%; I2 = 52.8%) in adults and children, respectively. P/LP variants in desmosomal genes were predominant in uncomplicated myocarditis (64%), whereas sarcomeric gene variants were more prevalent in complicated myocarditis (58% in adults and 71% in children). CONCLUSIONS: Genetic variants are present in a large proportion of patients with acute myocarditis. The prevalence of genetic variants and the genes involved vary according to age and clinical presentation.

An observational study assessing the use of Sirolimus-eluting balloons for side-branch treatment in the provisional stenting of coronary bifurcations.

Background: Drug eluting balloons (DEB) are a feasible method of rapid delivery of drug to a coronary vessel wall. Their efficacy has been established for the treatment of in-stent restenosis and small vessel disease but there is limited data for their use in bifurcation lesions. Objective: The aim of this study was to assess the effectiveness of provisional upfront side-branch DEB use in bifurcation lesions compared to a simple balloon (POBA) or upfront 2 stent bifurcation strategy. Methods: We conducted an observational study of 625 patients undergoing PCI to bifurcation lesions. All the patients had a DES deployed in the main vessel (MV). Decision on revascularization option for the side branch (SB) was made by the operator. The primary endpoint was target vessel failure. Secondary endpoints were target vessel myocardial infarction and all-cause mortality. Results: 311 patients had upfront DEB to the SB whilst the remaining were treated with either DES (188) or POBA (126). Baseline characteristics were similar aside from history of previous MI, which were higher in patients treated with DES or POBA, p = 0.009 whereas patients with previous CABG were likely to undergo DEB treatment (p = 0.004). TVF was more likely to occur in the POBA group (7.5 %) compared to the DEB (3.3 %) and DES (3.3 %) groups (p = 0.0019). There was no significant difference in TV-MI (p = 0.62) or death (p = 0.98) between the groups. Conclusion: This study suggests that provisional bifurcation stenting with upfront Sirolimus DEB use in the SB is an effective treatment for non-LMS bifurcation PCI.

A cost-effectiveness analysis of hypertrophic cardiomyopathy sudden cardiac death risk algorithms for implantable cardioverter defibrillator decision-making.

AIMS: To conduct a contemporary cost-effectiveness analysis examining the use of implantable cardioverter defibrillators (ICD) for primary prevention in patients with hypertrophic cardiomyopathy (HCM). METHODS: A discrete-time Markov model was used to determine the cost-effectiveness of different ICD decision-making rules for implantation. Several scenarios were investigated including the reference scenario of implantation rates according to observed real world practice. A 12-year time horizon with an annual cycle length was used. Transition probabilities used in the model were obtained using Bayesian analysis. The study has been reported according to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. RESULTS: Using a 5-year SCD risk threshold of 6% was cheaper than current practice and has marginally better total quality adjusted life years (QALYs). This is the most cost-effective of the options considered, with an incremental cost effectiveness ratio of £834 per QALY. Sensitivity analyses highlighted that this decision is largely driven by what health related quality of life (HRQL) is attributed to ICD patients and time horizon. CONCLUSION: We present a timely new perspective on HCM ICD cost-effectiveness, using methods reflecting real-world practice. While we have shown that a 6% 5-year SCD risk cut-off provides the best cohort stratification to aid ICD decision-making, this will also be influenced by the particular values of costs and HRQL for subgroups or at a local level. The process of explicitly demonstrating the main factors which drive conclusions from such an analysis will help to inform shared decision-making in this complex area for all stakeholders concerned.

Pericardial Fluid Analysis in Diagnosis and Prognosis of Patients Who Underwent Pericardiocentesis.

In this study, we aimed to examine the diagnostic yield of pericardial fluid biochemistry and cytology and their prognostic significance in patients with percutaneously drained pericardial effusions, with and without malignancy. This is a single-center, retrospective study of patients who underwent pericardiocentesis between 2010 and 2020. Data were extracted from electronic patient records, including procedural information, underlying diagnosis, and laboratory results. Patients were grouped into those with and without underlying malignancy. A Cox proportional hazards model was used to analyze the association of variables with mortality. The study included 179 patients; 50% had an underlying malignancy. There were no significant differences in pericardial fluid protein and lactate dehydrogenase between the 2 groups. Diagnostic yield from pericardial fluid analysis was greater in the malignant group (32% vs 11%, p = 0.002); 72% of newly diagnosed malignancies had positive fluid cytology. The 1-year survival was 86% and 33% in nonmalignant and malignant groups, respectively (p <0.001). Of 17 patients who died within the nonmalignant group, idiopathic effusions were the largest group (n = 6). In malignancy, lower pericardial fluid protein and higher serum C-reactive protein were associated with increased risk of mortality. In conclusion, pericardial fluid biochemistry has limited value in determining the etiology of pericardial effusions; fluid cytology is the most important diagnostic test. Mortality in malignant pericardial effusions may be associated with lower pericardial fluid protein levels and a higher serum C-reactive protein. Nonmalignant pericardial effusions do not have a benign prognosis and close follow-up is required.

The relation of ventricular arrhythmia electrophysiological characteristics to cardiac phenotype and circadian patterns in hypertrophic cardiomyopathy.

BACKGROUND: The triggers of ventricular arrhythmias (VAs) leading to sudden cardiac death in hypertrophic cardiomyopathy (HCM) are ill defined. We sought to examine the electrophysiological characteristics of VAs in HCM and study their relation to cardiac phenotype and circadian patterns using stored intracardiac electrocardiograms from implantable cardioverter defibrillators (ICDs). METHODS AND RESULTS: A single centre, observational cohort study of 230 consecutively evaluated ICD recipients with HCM [median age 42 years, 97% primary prevention, 51% with anti-tachycardia pacing (ATP)]. Fifty-six non-clustered VAs (39 initially treated with ATP and 17 with shocks) from 29 patients were analysed. Monomorphic ventricular tachycardia was the culprit arrhythmia in 86% of cases, ventricular fibrillation/flutter in 9%, and polymorphic ventricular tachycardia in 5%. Prior to the onset of VA the rhythm was sinus in 67%, atrial fibrillation/flutter in 19%, and 15% were paced ventricularly; tachycardia (cycle length <600 ms) was present in 25%. Ventricular arrhythmias were triggered by premature ventricular complexes (PVCs) in 72%, which were late-coupled (84%). Short-long-short initiation was seen in 2% and 26% of VAs were sudden-onset without preceding PVCs. Ventricular arrhythmia peaked at midday (with 20% occurring between 2300 and 0700), on Sundays and in May. The cardiac phenotype and time of the day did not predict the mode of initiation. Age at ICD implantation was the only independent predictor of VA cycle length (linear regression coefficient 0.67, 95% CI 0.02-1.32, P= 0.04). Anti-tachycardia pacing terminated 67% of VAs, but patients with ATP therapy had a similar incidence of appropriate shocks (log-rank test P= 0.25) and syncope (log rank P= 0.23) to patients with shock as initial therapy. CONCLUSIONS: Most VAs are monomorphic ventricular tachycardias triggered by late-coupled PVCs. They are frequently terminated by ATP, but ATP does not reduce the frequency of ICD shocks. Younger HCM patients have more rapid VAs, which may explain the peak of sudden cardiac death in early adulthood. The circadian periodicity is different from that observed in ischaemic heart disease, and is likely to relate to the distinct character of the arrhythmogenic substrate in HCM and its modulators.

An Observational Study Assessing the Predictors of Procedural Failure From the Radial Approach: Is Right Radial Access Always the Best?

OBJECTIVE: The study aimed to determine the predictors of procedural failure (coronary cannulation) in patients undergoing coronary angiography ± percutaneous coronary intervention (PCI) from the transradial (TR) approach. METHODS: We conducted an observational study of 20,315 consecutive patients undergoing TR angiography between 2016 and 2020. TR failure was described as inability to cannulate the coronary arteries. Univariate and multivariate analyses were performed to determine independent predictors of TR failure. RESULTS: Out of the study population, TR failure was observed in 365 (1.8%) patients, out of which 281 (77%) crossed over successfully to the transfemoral (TF) route and 84 (23%) to left radial access (LRA). Unsuccessful procedures were most likely seen in patients who were elderly, female, BAME background, short stature or with a history of hypertension, diabetes, and renal disease. On regression analysis, age (OR: 1.024; 95% Cl: 1.014-1.035), female gender (OR: 0.729; 95% Cl: 0.555-0.957), BAME (OR: 0.786; 95% Cl: 0.612-0.959), height (OR: 0.988; 95% Cl: 0.977-0.999), hypertension (OR: 1.510; 95% Cl: 1.147-1.987) and RRA (OR: 1.977; 95% Cl: 1.105-3.538) were independent predictors of TR failure. On further analysis, these predictors of failure were not seen from the LRA approach. CONCLUSION: This study identifies that rates of TR failure are low and that predictors of failure differ between the RRA and LRA. The difference in predictors between the 2 routes suggests that in patients when coronary cannulation is unsuccessful via the RRA then the LRA could be considered as a second access site. Further study is needed to see if in selected patient groups the LRA could be used as the first-choice access route.

Treatment Strategies and Outcomes of Emergency Left Main Percutaneous Coronary Intervention.

Emergency percutaneous coronary intervention of the left main (LM ePCI) coronary artery necessitated by acute coronary syndrome is associated with a high risk of mortality. However, optimal treatment strategies and related outcomes remain undefined in this group. We undertook a multi-center, retrospective, observational cohort study of consecutive patients requiring LM ePCI between 2011 and 2018 and reported the coronary anatomy, treatment strategies, outcomes, and predictors of mortality. A total of 116 consecutive cases were included. Patients were predominantly male (85%) with a median age of 68.0 years; 12 patients (10%) had previous coronary artery bypass grafting. ST-elevation was noted in 76 (66%); 30 (26%) presented with an out-of-hospital cardiac arrest (OOHCA) and 47 (41%) with cardiogenic shock. The most frequent pattern of disease was Medina 1,1,1, seen in 59 patients (51%). The commonest revascularization strategy was provisional stenting (95 cases, 82%) with improved or thrombolysis in myocardial infarction 3 flow seen in 85 cases (73%). All-cause mortality was 35% at 30 days, rising to 58% at 5 years. Adverse predictors of 30-day mortality included presentation with cardiogenic shock (p = 0.018) and OOHCA (p = 0.020), whereas improved flow and/or thrombolysis in myocardial infarction 3 flow in both circumflex and left anterior descending artery afforded a better prognosis (p = 0.028). In conclusion, patients who underwent LM ePCI are a high-risk subgroup and commonly present with cardiogenic shock and OOHCA. Provisional stenting appears to be the preferred option with the successful restoration of coronary flow in most cases despite complex anatomy. High 30-day mortality is driven by the presence of cardiogenic shock, OOHCA, and failure to restore or improve coronary flow.

Morphological and Physiological Characteristics of Ruptured Plaques in Native Arteries and Neoatherosclerotic Segments: An OCT-Based and Computational Fluid Dynamics Study.

Background: Intravascular imaging has been used to assess the morphology of lesions causing an acute coronary syndrome (ACS) in native vessels (NV) and identify differences between plaques that ruptured (PR) and caused an event and those that ruptured without clinical manifestations. However, there is no data about the morphological and physiological characteristics of neoatherosclerotic plaques that ruptured (PR-NA) which constitute a common cause of stent failure. Methods: We retrospectively analyzed data from patients admitted with an acute myocardial infarction that had optical coherence tomography (OCT) imaging of the culprit vessel before balloon pre-dilation. OCT pullbacks showing PR were segmented at every 0.4 mm. The extent of the formed cavity, lipid and calcific tissue, thrombus, and macrophages were measured, and the fibrous cap thickness (FCT) and the incidence of micro-channels and cholesterol crystals were reported. These data were used to reconstruct a representative model of the native and neoatherosclerotic lesion geometry that was processed with computational fluid dynamics (CFD) techniques to estimate the distribution of the endothelial shear stress and plaque structural stress. Result: Eighty patients were included in the present analysis: 56 had PR in NV (PR-NV group) and 24 in NA segments (PR-NA group). The PR-NV group had a larger minimum lumen area (2.93 ± 2.03 vs. 2.00 ± 1.26 mm2, p = 0.015) but similar lesion length and area stenosis compared to PR-NA group. The mean FCT (186 ± 65 vs. 232 ± 80 µm, p = 0.009) and the lipid index was smaller (16.7 ± 13.8 vs. 25.9 ± 14.1, p = 0.008) while the of calcific index (8.3 ± 9.5 vs. 2.2 ± 1.6%, p = 0.002) and the incidence of micro-channels (41.4 vs. 12.5%, p = 0.013) was higher in the PR-NV group. Conversely, there was no difference in the incidence of cholesterol crystals, thrombus burden or the location of the rupture site between groups. CFD analysis revealed higher maximum endothelial shear stress (19.1 vs. 11.0 Pa) and lower maximum plaque structural stress (38.8 vs. 95.1 kPa) in the PR-NA compared to the PR-NV model. Conclusion: We reported significant morphological and physiological differences between culprit ruptured plaques in native and stented segments. Further research is needed to better understand the causes of these differences and the mechanisms regulating neoatherosclerotic lesion destabilization.

Non-invasive characterization of pleural and pericardial effusions using T1 mapping by magnetic resonance imaging.

AIMS: Differentiating exudative from transudative effusions is clinically important and is currently performed via biochemical analysis of invasively obtained samples using Light's criteria. Diagnostic performance is however limited. Biochemical composition can be measured with T1 mapping using cardiovascular magnetic resonance (CMR) and hence may offer diagnostic utility for assessment of effusions. METHODS AND RESULTS: A phantom consisting of serially diluted human albumin solutions (25-200 g/L) was constructed and scanned at 1.5 T to derive the relationship between fluid T1 values and fluid albumin concentration. Native T1 values of pleural and pericardial effusions from 86 patients undergoing clinical CMR studies retrospectively analysed at four tertiary centres. Effusions were classified using Light's criteria where biochemical data was available (n = 55) or clinically in decompensated heart failure patients with presumed transudative effusions (n = 31). Fluid T1 and protein values were inversely correlated both in the phantom (r = -0.992) and clinical samples (r = -0.663, P < 0.0001). T1 values were lower in exudative compared to transudative pleural (3252 ± 207 ms vs. 3596 ± 213 ms, P < 0.0001) and pericardial (2749 ± 373 ms vs. 3337 ± 245 ms, P < 0.0001) effusions. The diagnostic accuracy of T1 mapping for detecting transudates was very good for pleural and excellent for pericardial effusions, respectively [area under the curve 0.88, (95% CI 0.764-0.996), P = 0.001, 79% sensitivity, 89% specificity, and 0.93, (95% CI 0.855-1.000), P < 0.0001, 95% sensitivity; 81% specificity]. CONCLUSION: Native T1 values of effusions measured using CMR correlate well with protein concentrations and may be helpful for discriminating between transudates and exudates. This may help focus the requirement for invasive diagnostic sampling, avoiding unnecessary intervention in patients with unequivocal transudative effusions.

Incidence and predictors of anti-bradycardia pacing in patients with Anderson-Fabry disease.

BACKGROUND: Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder associated with bradyarrhythmias. We sought to examine the nature of conduction system abnormalities and the indications and determinants of anti-bradycardia pacing in patients with AFD. METHODS AND RESULTS: We studied 204 patients with AFD (49% male, mean age 42 years) in an observational, longitudinal, retrospective cohort study. At baseline, 5 (2.5%) patients had pacemakers for the treatment of bradycardias [4/5 (80%) for atrioventricular disease; 1/5 (20%) for sinus node disease]. PR interval <120 ms was observed in 15 (7%); PR interval >200 ms in 6 (3%); QRS interval >120 ms 18 (9%); left QRS axis deviation in 16 (8%); and right-axis deviation in 2 (1%). Age was an independent determinant of prolonged PR interval, QRS duration and left QRS axis deviation. During follow-up (189 patients; 899 patient-years), 12 (6%) had a device implanted to treat spontaneously occurring bradyarrhythmias [5/12 (42%) for atrioventricular disease; 7/12 (58%) sinus node disease] with 8% 5-year cumulative incidence. Two independent predictors of future anti-bradycardia pacing were identified in a multivariable Cox model: QRS duration [hazard ratio (HR) 1.05, 95% confidence intervals (CI) 1.02-1.09, P= 0.001; receiver operating characteristic (ROC) curve c-statistic 0.726] and PR interval duration (HR 1.03, 95% CI 1.004-1.060, P = 0.023; ROC curve c-statistic 0.548). QRS duration ≥110 ms at baseline had a sensitivity of 64%, specificity of 84%, 49% positive predictive value, and 91% negative predictive value for identifying patients likely to require anti-bradycardia pacing. CONCLUSION: In patients with AFD increasing age is associated with PR and QRS interval prolongation and left QRS axis deviation. Pacing for atrioventricular and sinus node disease is common and patients with QRS≥110 ms should be closely monitored for bradyarrhythmias.

Is This the Prime Time for Transradial Access Left Ventricular Endomyocardial Biopsy?

Left ventricular endomyocardial biopsy (EMB) is an essential tool in the management of myocarditis and is conventionally performed via transfemoral access (TFA). Transradial access EMB (TRA-EMB) is a novel alternative and the authors sought to determine its safety and feasibility by conducting a systematic review of the literature. Medline was searched in 2020, and cohort demographics, procedural details and complications were extracted from selected studies. Four observational studies with a combined total of 496 procedures were included. TRA-EMB was most frequently performed with a sheathless MP1 guide catheter via the right radial artery. The most common complication was pericardial effusion (up to 11% in one study), but pericardial drainage for tamponade was rare (one reported case). Death and mitral valve damage have not been reported. TRA-EMB was successful in obtaining samples in 99% of reported procedures. The authors concluded that TRA-EMB is a safe and feasible alternative to TFA-EMB and the most common complication is uncomplicated pericardial effusion.

Diagnostic Impact of Repeated Expert Review & Long-Term Follow-Up in Determining Etiology of Idiopathic Cardiac Arrest.

Background Recognizing the etiology of sudden cardiac arrest (SCA) has an enormous impact on the management of victims and their immediate families. A significant proportion of SCA survivors with a structurally normal heart are not offered a diagnosis and there is no clear consensus on the type and duration of follow-up. We aimed to assess the utility of a multidisciplinary approach in optimizing diagnosis of cardiac arrest etiology during follow-up. Methods and Results We retrospectively assessed 327 consecutive SCA survivors (mean age 61.9±16.2 years, 80% men) who underwent secondary prevention implantable cardioverter defibrillators between May 2015 and November 2018. The initial diagnosis was recorded at the time of admission and follow-up diagnosis was deduced from subsequent clinic records, investigations, and outcomes of multidisciplinary team meetings. Structural heart disease accounted for 282 (86%) of SCAs. Forty-five (14%) patients had a structurally normal heart and underwent comprehensive testing and follow-up (mean duration 93±52 weeks). On initial evaluation, 14/45 (31%) of these received a diagnosis, rising to 29/45 (64%) with serial reviews during follow-up. Discussion in multidisciplinary team meetings and imaging reassessment accounted for 47% of new diagnoses. No additional diagnoses were made beyond 96 weeks. Nineteen (5.8%) fatalities occurred in the entire cohort, exclusively in patients with structural heart disease. Conclusions Systematic comprehensive testing combined with multidisciplinary expert team review of SCA survivors without structural heart disease improves the yield and time to diagnosis compared with previously published studies. This approach has positive implications in the management of SCA survivors and their families.

COVID-19 and changes in activity and treatment of ST elevation MI from a UK cardiac centre.

BACKGROUND: The international healthcare response to COVID-19 has been driven by epidemiological data related to case numbers and case fatality rate. Second order effects have been less well studied. This study aimed to characterise the changes in emergency activity of a high-volume cardiac catheterisation centre and to cautiously model any excess indirect morbidity and mortality. METHOD: Retrospective cohort study of patients admitted with acute coronary syndrome fulfilling criteria for the heart attack centre (HAC) pathway at St. Bartholomew's hospital, UK. Electronic data were collected for the study period March 16th - May 16th 2020 inclusive and stored on a dedicated research server. Standard governance procedures were observed in line with the British Cardiovascular Intervention Society audit. RESULTS: There was a 28% fall in the number of primary percutaneous coronary interventions (PCIs) for ST elevation myocardial infarction (STEMI) during the study period (111 vs. 154) and 36% fewer activations of the HAC pathway (312 vs. 485), compared to the same time period averaged across three preceding years. In the context of 'missing STEMIs', the excess harm attributable to COVID-19 could result in an absolute increase of 1.3% in mortality, 1.9% in nonfatal MI and 4.5% in recurrent ischemia. CONCLUSIONS: The emergency activity of a high-volume PCI centre was significantly reduced for STEMI during the peak of the first wave of COVID-19. Our data can be used as an exemplar to help future modelling within cardiovascular workstreams to refine aggregate estimates of the impact of COVID-19 and inform targeted policy action.