Myocarditis and Cardiac Complications Associated With COVID-19 and mRNA Vaccination: A Pragmatic Narrative Review to Guide Clinical Practice.

Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus is likely to remain endemic globally despite widespread vaccination. There is increasing concern for myocardial involvement and ensuing cardiac complications due to COVID-19, however, the available evidence suggests these risks are low. Pandemic publishing has resulted in rapid manuscript availability though pre-print servers. Subsequent article retractions, a lack of standardised definitions, over-reliance on isolated troponin elevation and the heterogeneity of studied patient groups (i.e. severe vs. symptomatic vs all infections) resulted in early concern for high rates of myocarditis in patients with and recovering from COVID-19. The estimated incidence of myocarditis in COVID-19 infection is 11 cases per 100,000 infections compared with an estimated 2.7 cases per 100,000 persons following mRNA vaccination. For substantiated cases, the clinical course of myocarditis related to COVID-19 or mRNA vaccination appears mild and self-limiting, with reports of severe/fulminant myocarditis being rare. There is limited data available on the management of myocarditis in these settings. Clinical guidance for appropriate use of cardiac investigations and monitoring in COVID-19 is needed for effective risk stratification and efficient use of cardiac resources in Australia. An amalgamation of national and international position statements and guidelines is helpful for guiding clinical practice. This paper reviews the current available evidence and guidelines and provides a summary of the risks and potential use of cardiac investigations and monitoring for patients with COVID-19.

Myocardial perfusion pressure in patients with hypertension and coronary artery disease: implications for DBP targets in hypertension management.

BACKGROUND: The target blood pressure (BP) in patients with hypertension and coronary artery disease (CAD) has been controversial. Whether patients with both diabetes mellitus and CAD should follow targets for either diabetes mellitus or CAD is uncertain. Focusing only on one determinant of coronary blood flow (CBF) - myocardial perfusion pressure (MPP) - coronary BP in patients with hypertension was used to estimate the impact of setting BP targets. METHODS: A consecutive series of 101 patients referred for coronary angiography for stable angina pectoris or possible CAD had BP measurements proximal and distal to coronary artery stenosis. Fractional flow reserve (FFR) was measured from adenosine-induced maximal hyperemia. DBP after the coronary stenosis was the MPP. The most severe coronary lesion for each person was selected. RESULTS: Of 101 patients, 65.0 ±â€Š10.6 years (mean ±â€ŠSD), there were 69 with hypertension and 33 with diabetes mellitus of whom 25 had diabetes mellitus along with hypertension. In hypertension, FFR was 0.83 ±â€Š0.08, range from 0.49 to 0.97, with 40% having FFR less than 0.8. There was a significant linear relationship between systemic DBP and MPP. CBF approximates zero with MMP of 50  mmHg under resting conditions and 40  mmHg with coronary vasodilatation. On the basis of our findings in hypertension, if DBP were 80, 70, 65 and 60  mmHg, 1.4, 7.1, 15.7 and 54.3%, respectively, of patients would have an MPP of less than 50  mmHg. The values were similar for patients with diabetes mellitus. CONCLUSION: In our patient group with moderate coronary artery stenosis, a target DBP of 60  mmHg or less would be associated with unacceptably low MPPs. In patients with diabetes mellitus, the presence and severity of CAD stenosis may be more important factor in setting BP targets for treatment of hypertension. Because the degree of coronary stenosis is unknown in most patients with hypertension and CAD, guideline recommendations should consider cautioning clinicians about the potential for myocardial ischaemia at low DBP.

Development and validation of the fractional flow reserve (FFR) angiographic scoring tool (FAST) to improve the angiographic grading and selection of intermediate lesions that require FFR assessment.

BACKGROUND: Visual angiographic assessment of intermediate coronary lesions is poor at determining the functional significance. We sought to identify independent clinical and angiographic parameters associated with stenosis functional significance and applied them in a weighted fractional flow reserve angiographic scoring tool (FAST) to improve intermediate lesion selection for fractional flow reserve (FFR) assessment. METHODS AND RESULTS: Data from 100 patients with intermediate lesions previously assessed by FFR were retrospectively analyzed, and four independent variables that predicted FFR of less than or equal to 0.8 were identified: quantitative coronary angiography percent diameter stenosis [odds ratio (OR) 1.22, P<0.001], length more than 20 mm (OR 7.6, P=0.004), stenosis haziness (OR 16.6, P=0.005), and multivessel disease (OR 7.8, P=0.019). Applying these variables into the FAST score, we prospectively assessed a further 109 intermediate lesions (prevalence of FFR ≤0.8 was 29% in this validation cohort) and found that FAST was highly discriminative, predicting an FFR of less than or equal to 0.8 with a c-statistic of 0.865 (95% confidence interval 0.793-0.937, P<0.0001). At the optimal cutoff value, FAST score of more than 2 had a negative predictive value of 96.5% and a sensitivity of 93.8%. It would have reduced the pressure wire usage in the validation cohort by 52.3% (57 out of 109 cases), with only two false negatives and associated cost savings. CONCLUSION: The FAST score is a simple angiographic assessment tool for intermediate lesions that comprises four angiographic variables. A score of 2 or lower indicates low likelihood of lesion hemodynamic significance.

Cardiac computed tomography follow-up of left atrial appendage exclusion using the Amplatzer Cardiac Plug device.

Functional exclusion of the left atrial appendage using transcatheter devices has been developed as an alternative therapy for atrial fibrillation in patients for whom formal anticoagulation is contraindicated. Noninvasive follow-up imaging of these devices is desirable. Transthoracic echocardiography has limitations due to field of view, limited available imaging windows, and metallic shadowing. Cardiac computed tomography has superior image resolution for determining device position and has the added capacity to noninvasively assess when exclusion of the appendage has occurred. This imaging technique is demonstrated in 2 cases of left atrial appendage closure using the Amplatzer Cardiac Plug (AGA Medical Corp, Plymouth, MN).

Fame comes at a cost: a Canadian analysis of procedural costs in use of pressure wire to guide multivessel percutaneous coronary intervention.

The FAME-study authors claimed that fractional flow reserve (FFR)-guided multivessel percutaneous coronary intervention (PCI) achieved superior clinical outcome and lower cost compared with no FFR. However, patients were intended to undergo multivessel PCI with drug eluting stents prior to randomization, which tipped the cost-analysis heavily in favour of FFR. We retrospectively evaluated 100 intermediate coronary lesions assessed by FFR, and determined whether to perform PCI based on visual angiographic assessment alone. We found that angiographic-guided treatment underestimated functional significance of intermediate lesions, resulting in fewer implanted stents compared to FFR guidance. This, in addition to the pressure wire cost, increased procedural expenditure 2- to 3-fold when using FFR-guidance.

Localized pulmonary artery compression due to saphenous vein graft perforation during percutaneous coronary intervention.

Saphenous vein graft interventions are recognised as high risk procedures for adverse outcomes. We present a case of a ruptured vein graft causing a focal hematoma that led to pulmonary artery compression and cardiogenic shock without the classical signs of tamponade. Multi-modality imaging revealed the aetiology and the hematoma resolved after the patient received cardio-pulmonary resuscitation during attempted percutaneous drainage. Localized pulmonary artery compression is a rare complication of percutaneous coronary interventions (PCI). Its recognition and management are discussed, with the importance of early detection and urgent invasive management emphasized.