SARS-CoV-2 vaccination and myocarditis in a highly vaccinated New Zealand population

Background

A higher incidence of myocarditis has been reported in those who have recently received mRNA SARS – CoV-2 vaccination.1 Canterbury District Health Board (CDHB) serves 578,290 people, including 441,852 adults, with one large tertiary referral hospital offering specialist cardiology services. In 2021 97% of eligible adults received at least one dose and 92% two doses of the BNT162b2 mRNA vaccine (Pfizer-BioNTech). During this time only 21 community cases of COVID-19 infection were reported. We investigated the incidence of myocarditis during the BNT162b2 mRNA vaccine rollout in comparison to the preceding 5 years assuming a stable population size.

Methods

All adult patients admitted to our hospital who received a diagnostic code of acute myocarditis (ICD10 codes I40, I41 and I51.4) during admission between 2016 and 2021 were included. Demographics and peak troponin concentration (hsTnI) were recorded. Vaccine-associated myocarditis was defined as that leading to admitted within 28 days of BNT162b2 vaccination. Myocarditis-associated mortality was defined as death occurring within 28 days of hospital admission. Incidence of myocarditis before and during COVID-19 vaccination was tested using ANOVA.

Results

Between 2016 and 2020 there were 178 total hospital admissions (annualised mean 35.6 [SD6.3] range 28–44) with myocarditis. The mean age was 47.8 [SD15.9] years, 38% were women, and median peak hsTnI 641 (IQR 95.25–8526) ng/L. One patient died within 28 days of admission. In 2021 there were 43 myocarditis admissions, mean age 49.7 [SD18] years, 42% women, with a median hsTnI 355 (IQR 106.5–1876.5) ng/L. Nine of these admissions were within 28 days of vaccination. They were 78% female, mean age 52.6 [SD24.8] years, median peak hsTnI 179 (IQR 52–528) ng/L. One patient died during admission. There was no variance in annual incidence of myocarditis during vaccine rollout (p=0.342).

Conclusion

In a highly vaccinated adult population largely free of COVID-19 infection there were few cases of myocarditis within 28 days of vaccination and no increase in incidence overall compared to the preceding 5 years.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Heart Foundation of New Zealand grant to C Greer

18F-sodium fluoride positron emission tomography and coronary plaque radiomics derived from computed tomography angiography for prediction of myocardial infarction

Background

Assessments of coronary disease activity with 18F-sodium fluoride positron emission tomography (18F-NaF PET) and radiomics-based precision coronary plaque phenotyping derived from contrast-enhanced computed tomography (CT) have both been shown to enhance risk stratification in patients with coronary artery disease (CAD). To date, no study has investigated whether these two promising methods (which can be obtained during a single imaging session on a hybrid PET/CT scanner) are interchangeable or can provide superior predictive performance when used in combination.

Purpose

We sought to investigate whether the prognostic information provided by latent morphological radiomic coronary plaque features and assessments of disease activity by 18F-NaF PET are complementary in prediction of myocardial infarction.

Methods

Patients with known CAD underwent coronary 18F-NaF PET and CT angiography on a hybrid PET/CT scanner. Coronary 18F-NaF uptake was determined by the coronary microcalcification activity (CMA). We performed quantitative plaque analysis of coronary CT angiography datasets. Additionally, coronary plaque segmentations on CT angiography were used to extract 1103 radiomic features. Using weighted correlation network analysis we derived latent morphological features of coronary plaques which were aggregated to patient-level radiomic normograms to predict myocardial infarction using univariate and multivariate Cox proportional hazard models.

Results

The study cohort comprised of 260 patients with established CAD (age: 65±9 years; 84% men); 179 (69%) participants showed increased coronary 18F-NaF activity (CMA >0). Over 53 [40–59] months of follow-up 18 patients had a myocardial infarction. Using weighted correlation network analysis, from the 1103 radiomic features we derived 15 distinct eigen radiomic features representing latent morphological coronary plaque patterns. On univariate cox modelling 7 of these emerged as predictors of myocardial infarction (Figure). Following adjustments for calcified, noncalcified and low-density noncalcified plaque volumes and 18F-NaF CMA 4 radiomic features (related to texture and geometry) remained independent predictors of myocardial infarction (Figure).

Conclusion(s)

In patients with established CAD latent morphological features of coronary plaques are predictors of myocardial infarction above and beyond plaque volumes and 18F-NaF uptake. Comprehensive plaque analysis with radiomics may enhance risk stratification of CAD patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIH, Wellcome Trust

Association of coronary artery calcium score groups with qualitative and quantitatively assessed adverse plaque

Introduction

Coronary artery calcification is a marker of cardiovascular risk, but its association with qualitatively and quantitatively assessed plaque subtypes on coronary computed tomography (CT) angiography (CCTA) is unknown.

Methods

In this post-hoc analysis, CT images and clinical outcomes were assessed in SCOT-HEART trial participants. Agatston coronary artery calcium score (CACS) was measured on non-contrast CT and was stratified as zero (0 Agatston units, AU), minimal (1 to 9AU), low (10 to 99AU), moderate (100 to 399AU), high (400 to 999AU) and very high (≥1000AU). Adverse plaques were investigated with qualitative (visual categorisation of positive remodelling, low-attenuation plaque, spotty calcification, napkin ring sign) and quantitative (calcified, non-calcified, low-attenuation and total plaque burden) methods.

Results

Images of 1769 patients were assessed (mean age 58±9 years, 56% male, median Agatston score 21 [interquartile range 0 to 230] AU). Of these 36% had a zero, 9% minimal, 20% low, 17% moderate, 10% high and 8% very high CACS. Amongst patients with a zero CACS, 14% had nonobstructive disease, 2% had obstructive disease, 2% had visually assessed adverse plaques and 13% had quantitative low-attenuation plaque (LAP) burden >4% (Figure 1). Non-calcified and low-attenuation plaque burden increased between patients with zero, minimal and low CACS (p<0.001), but there was no difference between those with medium, high and very high CACS. Over a median follow-up of 4.8 [4.1 to 5.7] years, fatal or non-fatal myocardial infarction occurred in 41 patients, 10% of whom had zero CACS. CACS ≥1000AU (Hazard ratio (HR) 4.55 [1.20 to 17.3], p=0.026) and low-attenuation plaque burden (HR 1.74 [1.19 to 2.54], p=0.004) were the only predictors of myocardial infarction, independent of obstructive disease and cardiovascular risk score. Figure 2 shows example CCTA images in a patient with zero CACS, non-calcified plaque (red), low attenuation plaque (orange) burden >4% and obstructive disease in the left anterior descending coronary artery.

Conclusions

In patients with stable chest pain, a zero CACS is associated with a good prognosis, but 1 in 6 have coronary artery disease, including the presence of adverse plaques.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart Foundation, National Institute of Health/National Heart, Lung, and Blood Institute

Hybrid 18f-sodium fluoride PET/CT of the thoracic aorta identifies patients at increased risk of stroke

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart Foundation Clinical Research Training Fellowship

Background

Calcification of the thoracic aorta is associated with poor vessel wall health. Early detection of this disease process may highlight those at risk of future cardiovascular events.

Purpose

To investigate the potential of hybrid 18F-sodium fluoride (18F-NaF, a marker of vascular disease and microcalcification activity) positron emission tomography/computed tomography (PET/CT) to predict aortic disease progression and adverse cardiovascular events in patients with established risk factors.

Methods

Between 2015 and 2017, 197 patients underwent 18F-NaF PET/CT of the thoracic aorta as part of a randomised controlled trial.  Baseline 18F-NaF aortic microcalcification activity (AMA) was calculated as the cumulative uptake in a standardised volume of interest of the arch and ascending aorta.  Thirty-seven patients underwent follow up CT enabling aortic calcium score progression calculation.  Fatal/non-fatal stroke (primary endpoint) and fatal/non-fatal myocardial infarction (MI, secondary endpoint) were recorded up to May 2020.  The association between baseline AMA and both the progression of aortic calcium score and defined endpoints was analysed.  AMA was stratified into tertiles (low, moderate or high). Data is presented as mean(SD) or median [IQR].

Results

18F-NaF AMA correlated with the progression of aortic calcium score (R = 0.42, P = 0.01).  During 3.8 (0.9) years of follow up, 14 patients experienced the primary (stroke, n = 5) or secondary (MI, n = 9) endpoint.  Patients who experienced stroke had higher AMA (171 [162-176] vs 150 [141 - 157], P = 0.0015). Increased cumulative incidence of stroke was seen in the highest AMA tertile (Figure, P = 0.019).  There was no association between AMA and MI (P > 0.05).

Conclusion

Aortic microcalcification activity, as measured using 18F-NaF PET/CT, predicts the progression of aortic wall calcification and is associated with an increased risk of stroke but not MI.  Consolidating these findings in further studies will improve stroke risk prediction using 18F-NaF PET/CT.

Table Baseline characteristics Overall n = 197 Low AMA (<144) n = 66 Moderate AMA (144-155) n = 66 High AMA (>155) n = 65 p-value (ANOVA / X2) Age (±sd) 65.17 (8.30) 64.02 (9.43) 65.47 (7.40) 66.03 (7.95) 0.364 Male Sex (%) 157 (80.5) 54 (83.1) 52 (78.8) 51 (79.7) 0.808 Ever Smoked (%) 101 (60.5) 37 (71.2) 32 (56.1) 32 (55.2) 0.164 Hypertension (%) 110 (56.4) 31 (47.7) 35 (53.0) 44 (68.8) 0.043 High Cholesterol (%) 188 (96.4) 60 (92.3) 65 (98.5) 63 (98.4) 0.093 Type II Diabetes (%) 37 (19.0) 16 (24.6) 9 (13.6) 12 (18.8) 0.277 AMA = aortic microcalcification activity, MI = myocardial infarction, sd = standard deviation, TIA = transient ischaemic attack, X2 = Chi squared Abstract Figure: AMA and Stroke

Dynamic Changes in High-Sensitivity Cardiac Troponin I in Response to Anthracycline-Based Chemotherapy

AIMS

Treatment advances have improved cancer-related outcomes and shifted interest towards minimising long-term iatrogenic complications, particularly chemotherapy-related cardiotoxicity. High-sensitivity cardiac troponin I (hs-cTnI) assays accurately quantify very low concentrations of plasma troponin and enable early detection of cardiomyocyte injury prior to the development of myocardial dysfunction. The profile of hs-cTnI in response to anthracycline-based treatment has not previously been described.

MATERIALS AND METHODS

This was a multicentre prospective observational cohort study. Female patients with newly diagnosed invasive breast cancer scheduled to receive anthracycline-based (epirubicin) chemotherapy were recruited. Blood sampling was carried out before and 24 h after each cycle. Hs-cTnI concentrations were measured using the Abbott ARCHITECT_STAT assay.

RESULTS

We recruited 78 women with a median (interquartile range) age of 52 (49-61) years. The median baseline troponin concentration was 1 (1-4) ng/l and the median cumulative epirubicin dose was 394 (300-405) mg/m². Following an initial 33% fall 24 h after anthracycline dosing (P < 0.001), hs-cTnI concentrations increased by a median of 50% (P < 0.001) with each successive treatment cycle. In total, 45 patients had troponin measured immediately before the sixth treatment cycle, 21 (46.6%) of whom had hs-cTnI concentrations ≥16 ng/l, indicating myocardial injury. Plasma hs-cTnI concentrations before the second treatment cycle were a strong predictor of subsequent myocardial injury.

CONCLUSIONS

Cardiotoxicity arising from anthracycline therapy is detectable in the earliest stages of breast cancer treatment and is cumulative with each treatment cycle. This injury is most reliably determined from blood sampling carried out before rather than after each treatment cycle.

P1695Incidence and outcomes of unstable angina compared to non-ST elevation myocardial infarction

Objective

Assess the incidence and compare characteristics and outcome of unstable angina (UA) and Non-ST-Elevation myocardial infarction (NSTEMI)

Design

Two independent prospective multicenter diagnostic studies (Advantageous Predictors of Acute Coronary Syndromes Evaluation (APACE) and High-Sensitivity Troponin in the Evaluation of Patients With Acute Coronary Syndrome (High-STEACS)) enrolling patients with acute chest discomfort presenting to the emergency department. Central adjudication of the final diagnosis was done by two independent cardiologists using all clinical information including serial measurements of high-sensitivity cardiac troponin (hs-cTn). All-cause death and future non-fatal MI were assessed at 30-days and 1-year.

Results

8992 patients were enrolled at 11 centres. UA was adjudicated in 366/4122 (8.9%) and 137/4870 (2.8%) patients in APACE and High-STEACS, respectively, and NSTEMI in 622 (15.1%) and 651 (13.4%). Coronary artery disease was pre-existing in 73% and 76% of patients with unstable angina. At 30-days, all-cause mortality in UA was substantially lower as compared to NSTEMI (0.5% versus 3.7%, p=0.002 in APACE, 0.7% versus 7.4%, p=0.004 in High-STEACS). Similarly, at 1-year in UA all-cause mortality was 3.3% [95% CI 1.2–5.3] vs 10.4% [7.9–12.9] in APACE, and 5.1% [0.7–9.5] vs 22.9% [19.3–26.4] in High-STEACS, and similar to non-cardiac chest pain (NCCP). In contrast, future non-fatal MI in APACE was comparable in UA and NSTEMI (11.2%, [7.8–14.6] and 7.9%, [5.7–10.2]), and higher than in NCCP (0.6%, [0.2–1.0]).

1-year survival free from future AMI

Conclusions

The incidence and the mortality of UA is substantially lower than that of NSTEMI, while the rate of future non-fatal MI is similar.

Acknowledgement/Funding

Swiss National Science Foundation, Swiss Heart Foundation, Cardiovascular Research Foundation Basel, British Heart Foundation Project Grants, Butler S

172Coronary 18F-sodium fluoride uptake predicts progression of coronary arterial calcification

Background

Combined positron emission tomography and computed tomography (PET-CT) using 18F-sodium fluoride (18F-NaF) to detect microcalcification provides the opportunity to gain important insights into disease activity in coronary atherosclerosis. However, the relationship between 18F-NaF uptake and progression of coronary calcification has not been determined.

Purpose

To determine the relationship between 18F-NaF uptake and progression of coronary calcification in patients with clinically stable coronary artery disease (CAD).

Methods

Patients with established, multivessel CAD underwent 18F-NaF PET-CT and CT coronary calcium scoring at baseline, with repeat CT calcium scoring at one year. Coronary arterial PET uptake was analysed qualitatively and semi-quantitatively in diseased vessels by measuring maximum tissue-to-background ratio (TBRmax) – defined as the maximum standardised uptake value in a plaque divided by mean blood pool activity measured in the right atrium. Coronary calcification was quantified by measuring calcium mass, volume, average calcium density and total Agatston score (AU).

Results

In total, 185 patients underwent baseline and repeat imaging (median age 66 years, 80% men), and 118 (64%) had increased 18F-NaF uptake in at least one vessel. Median total calcium score, volume, mass and average density were higher in patients with compared to those without increased 18F-NaF uptake (Table 1). At one year, patients with evidence of increased 18F-NaF uptake demonstrated more rapid progression of coronary calcification (97 [39–166] AU) versus those without uptake (35 [7–93] AU; p<0.0001). Amongst 18F-NaF-positive patients, the calcium score increased only in coronary segments with 18F-NaF uptake (baseline 90.5 [27.5–202] AU versus one year 135.5 [59.3–281.8] AU; p<0.0001) and not in 18F-NaF-negative segments (baseline 44.5 [16–110.5] AU versus one year 46.5 [18.25–114] AU; p=0.446). There was a moderate correlation between TBRmax and change in total calcium score, volume and mass at 1 year (Spearman's Rho = 0.37, 0.38, 0.46 respectively; p<0.0001 for all).

Coronary calcification at baseline in PET-negative and PET-positive patients All patients (n=185) 18F-NaF Positive (n=118) 18F-NaF Negative (n=67) P value Agatston Score (AU) 381 [107–892] 541 [245–1130] 136 [55–361] p<0.0001 Calcium Volume (mm3) 358 [131–787] 506 [251–1014] 131 [64–343] p<0.0001 Calcium Mass (mg) 71 [23–155] 100 [48–222] 24 [11–69] p<0.0001 Average Density (mg/mm3) 0.19 [0.17–0.22] 0.20 [0.18–0.23] 0.18 [0.16–0.20] p<0.0001

Conclusions

Coronary 18F-NaF uptake identifies both patients and individual coronary segments with greater disease and more rapid progression of coronary calcification over one year.

Acknowledgement/Funding

AstraZeneca (unrestricted educational grant). British Heart Foundation (CH/09/002, RE/13/3/30183, FS/17/79/33226) Wellcome Trust (WT103782AIA).

1269Dual antiplatelet therapy to inhibit myocardial injury in patients with high-risk coronary artery plaque: a randomized controlled trial

Background

High-risk coronary atherosclerotic plaque is associated with higher plasma troponin concentrations suggesting ongoing myocardial injury that may be a target for dual antiplatelet therapy.

Purpose

To determine whether ticagrelor reduces high-sensitivity troponin I concentrations in patients with established coronary artery disease and high-risk coronary plaque with 18F-fluoride uptake.

Methods

In a randomized double-blind placebo-controlled trial, patients with multivessel coronary artery disease underwent coronary 18F-fluoride positron emission tomography-computed tomography and measurement of high-sensitivity cardiac troponin I and were randomized (1:1) to ticagrelor 90 mg twice daily or matched placebo. The primary endpoint was troponin I concentration at 30 days in patients with increased coronary 18F-fluoride uptake.

Results

In total, 202 patients were randomized and 191 met the pre-specified criteria for inclusion in the primary analysis. In patients with increased coronary 18F-fluoride uptake (n=120/191) there was no evidence that ticagrelor had an effect on plasma troponin concentrationsat 30 days (ratio of geometric means for ticagrelor versusplacebo, 1.11, [95% confidence interval 0.90 to 1.36], p=0.32) (Table 1). Over 1 year, ticagrelor had no effect on troponin concentrations in patients with increased coronary 18F-fluoride uptake (ratio of geometric means, 0.86, 95% confidence interval 0.63 to 1.17, p=0.33).

Table 1 Adjusted Geometric Mean (GSE) Ratio of Geometric Means p-value Ticagrelor Placebo (95% CI) Cardiac troponin I, ng/L (18F-fluoride activity) 3.8 (1.1) 3.4 (1.1) 1.11 (0.90 to 1.36) 0.32 Cardiac Troponin I, ng/L (No 18F-fluoride activity) 2.4 (1.1) 2.3 (1.1) 1.02 (0.80 to 1.31) 0.87 Plasma high-sensitivity cardiac troponin I concentration (ng/L) at 30 days for the per-protocol population.Estimates are back transformed estimates from analysis of log transformed values at 30 days adjusting for age, sex and log transformed baseline troponin. Ratio of geometric means is Ticagrelor divided by Placebo. GSE, geometric standard error.

Conclusions

Dual antiplatelet therapy with ticagrelor does not reduce plasma troponin concentrations in patients with coronary 18F-fluoride uptake. This suggests that subclinical plaque thrombosis does not contribute to ongoing myocardial injury in this setting.

Clinical Trials Study ID: NCT02110303Study ID: NCT02110303

Acknowledgement/Funding

Wellcome Trust Senior Investigator Award WT103782AIA

249High-sensitivity cardiac troponin and the universal definition of myocardial infarction: a randomised controlled trial

Background

The Universal Definition of Myocardial Infarction recommends the 99th centile diagnostic threshold using a high-sensitivity cardiac troponin (hs-cTn) assay and the classification of patients by the etiology of myocardial injury. Whether implementation of this definition improves risk stratification, treatment or outcomes is unknown.

Methods

In a stepped-wedge cluster randomized controlled trial, we implemented a high-sensitivity troponin assay and the recommendations of the Universal Definition in 48,282 consecutive patients with suspected acute coronary syndrome across ten hospitals. In a pre-specified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death, and secondary outcome of non-cardiovascular death at one year across diagnostic categories as per the Fourth Universal Definition. We applied competing risks methodology in all analyses, using a cumulative incidence function and determining the cause-specific hazard ratio (csHR) for competing outcomes.

Results

Cardiac troponin concentrations were elevated in 21.5% (10,360/48,282) of all trial participants. Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4,471), type 2 myocardial infarction by 22% (205/916), acute myocardial injury by 36% (443/1,233) and chronic myocardial injury by 43% (389/898). The risk and rate of the primary outcome was highest in those with type 1 myocardial infarction, whereas the risk and rate of non-cardiovascular death was highest in those with acute myocardial injury (Table, Figure). Despite increases in anti-platelet therapy and coronary revascularization after implementation, the primary outcome was unchanged in patients with type 1 myocardial infarction (csHR 1.00, 95% CI 0.82 to 1.21), or in any other category.

Adjusted csHR for competing outcomes Myocardial infarction or cardiovascular death Non-cardiovascular death Adjusted csHR (95% CI) Adjusted csHR (95% CI) Type 1 myocardial infarction 5.64 (5.12 to 6.22) 0.83 (0.72 to 0.96) Type 2 myocardial infarction 3.50 (2.94 to 4.15) 1.72 (1.44 to 2.06) Acute myocardial injury 4.38 (3.80 to 5.05) 2.65 (2.33 to 3.00) Chronic myocardial injury 3.88 (3.31 to 4.55) 2.06 (1.77 to 2.40) Cox regression models adjusted for age, sex, diabetes, ischaemic heart disease, season, days since trial onset and site of recruitment (as a random effect).

Cumulative incidence and number at risk

Conclusions

Implementation of the recommendations of the Universal Definition identified patients with different risks of future cardiovascular and non-cardiovascular events, but did not improve outcomes. Greater understanding of the underlying mechanisms and effective strategies for the investigation and treatment of patients with myocardial injury and infarction are required if we are to improve outcomes.

Acknowledgement/Funding

British Heart Foundation

Cardiovascular PET-CT imaging: a new frontier?

Cardiovascular positron-emission tomography combined with computed tomography (PET-CT) has recently emerged as an imaging technology with the potential to simultaneously describe both anatomical structures and physiological processes in vivo. The scope for clinical application of this technique is vast, but to date this promise has not been realised. Nonetheless, significant research activity is underway to explore these possibilities and it is likely that the knowledge gained will have important diagnostic and therapeutic implications in due course. This review provides a brief overview of the current state of cardiovascular PET-CT and the likely direction of future developments.