External validation of a rapid algorithm using high-sensitivity troponin assay results for evaluating patients with suspected acute myocardial infarction

OBJECTIVE

We sought to validate the clinical performance of a rapid assessment pathway incorporating the Siemens Atellica IM high sensitivity cardiac troponin I (hs-cTnI) assay in patients presenting to the emergency department (ED) with suspected acute myocardial infarction (AMI).

METHODS

This was a multicentre prospective observational study of adult ED patients presenting to five Australian hospitals between November 2020 and September 2021. Participants included those with symptoms of suspected AMI (without ST-segment elevation MI on presentation ECG). The Siemen's Atellica IM hs-cTnI laboratory-based assay was used to measure troponin concentrations at admission and after 2-3 hours and cardiologists adjudicated final diagnoses. The HighSTEACS diagnostic algorithm was evaluated, incorporating hs-cTnI concentrations at presentation and absolute changes within the first 2 to 3 hours. The primary outcome was index AMI, including type 1 or 2 non-ST segment elevation MI (NSTEMI) or ST-elevation MI (STEMI) following presentation. 30-day major adverse cardiac outcomes (including AMI, urgent revascularisation or cardiac death) were also reported. The trial was registered with the Australian and New Zealand Clinical Trials Registry.

RESULTS

1994 patients were included. The average age was 56.2 years (SD=15.6), and 44.9% were women. 118 (5.9%) patients had confirmed index AMI. The 2-hour algorithm defined 61.3% of patients as low risk. Sensitivity was 99.1% (94.0%-99.9%) and negative predictive value was 99.9% (99.3%-100%). 24.4% of patients were deemed intermediate risk. When applying the parameters for high risk, 252 (14.3%) were identified, with a specificity of 91.5% (88.7%-93.6%) and a PPV of 42.0% (35.6-48.7%).

CONCLUSIONS

A 2-hour algorithm based on the HighSTEACS strategy using the Siemens Atellica IM hs-cTnI laboratory-based assay enables safe and efficient risk assessment of emergency patients with suspected AMI.

TRIAL REGISTRATION NUMBER

ACTRN12621000053820.

Trial of a Novel Radiation Shielding Device to Protect Staff in the Cardiac Catheter Laboratory

Continuous exposure to low-level scattered radiation to staff performing cardiac angiography and intervention is of concern. A novel shielding solution (NSS) (Rampart IC M1128) has the potential to provide greater shielding for staff present at the table-side. This study aimed to investigate the effectiveness of the NSS compared with a traditional shielding solution (TSS) in a randomized controlled trial that enrolled 100 patients who underwent cardiac angiography and/or intervention which were randomized to the NSS or TSS. Baseline patient characteristics and radiation dose data were collected. Staff who were scrubbed at the table-side wore 5 real-time dosimeters on the head, collar, waist, ankle, and under the apron. The median primary operator radiation dose was significantly lower (p <0.001) for all dosimeter locations with the NSS when compared with the TSS, being reduced by 86%, 80.0%, 100%, and 50.0% for the head, collar, waist, and leg respectively. Median under-apron dose was 0.0 µSv for both NSS and TSS. Median second operator dose was reduced by 100%, 100%, and 100% for the head, collar, and waist respectively (p <0.001). Median NSS and TSS dose at the ankle and under apron was 0.0 µSv. Median scrub nurse dose was reduced by 50% and 100% for the head and collar respectively (p <0.001). Median NSS and TSS dose at the waist, ankle, and under apron was 0.0 µSv. In conclusion, the NSS tested in this study demonstrates a significant decrease in radiation dose to operators and scrub nurses when compared with traditional radiation protection measures.

Single High-Sensitivity Point-of-Care Whole-Blood Cardiac Troponin I Measurement to Rule Out Acute Myocardial Infarction at Low Risk

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) laboratory assays are used to rule out myocardial infarction (MI) on presentation, but prolonged result turnaround times can delay patient management. Our primary aim was to identify patients at low risk of index MI using a rapid point-of-care (POC) whole-blood hs-cTnI assay at presentation with potential early patient discharge.

METHODS

Consecutive patients presenting to the emergency department from 2 prospective observational studies with suspected acute coronary syndrome were enrolled. A POC hs-cTnI assay (Atellica VTLi) threshold using whole blood at presentation, which resulted in a negative predictive value of ≥99.5% and sensitivity of >99% for index MI, was derived (SEIGE [Safe Emergency Department Discharge Rate]) and validated with plasma (SAMIE [Suspected Acute Myocardial Infarction in Emergency]). Event adjudications were established with hs-cTnI assay results from routine clinical care. The primary outcome was MI at 30 days.

RESULTS

A total of 1086 patients (8.1% with MI) were enrolled in a US derivation cohort (SEIGE) and 1486 (5.5% MI) in an Australian validation cohort (SAMIE). A derivation whole-blood POC hs-cTnI concentration of <4 ng/L provided a sensitivity of 98.9% (95% CI, 93.8%-100%) and negative predictive value of 99.5% (95% CI, 97.2%-100%) for ruling out MI. In the validation cohort, the sensitivity was 98.8% (95% CI, 93.3%-100%), and negative predictive value was 99.8% (95% CI, 99.1%-100%); 17.8% and 41.8%, respectively, were defined as low risk for discharge. The 30-day adverse cardiac events were 0.1% (n=1) for SEIGE and 0.8% (n=5) for SAMIE.

CONCLUSIONS

A POC whole-blood hs-cTnI assay permits accessible, rapid, and safe exclusion of MI and may expedite discharge from the emergency department.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04772157. URL: https://www.australianclinicaltrials.gov.au/anzctr_feed/form; Unique identifier: 12621000053820.

Corrigendum to "Coronary CT in Australia has high positive predictive value unaffected by site volume: An analysis of 510 positive CTCA scans with invasive angiographic correlation" [IJC Heart Vasc. 20 (2018) 46-49]

[This corrects the article DOI: 10.1016/j.ijcha.2018.03.005.].

Factors contributing to radiation dose for patients and operators during diagnostic cardiac angiography

INTRODUCTION

Diagnostic coronary angiography (CA) uses ionising radiation with relatively high doses, which impact on both patients and staff. This study sought to identify which patient and procedural factors impact patient and operator dose the most during CA.

METHODS

Patient and procedure related variables impacting on Kerma area product (PKA ) and operator dose (OD) were collected for 16 months. Procedures were separated into 10 different procedure categories. PKA was used for patient dose and OD was measured with an instantly downloadable dosimeter (IDD) - downloaded at the end of each procedure. High and low radiation dose was defined by binary variables based on the 75th percentile of the continuous measures. Univariate and multivariate regression were used to identify predictors.

RESULTS

Of 3860 patients included, the IDD was worn for 2591 (61.7%). Obesity (BMI > 30 compared to BMI < 25) was the strongest predictor for both a PKA (odds ratio (OR) = 19.1 (95% CI 13.5-26.9) P < 0.001) and OD (OR = 3.3 (2.4-4.4) P < 0.001) above the 75th percentile. Male gender, biplane imaging, the X-ray unit used, operator experience and procedure type also predicted a high PKA . Radial access, male gender, biplane imaging and procedure type also predicted a high OD.

CONCLUSION

Radiation dose during CA is multifactorial and is dependent on patient and procedure related variables. Many factors impact on both PKA and OD but obesity is the strongest predictor for both patients and operators to receive a high radiation dose.

Treatment of rotablation-induced ostial left circumflex perforation by papyrus covered stent and its fenestration to recover the left anterior descending artery during CHIP procedure

Coronary artery perforation is a rare complication of percutaneous coronary intervention (PCI). Covered stents have been successfully used in these situations. We report a case of ostial left circumflex (LCx) artery perforation during rotablation PCI of left main coronary artery (LMCA) and LCx artery. After failed attempts to balloon tamponade the perforation, a PK Papyrus covered stent was deployed from proximal LCx into LMCA. This resulted in acute exclusion of the left anterior descending (LAD) artery from coronary circulation. Using a dual lumen catheter, a stiff wire was advanced through the side port toward the occluded LAD to fenestrate the membrane of the covered stent. A series of balloons were used to dilate the fenestration in the covered stent to restore a normal flow into the LAD.

Coronary CT in Australia has high positive predictive value unaffected by site volume: An analysis of 510 positive CTCA scans with invasive angiographic correlation

Background

It was hypothesized that the accuracy of coronary CT angiography would be affected by case volume of the referring sites.

Methods

The positive predictive value (PPV) of CTCA performed at a tertiary hospital specialising in cardiothoracic medicine and services with lower case-volumes were calculated. The tertiary hospital used as the high case-volume reference centre was The Prince Charles Hospital, which performed >1500 CTCA scans per annum over the study period. The low case-volume services used in the study were suburban radiology services, each with <500 cases per year. The PPV of positive CTCA at the reference site was compared to the pooled PPV of all other sites as a combined cohort, using invasive angiography as the reference standard. 512 scans were included, n = 199 subjects in the reference centre cohort, and n = 311 subjects in the pooled community radiology practice cohort.

Results

The positive predictive value (PPV) of the high case-volume group (n = 199) was 0.7538. The PPV of the pooled low case-volume services (n = 589) was 0.7331, p = 0.604, with no statistically significant difference in positive predictive values.

Conclusions

There was no significant difference in PPV between the two groups. This suggests that high-volume and lower-volume sites both have high PPV in Australia, above the published pooled PPV of four large prospective diagnostic accuracy studies (Miller et al., 2008; Budoff et al., 2008; Meijboom et al., 2008; Achenbach, 2007).

Late gadolinium enhancement does occur in Tako-tsubo cardiomyopathy - A quantitative cardiac magnetic resonance and speckle tracking strain study

Background

Late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) has been recommended to distinguish Tako-tsubo cardiomyopathy (TTC) from either acute myocardial infarction or myocarditis.

Method

44 consecutive patients with confirmed Mayo Clinic criteria for TTC underwent CMR imaging at 1.5 Tesla during the acute phase. 10 patients who had CMRI to exclude scar related ventricular tachycardia, and had negative studies, were used as negative controls. LGE was quantitated at two signal intensity thresholds (CircleCVi software) at > 2 and > 5 standard-deviations (SD) above reference myocardium, and compared to biomarkers.

Findings

Mean door-to-CMR time was 57 hours. 18 patients (41%) had LGE > 2 SD localized to the area of abnormal wall motion, representing 28.9 ± 11.2% LV mass. In 16 of these 18 patients (89%) LGE signal intensity was > 5 SD above normal myocardium, representing 12.1 ± 10% LV mass. LGE signal intensity was significantly greater in TTC than in matched controls (p < 0.05) but lower than in STEMI patients (p < 0.05). Mean troponin was significantly higher in LGE positive patients (2.5 ± 1.8 vs 4.4 ± 6.9, p = 0.001). Mean ejection fraction (EF) by CMR was 45% ± 8.7 in LGE-negative, and 40% ± 7.1 in LGE-positive patients (p = 0.37). Recovery of segmental function was confirmed at follow-up, mean EF was 59% in both groups.

Conclusion

LGE was present in 41% of cases of TTC, 89% of which had intense enhancement > 5 SD above normal myocardium. Presence of LGE was associated with worse myocardial injury in the acute setting, with no difference in recovery of function.

Quantitation of mitral regurgitation after percutaneous MitraClip repair: comparison of Doppler echocardiography and cardiac magnetic resonance imaging

OBJECTIVE

Percutaneous valve intervention for severe mitral regurgitation (MR) using the MitraClip is a novel technology. Quantitative assessment of residual MR by transthoracic echocardiography (TTE) is challenging, with multiple eccentric jets and artifact from the clips. Cardiovascular magnetic resonance (CMR) is the reference standard for left and right ventricular volumetric assessment. CMR phase-contrast flow imaging has superior reproducibility for quantitation of MR compared to echocardiography. The objective of this study was to establish the feasibility and reproducibility of CMR in quantitating residual MR after MitraClip insertion in a prospective study.

METHODS

Twenty-five patients underwent successful MitraClip insertion. Nine were excluded due to non-magnetic resonance imaging (MRI) compatible implants or arrhythmia, leaving 16 who underwent a comprehensive CMR examination at 1.5 T (Siemens Aera) with multiplanar steady state free precession (SSFP) cine imaging (cine CMR), and phase-contrast flow acquisitions (flow CMR) at the mitral annulus atrial to the MitraClip, and the proximal aorta. Same-day echocardiography was performed with two-dimensional (2D) visualization and Doppler. CMR and echocardiographic data were independently and blindly analyzed by expert readers. Inter-rater comparison was made by concordance correlation coefficient (CCC) with 95% confidence intervals (CIs), and Bland-Altman (BA) methods.

RESULTS

Mean age was 79 years, and mean LVEF was 44%±11% by CMR and 54%±16% by echocardiography. Inter-observer reproducibility of echocardiographic visual categorical grading by expert readers was poor, with a CCC of 0.475 (-0.7, 0.74). Echocardiographic Doppler regurgitant fraction reproducibility was modest (CCC 0.59, 0.15-0.84; BA mean difference -3.7%, -38% to 31%). CMR regurgitant fraction reproducibility was excellent (CCC 0.95, 0.86-0.98; BA mean difference -2.4%, -11.9 to 7.0), with a lower mean difference and narrower limits of agreement compared to echocardiography. Categorical severity grading by CMR using published ranges had good inter-observer agreement (CCC 0.86, 0.62-0.95).

CONCLUSIONS

CMR performs very well in the quantitation of MR after MitraClip insertion, with excellent reproducibility compared to echocardiographic methods. CMR is a useful technique for the comprehensive evaluation of residual regurgitation in patients after MitraClip. Technical limitations exist for both techniques, and quantitation remains a challenge in some patients.

Unusual cases of foreign bodies in air passage in children

Tracheobronchial foreign bodies when not treated promptly continue to be a source of morbidity and mortality specially in the paediatric population. Chevaliar Jackson, through meticulous analysis of mechanical problems related to foreign bodies in the air and food passages and their solution, created a science of rehearsed and tested instrumental techniques for their extraction (Jackson and Jackson, 1936). They developed instruments to achieve remarkable results with an almost unbelievably low morbidity and mortality.Aspiration of foreign bodies is seen more commonly in the paediatric age group and nearly 94% of them occur in infants and children (Holinger and Holinger, 1978). According to Jackson, nearly 90% of these foreign body accidents are due to carelessness, and are therefore avoidable. We present two unusual cases of inorganic foreign bodies in the air passages in children with special reference to the problems encountered in their diagnosis and management.

Protective roles of quinone reductase and tamoxifen against estrogen-induced mammary tumorigenesis

We previously reported that antiestrogen-liganded estrogen receptor beta (ERbeta) transcriptionally activates the major detoxifying enzyme quinone reductase (QR) (NAD(P)H:quinone oxidoreductase). Further studies on the functional role of ERbeta-mediated upregulation of antioxidative enzymes indicated protective effects against estrogen-induced oxidative DNA damage (ODD). We now report on in vivo and in vitro studies that show that ERbeta-mediated upregulation of QR are involved in the protection against estrogen-induced mammary tumorigenesis. Using the August Copenhagen Irish (ACI) model of estrogen-induced carcinogenesis, we observed that increased ODD and decreased QR expression occur early in the process of estrogen-induced mammary tumorigenesis. Prevention of ACI mammary gland tumorigenesis by tamoxifen was accompanied by decreased ODD and increased QR levels. These correlative findings were supported by our findings that downregulation of QR levels led to increased levels of estrogen quinone metabolites and enhanced transformation potential of 17beta-estradiol treated MCF10A non-tumorigenic breast epithelial cells. Concurrent expression of ERbeta and treatment with 4-hydroxytamoxifen decreased tumorigenic potential of these MCF10A cells. We conclude that upregulation of QR, through induction by tamoxifen, can inhibit estrogen-induced ODD and mammary cell tumorigenesis, representing a possible novel mechanism of tamoxifen prevention against breast cancer.

Potential biomarker for early risk assessment of prostate cancer

BACKGROUND

Catechol estrogen quinones (CEQ) derived from 4-hydroxyestrone (4-OHE1) and 4-hydroxyestradiol (4-OHE2) react with DNA to form depurinating--N7Gua and--N3Ade adducts. This damage leads to mutations that can initiate breast and prostate cancer. To determine whether this damage occurs in humans, urine samples from men with prostate cancer and benign urological conditions, and healthy controls were analyzed. The objective was determining whether any of the cancer patients had formed the depurinating 4-OHE1(E2)-1-N3Ade adducts.

METHODS

The adducts were extracted from samples by using affinity columns equipped with a monoclonal antibody developed for detecting 4-OHE1(E2)-1-N3Ade adducts. Eluted extracts were separated by capillary electrophoresis with field-amplified sample stacking and/or ultraperformance liquid chromatography. Absorption/luminescence spectroscopies and mass spectrometry were used to identify the adducts.

RESULTS

4-OHE1-1-N3Ade was detected at higher levels in samples from subjects with prostate cancer (n = 7) and benign urological conditions (n = 4) compared to healthy males (n = 5).

CONCLUSION

This is the first demonstration that CEQ-derived DNA adducts are present in urine samples from subjects with prostate cancer.

Tuberculoma of the mastoid

Tuberculoma is a rare but known complication of tuberculosis. It rarely occurs in the mastoid bone. When it occurs in the middle ear cleft, it can lead to intracranial complications if there is a delay in the diagnosis and management. A rare case of tuberculosis of the middle ear cleft which presented as tuberculoma of the mastoid bone with infranuclear facial palsy is described. The tuberculoma was removed and a canal wall down tympanomastoidectomy was performed. Post-operatively the patient was kept on antituberculous therapy. The various problems encountered in the diagnosis and management of this case are discussed.