Phenotypic Characterisation of Obstructive Sleep Apnoea in Acute Coronary Syndrome.

BACKGROUND: Recent neutral randomised clinical trials have created clinical equipoise for treating obstructive sleep apnoea (OSA) for managing cardiovascular risk. The importance of defining the links between OSA and cardiovascular disease is needed with the aim of advancing the robustness of future clinical trials. We aimed to define the clinical correlates and characterise surrogate cardiovascular markers in patients with acute coronary syndrome (ACS) and OSA. METHOD: Overall, 66 patients diagnosed with ACS were studied. Patients underwent an unattended polysomnogram after hospital discharge (median [interquartile range] 62 [37-132] days). The Epworth Sleepiness Scale, Berlin, and STOP-BANG questionnaires were administered. Surrogate measures of vascular structure and function, and cardiovascular autonomic function were conducted. Pulse wave amplitude drop was derived from the pulse oximetry signals of the overnight polysomnogram. RESULTS: OSA (apnoea-hypopnea index [AHI] ≥5) was diagnosed in 94% of patients. Moderate-to-severe OSA (AHI≥15) was observed in 68% of patients. Daytime sleepiness (Epworth Sleepiness Scale ≥10) was reported in 17% of patients. OSA screening questionnaires were inadequate to identify moderate-to-severe OSA, with an area under the receiver operating characteristic curve of approximately 0.64. Arterial stiffness (carotid-femoral pulse wave velocity, 6.1 [5.2-6.8] vs 7.4 [6.6-8.6] m/s, p=0.002) and carotid intima-media thickness (0.8 [0.7-1.0] vs 0.9 [0.8-1.0] mm, p=0.027) was elevated in patients with moderate-to-severe OSA. After adjusting for age, sex and body mass index, these relationships were not statistically significant. No relationships were observed in other surrogate cardiovascular markers. CONCLUSIONS: A high prevalence of OSA in a mostly non-sleepy population with ACS was identified, highlighting a gross underdiagnosis of OSA among cardiovascular patients. The limitations of OSA screening questionnaires highlight the need for new models of OSA screening as part of cardiovascular risk management. A range of inconsistent abnormalities were observed in measures of vascular structure and function, and these appear to be largely explained by confounding factors. Further research is required to elucidate biomarkers for the presence and impact of OSA in ACS patients.

Advances in the Computational Assessment of Disturbed Coronary Flow and Wall Shear Stress: A Contemporary Review.

Coronary artery blood flow is influenced by various factors including vessel geometry, hemodynamic conditions, timing in the cardiac cycle, and rheological conditions. Multiple patterns of disturbed coronary flow may occur when blood flow separates from the laminar plane, associated with inefficient blood transit, and pathological processes modulated by the vascular endothelium in response to abnormal wall shear stress. Current simulation techniques, including computational fluid dynamics and fluid-structure interaction, can provide substantial detail on disturbed coronary flow and have advanced the contemporary understanding of the natural history of coronary disease. However, the clinical application of these techniques has been limited to hemodynamic assessment of coronary disease severity, with the potential to refine the assessment and management of coronary disease. Improved computational efficiency and large clinical trials are required to provide an incremental clinical benefit of these techniques beyond existing tools. This contemporary review is a clinically relevant overview of the disturbed coronary flow and its associated pathological consequences. The contemporary methods to assess disturbed flow are reviewed, including clinical applications of these techniques. Current limitations and future opportunities in the field are also discussed.

Cardiovascular presentations during the COVID-19 pandemic: an interrupted time series analysis.

BACKGROUND: The broader implications of the Coronavirus disease 2019 pandemic on cardiovascular hospitalizations remain unclear. We aimed to assess trends in cardiovascular presentations during the Coronavirus disease 2019 pandemic. METHODS: This multicentre study examined cardiovascular presentations from March 2018 to February 2023. Patients with cardiovascular presentations were identified through administrative health records using ICD-10-AM diagnosis codes. Four key study periods were analysed: T0-pre-pandemic, T1-first lockdown, T2-easing of restrictions and T3-release of restrictions and widespread vaccination. Interrupted time series analysis was used to predict weekly cardiovascular presentations, with the mean difference between actual and predicted numbers assessed for significance. RESULTS: Overall, 116 518 patients were included across three major public hospitals in Australia. Cardiovascular presentations were significantly lower in T1 than predicted, with a mean decline of 13.1% (SD 16.2%; P = 0.004). There was a significant difference between the expected and actual number of most cardiovascular presentations in T2 and T3, apart from a significant reduction in cardiomyopathy and heart failure presentations during T3 (4.5% [SD 23.7%]; P = 0.007). CONCLUSIONS: Cardiovascular presentations were significantly lower during the initial lockdown phase of the COVID-19 pandemic; this attenuated with easing of social restrictions and widespread vaccination, except for persistent reduction in cardiomyopathy and heart failure presentations.

Spontaneous Coronary Artery Dissection in Hyperdominant Left Anterior Coronary Descending Artery.

A hyperdominant left anterior descending coronary artery variation is a rare but important diagnosis because of the risk for large-territory ischemia. We describe a very rare presentation of spontaneous coronary artery dissection in the distal portion of a hyperdominant left anterior descending coronary artery. No similar cases have been described.

Cardiovascular outcomes for people hospitalised with COVID-19 in Australia, and the effect of vaccination: an observational cohort study.

OBJECTIVES: To assess the frequency of clinical cardiovascular outcomes for people hospitalised with coronavirus disease 2019 (COVID-19), and the impact of vaccination. STUDY DESIGN: Observational cohort study. SETTING, PARTICIPANTS: All index admissions of adults with laboratory-confirmed COVID-19 to 21 hospitals participating in the Australian Cardiovascular COVID-19 Registry (AUS-COVID), 4 September 2020 - 11 July 2022. MAIN OUTCOME MEASURES: Frequency of elevated troponin levels, new arrhythmia, new or deteriorating heart failure or cardiomyopathy, new pericarditis or myocarditis, new permanent pacemaker or implantable cardioverter-defibrillator, and pulmonary embolism. SECONDARY OUTCOMES: impact of COVID-19 vaccination on likelihood of in-hospital death, intubation, troponin elevation, and clinical cardiovascular events. RESULTS: The mean age of the 1714 people admitted to hospital with COVID-19 was 60.1 years (standard deviation, 20.6 years); 926 were men (54.0%), 181 patients died during their index admissions (10.6%), 299 required intensive care (17.4%). Thirty-eight patients (2.6%) developed new atrial fibrillation or flutter, 27 (2.6%) had pulmonary embolisms, new heart failure or cardiomyopathy was identified in 13 (0.9%), and pre-existing cardiomyopathy or heart failure was exacerbated in 21 of 110 patients (19%). Troponin was elevated in 369 of the 986 patients for whom it was assessed (37.4%); in-hospital mortality was higher for people with elevated troponin levels (86, 23% v 23, 3.7%; P < 0.001). The COVID-19 vaccination status of 580 patients was known (no doses, 232; at least one dose, 348). The likelihood of in-hospital death (adjusted odds ratio [aOR], 0.38; 95% confidence interval [CI], 0.18-0.79) and intubation (aOR, 0.30; 95% CI, 0.15-0.61) were lower for people who had received at least one vaccine dose, but not the likelihood of troponin elevation (aOR, 1.44; 95% CI, 0.80-2.58) or clinical cardiovascular events (aOR, 1.56; 95% CI, 0.59-4.16). CONCLUSIONS: Although troponin levels were elevated in a considerable proportion of people hospitalised with COVID-19, clinical cardiovascular events were infrequent, and their likelihood was not influenced by vaccination. COVID-19 vaccination, however, was associated with reduced likelihood of in-hospital death and intubation. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, ACTRN12620000486921 (prospective).

Aortic Stenosis and Renal Function: A Bidirectional Mendelian Randomization Analysis.

BACKGROUND: Large observational studies have demonstrated a clear inverse association between renal function and risk of aortic stenosis (AS). Whether this represents a causal, reverse causal or correlative relationship remains unclear. We investigated this using a bidirectional 2-sample Mendelian randomization approach. METHODS AND RESULTS: We collected summary statistics for the primary analysis of chronic kidney disease (CKD) and AS from genome-wide association study meta-analyses including 480 698 and 653 867 participants, respectively. We collected further genome-wide association study summary statistics from up to 1 004 040 participants for sensitivity analyses involving estimated glomerular filtration rate (eGFR) derived from creatinine, eGFR derived from cystatin C, and serum urea nitrogen. Inverse-variance weighted was the primary analysis method, with weighted-median, weighted-mode, Mendelian randomization-Egger, and Mendelian randomization-Pleiotropy Residual Sum and Outlier as sensitivity analyses. We did not find evidence of a causal relationship between genetically predicted CKD liability as the exposure and AS as the outcome (odds ratio [OR], 0.94 per unit increase in log odds of genetic liability to CKD [95% CI, 0.85-1.04], P=0.26) nor robust evidence of AS liability as the exposure and CKD as the outcome (OR, 1.04 per unit increase in log odds of genetic liability to AS [95% CI, 0.97-1.12], P=0.30). The sensitivity analyses were neutral overall, as were the analyses using eGFR derived from creatinine, eGFR derived from cystatin C, and serum urea nitrogen. All positive controls demonstrated strong significant associations. CONCLUSIONS: The present study did not find evidence of a substantial effect of genetically predicted renal impairment on risk of AS. This has important implications for research efforts that attempt to identify prevention and treatment targets for both CKD and AS.

A Systematic Review of Delayed High-Grade Atrioventricular Block After Transcatheter Aortic Valve Implantation.

Background: High-grade atrioventricular block (HGAVB) is common after transcatheter aortic valve implantation (TAVI), often necessitating permanent pacemaker (PPM) implantation. Delayed HGAVB has varying definitions but typically refers to onset 48 hours after TAVI or following discharge and may cause syncope and sudden cardiac death. This review estimates the incidence of delayed HGAVB and identifies limitations of current literature. Methods: A systematic review was performed of the following online databases: Medline, Cochrane, Web of Science, and Scopus. Studies that labelled the outcome of "delayed" or "late" atrioventricular block after TAVI were included; patients with previous PPM or aortic valve surgery were excluded. Initial search yielded 775 studies, which, after screening, was narrowed to 19 studies. Results: Nineteen studies with 14,898 patients were included. Mean age was 81.7 years, and 46.3% were male. Mean Society of Thoracic Surgeons (STS) score was 5.6%, and 31.3% of patients had known atrial fibrillation. The most common access site was transfemoral (84.8%), whereas balloon-expandable valves were used in 62.1%, self-expanding valves in 34.0%, and mechanically expanding valves in 3.9% of cases. The incidence of delayed HGAVB ranged from 1.7% to 14.6%, with significant methodologic heterogeneity noted among the included studies. Conclusions: Delayed HGAVB is a common and potentially serious complication of TAVI, with similar risk factors to acute HGAVB. With a move toward an early discharge strategy post-TAVI, further prospective study of delayed HGAVB is warranted to improve understanding of predisposing factors, incidence, timing, and implications.

Contexte: L'apparition d'un bloc atrioventriculaire de haut degré (BAVHD) est fréquente après l'implantation valvulaire aortique par cathéter (IVAC), ce qui nécessite souvent l'implantation d'un stimulateur cardiaque permanent. Les définitions d'un BAVHD tardif varient, mais elles font habituellement référence à l'apparition du bloc 48 heures après l'IVAC ou après le congé de l'hôpital. Le bloc peut alors provoquer une syncope et une mort subite d'origine cardiaque. Cette analyse vise à estimer l'incidence de la formation d'un BAVHD tardif et à définir les lacunes dans les publications actuelles. Méthodologie: Une analyse des études publiées dans les bases de données en ligne suivantes a été menée : Medline, Cochrane, Web of Science et Scopus. Les études dont le libellé comprenait l'issue du bloc atrioventriculaire tardif ou éloigné (« delayed ¼ ou « late ¼) ont été retenues. Les patients qui avaient antérieurement reçu un stimulateur cardiaque permanent ou subi une intervention chirurgicale de la valve aortique ont été exclus. La recherche initiale a permis de recenser 775 études, nombre qui a été réduit à 19 après l'application des critères de sélection. Résultats: Dix-neuf études totalisant 14 898 patients ont été retenues. L'âge moyen était 81,7 ans, et 46,3 % des patients étaient des hommes. Le score STS (Society of Thoracic Surgeons) moyen était de 5,6 %, et 31,3 % des patients avaient une fibrillation auriculaire. Le point d'accès le plus fréquent était par l'artère fémorale (84,8 %). Des valves expansibles par ballonnet ont été utilisées dans 62,1 % des cas, des valves auto-expansibles dans 34,0 % des cas et des valves expansibles mécaniquement dans 3,9 % des cas. L'incidence du BAVHD tardif variait de 1,7 % à 14,6 %, mais la méthodologie était très hétérogène d'une étude à l'autre. Conclusions: Le BAVHD tardif est une complication fréquente et potentiellement grave de l'IVAC, et ses facteurs de risque sont comparables à ceux du BAVHD aigu. Étant donné la volonté d'adopter une stratégie de congé précoce après une IVAC, une autre étude prospective sur le BAVHD tardif s'impose pour mieux comprendre les facteurs prédisposants, l'incidence, la chronologie et les implications.

Association between vessel-specific coronary Aggregated plaque burden, Agatston score and hemodynamic significance of coronary disease (The CAPTivAte study).

Background: CT coronary angiography (CTCA) is a guideline-endorsed assessment for patients with stable angina and suspected coronary disease. Although associated with excellent negative predictive value in ruling out obstructive coronary disease, there are limitations in the ability of CTCA to predict hemodynamically significant coronary disease. The CAPTivAte study aims to assess the utility of Aggregated Plaque Burden (APB) in predicting ischemia based on Fractional Flow Reserve (FFR). Methods: In this retrospective study, patients who had a CTCA and invasive FFR of the LAD were included. The entire length of the LAD was analyzed using semi-automated software which characterized total plaque burden and plaque morphological subtype (including Low Attenuation Plaque (LAP), Non-calcific plaque (NCP) and Calcific Plaque (CP). Aggregated Plaque Burden (APB) was calculated. Univariate and multivariate analysis were performed to assess the association between these CT-derived parameters and invasive FFR. Results: There were 145 patients included in this study. 84.8 % of patients were referred with stable angina. There was a significant linear association between APB and FFR in both univariate and multivariate analysis (Adjusted R-squared = 0.0469; p = 0.035). Mean Agatston scores are higher in FFR positive vessels compared to FFR negative vessels (371.6 (±443.8) vs 251.9 (±283.5, p = 0.0493). Conclusion: CTCA-derived APB is a reliable predictor of ischemia assessed using invasive FFR and may aid clinicians in rationalizing invasive vs non-invasive management strategies. Vessel-specific Agatston scores are significantly higher in FFR-positive vessels than in FFR-negative vessels. Associations between HU-derived plaque subtype and invasive FFR were inconclusive in this study.

Impact of the COVID-19 pandemic on provision of interventional cardiology and cardiac surgery services in Australia: a review of Medicare claims data.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted healthcare service provision worldwide. There is limited information on changes in invasive cardiovascular services during the pandemic, particularly in Australia. AIM: We sought to assess temporal trends on the use of interventional cardiology and cardiac surgery services before and following the COVID-19 pandemic in Australia. METHODS: Medicare Benefits Schedule items data from the Australian Government Services Australia on outpatient and private hospital interventional cardiology procedures (coronary angiogram, percutaneous coronary intervention and transcatheter aortic valve implantation) and cardiac surgery procedures (coronary artery bypass grafting [CABG] and surgical valve replacement, repair and annuloplasty) were analysed from March 2019 to 2021. This was superimposed on monthly COVID-19 case data obtained from the Australian Department of Health and Aged Care epidemiology reports. RESULTS: A sustained reduction in CABG (-10.1%) and surgical valve intervention (-11.1%) was appreciated from March 2019-2020 to March 2020-2021, in the first year of the COVID-19 pandemic. During this period, an overall increase (+25.9%) in the use of transcatheter aortic valve implantation was observed. Following the initial period of mandated isolation in March-April 2020, a reduction in coronary angiography (-29.1%) and percutaneous coronary intervention (-19.5%) was observed in comparison to March-April 2019; however, this was largely attenuated over time. CONCLUSIONS: The COVID-19 pandemic has resulted in reductions in the use of interventional cardiology and cardiac surgery services, with cardiac surgery most affected. However, an increase in uptake of transcatheter aortic valve implantation has been observed during the pandemic. This may have implications for future planning and resource allocation in the aftermath of the pandemic.

The ability of contemporary cardiologists to judge the ischemic impact of a coronary lesion visually.

BACKGROUND: Landmark trials showed that invasive pressure measurement (Fractional Flow Reserve, FFR) was a better guide to coronary stenting than visual assessment. However, present-day interventionists have benefited from extensive research and personal experience of mapping anatomy to hemodynamics. AIMS: To determine if visual assessment of the angiogram performs as well as invasive measurement of coronary physiology. METHODS: 25 interventional cardiologists independently visually assessed the single vessel coronary disease of 200 randomized participants in The Objective Randomized Blinded Investigation with optimal medical Therapy of Angioplasty in stable angina trial (ORBITA). They gave a visual prediction of the FFR and Instantaneous Wave-free Ratio (iFR), denoted vFFR and viFR respectively. Each judged each lesion on 2 occasions, so that every lesion had 50 vFFR, and 50 viFR assessments. The group consensus visual estimates (vFFR-group and viFR-group) and individual cardiologists' visual estimates (vFFR-individual and viFR-individual) were tested alongside invasively measured FFR and iFR for their ability to predict the placebo-controlled reduction in stress echo ischemia with stenting. RESULTS: Placebo-controlled ischemia improvement with stenting was predicted by vFFR-group (p < 0.0001) and viFR-group (p < 0.0001), vFFR-individual (p < 0.0001) and viFR-individual (p < 0.0001). There were no significant differences between the predictive performance of the group visual estimates and their invasive counterparts: p = 0.53 for vFFR vs FFR and p = 0.56 for viFR vs iFR. CONCLUSION: Visual assessment of the angiogram by contemporary experts, provides significant additional information on the amount of ischaemia which can be relieved by placebo-controlled stenting in single vessel coronary artery disease.

The effect of immunomodulatory drugs on aortic stenosis: a Mendelian randomisation analysis.

There are currently no approved pharmacological treatment options for aortic stenosis (AS), and there are limited identified drug targets for this chronic condition. It remains unclear whether inflammation plays a role in AS pathogenesis and whether immunomodulation could become a therapeutic target. We evaluated the potentially causal association between inflammation and AS by investigating the genetically proxied effects of tocilizumab (IL6 receptor, IL6R, inhibitor), canakinumab (IL1ß inhibitor) and colchicine (ß-tubulin inhibitor) through a Mendelian randomisation (MR) approach. Genetic proxies for these drugs were identified as single nucleotide polymorphisms (SNPs) in the gene, enhancer or promoter regions of IL6R, IL1ß or ß-tubulin gene isoforms, respectively, that were significantly associated with serum C-reactive protein (CRP) in a large European genome-wide association study (GWAS; 575,531 participants). These were paired with summary statistics from a large GWAS of AS in European patients (653,867 participants) to then perform primary inverse-variance weighted random effect and sensitivity MR analyses for each exposure. This analysis showed that genetically proxied tocilizumab was associated with reduced risk of AS (OR 0.56, 95% CI 0.45-0.70 per unit decrease in genetically predicted log-transformed CRP). Genetically proxied canakinumab was not associated with risk of AS (OR 0.80, 95% CI 0.51-1.26), and only one suitable SNP was identified to proxy the effect of colchicine (OR 34.37, 95% CI 1.99-592.89). The finding that genetically proxied tocilizumab was associated with reduced risk of AS is concordant with an inflammatory hypothesis of AS pathogenesis. Inhibition of IL6R may be a promising therapeutic target for AS management.

Recurrent Valve Frame Infolding in the 34mm Self-Expanding Medtronic Evolut Pro+ Transcatheter Valve System: A Single Centre Experience.

BACKGROUND: Valve frame infolding (VFI) is a rare complication (1-3%) of transcatheter aortic valve implantation (TAVI), which primarily occurs in large sized self-expanding valves. We report the incidence of VFI in a small group of patients with highly calcified and extra-large aortic annuli, who underwent implantation of the newer generation 34mm Medtronic Evolut Pro+ (EP+) valve system. METHODS: A retrospective review was conducted on all patients presenting to a single centre experienced with TAVI in Sydney, NSW, Australia, between June and October 2022, for transfemoral TAVI using the Medtronic 34mm EP+ valve system. VFI was diagnosed using fluoroscopy, and pre-procedure computed tomography (CT) was analysed offline. RESULTS: VFI occurred in four of 10 patients who underwent TAVI using the 34mm EP+ system. Between VFI and non-VFI patients, the annular size, aortic angulation and total calcium volume was similar. Calcium distribution between the coronary cusps was symmetrical in non-VFI patients (37%, 33% and 30%), compared to 52% in the non-coronary cusp (NCC) in VFI patients. The mean ellipticity index was higher in VFI versus non-VFI patients (22% vs 14%). CONCLUSION: The 34mm Medtronic EP+ valve system is vital for safe and effective treatment of a niche subgroup of patients with extra-large annuli and extensive calcification, however operators should be aware of the increased incidence of VFI. Heavy eccentric calcification at the NCC, as well as using the cusp-overlap implant technique may exacerbate VFI, while multiplanar fluoroscopic screening may improve recognition.

Lipids, Blood Pressure, and Diabetes Mellitus on Risk of Cardiovascular Diseases in East Asians: A Mendelian Randomization Study.

Elevated blood pressure, dyslipidemia, and impaired glycemic control are well-established cardiovascular risk factors in Europeans, but there are comparatively few studies focused on East Asian populations. This study evaluated the potential causal relations between traditional cardiovascular risk factors and disease risk in East Asians through a 2-sample Mendelian randomization approach. We collected summary statistics for blood pressure parameters, lipid subsets, and type 2 diabetes mellitus liability from large genome-wide association study meta-analyses conducted in East Asians and Europeans. These were paired with summary statistics for ischemic heart disease (IHD), ischemic stroke (IS), peripheral vascular disease, heart failure (HF) and atrial fibrillation (AF). We performed univariable Mendelian randomization analyses for each exposure-outcome pair, followed by multivariable analyses for the available lipid subsets. The genetically predicted risk factors associated with IHD and AF were similar between East Asians and Europeans. However, in East Asians only genetically predicted elevated blood pressure was significantly associated with IS (odds ratio 1.05, 95% confidence interval 1.04 to 1.06, p <0.0001) and HF (odds ratio 1.05, 95% confidence interval 1.04 to 1.06, p <0.0001), whereas nearly all genetically predicted risk factors were significantly associated with IS and HF in Europeans. In conclusion, this study provides supportive evidence for similar causal relations between traditional cardiovascular risk factors and IHD and AF in both East Asian and European ancestry populations. However, the identified risk factors for IS and HF differed between East Asians and Europeans, potentially highlighting distinct disease etiologies between these populations.

Vessel-Specific Outcomes of Deferred Revascularization Following Negative Fractional Flow Reserve.

Variations in myocardial supply area and hydrostatic pressure gradients result in greater likelihood of positive fractional flow reserve (FFR) in the left anterior descending (LAD) compared with the circumflex (Cx) and right coronary artery (RCA). However, the same FFR threshold for deferral of revascularization is applied to all arteries, without evidence that this results in equivalent outcomes. We assessed vessel-specific outcomes of deferred revascularization for the 3 major coronary arteries based on FFR > 0.8. In this retrospective study, data were obtained on consecutive patients who underwent indicated FFR assessment across 2 tertiary institutions. Patients with deferred revascularization were followed for 36 months for the primary end point of vessel-specific target lesion failure (TLF). Of 1,916 major coronary arteries (1,579 patients), the odds ratio of positive FFR was highest in the LAD (odds ratio 3.36, p <0.001). In total, 867 vessels (733 patients) with FFR > 0.8 had complete 3-year medical record follow-ups. The TLF rate for deferred vessels was 10.21%, 11.52%, and 10.96% for the LAD, Cx, and RCA respectively. In a multivariate analysis, there was no significant difference in the odds of TLF for the 0.84 (0.53 to 1.33, p = 0.459), 1.17 (0.68 to 2.01, p = 0.582), and 1.11 (0.62 to 2.00, p = 0.715) in the LAD, Cx, and RCA, respectively. In a multivariate analysis, diabetes mellitus was the only baseline characteristic significantly associated at risk of TLF (1.43 [1.01 to 2.02], p = 0.043). In conclusion, despite greater likelihood of positive FFR in the LAD, the FFR threshold for deferred revascularization resulted in equivalent outcomes in all 3 major coronary arteries, and patients with diabetes mellitus may represent a group that requires aggressive surveillance and risk factor modification after deferred revascularization.

Association between pre-existing cardiovascular disease, mortality and cardiovascular outcomes in hospitalised patients with COVID-19.

Background: Pre-existing cardiovascular disease and cardiovascular risk factors are common in patients with COVID-19 and there remain concerns for poorer in-hospital outcomes in this cohort. We aimed to analyse the relationship between pre-existing cardiovascular disease, mortality and cardiovascular outcomes in patients hospitalised with COVID-19 in a prospective, multicentre observational study. Method: This prospective, multicentre observational study included consecutive patients of age ≥18 in their index hospitalisation with laboratory-proven COVID-19 in Australia. Patients with suspected but not laboratory-proven COVID-19 and patients with no available past medical history were excluded. The primary exposure was pre-existing cardiovascular disease, defined as a composite of coronary artery disease, heart failure or cardiomyopathy, atrial fibrillation or flutter, severe valvular disease, peripheral arterial disease and stroke or transient ischaemic attack. The primary outcome was in-hospital mortality. Secondary outcomes were clinical cardiovascular complications (new onset atrial fibrillation or flutter, high-grade atrioventricular block, sustained ventricular tachycardia, new heart failure or cardiomyopathy, pericarditis, myocarditis or myopericarditis, pulmonary embolism and cardiac arrest) and myocardial injury. Results: 1,567 patients (mean age 60.7 (±20.5) years and 837 (53.4%) male) were included. Overall, 398 (25.4%) patients had pre-existing cardiovascular disease, 176 patients (11.2%) died, 75 (5.7%) had clinical cardiovascular complications and 345 (37.8%) had myocardial injury. Patients with pre-existing cardiovascular disease had significantly increased in-hospital mortality (aOR: 1.76 95% CI: 1.21-2.55, p = 0.003) and myocardial injury (aOR: 3.27, 95% CI: 2.23-4.79, p < 0.001). There was no significant association between pre-existing cardiovascular disease and in-hospital clinical cardiovascular complications (aOR: 1.10, 95% CI: 0.58-2.09, p = 0.766). On mediation analysis, the indirect effect and Sobel test were significant (p < 0.001), indicating that the relationship between pre-existing cardiovascular disease and in-hospital mortality was partially mediated by myocardial injury. Apart from age, other cardiovascular risk factors such as diabetes, hypercholesterolemia and hypertension had no significant impact on mortality, clinical cardiovascular complications or myocardial injury. Conclusions: Pre-existing cardiovascular disease is associated with significantly higher mortality in patients hospitalised with COVID-19. This relationship may be partly explained by increased risk of myocardial injury among patients with pre-existing cardiovascular disease which in turn is a marker associated with higher mortality.

Immediate recruitment of dormant coronary collaterals can provide more than half of normal resting perfusion during coronary occlusion in patients with coronary artery disease.

BACKGROUND: Dormant coronary collaterals are highly prevalent and clinically beneficial in cases of coronary occlusion. However, the magnitude of myocardial perfusion provided by immediate coronary collateral recruitment during acute occlusion is unknown. We aimed to quantify collateral myocardial perfusion during balloon occlusion in patients with coronary artery disease (CAD). METHODS: Patients without angiographically visible collaterals undergoing elective percutaneous transluminal coronary angioplasty (PTCA) to a single epicardial vessel underwent two scans with 99mTc-sestamibi myocardial perfusion single-photon emission computed tomography (SPECT). All subjects underwent at least three minutes of angiographically verified complete balloon occlusion, at which time an intravenous injection of the radiotracer was administered, followed by SPECT imaging. A second radiotracer injection followed by SPECT imaging was performed 24 h after PTCA. RESULTS: The study included 22 patients (median [interquartile range] age 68 [54-72] years. The perfusion defect extent was 19 [11-38] % of the LV, and the collateral perfusion at rest was 64 [58-67]% of normal. CONCLUSION: This is the first study to describe the magnitude of short-term changes in coronary microvascular collateral perfusion in patients with CAD. On average, despite coronary occlusion and an absence of angiographically visible collateral vessels, collaterals provided more than half of the normal perfusion.

Early Growth Response-1: Friend or Foe in the Heart?

Cardiovascular disease is a major cause of mortality and morbidity worldwide. Early growth response-1 (Egr-1) plays a critical regulatory role in a range of experimental models of cardiovascular diseases. Egr-1 is an immediate-early gene and is upregulated by various stimuli including shear stress, oxygen deprivation, oxidative stress and nutrient deprivation. However, recent research suggests a new, underexplored cardioprotective side of Egr-1. The main purpose of this review is to explore and summarise the dual nature of Egr-1 in cardiovascular pathobiology.

Prospective observational study on the accuracy of predictors of high-grade atrioventricular conduction block after transcatheter aortic valve implantation (CONDUCT-TAVI): study protocol, background and significance.

INTRODUCTION: Aortic stenosis is the most common cardiac valve pathology worldwide and has a mortality rate of over 50% at 5 years if left untreated. Transcatheter aortic valve implantation (TAVI) is a minimally invasive and highly effective alternative treatment option to open-heart surgery. High-grade atrioventricular conduction block (HGAVB) is one of the most common complications after TAVI and requires a permanent pacemaker. Due to this, patients are typically monitored for 48 hours post TAVI, however up to 40% of HGAVB may delayed, and occur after discharge. Delayed HGAVB can cause syncope or sudden unexplained cardiac death in a vulnerable population, and no accurate methods currently exist to identify patients at risk. METHODS AND ANALYSIS: The prospective observational study on the accuracy of predictors of high-grade atrioventricular conduction block after transcatheter aortic valve implantation (CONDUCT-TAVI) trial is an Australian-led, multicentre, prospective observational study, aiming to improve the prediction of HGAVB, after TAVI. The primary objective of the trial is to assess whether published and novel invasive electrophysiology predictors performed immediately before and after TAVI can help predict HGAVB after TAVI. The secondary objective aims to further evaluate the accuracy of previously published predictors of HGAVB after TAVI, including CT measurements, 12-lead ECG, valve characteristics, percentage oversizing and implantation depth. Follow-up will be for 2 years, and detailed continuous heart rhythm monitoring will be obtained by inserting an implantable loop recorder in all participants. ETHICS AND DISSEMINATION: Ethics approval has been obtained for the two participating centres. Results of the study will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ACTRN12621001700820.