Acute Coronary Syndrome in the COVID-19 Pandemic: Reduced Cases and Increased Ischaemic Time.

BACKGROUND: The COVID-19 pandemic has led to unprecedented stress on health care systems, and has affected acute coronary syndrome treatment at every step. This study aimed to examine the impact of COVID-19 on patient presentations with acute coronary syndromes during the first and second pandemic wave in Melbourne, Victoria. METHOD: A retrospective cohort study of adults presenting with cute coronary syndrome during the first pandemic wave from 1 March 2020 to 31 April 2020 and the second pandemic wave from 1 July 2020 to 31 August 2020 was compared to a control period from 1 March to 31 April 2019 at a single sub-tertiary referral centre in Melbourne, Victoria servicing a catchment area with a relatively high incidence of COVID-19 cases. RESULTS: Three-hundred-and-thirty-five (335) patients were hospitalised with acute coronary syndromes across all three time periods. The total number of patients presenting with an acute coronary syndrome was reduced during the pandemic, with a higher proportion of ST elevation myocardial infarctions. Ischaemic times increased with time from symptom onset to first medical contact rising from 191 minutes in the control period to 292 minutes in the first wave (p=0.06) and 271 minutes in the second wave (p=0.06). Coronary angiography with subsequent revascularisation significantly increased from 55% in the control period undergoing revascularisation to 69% in the first wave (p<0.001) and 74% in the second wave (p<0.001). CONCLUSION: A concerning reduction in acute coronary presentations occurred during the COVID-19 pandemic, associated with longer ischaemic times and a higher proportion requiring revascularisation. It is crucial that public awareness campaigns are instituted to address the contributing patient factors in future waves.

Management of atherosclerotic plaque in left internal mammary artery graft five years after angiographic patency: A case report.

BACKGROUND: The left internal mammary artery (LIMA) has demonstrated excellent long-term patency rates when used as a bypass conduit with complications usually occurring in the early postoperative period. The rapid development of de-novo atherosclerosis in a previously non-diseased LIMA, subsequently leading to an acute coronary syndrome (ACS) is rarely encountered. CASE SUMMARY: A 67-year-old man with history of triple coronary artery bypass graft (8 years ago) presented to our hospital with an ACS. He had undergone angiography 5 years ago to investigate episodic chest pain and imaging of the LIMA at the time did not demonstrate the atherosclerotic process. Emergent angiography demonstrated a severe diffuse stenosis in the proximal to mid segment of the LIMA, with embolization of a moderate sized thrombus to the distal skip segment. The LIMA stenosis was characterised by overlying haziness, consistent with acute plaque rupture, associated with residual luminal thrombus. The patient was managed with antithrombotic therapy to reduce the thrombus burden until repeat angiography after 72 h. At repeat angiography, the thrombus burden was substantially reduced at the distal skip segment as well as at the proximal to mid LIMA with the demonstration of multiple plaque cavities. This lesion was predilated and a 2.75 mm × 33 mm everolimus-eluting stent was implanted to a final diameter of 3.0 mm. The patient made a good clinical recovery and was discharged after 6 d. CONCLUSION: This case highlights the rapid and late development of atherosclerosis in a graft 5 years after documented patency and the importance for consideration of expectant thrombus management.

The Applicability of the American College of Cardiology Appropriate Use Criteria for Myocardial Perfusion Scintigraphy in Australia.

BACKGROUND: The American College of Cardiology (ACC) Appropriate Use Criteria (AUC) for radionuclide myocardial perfusion scans (MPS) was developed to promote its rational use in the assessment of stable ischaemic heart disease (IHD). We sought to validate the applicability of this document in the Australian context. METHODS: 1009 consecutive patients who underwent MPS were retrospectively audited at a single major metropolitan hospital in Victoria, Australia. Appropriateness was assigned based on the 2013 ACC AUC, and common indications and predictors of positive scan results were examined. RESULTS: The AUC was successfully applied (99.1%) retrospectively. A large proportion of scans were deemed appropriate (82.7%), whilst 7.8% were maybe appropriate. Positive detection rates in these groups were 17.0% and 17.9% respectively. Eighteen patients (1.8%) were unclassifiable, but had a detection rate of 44.4%. Positive predictors of an abnormal MPS result included prior history of coronary artery disease, typical angina, and following the conservative management of an acute coronary syndrome. Scans that were rarely appropriate had a detection rate of 0%. CONCLUSION: The retrospective application of the 2013 ACC AUC is feasible. Whilst the majority of the scans were appropriate, a group of unclassifiable patients was observed to have a high detection rate. Scans that were rarely appropriate could potentially be rationalised to reduce radiation risk.

Radiation exposure with the radial approach for diagnostic coronary angiography in a centre previously performing purely the femoral approach.

INTRODUCTION: Use of the radial approach for coronary angiography and percutaneous coronary intervention (PCI) is known to improve many patient outcome measures. However, there is some concern that it may be associated with increased patient radiation exposure. This study explores radiation exposure with the radial approach compared with the femoral approach in a centre previously performing purely femoral approach. PATIENTS AND METHODS: Data was collected retrospectively for all patients undergoing diagnostic coronary angiography over a six month period. PCIs and procedures with inherent technical difficulty or use of additional techniques (graft studies, optical coherence tomography, fractional flow reserve) were excluded. Dose area product (DAP) and fluoroscopy time (FT) were analysed for all remaining procedures (n=389), comparing radial (n=109) and femoral (n=280) approaches. RESULTS: The overall mean FT for transradial cases (7.45 mins) was significantly higher than for transfemoral cases (4.59 mins; p<0.001). The overall mean DAP for transradial cases (95.64 G Gycm(2)) was significantly higher than for transfemoral cases (70.25 Gycm(2), p<0.05)). Neither the FT nor the DAP decreased over the six month period. CONCLUSION: The radial approach was associated with significantly higher DAP and FT compared to the femoral approach during an initial introductory phase which was likely insufficient to develop radial proficiency. The results of this study are consistent with previous studies and may influence choice of access for non-emergent diagnostic coronary angiography before radial proficiency has been established, particularly for patients more susceptible to radiation risks.

Myocardial injury following coronary artery surgery versus angioplasty (MICASA): a randomised trial using biochemical markers and cardiac magnetic resonance imaging.

AIMS: To compare the frequency and extent of Troponin I and late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) defined injury following PCI compared with CABG in patients with multivessel and/or left main coronary artery disease (CAD), and interpret these finding in light of the new ESC/ACCF/AHA/WHF Task Force definitions for necrosis and infarction. METHODS AND RESULTS: Prospective, registered, single centre randomised controlled trial. Eighty patients with 3 vessel CAD (≥ 50% stenoses), or 2 vessel CAD including a type C lesion in the LAD, and/or left main disease were enrolled. Mean SYNTAX and EuroSCOREs were similar for both groups. Forty patients underwent PCI with drug eluting stents and 39 underwent CABG (one died prior to CABG). In the PCI group 6/38 (15.8%) patients had LGE, compared with 9/32 (28.1%) CABG patients (p = 0.25). Using the new Task Force definitions, necrosis occurred in 30/40 (75%) PCI patients and 35/35 (100%) CABG patients (p = 0.001), whilst infarction occurred in 30/40 (75%) PCI patients and 9/32 (28.1%) CABG patients (p = 0.0001). CONCLUSIONS: Periprocedural necrosis according to the Task Force definition was significantly lower in the PCI group, and universal in the CABG group. The incidence and extent of CMR defined infarction following PCI did not differ compared with CABG. This demonstrates that PCI can achieve revascularisation in complex patients without increased procedural myocardial damage.

Single centre experience with GORE-HELEX septal occluder for closure of PFO.

Several devices are available for percutaneous patent foramen ovale (PFO) closure. Over the past 3 years our planned treatment strategy of PFO closure has been routine use of the GORE-HELEX septal occluder device, followed by 6 months of aspirin therapy. We present the safety and feasibility of routinely using this device for all patients undergoing percutaneous PFO closure, with 3-month transthoracic echocardiogram (TTE) follow up. In total, 75 adult patients (44.0+/-11.7 years; 45.3% male) were referred for PFO closure during the study period. All patients underwent echocardiography prior to PFO closure. In 5 patients no PFO was found, and 1 patient had an atrial secundum defect closed using the Amplatzer septal occluder. Of the 69 remaining patients with PFO, 68/69 (98.6%) underwent closure with the GORE-HELEX device. Six of 69 cases required device retrieval and 5 of 6 were replaced successfully with a second GORE-HELEX device. One of the 6, a large PFO associated with atrial septal aneurysm, was replaced using the Amplatzer septal occluder. There were no major complications. At 3-month follow up, 65/68 (95.6%) had no residual shunt on TTE, and 3 patients had small residual shunts thought to be related to incomplete endothelialisation at 3 months. In conclusion, percutaneous PFO closure using the GORE-HELEX septal occluder device is safe and feasible, with no major peri-procedural complications and excellent short-term results at 3-month follow up.

Safety and feasibility of day case patent foramen ovale (PFO) closure facilitated by intracardiac echocardiography.

Ultrasound guided patent foramen ovale (PFO) closure has traditionally utilized transoesophageal echocardiography (TOE) under general anaesthesia. Some centres use fluoroscopic guidance alone to facilitate day case PFO closure. Intracardiac echocardiography (ICE) is performed via femoral vein access using an 11 Fr sheath providing accurate guidance without the necessity for general anaesthesia. The safety and feasibility of PFO closure using ICE guidance as a day case procedure have not been documented. We present a consecutive series of patients undergoing planned day case PFO closure under ICE guidance with transthoracic echocardiogram (TTE) follow up. Patients excluded from day case PFO closure were those with early pregnancy or unfavourable social circumstances. 53 consecutive adult patients (44.2+/-11.0 years; 24 males) were planned for day case PFO closure facilitated by ICE. Referral indications were stroke or TIA (n=39), peripheral embolism (n=6), decompression sickness (n=7) and severe migraine (n=1). All 53 patients underwent ICE, with 9/53 (17%) having an atrial septal aneurysm. In 5 patients no PFO was found. In the remaining 48 patients, PFO closure was achieved using the HELEX occluder (n=47) or the Amplatzer device (n=1). Mean procedure and fluoroscopy times were 31.0+/-12.4 and 5.3+/-3.9 min respectively. One patient failed same day discharge due to groin haematoma. There were no other complications. At 3 month follow up, 45/48 (94%) had no residual shunt, with 3 patients having small residual shunts on colour flow Doppler. In conclusion, percutaneous PFO closure as a day case procedure is safe and feasible when facilitated by ICE.

The Syntax score predicts peri-procedural myocardial necrosis during percutaneous coronary intervention.

BACKGROUND: Peri-procedural myocardial injury (PPI) during percutaneous coronary intervention (PCI) is common and associated with a poor outcome. No reliable angiographic or clinical predictors of PPI exist. We evaluated the ability of the SYNTAX score (SXscore), Gensini score, American Heart Association/American College of Cardiology (AHA/ACC) and Society for Cardiovascular Angiography and Intervention (SCAI) classifications to predict PPI. METHODS: Consecutive patients were included from two existing databases of PCI. Patients with coronary bypass grafts or instent restenosis were excluded. PPI was defined as troponin I elevation (>1.0 microg/L) at 6-24 h post-PCI. Delayed enhancement magnetic resonance imaging distinguished PPI territory in patients undergoing multi-vessel PCI. Quantitative coronary angiography was performed blinded to PPI. In total, 100 patients underwent PCI to 122 vessels. PPI occurred in 20/100 (20.0%) patients. RESULTS: Mean patient SXscore was higher in patients with PPI (20.6 vs. 12.4, p = 0.0001), however Gensini score was not significantly different (34.2 vs. 27.3, p = 0.15). Mean vessel SXscore was higher in vessels associated with PPI (12.1 vs. 7.6, p = 0.002), but not different for vessel Gensini score (16.2 vs. 13.6, p = 0.42). No vessels with AHA type A or B1 lesions were associated with PPI. Higher AHA scores (B2 and C) were associated with PPI (chi2 for trend 11.6, p = 0.0007). SCAI scores were not predictive of PPI (chi2 for trend 3.6, p = 0.06). By ROC analysis, a patient SXscore of > or = 17 predicted PPI with a sensitivity of 75.0% and specificity of 70.0%. CONCLUSION: Higher SXscores are predictive of myocardial injury, whilst AHA type A and B1 lesions have a high negative predictive value for PPI.

Intraobserver and interobserver variability of transesophageal echocardiography in aortic arch atheroma measurement.

BACKGROUND: The risk of stroke associated with aortic arch atheroma is proportional to plaque thickness, the accurate measurement of which may influence future therapeutic decisions. Transesophageal echocardiography is the procedure of choice for plaque measurement. This study examines the reproducibility of such measurements within the context of the Aortic Arch Related Cerebral Hazard Trial of antithrombotic therapy. METHODS: Atheroma images were remeasured by 3 independent blinded observers of varying expertise. Intraobserver and interobserver variability were calculated using Lin's concordance correlation coefficient (rho-c), the Bland-Altman method, and the kappa statistic. RESULTS: A total of 160 images were obtained from 96 patients (68% male; mean age 74 +/- 9 years). Mean plaque thickness was 5.1 +/- 2.3 mm, range 1.2 to 19.3 mm. For intraobserver variability, rho-c = 0.95, mean difference = 0.01 mm, and kappa = 0.71. For interobserver variability, rho-c ranged from 0.80 to 0.91; mean difference was 0.13 to 0.48 mm; and kappa was 0.61 to 0.69. By all statistical methods, agreement was at least substantial, although lower at greater plaque thicknesses. For the clinically relevant 4 mm, agreement was 84% to 88%. CONCLUSIONS: Transesophageal echocardiography measurement of aortic plaque is substantially reproducible across a range of observer experience and, thus, is a widely applicable, adequately reliable tool for clinical and research purposes.

Focal in-stent restenosis and in-stent thrombosis within the same bare-metal stent 5 years after deployment in a saphenous vein graft.

Complications of percutaneous coronary intervention include in-stent restenosis (ISR) and in-stent thrombosis (IST) which have different underlying pathophysiological processes and different treatment strategies. ISR is primarily due to excessive neointimal growth and occurs in 20-30% of bare-metal stents (BMS). Drug-eluting stents (DES) have decreased the rates of ISR (< 10%), but are potentially associated with increased IST related to delayed arterial healing and stent strut exposure. ISR of BMS typically occurs within 6 months of stent deployment. IST usually occurs within 12 months of DES deployment. We present a case of focal ISR and IST within the same BMS, confirmed with intravascular ultrasound, 5 years after deployment in a saphenous vein graft.